diff options
Diffstat (limited to '3rdparty/lzma/C/Delta.c')
-rw-r--r-- | 3rdparty/lzma/C/Delta.c | 167 |
1 files changed, 136 insertions, 31 deletions
diff --git a/3rdparty/lzma/C/Delta.c b/3rdparty/lzma/C/Delta.c index e3edd21edbb..c4a4499fe2a 100644 --- a/3rdparty/lzma/C/Delta.c +++ b/3rdparty/lzma/C/Delta.c @@ -1,5 +1,5 @@ /* Delta.c -- Delta converter -2009-05-26 : Igor Pavlov : Public domain */ +2021-02-09 : Igor Pavlov : Public domain */ #include "Precomp.h" @@ -12,53 +12,158 @@ void Delta_Init(Byte *state) state[i] = 0; } -static void MyMemCpy(Byte *dest, const Byte *src, unsigned size) -{ - unsigned i; - for (i = 0; i < size; i++) - dest[i] = src[i]; -} void Delta_Encode(Byte *state, unsigned delta, Byte *data, SizeT size) { - Byte buf[DELTA_STATE_SIZE]; - unsigned j = 0; - MyMemCpy(buf, state, delta); + Byte temp[DELTA_STATE_SIZE]; + + if (size == 0) + return; + + { + unsigned i = 0; + do + temp[i] = state[i]; + while (++i != delta); + } + + if (size <= delta) + { + unsigned i = 0, k; + do + { + Byte b = *data; + *data++ = (Byte)(b - temp[i]); + temp[i] = b; + } + while (++i != size); + + k = 0; + + do + { + if (i == delta) + i = 0; + state[k] = temp[i++]; + } + while (++k != delta); + + return; + } + { - SizeT i; - for (i = 0; i < size;) + Byte *p = data + size - delta; + { + unsigned i = 0; + do + state[i] = *p++; + while (++i != delta); + } { - for (j = 0; j < delta && i < size; i++, j++) + const Byte *lim = data + delta; + ptrdiff_t dif = -(ptrdiff_t)delta; + + if (((ptrdiff_t)size + dif) & 1) { - Byte b = data[i]; - data[i] = (Byte)(b - buf[j]); - buf[j] = b; + --p; *p = (Byte)(*p - p[dif]); } + + while (p != lim) + { + --p; *p = (Byte)(*p - p[dif]); + --p; *p = (Byte)(*p - p[dif]); + } + + dif = -dif; + + do + { + --p; *p = (Byte)(*p - temp[--dif]); + } + while (dif != 0); } } - if (j == delta) - j = 0; - MyMemCpy(state, buf + j, delta - j); - MyMemCpy(state + delta - j, buf, j); } + void Delta_Decode(Byte *state, unsigned delta, Byte *data, SizeT size) { - Byte buf[DELTA_STATE_SIZE]; - unsigned j = 0; - MyMemCpy(buf, state, delta); + unsigned i; + const Byte *lim; + + if (size == 0) + return; + + i = 0; + lim = data + size; + + if (size <= delta) + { + do + *data = (Byte)(*data + state[i++]); + while (++data != lim); + + for (; delta != i; state++, delta--) + *state = state[i]; + data -= i; + } + else { - SizeT i; - for (i = 0; i < size;) + /* + #define B(n) b ## n + #define I(n) Byte B(n) = state[n]; + #define U(n) { B(n) = (Byte)((B(n)) + *data++); data[-1] = (B(n)); } + #define F(n) if (data != lim) { U(n) } + + if (delta == 1) + { + I(0) + if ((lim - data) & 1) { U(0) } + while (data != lim) { U(0) U(0) } + data -= 1; + } + else if (delta == 2) { - for (j = 0; j < delta && i < size; i++, j++) + I(0) I(1) + lim -= 1; while (data < lim) { U(0) U(1) } + lim += 1; F(0) + data -= 2; + } + else if (delta == 3) + { + I(0) I(1) I(2) + lim -= 2; while (data < lim) { U(0) U(1) U(2) } + lim += 2; F(0) F(1) + data -= 3; + } + else if (delta == 4) + { + I(0) I(1) I(2) I(3) + lim -= 3; while (data < lim) { U(0) U(1) U(2) U(3) } + lim += 3; F(0) F(1) F(2) + data -= 4; + } + else + */ + { + do + { + *data = (Byte)(*data + state[i++]); + data++; + } + while (i != delta); + { - buf[j] = data[i] = (Byte)(buf[j] + data[i]); + ptrdiff_t dif = -(ptrdiff_t)delta; + do + *data = (Byte)(*data + data[dif]); + while (++data != lim); + data += dif; } } } - if (j == delta) - j = 0; - MyMemCpy(state, buf + j, delta - j); - MyMemCpy(state + delta - j, buf, j); + + do + *state++ = *data; + while (++data != lim); } |