p7zip/C/Xz.c
2017-10-11 12:35:36 +02:00

91 lines
1.9 KiB
C

/* Xz.c - Xz
2015-05-01 : Igor Pavlov : Public domain */
#include "Precomp.h"
#include "7zCrc.h"
#include "CpuArch.h"
#include "Xz.h"
#include "XzCrc64.h"
const Byte XZ_SIG[XZ_SIG_SIZE] = { 0xFD, '7', 'z', 'X', 'Z', 0 };
const Byte XZ_FOOTER_SIG[XZ_FOOTER_SIG_SIZE] = { 'Y', 'Z' };
unsigned Xz_WriteVarInt(Byte *buf, UInt64 v)
{
unsigned i = 0;
do
{
buf[i++] = (Byte)((v & 0x7F) | 0x80);
v >>= 7;
}
while (v != 0);
buf[i - 1] &= 0x7F;
return i;
}
void Xz_Construct(CXzStream *p)
{
p->numBlocks = p->numBlocksAllocated = 0;
p->blocks = 0;
p->flags = 0;
}
void Xz_Free(CXzStream *p, ISzAlloc *alloc)
{
alloc->Free(alloc, p->blocks);
p->numBlocks = p->numBlocksAllocated = 0;
p->blocks = 0;
}
unsigned XzFlags_GetCheckSize(CXzStreamFlags f)
{
unsigned t = XzFlags_GetCheckType(f);
return (t == 0) ? 0 : (4 << ((t - 1) / 3));
}
void XzCheck_Init(CXzCheck *p, unsigned mode)
{
p->mode = mode;
switch (mode)
{
case XZ_CHECK_CRC32: p->crc = CRC_INIT_VAL; break;
case XZ_CHECK_CRC64: p->crc64 = CRC64_INIT_VAL; break;
case XZ_CHECK_SHA256: Sha256_Init(&p->sha); break;
}
}
void XzCheck_Update(CXzCheck *p, const void *data, size_t size)
{
switch (p->mode)
{
case XZ_CHECK_CRC32: p->crc = CrcUpdate(p->crc, data, size); break;
case XZ_CHECK_CRC64: p->crc64 = Crc64Update(p->crc64, data, size); break;
case XZ_CHECK_SHA256: Sha256_Update(&p->sha, (const Byte *)data, size); break;
}
}
int XzCheck_Final(CXzCheck *p, Byte *digest)
{
switch (p->mode)
{
case XZ_CHECK_CRC32:
SetUi32(digest, CRC_GET_DIGEST(p->crc));
break;
case XZ_CHECK_CRC64:
{
int i;
UInt64 v = CRC64_GET_DIGEST(p->crc64);
for (i = 0; i < 8; i++, v >>= 8)
digest[i] = (Byte)(v & 0xFF);
break;
}
case XZ_CHECK_SHA256:
Sha256_Final(&p->sha, digest);
break;
default:
return 0;
}
return 1;
}