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-rw-r--r--src/lib/util/chd.cpp3279
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diff --git a/src/lib/util/chd.cpp b/src/lib/util/chd.cpp
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+++ b/src/lib/util/chd.cpp
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+// license:BSD-3-Clause
+// copyright-holders:Aaron Giles
+/***************************************************************************
+
+ chd.c
+
+ MAME Compressed Hunks of Data file format
+
+***************************************************************************/
+
+#include <assert.h>
+
+#include "chd.h"
+#include "avhuff.h"
+#include "hashing.h"
+#include "flac.h"
+#include "cdrom.h"
+#include "coretmpl.h"
+#include <zlib.h>
+#include <time.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <new>
+#include "eminline.h"
+
+
+//**************************************************************************
+// CONSTANTS
+//**************************************************************************
+
+// standard metadata formats
+const char *HARD_DISK_METADATA_FORMAT = "CYLS:%d,HEADS:%d,SECS:%d,BPS:%d";
+const char *CDROM_TRACK_METADATA_FORMAT = "TRACK:%d TYPE:%s SUBTYPE:%s FRAMES:%d";
+const char *CDROM_TRACK_METADATA2_FORMAT = "TRACK:%d TYPE:%s SUBTYPE:%s FRAMES:%d PREGAP:%d PGTYPE:%s PGSUB:%s POSTGAP:%d";
+const char *GDROM_TRACK_METADATA_FORMAT = "TRACK:%d TYPE:%s SUBTYPE:%s FRAMES:%d PAD:%d PREGAP:%d PGTYPE:%s PGSUB:%s POSTGAP:%d";
+const char *AV_METADATA_FORMAT = "FPS:%d.%06d WIDTH:%d HEIGHT:%d INTERLACED:%d CHANNELS:%d SAMPLERATE:%d";
+
+static const UINT32 METADATA_HEADER_SIZE = 16; // metadata header size
+
+static const UINT8 V34_MAP_ENTRY_FLAG_TYPE_MASK = 0x0f; // what type of hunk
+static const UINT8 V34_MAP_ENTRY_FLAG_NO_CRC = 0x10; // no CRC is present
+
+
+
+// V3-V4 entry types
+enum
+{
+ V34_MAP_ENTRY_TYPE_INVALID = 0, // invalid type
+ V34_MAP_ENTRY_TYPE_COMPRESSED = 1, // standard compression
+ V34_MAP_ENTRY_TYPE_UNCOMPRESSED = 2, // uncompressed data
+ V34_MAP_ENTRY_TYPE_MINI = 3, // mini: use offset as raw data
+ V34_MAP_ENTRY_TYPE_SELF_HUNK = 4, // same as another hunk in this file
+ V34_MAP_ENTRY_TYPE_PARENT_HUNK = 5, // same as a hunk in the parent file
+ V34_MAP_ENTRY_TYPE_2ND_COMPRESSED = 6 // compressed with secondary algorithm (usually FLAC CDDA)
+};
+
+// V5 compression types
+enum
+{
+ ///< codec #0
+ // these types are live when running
+ COMPRESSION_TYPE_0 = 0,
+ ///< codec #1
+ COMPRESSION_TYPE_1 = 1,
+ ///< codec #2
+ COMPRESSION_TYPE_2 = 2,
+ ///< codec #3
+ COMPRESSION_TYPE_3 = 3,
+ ///< no compression; implicit length = hunkbytes
+ COMPRESSION_NONE = 4,
+ ///< same as another block in this chd
+ COMPRESSION_SELF = 5,
+ ///< same as a hunk's worth of units in the parent chd
+ COMPRESSION_PARENT = 6,
+
+ ///< start of small RLE run (4-bit length)
+ // these additional pseudo-types are used for compressed encodings:
+ COMPRESSION_RLE_SMALL,
+ ///< start of large RLE run (8-bit length)
+ COMPRESSION_RLE_LARGE,
+ ///< same as the last COMPRESSION_SELF block
+ COMPRESSION_SELF_0,
+ ///< same as the last COMPRESSION_SELF block + 1
+ COMPRESSION_SELF_1,
+ ///< same block in the parent
+ COMPRESSION_PARENT_SELF,
+ ///< same as the last COMPRESSION_PARENT block
+ COMPRESSION_PARENT_0,
+ ///< same as the last COMPRESSION_PARENT block + 1
+ COMPRESSION_PARENT_1
+};
+
+
+
+//**************************************************************************
+// TYPE DEFINITIONS
+//**************************************************************************
+
+// ======================> metadata_entry
+
+// description of where a metadata entry lives within the file
+struct chd_file::metadata_entry
+{
+ UINT64 offset; // offset within the file of the header
+ UINT64 next; // offset within the file of the next header
+ UINT64 prev; // offset within the file of the previous header
+ UINT32 length; // length of the metadata
+ UINT32 metatag; // metadata tag
+ UINT8 flags; // flag bits
+};
+
+
+// ======================> metadata_hash
+
+struct chd_file::metadata_hash
+{
+ UINT8 tag[4]; // tag of the metadata in big-endian
+ sha1_t sha1; // hash data
+};
+
+
+
+//**************************************************************************
+// INLINE FUNCTIONS
+//**************************************************************************
+
+//-------------------------------------------------
+// be_read - extract a big-endian number from
+// a byte buffer
+//-------------------------------------------------
+
+inline UINT64 chd_file::be_read(const UINT8 *base, int numbytes)
+{
+ UINT64 result = 0;
+ while (numbytes--)
+ result = (result << 8) | *base++;
+ return result;
+}
+
+
+//-------------------------------------------------
+// be_write - write a big-endian number to a byte
+// buffer
+//-------------------------------------------------
+
+inline void chd_file::be_write(UINT8 *base, UINT64 value, int numbytes)
+{
+ base += numbytes;
+ while (numbytes--)
+ {
+ *--base = value;
+ value >>= 8;
+ }
+}
+
+
+//-------------------------------------------------
+// be_read_sha1 - fetch a sha1_t from a data
+// stream in bigendian order
+//-------------------------------------------------
+
+inline sha1_t chd_file::be_read_sha1(const UINT8 *base)
+{
+ sha1_t result;
+ memcpy(&result.m_raw[0], base, sizeof(result.m_raw));
+ return result;
+}
+
+
+//-------------------------------------------------
+// be_write_sha1 - write a sha1_t to a data
+// stream in bigendian order
+//-------------------------------------------------
+
+inline void chd_file::be_write_sha1(UINT8 *base, sha1_t value)
+{
+ memcpy(base, &value.m_raw[0], sizeof(value.m_raw));
+}
+
+
+//-------------------------------------------------
+// file_read - read from the file at the given
+// offset; on failure throw an error
+//-------------------------------------------------
+
+inline void chd_file::file_read(UINT64 offset, void *dest, UINT32 length)
+{
+ // no file = failure
+ if (m_file == NULL)
+ throw CHDERR_NOT_OPEN;
+
+ // seek and read
+ core_fseek(m_file, offset, SEEK_SET);
+ UINT32 count = core_fread(m_file, dest, length);
+ if (count != length)
+ throw CHDERR_READ_ERROR;
+}
+
+
+//-------------------------------------------------
+// file_write - write to the file at the given
+// offset; on failure throw an error
+//-------------------------------------------------
+
+inline void chd_file::file_write(UINT64 offset, const void *source, UINT32 length)
+{
+ // no file = failure
+ if (m_file == NULL)
+ throw CHDERR_NOT_OPEN;
+
+ // seek and write
+ core_fseek(m_file, offset, SEEK_SET);
+ UINT32 count = core_fwrite(m_file, source, length);
+ if (count != length)
+ throw CHDERR_WRITE_ERROR;
+}
+
+
+//-------------------------------------------------
+// file_append - append to the file at the given
+// offset, ensuring we start at the given
+// alignment; on failure throw an error
+//-------------------------------------------------
+
+inline UINT64 chd_file::file_append(const void *source, UINT32 length, UINT32 alignment)
+{
+ // no file = failure
+ if (m_file == NULL)
+ throw CHDERR_NOT_OPEN;
+
+ // seek to the end and align if necessary
+ core_fseek(m_file, 0, SEEK_END);
+ if (alignment != 0)
+ {
+ UINT64 offset = core_ftell(m_file);
+ UINT32 delta = offset % alignment;
+ if (delta != 0)
+ {
+ // pad with 0's from a local buffer
+ UINT8 buffer[1024];
+ memset(buffer, 0, sizeof(buffer));
+ delta = alignment - delta;
+ while (delta != 0)
+ {
+ UINT32 bytes_to_write = MIN(sizeof(buffer), delta);
+ UINT32 count = core_fwrite(m_file, buffer, bytes_to_write);
+ if (count != bytes_to_write)
+ throw CHDERR_WRITE_ERROR;
+ delta -= bytes_to_write;
+ }
+ }
+ }
+
+ // write the real data
+ UINT64 offset = core_ftell(m_file);
+ UINT32 count = core_fwrite(m_file, source, length);
+ if (count != length)
+ throw CHDERR_READ_ERROR;
+ return offset;
+}
+
+
+//-------------------------------------------------
+// bits_for_value - return the number of bits
+// necessary to represent all numbers 0..value
+//-------------------------------------------------
+
+inline UINT8 chd_file::bits_for_value(UINT64 value)
+{
+ UINT8 result = 0;
+ while (value != 0)
+ value >>= 1, result++;
+ return result;
+}
+
+
+
+//**************************************************************************
+// CHD FILE MANAGEMENT
+//**************************************************************************
+
+/**
+ * @fn chd_file::chd_file()
+ *
+ * @brief -------------------------------------------------
+ * chd_file - constructor
+ * -------------------------------------------------.
+ */
+
+chd_file::chd_file()
+ : m_file(NULL),
+ m_owns_file(false)
+{
+ // reset state
+ memset(m_decompressor, 0, sizeof(m_decompressor));
+ close();
+}
+
+/**
+ * @fn chd_file::~chd_file()
+ *
+ * @brief -------------------------------------------------
+ * ~chd_file - destructor
+ * -------------------------------------------------.
+ */
+
+chd_file::~chd_file()
+{
+ // close any open files
+ close();
+}
+
+/**
+ * @fn sha1_t chd_file::sha1()
+ *
+ * @brief -------------------------------------------------
+ * sha1 - return our SHA1 value
+ * -------------------------------------------------.
+ *
+ * @return A sha1_t.
+ */
+
+sha1_t chd_file::sha1()
+{
+ try
+ {
+ // read the big-endian version
+ UINT8 rawbuf[sizeof(sha1_t)];
+ file_read(m_sha1_offset, rawbuf, sizeof(rawbuf));
+ return be_read_sha1(rawbuf);
+ }
+ catch (chd_error &)
+ {
+ // on failure, return NULL
+ return sha1_t::null;
+ }
+}
+
+/**
+ * @fn sha1_t chd_file::raw_sha1()
+ *
+ * @brief -------------------------------------------------
+ * raw_sha1 - return our raw SHA1 value
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_UNSUPPORTED_VERSION Thrown when a chderr unsupported version error
+ * condition occurs.
+ *
+ * @return A sha1_t.
+ */
+
+sha1_t chd_file::raw_sha1()
+{
+ try
+ {
+ // determine offset within the file for data-only
+ if (m_rawsha1_offset == 0)
+ throw CHDERR_UNSUPPORTED_VERSION;
+
+ // read the big-endian version
+ UINT8 rawbuf[sizeof(sha1_t)];
+ file_read(m_rawsha1_offset, rawbuf, sizeof(rawbuf));
+ return be_read_sha1(rawbuf);
+ }
+ catch (chd_error &)
+ {
+ // on failure, return NULL
+ return sha1_t::null;
+ }
+}
+
+/**
+ * @fn sha1_t chd_file::parent_sha1()
+ *
+ * @brief -------------------------------------------------
+ * parent_sha1 - return our parent's SHA1 value
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_UNSUPPORTED_VERSION Thrown when a chderr unsupported version error
+ * condition occurs.
+ *
+ * @return A sha1_t.
+ */
+
+sha1_t chd_file::parent_sha1()
+{
+ try
+ {
+ // determine offset within the file
+ if (m_parentsha1_offset == 0)
+ throw CHDERR_UNSUPPORTED_VERSION;
+
+ // read the big-endian version
+ UINT8 rawbuf[sizeof(sha1_t)];
+ file_read(m_parentsha1_offset, rawbuf, sizeof(rawbuf));
+ return be_read_sha1(rawbuf);
+ }
+ catch (chd_error &)
+ {
+ // on failure, return NULL
+ return sha1_t::null;
+ }
+}
+
+/**
+ * @fn chd_error chd_file::hunk_info(UINT32 hunknum, chd_codec_type &compressor, UINT32 &compbytes)
+ *
+ * @brief -------------------------------------------------
+ * hunk_info - return information about this hunk
+ * -------------------------------------------------.
+ *
+ * @param hunknum The hunknum.
+ * @param [in,out] compressor The compressor.
+ * @param [in,out] compbytes The compbytes.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::hunk_info(UINT32 hunknum, chd_codec_type &compressor, UINT32 &compbytes)
+{
+ // error if invalid
+ if (hunknum >= m_hunkcount)
+ return CHDERR_HUNK_OUT_OF_RANGE;
+
+ // get the map pointer
+ UINT8 *rawmap;
+ switch (m_version)
+ {
+ // v3/v4 map entries
+ case 3:
+ case 4:
+ rawmap = &m_rawmap[16 * hunknum];
+ switch (rawmap[15] & V34_MAP_ENTRY_FLAG_TYPE_MASK)
+ {
+ case V34_MAP_ENTRY_TYPE_COMPRESSED:
+ compressor = CHD_CODEC_ZLIB;
+ compbytes = be_read(&rawmap[12], 2) + (rawmap[14] << 16);
+ break;
+
+ case V34_MAP_ENTRY_TYPE_UNCOMPRESSED:
+ compressor = CHD_CODEC_NONE;
+ compbytes = m_hunkbytes;
+ break;
+
+ case V34_MAP_ENTRY_TYPE_MINI:
+ compressor = CHD_CODEC_MINI;
+ compbytes = 0;
+ break;
+
+ case V34_MAP_ENTRY_TYPE_SELF_HUNK:
+ compressor = CHD_CODEC_SELF;
+ compbytes = 0;
+ break;
+
+ case V34_MAP_ENTRY_TYPE_PARENT_HUNK:
+ compressor = CHD_CODEC_PARENT;
+ compbytes = 0;
+ break;
+ }
+ break;
+
+ // v5 map entries
+ case 5:
+ rawmap = &m_rawmap[m_mapentrybytes * hunknum];
+
+ // uncompressed case
+ if (!compressed())
+ {
+ if (be_read(&rawmap[0], 4) == 0)
+ {
+ compressor = CHD_CODEC_PARENT;
+ compbytes = 0;
+ }
+ else
+ {
+ compressor = CHD_CODEC_NONE;
+ compbytes = m_hunkbytes;
+ }
+ break;
+ }
+
+ // compressed case
+ switch (rawmap[0])
+ {
+ case COMPRESSION_TYPE_0:
+ case COMPRESSION_TYPE_1:
+ case COMPRESSION_TYPE_2:
+ case COMPRESSION_TYPE_3:
+ compressor = m_compression[rawmap[0]];
+ compbytes = be_read(&rawmap[1], 3);
+ break;
+
+ case COMPRESSION_NONE:
+ compressor = CHD_CODEC_NONE;
+ compbytes = m_hunkbytes;
+ break;
+
+ case COMPRESSION_SELF:
+ compressor = CHD_CODEC_SELF;
+ compbytes = 0;
+ break;
+
+ case COMPRESSION_PARENT:
+ compressor = CHD_CODEC_PARENT;
+ compbytes = 0;
+ break;
+
+ default:
+ return CHDERR_UNKNOWN_COMPRESSION;
+ }
+ break;
+ }
+ return CHDERR_NONE;
+}
+
+/**
+ * @fn void chd_file::set_raw_sha1(sha1_t rawdata)
+ *
+ * @brief -------------------------------------------------
+ * set_raw_sha1 - set our SHA1 values
+ * -------------------------------------------------.
+ *
+ * @param rawdata The rawdata.
+ */
+
+void chd_file::set_raw_sha1(sha1_t rawdata)
+{
+ // create a big-endian version
+ UINT8 rawbuf[sizeof(sha1_t)];
+ be_write_sha1(rawbuf, rawdata);
+
+ // write to the header
+ UINT64 offset = (m_rawsha1_offset != 0) ? m_rawsha1_offset : m_sha1_offset;
+ assert(offset != 0);
+ file_write(offset, rawbuf, sizeof(rawbuf));
+
+ // if we have a separate rawsha1_offset, update the full sha1 as well
+ if (m_rawsha1_offset != 0)
+ metadata_update_hash();
+}
+
+/**
+ * @fn void chd_file::set_parent_sha1(sha1_t parent)
+ *
+ * @brief -------------------------------------------------
+ * set_parent_sha1 - set the parent SHA1 value
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_INVALID_FILE Thrown when a chderr invalid file error condition occurs.
+ *
+ * @param parent The parent.
+ */
+
+void chd_file::set_parent_sha1(sha1_t parent)
+{
+ // if no file, fail
+ if (m_file == NULL)
+ throw CHDERR_INVALID_FILE;
+
+ // create a big-endian version
+ UINT8 rawbuf[sizeof(sha1_t)];
+ be_write_sha1(rawbuf, parent);
+
+ // write to the header
+ assert(m_parentsha1_offset != 0);
+ file_write(m_parentsha1_offset, rawbuf, sizeof(rawbuf));
+}
+
+/**
+ * @fn chd_error chd_file::create(core_file &file, UINT64 logicalbytes, UINT32 hunkbytes, UINT32 unitbytes, chd_codec_type compression[4])
+ *
+ * @brief -------------------------------------------------
+ * create - create a new file with no parent using an existing opened file handle
+ * -------------------------------------------------.
+ *
+ * @param [in,out] file The file.
+ * @param logicalbytes The logicalbytes.
+ * @param hunkbytes The hunkbytes.
+ * @param unitbytes The unitbytes.
+ * @param compression The compression.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::create(core_file &file, UINT64 logicalbytes, UINT32 hunkbytes, UINT32 unitbytes, chd_codec_type compression[4])
+{
+ // make sure we don't already have a file open
+ if (m_file != NULL)
+ return CHDERR_ALREADY_OPEN;
+
+ // set the header parameters
+ m_logicalbytes = logicalbytes;
+ m_hunkbytes = hunkbytes;
+ m_unitbytes = unitbytes;
+ memcpy(m_compression, compression, sizeof(m_compression));
+ m_parent = NULL;
+
+ // take ownership of the file
+ m_file = &file;
+ m_owns_file = false;
+ return create_common();
+}
+
+/**
+ * @fn chd_error chd_file::create(core_file &file, UINT64 logicalbytes, UINT32 hunkbytes, chd_codec_type compression[4], chd_file &parent)
+ *
+ * @brief -------------------------------------------------
+ * create - create a new file with a parent using an existing opened file handle
+ * -------------------------------------------------.
+ *
+ * @param [in,out] file The file.
+ * @param logicalbytes The logicalbytes.
+ * @param hunkbytes The hunkbytes.
+ * @param compression The compression.
+ * @param [in,out] parent The parent.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::create(core_file &file, UINT64 logicalbytes, UINT32 hunkbytes, chd_codec_type compression[4], chd_file &parent)
+{
+ // make sure we don't already have a file open
+ if (m_file != NULL)
+ return CHDERR_ALREADY_OPEN;
+
+ // set the header parameters
+ m_logicalbytes = logicalbytes;
+ m_hunkbytes = hunkbytes;
+ m_unitbytes = parent.unit_bytes();
+ memcpy(m_compression, compression, sizeof(m_compression));
+ m_parent = &parent;
+
+ // take ownership of the file
+ m_file = &file;
+ m_owns_file = false;
+ return create_common();
+}
+
+/**
+ * @fn chd_error chd_file::create(const char *filename, UINT64 logicalbytes, UINT32 hunkbytes, UINT32 unitbytes, chd_codec_type compression[4])
+ *
+ * @brief -------------------------------------------------
+ * create - create a new file with no parent using a filename
+ * -------------------------------------------------.
+ *
+ * @param filename Filename of the file.
+ * @param logicalbytes The logicalbytes.
+ * @param hunkbytes The hunkbytes.
+ * @param unitbytes The unitbytes.
+ * @param compression The compression.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::create(const char *filename, UINT64 logicalbytes, UINT32 hunkbytes, UINT32 unitbytes, chd_codec_type compression[4])
+{
+ // make sure we don't already have a file open
+ if (m_file != NULL)
+ return CHDERR_ALREADY_OPEN;
+
+ // create the new file
+ core_file *file = NULL;
+ file_error filerr = core_fopen(filename, OPEN_FLAG_READ | OPEN_FLAG_WRITE | OPEN_FLAG_CREATE, &file);
+ if (filerr != FILERR_NONE)
+ return CHDERR_FILE_NOT_FOUND;
+
+ // create the file normally, then claim the file
+ chd_error chderr = create(*file, logicalbytes, hunkbytes, unitbytes, compression);
+ m_owns_file = true;
+
+ // if an error happened, close and delete the file
+ if (chderr != CHDERR_NONE)
+ {
+ core_fclose(file);
+ osd_rmfile(filename);
+ }
+ return chderr;
+}
+
+/**
+ * @fn chd_error chd_file::create(const char *filename, UINT64 logicalbytes, UINT32 hunkbytes, chd_codec_type compression[4], chd_file &parent)
+ *
+ * @brief -------------------------------------------------
+ * create - create a new file with a parent using a filename
+ * -------------------------------------------------.
+ *
+ * @param filename Filename of the file.
+ * @param logicalbytes The logicalbytes.
+ * @param hunkbytes The hunkbytes.
+ * @param compression The compression.
+ * @param [in,out] parent The parent.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::create(const char *filename, UINT64 logicalbytes, UINT32 hunkbytes, chd_codec_type compression[4], chd_file &parent)
+{
+ // make sure we don't already have a file open
+ if (m_file != NULL)
+ return CHDERR_ALREADY_OPEN;
+
+ // create the new file
+ core_file *file = NULL;
+ file_error filerr = core_fopen(filename, OPEN_FLAG_READ | OPEN_FLAG_WRITE | OPEN_FLAG_CREATE, &file);
+ if (filerr != FILERR_NONE)
+ return CHDERR_FILE_NOT_FOUND;
+
+ // create the file normally, then claim the file
+ chd_error chderr = create(*file, logicalbytes, hunkbytes, compression, parent);
+ m_owns_file = true;
+
+ // if an error happened, close and delete the file
+ if (chderr != CHDERR_NONE)
+ {
+ core_fclose(file);
+ osd_rmfile(filename);
+ }
+ return chderr;
+}
+
+/**
+ * @fn chd_error chd_file::open(const char *filename, bool writeable, chd_file *parent)
+ *
+ * @brief -------------------------------------------------
+ * open - open an existing file for read or read/write
+ * -------------------------------------------------.
+ *
+ * @param filename Filename of the file.
+ * @param writeable true if writeable.
+ * @param [in,out] parent If non-null, the parent.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::open(const char *filename, bool writeable, chd_file *parent)
+{
+ // make sure we don't already have a file open
+ if (m_file != NULL)
+ return CHDERR_ALREADY_OPEN;
+
+ // open the file
+ UINT32 openflags = writeable ? (OPEN_FLAG_READ | OPEN_FLAG_WRITE) : OPEN_FLAG_READ;
+ core_file *file = NULL;
+ file_error filerr = core_fopen(filename, openflags, &file);
+ if (filerr != FILERR_NONE)
+ return CHDERR_FILE_NOT_FOUND;
+
+ // now open the CHD
+ chd_error err = open(*file, writeable, parent);
+ if (err != CHDERR_NONE)
+ {
+ core_fclose(file);
+ return err;
+ }
+
+ // we now own this file
+ m_owns_file = true;
+ return err;
+}
+
+/**
+ * @fn chd_error chd_file::open(core_file &file, bool writeable, chd_file *parent)
+ *
+ * @brief -------------------------------------------------
+ * open - open an existing file for read or read/write
+ * -------------------------------------------------.
+ *
+ * @param [in,out] file The file.
+ * @param writeable true if writeable.
+ * @param [in,out] parent If non-null, the parent.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::open(core_file &file, bool writeable, chd_file *parent)
+{
+ // make sure we don't already have a file open
+ if (m_file != NULL)
+ return CHDERR_ALREADY_OPEN;
+
+ // open the file
+ m_file = &file;
+ m_owns_file = false;
+ m_parent = parent;
+ return open_common(writeable);
+}
+
+/**
+ * @fn void chd_file::close()
+ *
+ * @brief -------------------------------------------------
+ * close - close a CHD file for access
+ * -------------------------------------------------.
+ */
+
+void chd_file::close()
+{
+ // reset file characteristics
+ if (m_owns_file && m_file != NULL)
+ core_fclose(m_file);
+ m_file = NULL;
+ m_owns_file = false;
+ m_allow_reads = false;
+ m_allow_writes = false;
+
+ // reset core parameters from the header
+ m_version = HEADER_VERSION;
+ m_logicalbytes = 0;
+ m_mapoffset = 0;
+ m_metaoffset = 0;
+ m_hunkbytes = 0;
+ m_hunkcount = 0;
+ m_unitbytes = 0;
+ m_unitcount = 0;
+ memset(m_compression, 0, sizeof(m_compression));
+ m_parent = NULL;
+ m_parent_missing = false;
+
+ // reset key offsets within the header
+ m_mapoffset_offset = 0;
+ m_metaoffset_offset = 0;
+ m_sha1_offset = 0;
+ m_rawsha1_offset = 0;
+ m_parentsha1_offset = 0;
+
+ // reset map information
+ m_mapentrybytes = 0;
+ m_rawmap.clear();
+
+ // reset compression management
+ for (int decompnum = 0; decompnum < ARRAY_LENGTH(m_decompressor); decompnum++)
+ {
+ delete m_decompressor[decompnum];
+ m_decompressor[decompnum] = NULL;
+ }
+ m_compressed.clear();
+
+ // reset caching
+ m_cache.clear();
+ m_cachehunk = ~0;
+}
+
+/**
+ * @fn chd_error chd_file::read_hunk(UINT32 hunknum, void *buffer)
+ *
+ * @brief -------------------------------------------------
+ * read - read a single hunk from the CHD file
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_NOT_OPEN Thrown when a chderr not open error condition occurs.
+ * @exception CHDERR_HUNK_OUT_OF_RANGE Thrown when a chderr hunk out of range error
+ * condition occurs.
+ * @exception CHDERR_DECOMPRESSION_ERROR Thrown when a chderr decompression error error
+ * condition occurs.
+ * @exception CHDERR_REQUIRES_PARENT Thrown when a chderr requires parent error condition
+ * occurs.
+ * @exception CHDERR_READ_ERROR Thrown when a chderr read error error condition
+ * occurs.
+ *
+ * @param hunknum The hunknum.
+ * @param [in,out] buffer If non-null, the buffer.
+ *
+ * @return The hunk.
+ */
+
+chd_error chd_file::read_hunk(UINT32 hunknum, void *buffer)
+{
+ // wrap this for clean reporting
+ try
+ {
+ // punt if no file
+ if (m_file == NULL)
+ throw CHDERR_NOT_OPEN;
+
+ // return an error if out of range
+ if (hunknum >= m_hunkcount)
+ throw CHDERR_HUNK_OUT_OF_RANGE;
+
+ // get a pointer to the map entry
+ UINT64 blockoffs;
+ UINT32 blocklen;
+ UINT32 blockcrc;
+ UINT8 *rawmap;
+ UINT8 *dest = reinterpret_cast<UINT8 *>(buffer);
+ switch (m_version)
+ {
+ // v3/v4 map entries
+ case 3:
+ case 4:
+ rawmap = &m_rawmap[16 * hunknum];
+ blockoffs = be_read(&rawmap[0], 8);
+ blockcrc = be_read(&rawmap[8], 4);
+ switch (rawmap[15] & V34_MAP_ENTRY_FLAG_TYPE_MASK)
+ {
+ case V34_MAP_ENTRY_TYPE_COMPRESSED:
+ blocklen = be_read(&rawmap[12], 2) + (rawmap[14] << 16);
+ file_read(blockoffs, &m_compressed[0], blocklen);
+ m_decompressor[0]->decompress(&m_compressed[0], blocklen, dest, m_hunkbytes);
+ if (!(rawmap[15] & V34_MAP_ENTRY_FLAG_NO_CRC) && dest != NULL && crc32_creator::simple(dest, m_hunkbytes) != blockcrc)
+ throw CHDERR_DECOMPRESSION_ERROR;
+ return CHDERR_NONE;
+
+ case V34_MAP_ENTRY_TYPE_UNCOMPRESSED:
+ file_read(blockoffs, dest, m_hunkbytes);
+ if (!(rawmap[15] & V34_MAP_ENTRY_FLAG_NO_CRC) && crc32_creator::simple(dest, m_hunkbytes) != blockcrc)
+ throw CHDERR_DECOMPRESSION_ERROR;
+ return CHDERR_NONE;
+
+ case V34_MAP_ENTRY_TYPE_MINI:
+ be_write(dest, blockoffs, 8);
+ for (UINT32 bytes = 8; bytes < m_hunkbytes; bytes++)
+ dest[bytes] = dest[bytes - 8];
+ if (!(rawmap[15] & V34_MAP_ENTRY_FLAG_NO_CRC) && crc32_creator::simple(dest, m_hunkbytes) != blockcrc)
+ throw CHDERR_DECOMPRESSION_ERROR;
+ return CHDERR_NONE;
+
+ case V34_MAP_ENTRY_TYPE_SELF_HUNK:
+ return read_hunk(blockoffs, dest);
+
+ case V34_MAP_ENTRY_TYPE_PARENT_HUNK:
+ if (m_parent_missing)
+ throw CHDERR_REQUIRES_PARENT;
+ return m_parent->read_hunk(blockoffs, dest);
+ }
+ break;
+
+ // v5 map entries
+ case 5:
+ rawmap = &m_rawmap[m_mapentrybytes * hunknum];
+
+ // uncompressed case
+ if (!compressed())
+ {
+ blockoffs = UINT64(be_read(rawmap, 4)) * UINT64(m_hunkbytes);
+ if (blockoffs != 0)
+ file_read(blockoffs, dest, m_hunkbytes);
+ else if (m_parent_missing)
+ throw CHDERR_REQUIRES_PARENT;
+ else if (m_parent != NULL)
+ m_parent->read_hunk(hunknum, dest);
+ else
+ memset(dest, 0, m_hunkbytes);
+ return CHDERR_NONE;
+ }
+
+ // compressed case
+ blocklen = be_read(&rawmap[1], 3);
+ blockoffs = be_read(&rawmap[4], 6);
+ blockcrc = be_read(&rawmap[10], 2);
+ switch (rawmap[0])
+ {
+ case COMPRESSION_TYPE_0:
+ case COMPRESSION_TYPE_1:
+ case COMPRESSION_TYPE_2:
+ case COMPRESSION_TYPE_3:
+ file_read(blockoffs, &m_compressed[0], blocklen);
+ m_decompressor[rawmap[0]]->decompress(&m_compressed[0], blocklen, dest, m_hunkbytes);
+ if (!m_decompressor[rawmap[0]]->lossy() && dest != NULL && crc16_creator::simple(dest, m_hunkbytes) != blockcrc)
+ throw CHDERR_DECOMPRESSION_ERROR;
+ if (m_decompressor[rawmap[0]]->lossy() && crc16_creator::simple(&m_compressed[0], blocklen) != blockcrc)
+ throw CHDERR_DECOMPRESSION_ERROR;
+ return CHDERR_NONE;
+
+ case COMPRESSION_NONE:
+ file_read(blockoffs, dest, m_hunkbytes);
+ if (crc16_creator::simple(dest, m_hunkbytes) != blockcrc)
+ throw CHDERR_DECOMPRESSION_ERROR;
+ return CHDERR_NONE;
+
+ case COMPRESSION_SELF:
+ return read_hunk(blockoffs, dest);
+
+ case COMPRESSION_PARENT:
+ if (m_parent_missing)
+ throw CHDERR_REQUIRES_PARENT;
+ return m_parent->read_bytes(UINT64(blockoffs) * UINT64(m_parent->unit_bytes()), dest, m_hunkbytes);
+ }
+ break;
+ }
+
+ // if we get here, something was wrong
+ throw CHDERR_READ_ERROR;
+ }
+
+ // just return errors
+ catch (chd_error &err)
+ {
+ return err;
+ }
+}
+
+/**
+ * @fn chd_error chd_file::write_hunk(UINT32 hunknum, const void *buffer)
+ *
+ * @brief -------------------------------------------------
+ * write - write a single hunk to the CHD file
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_NOT_OPEN Thrown when a chderr not open error condition occurs.
+ * @exception CHDERR_HUNK_OUT_OF_RANGE Thrown when a chderr hunk out of range error
+ * condition occurs.
+ * @exception CHDERR_FILE_NOT_WRITEABLE Thrown when a chderr file not writeable error
+ * condition occurs.
+ *
+ * @param hunknum The hunknum.
+ * @param buffer The buffer.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::write_hunk(UINT32 hunknum, const void *buffer)
+{
+ // wrap this for clean reporting
+ try
+ {
+ // punt if no file
+ if (m_file == NULL)
+ throw CHDERR_NOT_OPEN;
+
+ // return an error if out of range
+ if (hunknum >= m_hunkcount)
+ throw CHDERR_HUNK_OUT_OF_RANGE;
+
+ // if not writeable, fail
+ if (!m_allow_writes)
+ throw CHDERR_FILE_NOT_WRITEABLE;
+
+ // uncompressed writes only via this interface
+ if (compressed())
+ throw CHDERR_FILE_NOT_WRITEABLE;
+
+ // see if we have allocated the space on disk for this hunk
+ UINT8 *rawmap = &m_rawmap[hunknum * 4];
+ UINT32 rawentry = be_read(rawmap, 4);
+
+ // if not, allocate one now
+ if (rawentry == 0)
+ {
+ // first make sure we need to allocate it
+ bool all_zeros = true;
+ const UINT32 *scan = reinterpret_cast<const UINT32 *>(buffer);
+ for (UINT32 index = 0; index < m_hunkbytes / 4; index++)
+ if (scan[index] != 0)
+ {
+ all_zeros = false;
+ break;
+ }
+
+ // if it's all zeros, do nothing more
+ if (all_zeros)
+ return CHDERR_NONE;
+
+ // append new data to the end of the file, aligning the first chunk
+ rawentry = file_append(buffer, m_hunkbytes, m_hunkbytes) / m_hunkbytes;
+
+ // write the map entry back
+ be_write(rawmap, rawentry, 4);
+ file_write(m_mapoffset + hunknum * 4, rawmap, 4);
+
+ // update the cached hunk if we just wrote it
+ if (hunknum == m_cachehunk && buffer != &m_cache[0])
+ memcpy(&m_cache[0], buffer, m_hunkbytes);
+ }
+
+ // otherwise, just overwrite
+ else
+ file_write(UINT64(rawentry) * UINT64(m_hunkbytes), buffer, m_hunkbytes);
+ return CHDERR_NONE;
+ }
+
+ // just return errors
+ catch (chd_error &err)
+ {
+ return err;
+ }
+}
+
+/**
+ * @fn chd_error chd_file::read_units(UINT64 unitnum, void *buffer, UINT32 count)
+ *
+ * @brief -------------------------------------------------
+ * read_units - read the given number of units from the CHD
+ * -------------------------------------------------.
+ *
+ * @param unitnum The unitnum.
+ * @param [in,out] buffer If non-null, the buffer.
+ * @param count Number of.
+ *
+ * @return The units.
+ */
+
+chd_error chd_file::read_units(UINT64 unitnum, void *buffer, UINT32 count)
+{
+ return read_bytes(unitnum * UINT64(m_unitbytes), buffer, count * m_unitbytes);
+}
+
+/**
+ * @fn chd_error chd_file::write_units(UINT64 unitnum, const void *buffer, UINT32 count)
+ *
+ * @brief -------------------------------------------------
+ * write_units - write the given number of units to the CHD
+ * -------------------------------------------------.
+ *
+ * @param unitnum The unitnum.
+ * @param buffer The buffer.
+ * @param count Number of.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::write_units(UINT64 unitnum, const void *buffer, UINT32 count)
+{
+ return write_bytes(unitnum * UINT64(m_unitbytes), buffer, count * m_unitbytes);
+}
+
+/**
+ * @fn chd_error chd_file::read_bytes(UINT64 offset, void *buffer, UINT32 bytes)
+ *
+ * @brief -------------------------------------------------
+ * read_bytes - read from the CHD at a byte level, using the cache to handle partial
+ * hunks
+ * -------------------------------------------------.
+ *
+ * @param offset The offset.
+ * @param [in,out] buffer If non-null, the buffer.
+ * @param bytes The bytes.
+ *
+ * @return The bytes.
+ */
+
+chd_error chd_file::read_bytes(UINT64 offset, void *buffer, UINT32 bytes)
+{
+ // iterate over hunks
+ UINT32 first_hunk = offset / m_hunkbytes;
+ UINT32 last_hunk = (offset + bytes - 1) / m_hunkbytes;
+ UINT8 *dest = reinterpret_cast<UINT8 *>(buffer);
+ for (UINT32 curhunk = first_hunk; curhunk <= last_hunk; curhunk++)
+ {
+ // determine start/end boundaries
+ UINT32 startoffs = (curhunk == first_hunk) ? (offset % m_hunkbytes) : 0;
+ UINT32 endoffs = (curhunk == last_hunk) ? ((offset + bytes - 1) % m_hunkbytes) : (m_hunkbytes - 1);
+
+ // if it's a full block, just read directly from disk unless it's the cached hunk
+ chd_error err = CHDERR_NONE;
+ if (startoffs == 0 && endoffs == m_hunkbytes - 1 && curhunk != m_cachehunk)
+ err = read_hunk(curhunk, dest);
+
+ // otherwise, read from the cache
+ else
+ {
+ if (curhunk != m_cachehunk)
+ {
+ err = read_hunk(curhunk, &m_cache[0]);
+ if (err != CHDERR_NONE)
+ return err;
+ m_cachehunk = curhunk;
+ }
+ memcpy(dest, &m_cache[startoffs], endoffs + 1 - startoffs);
+ }
+
+ // handle errors and advance
+ if (err != CHDERR_NONE)
+ return err;
+ dest += endoffs + 1 - startoffs;
+ }
+ return CHDERR_NONE;
+}
+
+/**
+ * @fn chd_error chd_file::write_bytes(UINT64 offset, const void *buffer, UINT32 bytes)
+ *
+ * @brief -------------------------------------------------
+ * write_bytes - write to the CHD at a byte level, using the cache to handle partial
+ * hunks
+ * -------------------------------------------------.
+ *
+ * @param offset The offset.
+ * @param buffer The buffer.
+ * @param bytes The bytes.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::write_bytes(UINT64 offset, const void *buffer, UINT32 bytes)
+{
+ // iterate over hunks
+ UINT32 first_hunk = offset / m_hunkbytes;
+ UINT32 last_hunk = (offset + bytes - 1) / m_hunkbytes;
+ const UINT8 *source = reinterpret_cast<const UINT8 *>(buffer);
+ for (UINT32 curhunk = first_hunk; curhunk <= last_hunk; curhunk++)
+ {
+ // determine start/end boundaries
+ UINT32 startoffs = (curhunk == first_hunk) ? (offset % m_hunkbytes) : 0;
+ UINT32 endoffs = (curhunk == last_hunk) ? ((offset + bytes - 1) % m_hunkbytes) : (m_hunkbytes - 1);
+
+ // if it's a full block, just write directly to disk unless it's the cached hunk
+ chd_error err = CHDERR_NONE;
+ if (startoffs == 0 && endoffs == m_hunkbytes - 1 && curhunk != m_cachehunk)
+ err = write_hunk(curhunk, source);
+
+ // otherwise, write from the cache
+ else
+ {
+ if (curhunk != m_cachehunk)
+ {
+ err = read_hunk(curhunk, &m_cache[0]);
+ if (err != CHDERR_NONE)
+ return err;
+ m_cachehunk = curhunk;
+ }
+ memcpy(&m_cache[startoffs], source, endoffs + 1 - startoffs);
+ err = write_hunk(curhunk, &m_cache[0]);
+ }
+
+ // handle errors and advance
+ if (err != CHDERR_NONE)
+ return err;
+ source += endoffs + 1 - startoffs;
+ }
+ return CHDERR_NONE;
+}
+
+/**
+ * @fn chd_error chd_file::read_metadata(chd_metadata_tag searchtag, UINT32 searchindex, std::string &output)
+ *
+ * @brief -------------------------------------------------
+ * read_metadata - read the indexed metadata of the given type
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_METADATA_NOT_FOUND Thrown when a chderr metadata not found error
+ * condition occurs.
+ *
+ * @param searchtag The searchtag.
+ * @param searchindex The searchindex.
+ * @param [in,out] output The output.
+ *
+ * @return The metadata.
+ */
+
+chd_error chd_file::read_metadata(chd_metadata_tag searchtag, UINT32 searchindex, std::string &output)
+{
+ // wrap this for clean reporting
+ try
+ {
+ // if we didn't find it, just return
+ metadata_entry metaentry;
+ if (!metadata_find(searchtag, searchindex, metaentry))
+ throw CHDERR_METADATA_NOT_FOUND;
+
+ // read the metadata
+ // TODO: how to properly allocate a dynamic char buffer?
+ char* metabuf = new char[metaentry.length+1];
+ memset(metabuf, 0x00, metaentry.length+1);
+ file_read(metaentry.offset + METADATA_HEADER_SIZE, metabuf, metaentry.length);
+ output.assign(metabuf);
+ delete[] metabuf;
+ return CHDERR_NONE;
+ }
+
+ // just return errors
+ catch (chd_error &err)
+ {
+ return err;
+ }
+}
+
+/**
+ * @fn chd_error chd_file::read_metadata(chd_metadata_tag searchtag, UINT32 searchindex, dynamic_buffer &output)
+ *
+ * @brief Reads a metadata.
+ *
+ * @exception CHDERR_METADATA_NOT_FOUND Thrown when a chderr metadata not found error
+ * condition occurs.
+ *
+ * @param searchtag The searchtag.
+ * @param searchindex The searchindex.
+ * @param [in,out] output The output.
+ *
+ * @return The metadata.
+ */
+
+chd_error chd_file::read_metadata(chd_metadata_tag searchtag, UINT32 searchindex, dynamic_buffer &output)
+{
+ // wrap this for clean reporting
+ try
+ {
+ // if we didn't find it, just return
+ metadata_entry metaentry;
+ if (!metadata_find(searchtag, searchindex, metaentry))
+ throw CHDERR_METADATA_NOT_FOUND;
+
+ // read the metadata
+ output.resize(metaentry.length);
+ file_read(metaentry.offset + METADATA_HEADER_SIZE, &output[0], metaentry.length);
+ return CHDERR_NONE;
+ }
+
+ // just return errors
+ catch (chd_error &err)
+ {
+ return err;
+ }
+}
+
+/**
+ * @fn chd_error chd_file::read_metadata(chd_metadata_tag searchtag, UINT32 searchindex, void *output, UINT32 outputlen, UINT32 &resultlen)
+ *
+ * @brief Reads a metadata.
+ *
+ * @exception CHDERR_METADATA_NOT_FOUND Thrown when a chderr metadata not found error
+ * condition occurs.
+ *
+ * @param searchtag The searchtag.
+ * @param searchindex The searchindex.
+ * @param [in,out] output If non-null, the output.
+ * @param outputlen The outputlen.
+ * @param [in,out] resultlen The resultlen.
+ *
+ * @return The metadata.
+ */
+
+chd_error chd_file::read_metadata(chd_metadata_tag searchtag, UINT32 searchindex, void *output, UINT32 outputlen, UINT32 &resultlen)
+{
+ // wrap this for clean reporting
+ try
+ {
+ // if we didn't find it, just return
+ metadata_entry metaentry;
+ if (!metadata_find(searchtag, searchindex, metaentry))
+ throw CHDERR_METADATA_NOT_FOUND;
+
+ // read the metadata
+ resultlen = metaentry.length;
+ file_read(metaentry.offset + METADATA_HEADER_SIZE, output, MIN(outputlen, resultlen));
+ return CHDERR_NONE;
+ }
+
+ // just return errors
+ catch (chd_error &err)
+ {
+ return err;
+ }
+}
+
+/**
+ * @fn chd_error chd_file::read_metadata(chd_metadata_tag searchtag, UINT32 searchindex, dynamic_buffer &output, chd_metadata_tag &resulttag, UINT8 &resultflags)
+ *
+ * @brief Reads a metadata.
+ *
+ * @exception CHDERR_METADATA_NOT_FOUND Thrown when a chderr metadata not found error
+ * condition occurs.
+ *
+ * @param searchtag The searchtag.
+ * @param searchindex The searchindex.
+ * @param [in,out] output The output.
+ * @param [in,out] resulttag The resulttag.
+ * @param [in,out] resultflags The resultflags.
+ *
+ * @return The metadata.
+ */
+
+chd_error chd_file::read_metadata(chd_metadata_tag searchtag, UINT32 searchindex, dynamic_buffer &output, chd_metadata_tag &resulttag, UINT8 &resultflags)
+{
+ // wrap this for clean reporting
+ try
+ {
+ // if we didn't find it, just return
+ metadata_entry metaentry;
+ if (!metadata_find(searchtag, searchindex, metaentry))
+ throw CHDERR_METADATA_NOT_FOUND;
+
+ // read the metadata
+ output.resize(metaentry.length);
+ file_read(metaentry.offset + METADATA_HEADER_SIZE, &output[0], metaentry.length);
+ resulttag = metaentry.metatag;
+ resultflags = metaentry.flags;
+ return CHDERR_NONE;
+ }
+
+ // just return errors
+ catch (chd_error &err)
+ {
+ return err;
+ }
+}
+
+/**
+ * @fn chd_error chd_file::write_metadata(chd_metadata_tag metatag, UINT32 metaindex, const void *inputbuf, UINT32 inputlen, UINT8 flags)
+ *
+ * @brief -------------------------------------------------
+ * write_metadata - write the indexed metadata of the given type
+ * -------------------------------------------------.
+ *
+ * @param metatag The metatag.
+ * @param metaindex The metaindex.
+ * @param inputbuf The inputbuf.
+ * @param inputlen The inputlen.
+ * @param flags The flags.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::write_metadata(chd_metadata_tag metatag, UINT32 metaindex, const void *inputbuf, UINT32 inputlen, UINT8 flags)
+{
+ // wrap this for clean reporting
+ try
+ {
+ // must write at least 1 byte and no more than 16MB
+ if (inputlen < 1 || inputlen >= 16 * 1024 * 1024)
+ return CHDERR_INVALID_PARAMETER;
+
+ // find the entry if it already exists
+ metadata_entry metaentry;
+ bool finished = false;
+ if (metadata_find(metatag, metaindex, metaentry))
+ {
+ // if the new data fits over the old data, just overwrite
+ if (inputlen <= metaentry.length)
+ {
+ file_write(metaentry.offset + METADATA_HEADER_SIZE, inputbuf, inputlen);
+
+ // if the lengths don't match, we need to update the length in our header
+ if (inputlen != metaentry.length)
+ {
+ UINT8 length[3];
+ be_write(length, inputlen, 3);
+ file_write(metaentry.offset + 5, length, sizeof(length));
+ }
+
+ // indicate we did everything
+ finished = true;
+ }
+
+ // if it doesn't fit, unlink the current entry
+ else
+ metadata_set_previous_next(metaentry.prev, metaentry.next);
+ }
+
+ // if not yet done, create a new entry and append
+ if (!finished)
+ {
+ // now build us a new entry
+ UINT8 raw_meta_header[METADATA_HEADER_SIZE];
+ be_write(&raw_meta_header[0], metatag, 4);
+ raw_meta_header[4] = flags;
+ be_write(&raw_meta_header[5], (inputlen & 0x00ffffff) | (flags << 24), 3);
+ be_write(&raw_meta_header[8], 0, 8);
+
+ // append the new header, then the data
+ UINT64 offset = file_append(raw_meta_header, sizeof(raw_meta_header));
+ file_append(inputbuf, inputlen);
+
+ // set the previous entry to point to us
+ metadata_set_previous_next(metaentry.prev, offset);
+ }
+
+ // update the hash
+ metadata_update_hash();
+ return CHDERR_NONE;
+ }
+
+ // return any errors
+ catch (chd_error &err)
+ {
+ return err;
+ }
+}
+
+/**
+ * @fn chd_error chd_file::delete_metadata(chd_metadata_tag metatag, UINT32 metaindex)
+ *
+ * @brief -------------------------------------------------
+ * delete_metadata - remove the given metadata from the list
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_METADATA_NOT_FOUND Thrown when a chderr metadata not found error
+ * condition occurs.
+ *
+ * @param metatag The metatag.
+ * @param metaindex The metaindex.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::delete_metadata(chd_metadata_tag metatag, UINT32 metaindex)
+{
+ // wrap this for clean reporting
+ try
+ {
+ // find the entry
+ metadata_entry metaentry;
+ if (!metadata_find(metatag, metaindex, metaentry))
+ throw CHDERR_METADATA_NOT_FOUND;
+
+ // point the previous to the next, unlinking us
+ metadata_set_previous_next(metaentry.prev, metaentry.next);
+ return CHDERR_NONE;
+ }
+
+ // return any errors
+ catch (chd_error &err)
+ {
+ return err;
+ }
+}
+
+/**
+ * @fn chd_error chd_file::clone_all_metadata(chd_file &source)
+ *
+ * @brief -------------------------------------------------
+ * clone_all_metadata - clone the metadata from one CHD to a second
+ * -------------------------------------------------.
+ *
+ * @exception err Thrown when an error error condition occurs.
+ *
+ * @param [in,out] source Another instance to copy.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::clone_all_metadata(chd_file &source)
+{
+ // wrap this for clean reporting
+ try
+ {
+ // iterate over metadata entries in the source
+ dynamic_buffer filedata;
+ metadata_entry metaentry;
+ metaentry.metatag = 0;
+ metaentry.length = 0;
+ metaentry.next = 0;
+ metaentry.flags = 0;
+ for (bool has_data = source.metadata_find(CHDMETATAG_WILDCARD, 0, metaentry); has_data; has_data = source.metadata_find(CHDMETATAG_WILDCARD, 0, metaentry, true))
+ {
+ // read the metadata item
+ filedata.resize(metaentry.length);
+ source.file_read(metaentry.offset + METADATA_HEADER_SIZE, &filedata[0], metaentry.length);
+
+ // write it to the destination
+ chd_error err = write_metadata(metaentry.metatag, (UINT32)-1, &filedata[0], metaentry.length, metaentry.flags);
+ if (err != CHDERR_NONE)
+ throw err;
+ }
+ return CHDERR_NONE;
+ }
+
+ // return any errors
+ catch (chd_error &err)
+ {
+ return err;
+ }
+}
+
+/**
+ * @fn sha1_t chd_file::compute_overall_sha1(sha1_t rawsha1)
+ *
+ * @brief -------------------------------------------------
+ * compute_overall_sha1 - iterate through the metadata and compute the overall hash of
+ * the CHD file
+ * -------------------------------------------------.
+ *
+ * @param rawsha1 The first rawsha.
+ *
+ * @return The calculated overall sha 1.
+ */
+
+sha1_t chd_file::compute_overall_sha1(sha1_t rawsha1)
+{
+ // only works for v4 and above
+ if (m_version < 4)
+ return rawsha1;
+
+ // iterate over metadata
+ dynamic_buffer filedata;
+ std::vector<metadata_hash> hasharray;
+ metadata_entry metaentry;
+ for (bool has_data = metadata_find(CHDMETATAG_WILDCARD, 0, metaentry); has_data; has_data = metadata_find(CHDMETATAG_WILDCARD, 0, metaentry, true))
+ {
+ // if not checksumming, continue
+ if ((metaentry.flags & CHD_MDFLAGS_CHECKSUM) == 0)
+ continue;
+
+ // allocate memory and read the data
+ filedata.resize(metaentry.length);
+ file_read(metaentry.offset + METADATA_HEADER_SIZE, &filedata[0], metaentry.length);
+
+ // create an entry for this metadata and add it
+ metadata_hash hashentry;
+ be_write(hashentry.tag, metaentry.metatag, 4);
+ hashentry.sha1 = sha1_creator::simple(&filedata[0], metaentry.length);
+ hasharray.push_back(hashentry);
+ }
+
+ // sort the array
+ if (!hasharray.empty())
+ qsort(&hasharray[0], hasharray.size(), sizeof(hasharray[0]), metadata_hash_compare);
+
+ // read the raw data hash from our header and start a new SHA1 with that data
+ sha1_creator overall_sha1;
+ overall_sha1.append(&rawsha1, sizeof(rawsha1));
+ if (!hasharray.empty())
+ overall_sha1.append(&hasharray[0], hasharray.size() * sizeof(hasharray[0]));
+ return overall_sha1.finish();
+}
+
+/**
+ * @fn chd_error chd_file::codec_configure(chd_codec_type codec, int param, void *config)
+ *
+ * @brief -------------------------------------------------
+ * codec_config - set internal codec parameters
+ * -------------------------------------------------.
+ *
+ * @param codec The codec.
+ * @param param The parameter.
+ * @param [in,out] config If non-null, the configuration.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::codec_configure(chd_codec_type codec, int param, void *config)
+{
+ // wrap this for clean reporting
+ try
+ {
+ // find the codec and call its configuration
+ for (int codecnum = 0; codecnum < ARRAY_LENGTH(m_compression); codecnum++)
+ if (m_compression[codecnum] == codec)
+ {
+ m_decompressor[codecnum]->configure(param, config);
+ return CHDERR_NONE;
+ }
+ return CHDERR_INVALID_PARAMETER;
+ }
+
+ // return any errors
+ catch (chd_error &err)
+ {
+ return err;
+ }
+}
+
+/**
+ * @fn const char *chd_file::error_string(chd_error err)
+ *
+ * @brief -------------------------------------------------
+ * error_string - return an error string for the given CHD error
+ * -------------------------------------------------.
+ *
+ * @param err The error.
+ *
+ * @return null if it fails, else a char*.
+ */
+
+const char *chd_file::error_string(chd_error err)
+{
+ switch (err)
+ {
+ case CHDERR_NONE: return "no error";
+ case CHDERR_NO_INTERFACE: return "no drive interface";
+ case CHDERR_OUT_OF_MEMORY: return "out of memory";
+ case CHDERR_NOT_OPEN: return "file not open";
+ case CHDERR_ALREADY_OPEN: return "file already open";
+ case CHDERR_INVALID_FILE: return "invalid file";
+ case CHDERR_INVALID_PARAMETER: return "invalid parameter";
+ case CHDERR_INVALID_DATA: return "invalid data";
+ case CHDERR_FILE_NOT_FOUND: return "file not found";
+ case CHDERR_REQUIRES_PARENT: return "requires parent";
+ case CHDERR_FILE_NOT_WRITEABLE: return "file not writeable";
+ case CHDERR_READ_ERROR: return "read error";
+ case CHDERR_WRITE_ERROR: return "write error";
+ case CHDERR_CODEC_ERROR: return "codec error";
+ case CHDERR_INVALID_PARENT: return "invalid parent";
+ case CHDERR_HUNK_OUT_OF_RANGE: return "hunk out of range";
+ case CHDERR_DECOMPRESSION_ERROR: return "decompression error";
+ case CHDERR_COMPRESSION_ERROR: return "compression error";
+ case CHDERR_CANT_CREATE_FILE: return "can't create file";
+ case CHDERR_CANT_VERIFY: return "can't verify file";
+ case CHDERR_NOT_SUPPORTED: return "operation not supported";
+ case CHDERR_METADATA_NOT_FOUND: return "can't find metadata";
+ case CHDERR_INVALID_METADATA_SIZE: return "invalid metadata size";
+ case CHDERR_UNSUPPORTED_VERSION: return "mismatched DIFF and CHD or unsupported CHD version";
+ case CHDERR_VERIFY_INCOMPLETE: return "incomplete verify";
+ case CHDERR_INVALID_METADATA: return "invalid metadata";
+ case CHDERR_INVALID_STATE: return "invalid state";
+ case CHDERR_OPERATION_PENDING: return "operation pending";
+ case CHDERR_UNSUPPORTED_FORMAT: return "unsupported format";
+ case CHDERR_UNKNOWN_COMPRESSION: return "unknown compression type";
+ case CHDERR_WALKING_PARENT: return "currently examining parent";
+ case CHDERR_COMPRESSING: return "currently compressing";
+ default: return "undocumented error";
+ }
+}
+
+
+
+//**************************************************************************
+// INTERNAL HELPERS
+//**************************************************************************
+
+/**
+ * @fn UINT32 chd_file::guess_unitbytes()
+ *
+ * @brief -------------------------------------------------
+ * guess_unitbytes - for older CHD formats, take a guess at the bytes/unit based on
+ * metadata
+ * -------------------------------------------------.
+ *
+ * @return An UINT32.
+ */
+
+UINT32 chd_file::guess_unitbytes()
+{
+ // look for hard disk metadata; if found, then the unit size == sector size
+ std::string metadata;
+ int i0, i1, i2, i3;
+ if (read_metadata(HARD_DISK_METADATA_TAG, 0, metadata) == CHDERR_NONE && sscanf(metadata.c_str(), HARD_DISK_METADATA_FORMAT, &i0, &i1, &i2, &i3) == 4)
+ return i3;
+
+ // look for CD-ROM metadata; if found, then the unit size == CD frame size
+ if (read_metadata(CDROM_OLD_METADATA_TAG, 0, metadata) == CHDERR_NONE ||
+ read_metadata(CDROM_TRACK_METADATA_TAG, 0, metadata) == CHDERR_NONE ||
+ read_metadata(CDROM_TRACK_METADATA2_TAG, 0, metadata) == CHDERR_NONE ||
+ read_metadata(GDROM_OLD_METADATA_TAG, 0, metadata) == CHDERR_NONE ||
+ read_metadata(GDROM_TRACK_METADATA_TAG, 0, metadata) == CHDERR_NONE)
+ return CD_FRAME_SIZE;
+
+ // otherwise, just map 1:1 with the hunk size
+ return m_hunkbytes;
+}
+
+/**
+ * @fn void chd_file::parse_v3_header(UINT8 *rawheader, sha1_t &parentsha1)
+ *
+ * @brief -------------------------------------------------
+ * parse_v3_header - parse the header from a v3 file and configure core parameters
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_INVALID_FILE Thrown when a chderr invalid file error condition
+ * occurs.
+ * @exception CHDERR_UNKNOWN_COMPRESSION Thrown when a chderr unknown compression error
+ * condition occurs.
+ *
+ * @param [in,out] rawheader If non-null, the rawheader.
+ * @param [in,out] parentsha1 The first parentsha.
+ */
+
+void chd_file::parse_v3_header(UINT8 *rawheader, sha1_t &parentsha1)
+{
+ // verify header length
+ if (be_read(&rawheader[8], 4) != V3_HEADER_SIZE)
+ throw CHDERR_INVALID_FILE;
+
+ // extract core info
+ m_logicalbytes = be_read(&rawheader[28], 8);
+ m_mapoffset = 120;
+ m_metaoffset = be_read(&rawheader[36], 8);
+ m_hunkbytes = be_read(&rawheader[76], 4);
+ m_hunkcount = be_read(&rawheader[24], 4);
+
+ // extract parent SHA-1
+ UINT32 flags = be_read(&rawheader[16], 4);
+ m_allow_writes = (flags & 2) == 0;
+
+ // determine compression
+ switch (be_read(&rawheader[20], 4))
+ {
+ case 0: m_compression[0] = CHD_CODEC_NONE; break;
+ case 1: m_compression[0] = CHD_CODEC_ZLIB; break;
+ case 2: m_compression[0] = CHD_CODEC_ZLIB; break;
+ case 3: m_compression[0] = CHD_CODEC_AVHUFF; break;
+ default: throw CHDERR_UNKNOWN_COMPRESSION;
+ }
+ m_compression[1] = m_compression[2] = m_compression[3] = CHD_CODEC_NONE;
+
+ // describe the format
+ m_mapoffset_offset = 0;
+ m_metaoffset_offset = 36;
+ m_sha1_offset = 80;
+ m_rawsha1_offset = 0;
+ m_parentsha1_offset = 100;
+
+ // determine properties of map entries
+ m_mapentrybytes = 16;
+
+ // extract parent SHA-1
+ if (flags & 1)
+ parentsha1 = be_read_sha1(&rawheader[m_parentsha1_offset]);
+
+ // guess at the units based on snooping the metadata
+ m_unitbytes = guess_unitbytes();
+ m_unitcount = (m_logicalbytes + m_unitbytes - 1) / m_unitbytes;
+}
+
+/**
+ * @fn void chd_file::parse_v4_header(UINT8 *rawheader, sha1_t &parentsha1)
+ *
+ * @brief -------------------------------------------------
+ * parse_v4_header - parse the header from a v4 file and configure core parameters
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_INVALID_FILE Thrown when a chderr invalid file error condition
+ * occurs.
+ * @exception CHDERR_UNKNOWN_COMPRESSION Thrown when a chderr unknown compression error
+ * condition occurs.
+ *
+ * @param [in,out] rawheader If non-null, the rawheader.
+ * @param [in,out] parentsha1 The first parentsha.
+ */
+
+void chd_file::parse_v4_header(UINT8 *rawheader, sha1_t &parentsha1)
+{
+ // verify header length
+ if (be_read(&rawheader[8], 4) != V4_HEADER_SIZE)
+ throw CHDERR_INVALID_FILE;
+
+ // extract core info
+ m_logicalbytes = be_read(&rawheader[28], 8);
+ m_mapoffset = 108;
+ m_metaoffset = be_read(&rawheader[36], 8);
+ m_hunkbytes = be_read(&rawheader[44], 4);
+ m_hunkcount = be_read(&rawheader[24], 4);
+
+ // extract parent SHA-1
+ UINT32 flags = be_read(&rawheader[16], 4);
+ m_allow_writes = (flags & 2) == 0;
+
+ // determine compression
+ switch (be_read(&rawheader[20], 4))
+ {
+ case 0: m_compression[0] = CHD_CODEC_NONE; break;
+ case 1: m_compression[0] = CHD_CODEC_ZLIB; break;
+ case 2: m_compression[0] = CHD_CODEC_ZLIB; break;
+ case 3: m_compression[0] = CHD_CODEC_AVHUFF; break;
+ default: throw CHDERR_UNKNOWN_COMPRESSION;
+ }
+ m_compression[1] = m_compression[2] = m_compression[3] = CHD_CODEC_NONE;
+
+ // describe the format
+ m_mapoffset_offset = 0;
+ m_metaoffset_offset = 36;
+ m_sha1_offset = 48;
+ m_rawsha1_offset = 88;
+ m_parentsha1_offset = 68;
+
+ // determine properties of map entries
+ m_mapentrybytes = 16;
+
+ // extract parent SHA-1
+ if (flags & 1)
+ parentsha1 = be_read_sha1(&rawheader[m_parentsha1_offset]);
+
+ // guess at the units based on snooping the metadata
+ m_unitbytes = guess_unitbytes();
+ m_unitcount = (m_logicalbytes + m_unitbytes - 1) / m_unitbytes;
+}
+
+/**
+ * @fn void chd_file::parse_v5_header(UINT8 *rawheader, sha1_t &parentsha1)
+ *
+ * @brief -------------------------------------------------
+ * parse_v5_header - read the header from a v5 file and configure core parameters
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_INVALID_FILE Thrown when a chderr invalid file error condition occurs.
+ *
+ * @param [in,out] rawheader If non-null, the rawheader.
+ * @param [in,out] parentsha1 The first parentsha.
+ */
+
+void chd_file::parse_v5_header(UINT8 *rawheader, sha1_t &parentsha1)
+{
+ // verify header length
+ if (be_read(&rawheader[8], 4) != V5_HEADER_SIZE)
+ throw CHDERR_INVALID_FILE;
+
+ // extract core info
+ m_logicalbytes = be_read(&rawheader[32], 8);
+ m_mapoffset = be_read(&rawheader[40], 8);
+ m_metaoffset = be_read(&rawheader[48], 8);
+ m_hunkbytes = be_read(&rawheader[56], 4);
+ m_hunkcount = (m_logicalbytes + m_hunkbytes - 1) / m_hunkbytes;
+ m_unitbytes = be_read(&rawheader[60], 4);
+ m_unitcount = (m_logicalbytes + m_unitbytes - 1) / m_unitbytes;
+
+ // determine compression
+ m_compression[0] = be_read(&rawheader[16], 4);
+ m_compression[1] = be_read(&rawheader[20], 4);
+ m_compression[2] = be_read(&rawheader[24], 4);
+ m_compression[3] = be_read(&rawheader[28], 4);
+
+ m_allow_writes = !compressed();
+
+ // describe the format
+ m_mapoffset_offset = 40;
+ m_metaoffset_offset = 48;
+ m_sha1_offset = 84;
+ m_rawsha1_offset = 64;
+ m_parentsha1_offset = 104;
+
+ // determine properties of map entries
+ m_mapentrybytes = compressed() ? 12 : 4;
+
+ // extract parent SHA-1
+ parentsha1 = be_read_sha1(&rawheader[m_parentsha1_offset]);
+}
+
+/**
+ * @fn chd_error chd_file::compress_v5_map()
+ *
+ * @brief -------------------------------------------------
+ * compress_v5_map - compress the v5 map and write it to the end of the file
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_COMPRESSION_ERROR Thrown when a chderr compression error error
+ * condition occurs.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::compress_v5_map()
+{
+ try
+ {
+ // first get a CRC-16 of the original rawmap
+ crc16_t mapcrc = crc16_creator::simple(&m_rawmap[0], m_hunkcount * 12);
+
+ // create a buffer to hold the RLE data
+ dynamic_buffer compression_rle(m_hunkcount);
+ UINT8 *dest = &compression_rle[0];
+
+ // use a huffman encoder for 16 different codes, maximum length is 8 bits
+ huffman_encoder<16, 8> encoder;
+ encoder.histo_reset();
+
+ // RLE-compress the compression type since we expect runs of the same
+ UINT32 max_self = 0;
+ UINT32 last_self = 0;
+ UINT64 max_parent = 0;
+ UINT64 last_parent = 0;
+ UINT32 max_complen = 0;
+ UINT8 lastcomp = 0;
+ int count = 0;
+ for (int hunknum = 0; hunknum < m_hunkcount; hunknum++)
+ {
+ UINT8 curcomp = m_rawmap[hunknum * 12 + 0];
+
+ // promote self block references to more compact forms
+ if (curcomp == COMPRESSION_SELF)
+ {
+ UINT32 refhunk = be_read(&m_rawmap[hunknum * 12 + 4], 6);
+ if (refhunk == last_self)
+ curcomp = COMPRESSION_SELF_0;
+ else if (refhunk == last_self + 1)
+ curcomp = COMPRESSION_SELF_1;
+ else
+ max_self = MAX(max_self, refhunk);
+ last_self = refhunk;
+ }
+
+ // promote parent block references to more compact forms
+ else if (curcomp == COMPRESSION_PARENT)
+ {
+ UINT32 refunit = be_read(&m_rawmap[hunknum * 12 + 4], 6);
+ if (refunit == (UINT64(hunknum) * UINT64(m_hunkbytes)) / m_unitbytes)
+ curcomp = COMPRESSION_PARENT_SELF;
+ else if (refunit == last_parent)
+ curcomp = COMPRESSION_PARENT_0;
+ else if (refunit == last_parent + m_hunkbytes / m_unitbytes)
+ curcomp = COMPRESSION_PARENT_1;
+ else
+ max_parent = MAX(max_parent, refunit);
+ last_parent = refunit;
+ }
+
+ // track maximum compressed length
+ else //if (curcomp >= COMPRESSION_TYPE_0 && curcomp <= COMPRESSION_TYPE_3)
+ max_complen = MAX(max_complen, be_read(&m_rawmap[hunknum * 12 + 1], 3));
+
+ // track repeats
+ if (curcomp == lastcomp)
+ count++;
+
+ // if no repeat, or we're at the end, flush it
+ if (curcomp != lastcomp || hunknum == m_hunkcount - 1)
+ {
+ while (count != 0)
+ {
+ if (count < 3)
+ encoder.histo_one(*dest++ = lastcomp), count--;
+ else if (count <= 3+15)
+ {
+ encoder.histo_one(*dest++ = COMPRESSION_RLE_SMALL);
+ encoder.histo_one(*dest++ = count - 3);
+ count = 0;
+ }
+ else
+ {
+ int this_count = MIN(count, 3+16+255);
+ encoder.histo_one(*dest++ = COMPRESSION_RLE_LARGE);
+ encoder.histo_one(*dest++ = (this_count - 3 - 16) >> 4);
+ encoder.histo_one(*dest++ = (this_count - 3 - 16) & 15);
+ count -= this_count;
+ }
+ }
+ if (curcomp != lastcomp)
+ encoder.histo_one(*dest++ = lastcomp = curcomp);
+ }
+ }
+
+ // compute a tree and export it to the buffer
+ dynamic_buffer compressed(m_hunkcount * 6);
+ bitstream_out bitbuf(&compressed[16], compressed.size() - 16);
+ huffman_error err = encoder.compute_tree_from_histo();
+ if (err != HUFFERR_NONE)
+ throw CHDERR_COMPRESSION_ERROR;
+ err = encoder.export_tree_rle(bitbuf);
+ if (err != HUFFERR_NONE)
+ throw CHDERR_COMPRESSION_ERROR;
+
+ // encode the data
+ for (UINT8 *src = &compression_rle[0]; src < dest; src++)
+ encoder.encode_one(bitbuf, *src);
+
+ // determine the number of bits we need to hold the a length
+ // and a hunk index
+ UINT8 lengthbits = bits_for_value(max_complen);
+ UINT8 selfbits = bits_for_value(max_self);
+ UINT8 parentbits = bits_for_value(max_parent);
+
+ // for each compression type, output the relevant data
+ lastcomp = 0;
+ count = 0;
+ UINT8 *src = &compression_rle[0];
+ UINT64 firstoffs = 0;
+ for (int hunknum = 0; hunknum < m_hunkcount; hunknum++)
+ {
+ UINT8 *rawmap = &m_rawmap[hunknum * 12];
+ UINT32 length = be_read(&rawmap[1], 3);
+ UINT64 offset = be_read(&rawmap[4], 6);
+ UINT16 crc = be_read(&rawmap[10], 2);
+
+ // if no count remaining, fetch the next entry
+ if (count == 0)
+ {
+ UINT8 val = *src++;
+ if (val == COMPRESSION_RLE_SMALL)
+ count = 2 + *src++;
+ else if (val == COMPRESSION_RLE_LARGE)
+ count = 2 + 16 + (*src++ << 4), count += *src++;
+ else
+ lastcomp = val;
+ }
+ else
+ count--;
+
+ // output additional data needed for this entry
+ switch (lastcomp)
+ {
+ case COMPRESSION_TYPE_0:
+ case COMPRESSION_TYPE_1:
+ case COMPRESSION_TYPE_2:
+ case COMPRESSION_TYPE_3:
+ assert(length < (1 << lengthbits));
+ bitbuf.write(length, lengthbits);
+ bitbuf.write(crc, 16);
+ if (firstoffs == 0)
+ firstoffs = offset;
+ break;
+
+ case COMPRESSION_NONE:
+ bitbuf.write(crc, 16);
+ if (firstoffs == 0)
+ firstoffs = offset;
+ break;
+
+ case COMPRESSION_SELF:
+ assert(offset < (UINT64(1) << selfbits));
+ bitbuf.write(offset, selfbits);
+ break;
+
+ case COMPRESSION_PARENT:
+ assert(offset < (UINT64(1) << parentbits));
+ bitbuf.write(offset, parentbits);
+ break;
+
+ case COMPRESSION_SELF_0:
+ case COMPRESSION_SELF_1:
+ case COMPRESSION_PARENT_SELF:
+ case COMPRESSION_PARENT_0:
+ case COMPRESSION_PARENT_1:
+ break;
+ }
+ }
+
+ // write the map header
+ UINT32 complen = bitbuf.flush();
+ assert(!bitbuf.overflow());
+ be_write(&compressed[0], complen, 4);
+ be_write(&compressed[4], firstoffs, 6);
+ be_write(&compressed[10], mapcrc, 2);
+ compressed[12] = lengthbits;
+ compressed[13] = selfbits;
+ compressed[14] = parentbits;
+ compressed[15] = 0;
+
+ // write the result
+ m_mapoffset = file_append(&compressed[0], complen + 16);
+
+ // then write the map offset
+ UINT8 rawbuf[sizeof(UINT64)];
+ be_write(rawbuf, m_mapoffset, 8);
+ file_write(m_mapoffset_offset, rawbuf, sizeof(rawbuf));
+ return CHDERR_NONE;
+ }
+ catch (chd_error &err)
+ {
+ return err;
+ }
+}
+
+/**
+ * @fn void chd_file::decompress_v5_map()
+ *
+ * @brief -------------------------------------------------
+ * decompress_v5_map - decompress the v5 map
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_DECOMPRESSION_ERROR Thrown when a chderr decompression error error
+ * condition occurs.
+ */
+
+void chd_file::decompress_v5_map()
+{
+ // if no offset, we haven't written it yet
+ if (m_mapoffset == 0)
+ {
+ memset(&m_rawmap[0], 0xff, m_rawmap.size());
+ return;
+ }
+
+ // read the reader
+ UINT8 rawbuf[16];
+ file_read(m_mapoffset, rawbuf, sizeof(rawbuf));
+ UINT32 mapbytes = be_read(&rawbuf[0], 4);
+ UINT64 firstoffs = be_read(&rawbuf[4], 6);
+ UINT16 mapcrc = be_read(&rawbuf[10], 2);
+ UINT8 lengthbits = rawbuf[12];
+ UINT8 selfbits = rawbuf[13];
+ UINT8 parentbits = rawbuf[14];
+
+ // now read the map
+ dynamic_buffer compressed(mapbytes);
+ file_read(m_mapoffset + 16, &compressed[0], mapbytes);
+ bitstream_in bitbuf(&compressed[0], compressed.size());
+
+ // first decode the compression types
+ huffman_decoder<16, 8> decoder;
+ huffman_error err = decoder.import_tree_rle(bitbuf);
+ if (err != HUFFERR_NONE)
+ throw CHDERR_DECOMPRESSION_ERROR;
+ UINT8 lastcomp = 0;
+ int repcount = 0;
+ for (int hunknum = 0; hunknum < m_hunkcount; hunknum++)
+ {
+ UINT8 *rawmap = &m_rawmap[hunknum * 12];
+ if (repcount > 0)
+ rawmap[0] = lastcomp, repcount--;
+ else
+ {
+ UINT8 val = decoder.decode_one(bitbuf);
+ if (val == COMPRESSION_RLE_SMALL)
+ rawmap[0] = lastcomp, repcount = 2 + decoder.decode_one(bitbuf);
+ else if (val == COMPRESSION_RLE_LARGE)
+ rawmap[0] = lastcomp, repcount = 2 + 16 + (decoder.decode_one(bitbuf) << 4), repcount += decoder.decode_one(bitbuf);
+ else
+ rawmap[0] = lastcomp = val;
+ }
+ }
+
+ // then iterate through the hunks and extract the needed data
+ UINT64 curoffset = firstoffs;
+ UINT32 last_self = 0;
+ UINT64 last_parent = 0;
+ for (int hunknum = 0; hunknum < m_hunkcount; hunknum++)
+ {
+ UINT8 *rawmap = &m_rawmap[hunknum * 12];
+ UINT64 offset = curoffset;
+ UINT32 length = 0;
+ UINT16 crc = 0;
+ switch (rawmap[0])
+ {
+ // base types
+ case COMPRESSION_TYPE_0:
+ case COMPRESSION_TYPE_1:
+ case COMPRESSION_TYPE_2:
+ case COMPRESSION_TYPE_3:
+ curoffset += length = bitbuf.read(lengthbits);
+ crc = bitbuf.read(16);
+ break;
+
+ case COMPRESSION_NONE:
+ curoffset += length = m_hunkbytes;
+ crc = bitbuf.read(16);
+ break;
+
+ case COMPRESSION_SELF:
+ last_self = offset = bitbuf.read(selfbits);
+ break;
+
+ case COMPRESSION_PARENT:
+ offset = bitbuf.read(parentbits);
+ last_parent = offset;
+ break;
+
+ // pseudo-types; convert into base types
+ case COMPRESSION_SELF_1:
+ last_self++;
+ case COMPRESSION_SELF_0:
+ rawmap[0] = COMPRESSION_SELF;
+ offset = last_self;
+ break;
+
+ case COMPRESSION_PARENT_SELF:
+ rawmap[0] = COMPRESSION_PARENT;
+ last_parent = offset = (UINT64(hunknum) * UINT64(m_hunkbytes)) / m_unitbytes;
+ break;
+
+ case COMPRESSION_PARENT_1:
+ last_parent += m_hunkbytes / m_unitbytes;
+ case COMPRESSION_PARENT_0:
+ rawmap[0] = COMPRESSION_PARENT;
+ offset = last_parent;
+ break;
+ }
+ be_write(&rawmap[1], length, 3);
+ be_write(&rawmap[4], offset, 6);
+ be_write(&rawmap[10], crc, 2);
+ }
+
+ // verify the final CRC
+ if (crc16_creator::simple(&m_rawmap[0], m_hunkcount * 12) != mapcrc)
+ throw CHDERR_DECOMPRESSION_ERROR;
+}
+
+/**
+ * @fn chd_error chd_file::create_common()
+ *
+ * @brief -------------------------------------------------
+ * create_common - command path when creating a new CHD file
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_UNSUPPORTED_VERSION Thrown when a chderr unsupported version error
+ * condition occurs.
+ * @exception CHDERR_INVALID_PARAMETER Thrown when a chderr invalid parameter error
+ * condition occurs.
+ * @exception CHDERR_UNKNOWN_COMPRESSION Thrown when a chderr unknown compression error
+ * condition occurs.
+ *
+ * @return The new common.
+ */
+
+chd_error chd_file::create_common()
+{
+ // wrap in try for proper error handling
+ try
+ {
+ m_version = HEADER_VERSION;
+ m_metaoffset = 0;
+
+ // if we have a parent, it must be V3 or later
+ if (m_parent != NULL && m_parent->version() < 3)
+ throw CHDERR_UNSUPPORTED_VERSION;
+
+ // must be an even number of units per hunk
+ if (m_hunkbytes % m_unitbytes != 0)
+ throw CHDERR_INVALID_PARAMETER;
+ if (m_parent != NULL && m_unitbytes != m_parent->unit_bytes())
+ throw CHDERR_INVALID_PARAMETER;
+
+ // verify the compression types
+ bool found_zero = false;
+ for (int codecnum = 0; codecnum < ARRAY_LENGTH(m_compression); codecnum++)
+ {
+ // once we hit an empty slot, all later slots must be empty as well
+ if (m_compression[codecnum] == CHD_CODEC_NONE)
+ found_zero = true;
+ else if (found_zero)
+ throw CHDERR_INVALID_PARAMETER;
+ else if (!chd_codec_list::codec_exists(m_compression[codecnum]))
+ throw CHDERR_UNKNOWN_COMPRESSION;
+ }
+
+ // create our V5 header
+ UINT8 rawheader[V5_HEADER_SIZE];
+ memcpy(&rawheader[0], "MComprHD", 8);
+ be_write(&rawheader[8], V5_HEADER_SIZE, 4);
+ be_write(&rawheader[12], m_version, 4);
+ be_write(&rawheader[16], m_compression[0], 4);
+ be_write(&rawheader[20], m_compression[1], 4);
+ be_write(&rawheader[24], m_compression[2], 4);
+ be_write(&rawheader[28], m_compression[3], 4);
+ be_write(&rawheader[32], m_logicalbytes, 8);
+ be_write(&rawheader[40], compressed() ? 0 : V5_HEADER_SIZE, 8);
+ be_write(&rawheader[48], m_metaoffset, 8);
+ be_write(&rawheader[56], m_hunkbytes, 4);
+ be_write(&rawheader[60], m_unitbytes, 4);
+ be_write_sha1(&rawheader[64], sha1_t::null);
+ be_write_sha1(&rawheader[84], sha1_t::null);
+ be_write_sha1(&rawheader[104], (m_parent != NULL) ? m_parent->sha1() : sha1_t::null);
+
+ // write the resulting header
+ file_write(0, rawheader, sizeof(rawheader));
+
+ // parse it back out to set up fields appropriately
+ sha1_t parentsha1;
+ parse_v5_header(rawheader, parentsha1);
+
+ // writes are obviously permitted; reads only if uncompressed
+ m_allow_writes = true;
+ m_allow_reads = !compressed();
+
+ // write out the map (if not compressed)
+ if (!compressed())
+ {
+ UINT32 mapsize = m_mapentrybytes * m_hunkcount;
+ UINT8 buffer[4096] = { 0 };
+ UINT64 offset = m_mapoffset;
+ while (mapsize != 0)
+ {
+ UINT32 bytes_to_write = MIN(mapsize, sizeof(buffer));
+ file_write(offset, buffer, bytes_to_write);
+ offset += bytes_to_write;
+ mapsize -= bytes_to_write;
+ }
+ }
+
+ // finish opening the file
+ create_open_common();
+ }
+
+ // handle errors by closing ourself
+ catch (chd_error &err)
+ {
+ close();
+ return err;
+ }
+ catch (...)
+ {
+ close();
+ throw;
+ }
+ return CHDERR_NONE;
+}
+
+/**
+ * @fn chd_error chd_file::open_common(bool writeable)
+ *
+ * @brief -------------------------------------------------
+ * open_common - common path when opening an existing CHD file for input
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_INVALID_FILE Thrown when a chderr invalid file error condition
+ * occurs.
+ * @exception CHDERR_UNSUPPORTED_VERSION Thrown when a chderr unsupported version error
+ * condition occurs.
+ * @exception CHDERR_FILE_NOT_WRITEABLE Thrown when a chderr file not writeable error
+ * condition occurs.
+ * @exception CHDERR_INVALID_PARENT Thrown when a chderr invalid parent error condition
+ * occurs.
+ * @exception CHDERR_INVALID_PARAMETER Thrown when a chderr invalid parameter error
+ * condition occurs.
+ *
+ * @param writeable true if writeable.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file::open_common(bool writeable)
+{
+ // wrap in try for proper error handling
+ try
+ {
+ // reads are always permitted
+ m_allow_reads = true;
+
+ // read the raw header
+ UINT8 rawheader[MAX_HEADER_SIZE];
+ file_read(0, rawheader, sizeof(rawheader));
+
+ // verify the signature
+ if (memcmp(rawheader, "MComprHD", 8) != 0)
+ throw CHDERR_INVALID_FILE;
+
+ // only allow writes to the most recent version
+ m_version = be_read(&rawheader[12], 4);
+ if (writeable && m_version < HEADER_VERSION)
+ throw CHDERR_UNSUPPORTED_VERSION;
+
+ // read the header if we support it
+ sha1_t parentsha1 = sha1_t::null;
+ switch (m_version)
+ {
+ case 3: parse_v3_header(rawheader, parentsha1); break;
+ case 4: parse_v4_header(rawheader, parentsha1); break;
+ case 5: parse_v5_header(rawheader, parentsha1); break;
+ default: throw CHDERR_UNSUPPORTED_VERSION;
+ }
+
+ if (writeable && !m_allow_writes)
+ throw CHDERR_FILE_NOT_WRITEABLE;
+
+ // make sure we have a parent if we need one (and don't if we don't)
+ if (parentsha1 != sha1_t::null)
+ {
+ if (m_parent == NULL)
+ m_parent_missing = true;
+ else if (m_parent->sha1() != parentsha1)
+ throw CHDERR_INVALID_PARENT;
+ }
+ else if (m_parent != NULL)
+ throw CHDERR_INVALID_PARAMETER;
+
+ // finish opening the file
+ create_open_common();
+ return CHDERR_NONE;
+ }
+
+ // handle errors by closing ourself
+ catch (chd_error &err)
+ {
+ close();
+ return err;
+ }
+}
+
+/**
+ * @fn void chd_file::create_open_common()
+ *
+ * @brief -------------------------------------------------
+ * create_open_common - common code for handling creation and opening of a file
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_UNKNOWN_COMPRESSION Thrown when a chderr unknown compression error
+ * condition occurs.
+ */
+
+void chd_file::create_open_common()
+{
+ // verify the compression types and initialize the codecs
+ for (int decompnum = 0; decompnum < ARRAY_LENGTH(m_compression); decompnum++)
+ {
+ m_decompressor[decompnum] = chd_codec_list::new_decompressor(m_compression[decompnum], *this);
+ if (m_decompressor[decompnum] == NULL && m_compression[decompnum] != 0)
+ throw CHDERR_UNKNOWN_COMPRESSION;
+ }
+
+ // read the map; v5+ compressed drives need to read and decompress their map
+ m_rawmap.resize(m_hunkcount * m_mapentrybytes);
+ if (m_version >= 5 && compressed())
+ decompress_v5_map();
+ else
+ file_read(m_mapoffset, &m_rawmap[0], m_rawmap.size());
+
+ // allocate the temporary compressed buffer and a buffer for caching
+ m_compressed.resize(m_hunkbytes);
+ m_cache.resize(m_hunkbytes);
+}
+
+/**
+ * @fn void chd_file::verify_proper_compression_append(UINT32 hunknum)
+ *
+ * @brief -------------------------------------------------
+ * verify_proper_compression_append - verify that the given hunk is a proper candidate
+ * for appending to a compressed CHD
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_NOT_OPEN Thrown when a chderr not open error condition occurs.
+ * @exception CHDERR_HUNK_OUT_OF_RANGE Thrown when a chderr hunk out of range error
+ * condition occurs.
+ * @exception CHDERR_FILE_NOT_WRITEABLE Thrown when a chderr file not writeable error
+ * condition occurs.
+ * @exception CHDERR_COMPRESSION_ERROR Thrown when a chderr compression error error
+ * condition occurs.
+ *
+ * @param hunknum The hunknum.
+ */
+
+void chd_file::verify_proper_compression_append(UINT32 hunknum)
+{
+ // punt if no file
+ if (m_file == NULL)
+ throw CHDERR_NOT_OPEN;
+
+ // return an error if out of range
+ if (hunknum >= m_hunkcount)
+ throw CHDERR_HUNK_OUT_OF_RANGE;
+
+ // if not writeable, fail
+ if (!m_allow_writes)
+ throw CHDERR_FILE_NOT_WRITEABLE;
+
+ // compressed writes only via this interface
+ if (!compressed())
+ throw CHDERR_FILE_NOT_WRITEABLE;
+
+ // only permitted to write new blocks
+ UINT8 *rawmap = &m_rawmap[hunknum * 12];
+ if (rawmap[0] != 0xff)
+ throw CHDERR_COMPRESSION_ERROR;
+
+ // if this isn't the first block, only permitted to write immediately
+ // after the previous one
+ if (hunknum != 0 && rawmap[-12] == 0xff)
+ throw CHDERR_COMPRESSION_ERROR;
+}
+
+/**
+ * @fn void chd_file::hunk_write_compressed(UINT32 hunknum, INT8 compression, const UINT8 *compressed, UINT32 complength, crc16_t crc16)
+ *
+ * @brief -------------------------------------------------
+ * hunk_write_compressed - write a hunk to a compressed CHD, discovering the best
+ * technique
+ * -------------------------------------------------.
+ *
+ * @param hunknum The hunknum.
+ * @param compression The compression.
+ * @param compressed The compressed.
+ * @param complength The complength.
+ * @param crc16 The CRC 16.
+ */
+
+void chd_file::hunk_write_compressed(UINT32 hunknum, INT8 compression, const UINT8 *compressed, UINT32 complength, crc16_t crc16)
+{
+ // verify that we are appending properly to a compressed file
+ verify_proper_compression_append(hunknum);
+
+ // write the final result
+ UINT64 offset = file_append(compressed, complength);
+
+ // update the map entry
+ UINT8 *rawmap = &m_rawmap[hunknum * 12];
+ rawmap[0] = (compression == -1) ? COMPRESSION_NONE : compression;
+ be_write(&rawmap[1], complength, 3);
+ be_write(&rawmap[4], offset, 6);
+ be_write(&rawmap[10], crc16, 2);
+}
+
+/**
+ * @fn void chd_file::hunk_copy_from_self(UINT32 hunknum, UINT32 otherhunk)
+ *
+ * @brief -------------------------------------------------
+ * hunk_copy_from_self - mark a hunk as being a copy of another hunk in the same CHD
+ * -------------------------------------------------.
+ *
+ * @exception CHDERR_INVALID_PARAMETER Thrown when a chderr invalid parameter error
+ * condition occurs.
+ *
+ * @param hunknum The hunknum.
+ * @param otherhunk The otherhunk.
+ */
+
+void chd_file::hunk_copy_from_self(UINT32 hunknum, UINT32 otherhunk)
+{
+ // verify that we are appending properly to a compressed file
+ verify_proper_compression_append(hunknum);
+
+ // only permitted to reference prior hunks
+ if (otherhunk >= hunknum)
+ throw CHDERR_INVALID_PARAMETER;
+
+ // update the map entry
+ UINT8 *rawmap = &m_rawmap[hunknum * 12];
+ rawmap[0] = COMPRESSION_SELF;
+ be_write(&rawmap[1], 0, 3);
+ be_write(&rawmap[4], otherhunk, 6);
+ be_write(&rawmap[10], 0, 2);
+}
+
+/**
+ * @fn void chd_file::hunk_copy_from_parent(UINT32 hunknum, UINT64 parentunit)
+ *
+ * @brief -------------------------------------------------
+ * hunk_copy_from_parent - mark a hunk as being a copy of a hunk from a parent CHD
+ * -------------------------------------------------.
+ *
+ * @param hunknum The hunknum.
+ * @param parentunit The parentunit.
+ */
+
+void chd_file::hunk_copy_from_parent(UINT32 hunknum, UINT64 parentunit)
+{
+ // verify that we are appending properly to a compressed file
+ verify_proper_compression_append(hunknum);
+
+ // update the map entry
+ UINT8 *rawmap = &m_rawmap[hunknum * 12];
+ rawmap[0] = COMPRESSION_PARENT;
+ be_write(&rawmap[1], 0, 3);
+ be_write(&rawmap[4], parentunit, 6);
+ be_write(&rawmap[10], 0, 2);
+}
+
+/**
+ * @fn bool chd_file::metadata_find(chd_metadata_tag metatag, INT32 metaindex, metadata_entry &metaentry, bool resume)
+ *
+ * @brief -------------------------------------------------
+ * metadata_find - find a metadata entry
+ * -------------------------------------------------.
+ *
+ * @param metatag The metatag.
+ * @param metaindex The metaindex.
+ * @param [in,out] metaentry The metaentry.
+ * @param resume true to resume.
+ *
+ * @return true if it succeeds, false if it fails.
+ */
+
+bool chd_file::metadata_find(chd_metadata_tag metatag, INT32 metaindex, metadata_entry &metaentry, bool resume)
+{
+ // start at the beginning unless we're resuming a previous search
+ if (!resume)
+ {
+ metaentry.offset = m_metaoffset;
+ metaentry.prev = 0;
+ }
+ else
+ {
+ metaentry.prev = metaentry.offset;
+ metaentry.offset = metaentry.next;
+ }
+
+ // loop until we run out of options
+ while (metaentry.offset != 0)
+ {
+ // read the raw header
+ UINT8 raw_meta_header[METADATA_HEADER_SIZE];
+ file_read(metaentry.offset, raw_meta_header, sizeof(raw_meta_header));
+
+ // extract the data
+ metaentry.metatag = be_read(&raw_meta_header[0], 4);
+ metaentry.flags = raw_meta_header[4];
+ metaentry.length = be_read(&raw_meta_header[5], 3);
+ metaentry.next = be_read(&raw_meta_header[8], 8);
+
+ // if we got a match, proceed
+ if (metatag == CHDMETATAG_WILDCARD || metaentry.metatag == metatag)
+ if (metaindex-- == 0)
+ return true;
+
+ // no match, fetch the next link
+ metaentry.prev = metaentry.offset;
+ metaentry.offset = metaentry.next;
+ }
+
+ // if we get here, we didn't find it
+ return false;
+}
+
+/**
+ * @fn void chd_file::metadata_set_previous_next(UINT64 prevoffset, UINT64 nextoffset)
+ *
+ * @brief -------------------------------------------------
+ * metadata_set_previous_next - set the 'next' offset of a piece of metadata
+ * -------------------------------------------------.
+ *
+ * @param prevoffset The prevoffset.
+ * @param nextoffset The nextoffset.
+ */
+
+void chd_file::metadata_set_previous_next(UINT64 prevoffset, UINT64 nextoffset)
+{
+ UINT64 offset = 0;
+
+ // if we were the first entry, make the next entry the first
+ if (prevoffset == 0)
+ {
+ offset = m_metaoffset_offset;
+ m_metaoffset = nextoffset;
+ }
+
+ // otherwise, update the link in the previous header
+ else
+ offset = prevoffset + 8;
+
+ // create a big-endian version
+ UINT8 rawbuf[sizeof(UINT64)];
+ be_write(rawbuf, nextoffset, 8);
+
+ // write to the header and update our local copy
+ file_write(offset, rawbuf, sizeof(rawbuf));
+}
+
+/**
+ * @fn void chd_file::metadata_update_hash()
+ *
+ * @brief -------------------------------------------------
+ * metadata_update_hash - compute the SHA1 hash of all metadata that requests it
+ * -------------------------------------------------.
+ */
+
+void chd_file::metadata_update_hash()
+{
+ // only works for V4 and above, and only for compressed CHDs
+ if (m_version < 4 || !compressed())
+ return;
+
+ // compute the new overall hash
+ sha1_t fullsha1 = compute_overall_sha1(raw_sha1());
+
+ // create a big-endian version
+ UINT8 rawbuf[sizeof(sha1_t)];
+ be_write_sha1(&rawbuf[0], fullsha1);
+
+ // write to the header
+ file_write(m_sha1_offset, rawbuf, sizeof(rawbuf));
+}
+
+/**
+ * @fn int CLIB_DECL chd_file::metadata_hash_compare(const void *elem1, const void *elem2)
+ *
+ * @brief -------------------------------------------------
+ * metadata_hash_compare - compare two hash entries
+ * -------------------------------------------------.
+ *
+ * @param elem1 The first element.
+ * @param elem2 The second element.
+ *
+ * @return A CLIB_DECL.
+ */
+
+int CLIB_DECL chd_file::metadata_hash_compare(const void *elem1, const void *elem2)
+{
+ return memcmp(elem1, elem2, sizeof(metadata_hash));
+}
+
+
+
+//**************************************************************************
+// CHD COMPRESSOR
+//**************************************************************************
+
+/**
+ * @fn chd_file_compressor::chd_file_compressor()
+ *
+ * @brief -------------------------------------------------
+ * chd_file_compressor - constructor
+ * -------------------------------------------------.
+ */
+
+chd_file_compressor::chd_file_compressor()
+ : m_walking_parent(false),
+ m_total_in(0),
+ m_total_out(0),
+ m_read_queue(NULL),
+ m_read_queue_offset(0),
+ m_read_done_offset(0),
+ m_read_error(false),
+ m_work_queue(NULL),
+ m_write_hunk(0)
+{
+ // zap arrays
+ memset(m_codecs, 0, sizeof(m_codecs));
+
+ // allocate work queues
+ m_read_queue = osd_work_queue_alloc(WORK_QUEUE_FLAG_IO);
+ m_work_queue = osd_work_queue_alloc(WORK_QUEUE_FLAG_MULTI);
+}
+
+/**
+ * @fn chd_file_compressor::~chd_file_compressor()
+ *
+ * @brief -------------------------------------------------
+ * ~chd_file_compressor - destructor
+ * -------------------------------------------------.
+ */
+
+chd_file_compressor::~chd_file_compressor()
+{
+ // free the work queues
+ osd_work_queue_free(m_read_queue);
+ osd_work_queue_free(m_work_queue);
+
+ // delete allocated arrays
+ for (int codecnum = 0; codecnum < ARRAY_LENGTH(m_codecs); codecnum++)
+ delete m_codecs[codecnum];
+}
+
+/**
+ * @fn void chd_file_compressor::compress_begin()
+ *
+ * @brief -------------------------------------------------
+ * compress_begin - initiate compression
+ * -------------------------------------------------.
+ */
+
+void chd_file_compressor::compress_begin()
+{
+ // reset state
+ m_walking_parent = (m_parent != NULL);
+ m_total_in = 0;
+ m_total_out = 0;
+ m_compsha1.reset();
+
+ // reset our maps
+ m_parent_map.reset();
+ m_current_map.reset();
+
+ // reset read state
+ m_read_queue_offset = 0;
+ m_read_done_offset = 0;
+ m_read_error = false;
+
+ // reset work item state
+ m_work_buffer.resize(hunk_bytes() * (WORK_BUFFER_HUNKS + 1));
+ memset(&m_work_buffer[0], 0, m_work_buffer.size());
+ m_compressed_buffer.resize(hunk_bytes() * WORK_BUFFER_HUNKS);
+ for (int itemnum = 0; itemnum < WORK_BUFFER_HUNKS; itemnum++)
+ {
+ work_item &item = m_work_item[itemnum];
+ item.m_compressor = this;
+ item.m_data = &m_work_buffer[hunk_bytes() * itemnum];
+ item.m_compressed = &m_compressed_buffer[hunk_bytes() * itemnum];
+ item.m_hash.resize(hunk_bytes() / unit_bytes());
+ }
+
+ // initialize codec instances
+ for (int instance = 0; instance < ARRAY_LENGTH(m_codecs); instance++)
+ {
+ delete m_codecs[instance];
+ m_codecs[instance] = new chd_compressor_group(*this, m_compression);
+ }
+
+ // reset write state
+ m_write_hunk = 0;
+}
+
+/**
+ * @fn chd_error chd_file_compressor::compress_continue(double &progress, double &ratio)
+ *
+ * @brief -------------------------------------------------
+ * compress_continue - continue compression
+ * -------------------------------------------------.
+ *
+ * @param [in,out] progress The progress.
+ * @param [in,out] ratio The ratio.
+ *
+ * @return A chd_error.
+ */
+
+chd_error chd_file_compressor::compress_continue(double &progress, double &ratio)
+{
+ // if we got an error, return an error
+ if (m_read_error)
+ return CHDERR_READ_ERROR;
+
+ // if done reading, queue some more
+ while (m_read_queue_offset < m_logicalbytes && osd_work_queue_items(m_read_queue) < 2)
+ {
+ // see if we have enough free work items to read the next half of a buffer
+ UINT32 startitem = m_read_queue_offset / hunk_bytes();
+ UINT32 enditem = startitem + WORK_BUFFER_HUNKS / 2;
+ UINT32 curitem;
+ for (curitem = startitem; curitem < enditem; curitem++)
+ if (m_work_item[curitem % WORK_BUFFER_HUNKS].m_status != WS_READY)
+ break;
+
+ // if it's not all clear, defer
+ if (curitem != enditem)
+ break;
+
+ // if we're walking the parent, we want one more item to have cleared so we
+ // can read an extra hunk there
+ if (m_walking_parent && m_work_item[curitem % WORK_BUFFER_HUNKS].m_status != WS_READY)
+ break;
+
+ // queue the next read
+ for (curitem = startitem; curitem < enditem; curitem++)
+ atomic_exchange32(&m_work_item[curitem % WORK_BUFFER_HUNKS].m_status, WS_READING);
+ osd_work_item_queue(m_read_queue, async_read_static, this, WORK_ITEM_FLAG_AUTO_RELEASE);
+ m_read_queue_offset += WORK_BUFFER_HUNKS * hunk_bytes() / 2;
+ }
+
+ // flush out any finished items
+ while (m_work_item[m_write_hunk % WORK_BUFFER_HUNKS].m_status == WS_COMPLETE)
+ {
+ work_item &item = m_work_item[m_write_hunk % WORK_BUFFER_HUNKS];
+
+ // free any OSD work item
+ if (item.m_osd != NULL)
+ osd_work_item_release(item.m_osd);
+ item.m_osd = NULL;
+
+ // for parent walking, just add to the hashmap
+ if (m_walking_parent)
+ {
+ UINT32 uph = hunk_bytes() / unit_bytes();
+ UINT32 units = uph;
+ if (item.m_hunknum == hunk_count() - 1 || !compressed())
+ units = 1;
+ for (UINT32 unit = 0; unit < units; unit++)
+ if (m_parent_map.find(item.m_hash[unit].m_crc16, item.m_hash[unit].m_sha1) == hashmap::NOT_FOUND)
+ m_parent_map.add(item.m_hunknum * uph + unit, item.m_hash[unit].m_crc16, item.m_hash[unit].m_sha1);
+ }
+
+ // if we're uncompressed, use regular writes
+ else if (!compressed())
+ {
+ chd_error err = write_hunk(item.m_hunknum, item.m_data);
+ if (err != CHDERR_NONE)
+ return err;
+
+ // writes of all-0 data don't actually take space, so see if we count this
+ chd_codec_type codec = CHD_CODEC_NONE;
+ UINT32 complen;
+ hunk_info(item.m_hunknum, codec, complen);
+ if (codec == CHD_CODEC_NONE)
+ m_total_out += m_hunkbytes;
+ }
+
+ // for compressing, process the result
+ else do
+ {
+ // first see if the hunk is in the parent or self maps
+ UINT64 selfhunk = m_current_map.find(item.m_hash[0].m_crc16, item.m_hash[0].m_sha1);
+ if (selfhunk != hashmap::NOT_FOUND)
+ {
+ hunk_copy_from_self(item.m_hunknum, selfhunk);
+ break;
+ }
+
+ // if not, see if it's in the parent map
+ if (m_parent != NULL)
+ {
+ UINT64 parentunit = m_parent_map.find(item.m_hash[0].m_crc16, item.m_hash[0].m_sha1);
+ if (parentunit != hashmap::NOT_FOUND)
+ {
+ hunk_copy_from_parent(item.m_hunknum, parentunit);
+ break;
+ }
+ }
+
+ // otherwise, append it compressed and add to the self map
+ hunk_write_compressed(item.m_hunknum, item.m_compression, item.m_compressed, item.m_complen, item.m_hash[0].m_crc16);
+ m_total_out += item.m_complen;
+ m_current_map.add(item.m_hunknum, item.m_hash[0].m_crc16, item.m_hash[0].m_sha1);
+ } while (0);
+
+ // reset the item and advance
+ atomic_exchange32(&item.m_status, WS_READY);
+ m_write_hunk++;
+
+ // if we hit the end, finalize
+ if (m_write_hunk == m_hunkcount)
+ {
+ // if this is just walking the parent, reset and get ready for compression
+ if (m_walking_parent)
+ {
+ m_walking_parent = false;
+ m_read_queue_offset = m_read_done_offset = 0;
+ m_write_hunk = 0;
+ for (int itemnum = 0; itemnum < WORK_BUFFER_HUNKS; itemnum++)
+ atomic_exchange32(&m_work_item[itemnum].m_status, WS_READY);
+ }
+
+ // wait for all reads to finish and if we're compressed, write the final SHA1 and map
+ else
+ {
+ osd_work_queue_wait(m_read_queue, 30 * osd_ticks_per_second());
+ if (!compressed())
+ return CHDERR_NONE;
+ set_raw_sha1(m_compsha1.finish());
+ return compress_v5_map();
+ }
+ }
+ }
+
+ // update progress and ratio
+ if (m_walking_parent)
+ progress = double(m_read_done_offset) / double(logical_bytes());
+ else
+ progress = double(m_write_hunk) / double(m_hunkcount);
+ ratio = (m_total_in == 0) ? 1.0 : double(m_total_out) / double(m_total_in);
+
+ // if we're waiting for work, wait
+ while (m_work_item[m_write_hunk % WORK_BUFFER_HUNKS].m_status != WS_COMPLETE && m_work_item[m_write_hunk % WORK_BUFFER_HUNKS].m_osd != NULL)
+ osd_work_item_wait(m_work_item[m_write_hunk % WORK_BUFFER_HUNKS].m_osd, osd_ticks_per_second());
+
+ return m_walking_parent ? CHDERR_WALKING_PARENT : CHDERR_COMPRESSING;
+}
+
+/**
+ * @fn void *chd_file_compressor::async_walk_parent_static(void *param, int threadid)
+ *
+ * @brief -------------------------------------------------
+ * async_walk_parent - handle asynchronous parent walking operations
+ * -------------------------------------------------.
+ *
+ * @param [in,out] param If non-null, the parameter.
+ * @param threadid The threadid.
+ *
+ * @return null if it fails, else a void*.
+ */
+
+void *chd_file_compressor::async_walk_parent_static(void *param, int threadid)
+{
+ work_item *item = reinterpret_cast<work_item *>(param);
+ item->m_compressor->async_walk_parent(*item);
+ return NULL;
+}
+
+/**
+ * @fn void chd_file_compressor::async_walk_parent(work_item &item)
+ *
+ * @brief Asynchronous walk parent.
+ *
+ * @param [in,out] item The item.
+ */
+
+void chd_file_compressor::async_walk_parent(work_item &item)
+{
+ // compute CRC-16 and SHA-1 hashes for each unit, unless we're the last one or we're uncompressed
+ UINT32 units = hunk_bytes() / unit_bytes();
+ if (item.m_hunknum == m_hunkcount - 1 || !compressed())
+ units = 1;
+ for (UINT32 unit = 0; unit < units; unit++)
+ {
+ item.m_hash[unit].m_crc16 = crc16_creator::simple(item.m_data + unit * unit_bytes(), hunk_bytes());
+ item.m_hash[unit].m_sha1 = sha1_creator::simple(item.m_data + unit * unit_bytes(), hunk_bytes());
+ }
+ atomic_exchange32(&item.m_status, WS_COMPLETE);
+}
+
+/**
+ * @fn void *chd_file_compressor::async_compress_hunk_static(void *param, int threadid)
+ *
+ * @brief -------------------------------------------------
+ * async_compress_hunk - handle asynchronous hunk compression
+ * -------------------------------------------------.
+ *
+ * @param [in,out] param If non-null, the parameter.
+ * @param threadid The threadid.
+ *
+ * @return null if it fails, else a void*.
+ */
+
+void *chd_file_compressor::async_compress_hunk_static(void *param, int threadid)
+{
+ work_item *item = reinterpret_cast<work_item *>(param);
+ item->m_compressor->async_compress_hunk(*item, threadid);
+ return NULL;
+}
+
+/**
+ * @fn void chd_file_compressor::async_compress_hunk(work_item &item, int threadid)
+ *
+ * @brief Asynchronous compress hunk.
+ *
+ * @param [in,out] item The item.
+ * @param threadid The threadid.
+ */
+
+void chd_file_compressor::async_compress_hunk(work_item &item, int threadid)
+{
+ // use our thread's codec
+ assert(threadid < ARRAY_LENGTH(m_codecs));
+ item.m_codecs = m_codecs[threadid];
+
+ // compute CRC-16 and SHA-1 hashes
+ item.m_hash[0].m_crc16 = crc16_creator::simple(item.m_data, hunk_bytes());
+ item.m_hash[0].m_sha1 = sha1_creator::simple(item.m_data, hunk_bytes());
+
+ // find the best compression scheme, unless we already have a self or parent match
+ // (note we may miss a self match from blocks not yet added, but this just results in extra work)
+ // TODO: data race
+ if (m_current_map.find(item.m_hash[0].m_crc16, item.m_hash[0].m_sha1) == hashmap::NOT_FOUND &&
+ m_parent_map.find(item.m_hash[0].m_crc16, item.m_hash[0].m_sha1) == hashmap::NOT_FOUND)
+ item.m_compression = item.m_codecs->find_best_compressor(item.m_data, item.m_compressed, item.m_complen);
+
+ // mark us complete
+ atomic_exchange32(&item.m_status, WS_COMPLETE);
+}
+
+/**
+ * @fn void *chd_file_compressor::async_read_static(void *param, int threadid)
+ *
+ * @brief -------------------------------------------------
+ * async_read - handle asynchronous source file reading
+ * -------------------------------------------------.
+ *
+ * @param [in,out] param If non-null, the parameter.
+ * @param threadid The threadid.
+ *
+ * @return null if it fails, else a void*.
+ */
+
+void *chd_file_compressor::async_read_static(void *param, int threadid)
+{
+ reinterpret_cast<chd_file_compressor *>(param)->async_read();
+ return NULL;
+}
+
+/**
+ * @fn void chd_file_compressor::async_read()
+ *
+ * @brief Asynchronous read.
+ */
+
+void chd_file_compressor::async_read()
+{
+ // if in the error or complete state, stop
+ if (m_read_error)
+ return;
+
+ // determine parameters for the read
+ UINT32 work_buffer_bytes = WORK_BUFFER_HUNKS * hunk_bytes();
+ UINT32 numbytes = work_buffer_bytes / 2;
+ if (m_read_done_offset + numbytes > logical_bytes())
+ numbytes = logical_bytes() - m_read_done_offset;
+
+ // catch any exceptions coming out of here
+ try
+ {
+ // do the read
+ UINT8 *dest = &m_work_buffer[0] + (m_read_done_offset % work_buffer_bytes);
+ assert(dest == &m_work_buffer[0] || dest == &m_work_buffer[work_buffer_bytes/2]);
+ UINT64 end_offset = m_read_done_offset + numbytes;
+
+ // if walking the parent, read in hunks from the parent CHD
+ if (m_walking_parent)
+ {
+ UINT8 *curdest = dest;
+ for (UINT64 curoffs = m_read_done_offset; curoffs < end_offset + 1; curoffs += hunk_bytes())
+ {
+ m_parent->read_hunk(curoffs / hunk_bytes(), curdest);
+ curdest += hunk_bytes();
+ }
+ }
+
+ // otherwise, call the virtual function
+ else
+ read_data(dest, m_read_done_offset, numbytes);
+
+ // spawn off work for each hunk
+ for (UINT64 curoffs = m_read_done_offset; curoffs < end_offset; curoffs += hunk_bytes())
+ {
+ UINT32 hunknum = curoffs / hunk_bytes();
+ work_item &item = m_work_item[hunknum % WORK_BUFFER_HUNKS];
+ assert(item.m_status == WS_READING);
+ atomic_exchange32(&item.m_status, WS_QUEUED);
+ item.m_hunknum = hunknum;
+ item.m_osd = osd_work_item_queue(m_work_queue, m_walking_parent ? async_walk_parent_static : async_compress_hunk_static, &item, 0);
+ }
+
+ // continue the running SHA-1
+ if (!m_walking_parent)
+ {
+ if (compressed())
+ m_compsha1.append(dest, numbytes);
+ m_total_in += numbytes;
+ }
+
+ // advance the read pointer
+ m_read_done_offset += numbytes;
+ }
+ catch (chd_error& err)
+ {
+ fprintf(stderr, "CHD error occurred: %s\n", chd_file::error_string(err));
+ m_read_error = true;
+ }
+ catch (std::exception& ex)
+ {
+ fprintf(stderr, "exception occurred: %s\n", ex.what());
+ m_read_error = true;
+ }
+}
+
+
+
+//**************************************************************************
+// CHD COMPRESSOR HASHMAP
+//**************************************************************************
+
+/**
+ * @fn chd_file_compressor::hashmap::hashmap()
+ *
+ * @brief -------------------------------------------------
+ * hashmap - constructor
+ * -------------------------------------------------.
+ */
+
+chd_file_compressor::hashmap::hashmap()
+ : m_block_list(new entry_block(NULL))
+{
+ // initialize the map to empty
+ memset(m_map, 0, sizeof(m_map));
+}
+
+/**
+ * @fn chd_file_compressor::hashmap::~hashmap()
+ *
+ * @brief -------------------------------------------------
+ * ~hashmap - destructor
+ * -------------------------------------------------.
+ */
+
+chd_file_compressor::hashmap::~hashmap()
+{
+ reset();
+ delete m_block_list;
+}
+
+/**
+ * @fn void chd_file_compressor::hashmap::reset()
+ *
+ * @brief -------------------------------------------------
+ * reset - reset the state of the map
+ * -------------------------------------------------.
+ */
+
+void chd_file_compressor::hashmap::reset()
+{
+ // delete all the blocks
+ while (m_block_list->m_next != NULL)
+ {
+ entry_block *block = m_block_list;
+ m_block_list = block->m_next;
+ delete block;
+ }
+ m_block_list->m_nextalloc = 0;
+
+ // reset the hash
+ memset(m_map, 0, sizeof(m_map));
+}
+
+/**
+ * @fn UINT64 chd_file_compressor::hashmap::find(crc16_t crc16, sha1_t sha1)
+ *
+ * @brief -------------------------------------------------
+ * find - find an item in the CRC map
+ * -------------------------------------------------.
+ *
+ * @param crc16 The CRC 16.
+ * @param sha1 The first sha.
+ *
+ * @return An UINT64.
+ */
+
+UINT64 chd_file_compressor::hashmap::find(crc16_t crc16, sha1_t sha1)
+{
+ // look up the entry in the map
+ for (entry_t *entry = m_map[crc16]; entry != NULL; entry = entry->m_next)
+ if (entry->m_sha1 == sha1)
+ return entry->m_itemnum;
+ return NOT_FOUND;
+}
+
+/**
+ * @fn void chd_file_compressor::hashmap::add(UINT64 itemnum, crc16_t crc16, sha1_t sha1)
+ *
+ * @brief -------------------------------------------------
+ * add - add an item to the CRC map
+ * -------------------------------------------------.
+ *
+ * @param itemnum The itemnum.
+ * @param crc16 The CRC 16.
+ * @param sha1 The first sha.
+ */
+
+void chd_file_compressor::hashmap::add(UINT64 itemnum, crc16_t crc16, sha1_t sha1)
+{
+ // add to the appropriate map
+ if (m_block_list->m_nextalloc == ARRAY_LENGTH(m_block_list->m_array))
+ m_block_list = new entry_block(m_block_list);
+ entry_t *entry = &m_block_list->m_array[m_block_list->m_nextalloc++];
+ entry->m_itemnum = itemnum;
+ entry->m_sha1 = sha1;
+ entry->m_next = m_map[crc16];
+ m_map[crc16] = entry;
+}