// license:BSD-3-Clause
// copyright-holders:Aaron Giles
/***************************************************************************
split.c
Simple file splitter/joiner with hashes.
****************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include "corefile.h"
#include "corestr.h"
#include "sha1.h"
#define DEFAULT_SPLIT_SIZE 100
#define MAX_PARTS 1000
/***************************************************************************
CORE IMPLEMENTATION
***************************************************************************/
/*-------------------------------------------------
compute_hash_as_string - compute an SHA1
hash over a buffer and return a string
-------------------------------------------------*/
static void compute_hash_as_string(std::string &buffer, void *data, uint32_t length)
{
char expanded[SHA1_DIGEST_SIZE * 2];
uint8_t sha1digest[SHA1_DIGEST_SIZE];
struct sha1_ctx sha1;
int ch;
// compute the SHA1
sha1_init(&sha1);
sha1_update(&sha1, length, (const uint8_t *)data);
sha1_final(&sha1);
sha1_digest(&sha1, sizeof(sha1digest), sha1digest);
// expand the digest to a string
for (ch = 0; ch < SHA1_DIGEST_SIZE; ch++)
{
expanded[ch * 2 + 0] = "0123456789ABCDEF"[sha1digest[ch] >> 4];
expanded[ch * 2 + 1] = "0123456789ABCDEF"[sha1digest[ch] & 15];
}
// copy it to the buffer
buffer.assign(expanded, sizeof(expanded));
}
/*-------------------------------------------------
split_file - split a file into multiple parts
-------------------------------------------------*/
static int split_file(const char *filename, const char *basename, uint32_t splitsize)
{
std::string outfilename, basefilename, splitfilename;
util::core_file::ptr outfile, infile, splitfile;
std::string computedhash;
void *splitbuffer = nullptr;
int index, partnum;
uint64_t totallength;
osd_file::error filerr;
int error = 1;
// convert split size to MB
if (splitsize > 500)
{
fprintf(stderr, "Fatal error: maximum split size is 500MB (even that is way huge!)\n");
goto cleanup;
}
splitsize *= 1024 * 1024;
// open the file for read
filerr = util::core_file::open(filename, OPEN_FLAG_READ, infile);
if (filerr != osd_file::error::NONE)
{
fprintf(stderr, "Fatal error: unable to open file '%s'\n", filename);
goto cleanup;
}
// get the total length
totallength = infile->size();
if (totallength < splitsize)
{
fprintf(stderr, "Fatal error: file is smaller than the split size\n");
goto cleanup;
}
if ((uint64_t)splitsize * MAX_PARTS < totallength)
{
fprintf(stderr, "Fatal error: too many splits (maximum is %d)\n", MAX_PARTS);
goto cleanup;
}
// allocate a buffer for reading
splitbuffer = malloc(splitsize);
if (splitbuffer == nullptr)
{
fprintf(stderr, "Fatal error: unable to allocate memory for the split\n");
goto cleanup;
}
// find the base name of the file
basefilename.assign(basename);
index = basefilename.find_last_of(PATH_SEPARATOR[0]);
if (index != -1)
basefilename.erase(0, index + 1);
// compute the split filename
splitfilename.assign(basename).append(".split");
// create the split file
filerr = util::core_file::open(splitfilename, OPEN_FLAG_WRITE | OPEN_FLAG_CREATE | OPEN_FLAG_NO_BOM, splitfile);
if (filerr != osd_file::error::NONE)
{
fprintf(stderr, "Fatal error: unable to create split file '%s'\n", splitfilename.c_str());
goto cleanup;
}
// write the basics out
splitfile->printf("splitfile=%s\n", basefilename.c_str());
splitfile->printf("splitsize=%d\n", splitsize);
printf("Split file is '%s'\n", splitfilename.c_str());
printf("Splitting file %s into chunks of %dMB...\n", basefilename.c_str(), splitsize / (1024 * 1024));
// now iterate until done
for (partnum = 0; partnum < 1000; partnum++)
{
uint32_t actual, length;
printf("Reading part %d...", partnum);
// read as much as we can from the file
length = infile->read(splitbuffer, splitsize);
if (length == 0)
break;
// hash what we have
compute_hash_as_string(computedhash, splitbuffer, length);
// write that info to the split file
splitfile->printf("hash=%s file=%s.%03d\n", computedhash.c_str(), basefilename.c_str(), partnum);
// compute the full filename for this guy
outfilename = string_format("%s.%03d", basename, partnum);
// create it
filerr = util::core_file::open(outfilename, OPEN_FLAG_WRITE | OPEN_FLAG_CREATE, outfile);
if (filerr != osd_file::error::NONE)
{
printf("\n");
fprintf(stderr, "Fatal error: unable to create output file '%s'\n", outfilename.c_str());
goto cleanup;
}
printf(" writing %s.%03d...", basefilename.c_str(), partnum);
// write the data
actual = outfile->write(splitbuffer, length);
if (actual != length)
{
printf("\n");
fprintf(stderr, "Fatal error: Error writing output file (out of space?)\n");
goto cleanup;
}
outfile.reset();
printf(" done\n");
// stop if this is the end
if (length < splitsize)
break;
}
printf("File split successfully\n");
// if we get here, clear the errors
error = 0;
cleanup:
if (splitfile)
{
splitfile.reset();
if (error != 0)
remove(splitfilename.c_str());
}
if (infile)
infile.reset();
if (outfile)
{
outfile.reset();
if (error != 0)
remove(outfilename.c_str());
}
if (splitbuffer != nullptr)
free(splitbuffer);
return error;
}
/*-------------------------------------------------
join_file - rejoin a file from its split
parts
-------------------------------------------------*/
static int join_file(const char *filename, const char *outname, int write_output)
{
std::string expectedhash, computedhash;
std::string outfilename, infilename;
std::string basepath;
util::core_file::ptr outfile, infile, splitfile;
void *splitbuffer = nullptr;
osd_file::error filerr;
uint32_t splitsize;
char buffer[256];
int error = 1;
int index;
// open the file for read
filerr = util::core_file::open(filename, OPEN_FLAG_READ, splitfile);
if (filerr != osd_file::error::NONE)
{
fprintf(stderr, "Fatal error: unable to open file '%s'\n", filename);
goto cleanup;
}
// read the first line and verify this is a split file
if (!splitfile->gets(buffer, sizeof(buffer)) || strncmp(buffer, "splitfile=", 10) != 0)
{
fprintf(stderr, "Fatal error: corrupt or incomplete split file at line:\n%s\n", buffer);
goto cleanup;
}
outfilename.assign(buffer + 10);
strtrimspace(outfilename);
// compute the base path
basepath.assign(filename);
index = basepath.find_last_of(PATH_SEPARATOR[0]);
if (index != -1)
basepath.erase(index + 1);
else
basepath.clear();
// override the output filename if specified, otherwise prepend the path
if (outname != nullptr)
outfilename.assign(outname);
else
outfilename.insert(0, basepath);
// read the split size
if (!splitfile->gets(buffer, sizeof(buffer)) || sscanf(buffer, "splitsize=%d", &splitsize) != 1)
{
fprintf(stderr, "Fatal error: corrupt or incomplete split file at line:\n%s\n", buffer);
goto cleanup;
}
// attempt to open the new file
if (write_output)
{
// don't overwrite the original!
filerr = util::core_file::open(outfilename, OPEN_FLAG_READ, outfile);
if (filerr == osd_file::error::NONE)
{
outfile.reset();
fprintf(stderr, "Fatal error: output file '%s' already exists\n", outfilename.c_str());
goto cleanup;
}
// open the output for write
filerr = util::core_file::open(outfilename, OPEN_FLAG_WRITE | OPEN_FLAG_CREATE, outfile);
if (filerr != osd_file::error::NONE)
{
fprintf(stderr, "Fatal error: unable to create file '%s'\n", outfilename.c_str());
goto cleanup;
}
}
printf("%s file '%s'...\n", write_output ? "Joining" : "Verifying", outfilename.c_str());
// now iterate through each file
while (splitfile->gets(buffer, sizeof(buffer)))
{
uint32_t length, actual;
// make sure the hash and filename are in the right place
if (strncmp(buffer, "hash=", 5) != 0 || strncmp(buffer + 5 + SHA1_DIGEST_SIZE * 2, " file=", 6) != 0)
{
fprintf(stderr, "Fatal error: corrupt or incomplete split file at line:\n%s\n", buffer);
goto cleanup;
}
expectedhash.assign(buffer + 5, SHA1_DIGEST_SIZE * 2);
infilename.assign(buffer + 5 + SHA1_DIGEST_SIZE * 2 + 6);
strtrimspace(infilename);
printf(" Reading file '%s'...", infilename.c_str());
// read the file's contents
infilename.insert(0, basepath);
filerr = util::core_file::load(infilename.c_str(), &splitbuffer, length);
if (filerr != osd_file::error::NONE)
{
printf("\n");
fprintf(stderr, "Fatal error: unable to load file '%s'\n", infilename.c_str());
goto cleanup;
}
// hash the contents
compute_hash_as_string(computedhash, splitbuffer, length);
// compare
if (computedhash.compare(expectedhash)!=0)
{
printf("\n");
fprintf(stderr, "Fatal error: file '%s' has incorrect hash\n Expected: %s\n Computed: %s\n", infilename.c_str(), expectedhash.c_str(), computedhash.c_str());
goto cleanup;
}
// append to the file
if (write_output)
{
printf(" writing...");
actual = outfile->write(splitbuffer, length);
if (actual != length)
{
printf("\n");
fprintf(stderr, "Fatal error: Error writing output file (out of space?)\n");
goto cleanup;
}
printf(" done\n");
}
else
printf(" verified\n");
// release allocated memory
free(splitbuffer);
splitbuffer = nullptr;
}
if (write_output)
printf("File re-created successfully\n");
else
printf("File verified successfully\n");
// if we get here, clear the errors
error = 0;
cleanup:
if (splitfile)
splitfile.reset();
if (infile)
infile.reset();
if (outfile)
{
outfile.reset();
if (error != 0)
remove(outfilename.c_str());
}
if (splitbuffer != nullptr)
free(splitbuffer);
return error;
}
/*-------------------------------------------------
main - primary entry point
-------------------------------------------------*/
int main(int argc, char *argv[])
{
int result;
/* skip if no command */
if (argc < 2)
goto usage;
/* split command */
if (core_stricmp(argv[1], "-split") == 0)
{
if (argc != 4 && argc != 5)
goto usage;
result = split_file(argv[2], argv[3], (argc < 5) ? DEFAULT_SPLIT_SIZE : atoi(argv[4]));
}
/* join command */
else if (core_stricmp(argv[1], "-join") == 0)
{
if (argc != 3 && argc != 4)
goto usage;
result = join_file(argv[2], (argc >= 4) ? argv[3] : nullptr, true);
}
/* verify command */
else if (core_stricmp(argv[1], "-verify") == 0)
{
if (argc != 3)
goto usage;
result = join_file(argv[2], nullptr, false);
}
else
goto usage;
return result;
usage:
fprintf(stderr,
"Usage:\n"
" split -split <bigfile> <basename> [<size>] -- split file into parts\n"
" split -join <splitfile> [<outputfile>] -- join file parts into original file\n"
" split -verify <splitfile> -- verify a split file\n"
"\n"
"Where:\n"
" <bigfile> is the large file you wish to split\n"
" <basename> is the base path and name to assign to the split files\n"
" <size> is the optional split size, in MB (100MB is the default)\n"
" <splitfile> is the name of the <basename>.split generated with -split\n"
" <outputfile> is the name of the file to output (defaults to original name)\n"
);
return 0;
}