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Move file CRC32 code into crc32.h

This commit is contained in:
Jeffrey Pfau 2014-07-20 15:11:22 -07:00
parent 7a0f86ae99
commit 381fc94d73
3 changed files with 34 additions and 20 deletions
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29
src/util/crc32.c
View File

@ -42,6 +42,12 @@
#include "util/crc32.h"
#include "util/vfs.h"
enum {
BUFFER_SIZE = 1024
};
static uint32_t crc32Table[] = {
0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
@ -102,3 +108,26 @@ uint32_t updateCrc32(uint32_t crc, const void* buf, size_t size) {
return ~crc;
}
uint32_t fileCrc32(struct VFile* vf, size_t endOffset) {
char buffer[BUFFER_SIZE];
size_t blocksize;
size_t alreadyRead = 0;
if (vf->seek(vf, 0, SEEK_SET) < 0) {
return 0;
}
uint32_t crc = 0;
while (alreadyRead < endOffset) {
size_t toRead = sizeof(buffer);
if (toRead + alreadyRead > endOffset) {
toRead = endOffset - alreadyRead;
}
blocksize = vf->read(vf, buffer, toRead);
alreadyRead += blocksize;
crc = updateCrc32(crc, buffer, blocksize);
if (blocksize < toRead) {
return 0;
}
}
return crc;
}

3
src/util/crc32.h
View File

@ -4,7 +4,10 @@
#include <stdint.h>
#include <string.h>
struct VFile;
uint32_t crc32(const void* buf, size_t size);
uint32_t updateCrc32(uint32_t crc, const void* buf, size_t size);
uint32_t fileCrc32(struct VFile* file, size_t endOffset);
#endif

22
src/util/patch-ups.c
View File

@ -8,8 +8,6 @@ enum {
IN_CHECKSUM = -12,
OUT_CHECKSUM = -8,
PATCH_CHECKSUM = -4,
BUFFER_SIZE = 1024
};
static size_t _UPSOutputSize(struct Patch* patch, size_t inSize);
@ -19,7 +17,7 @@ static size_t _UPSDecodeLength(struct VFile* vf);
bool loadPatchUPS(struct Patch* patch) {
patch->vf->seek(patch->vf, 0, SEEK_SET);
char buffer[BUFFER_SIZE];
char buffer[4];
if (patch->vf->read(patch->vf, buffer, 4) != 4) {
return false;
}
@ -36,23 +34,7 @@ bool loadPatchUPS(struct Patch* patch) {
return false;
}
size_t blocksize;
size_t alreadyRead = 0;
patch->vf->seek(patch->vf, 0, SEEK_SET);
uint32_t crc = 0;
while (alreadyRead < filesize + PATCH_CHECKSUM) {
size_t toRead = sizeof(buffer);
if (toRead + alreadyRead > filesize + PATCH_CHECKSUM) {
toRead = filesize + PATCH_CHECKSUM - alreadyRead;
}
blocksize = patch->vf->read(patch->vf, buffer, toRead);
alreadyRead += blocksize;
crc = updateCrc32(crc, buffer, blocksize);
if (blocksize < toRead) {
return 0;
}
}
uint32_t crc = fileCrc32(patch->vf, filesize + PATCH_CHECKSUM);
if (crc != goodCrc32) {
return false;
}