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Merge pull request #3593 from janisozaur/decode-rle-speedup

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Use memset/memcpy functions for RLE chunk decoding
This commit is contained in:
Ted John
2016-05-14 16:03:32 +01:00
parent d0d2ad7ded 90bcca11d2
commit 498e4b67df
1 changed files with 22 additions and 18 deletions
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40
src/util/sawyercoding.c
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@@ -293,21 +293,22 @@ int sawyercoding_validate_track_checksum(const uint8* src, size_t length){
*/
static size_t decode_chunk_rle(const uint8* src_buffer, uint8* dst_buffer, size_t length)
{
size_t i, j, count;
size_t count;
uint8 *dst, rleCodeByte;
dst = dst_buffer;
for (i = 0; i < length; i++) {
for (int i = 0; i < length; i++) {
rleCodeByte = src_buffer[i];
if (rleCodeByte & 128) {
i++;
count = 257 - rleCodeByte;
for (j = 0; j < count; j++)
*dst++ = src_buffer[i];
memset(dst, src_buffer[i], count);
dst = (uint8*)((uintptr_t)dst + count);
} else {
for (j = 0; j <= rleCodeByte; j++)
*dst++ = src_buffer[++i];
memcpy(dst, src_buffer + i + 1, rleCodeByte + 1);
dst = (uint8*)((uintptr_t)dst + rleCodeByte + 1);
i += rleCodeByte + 1;
}
}
@@ -321,7 +322,7 @@ static size_t decode_chunk_rle(const uint8* src_buffer, uint8* dst_buffer, size_
*/
static size_t decode_chunk_repeat(uint8 *buffer, size_t length)
{
size_t i, j, count;
size_t i, count;
uint8 *src, *dst, *copyOffset;
// Backup buffer
@@ -335,8 +336,8 @@ static size_t decode_chunk_repeat(uint8 *buffer, size_t length)
} else {
count = (src[i] & 7) + 1;
copyOffset = dst + (int)(src[i] >> 3) - 32;
for (j = 0; j < count; j++)
*dst++ = *copyOffset++;
memcpy(dst, copyOffset, count);
dst = (uint8*)((uintptr_t)dst + count);
}
}
@@ -381,9 +382,10 @@ static size_t encode_chunk_rle(const uint8 *src_buffer, uint8 *dst_buffer, size_
if ((count && *src == src[1]) || count > 125){
*dst++ = count - 1;
for (; count != 0; --count){
*dst++ = *src_norm_start++;
}
memcpy(dst, src_norm_start, count);
dst += count;
src_norm_start += count;
count = 0;
}
if (*src == src[1]){
for (; (count < 125) && ((src + count) < end_src); count++){
@@ -403,9 +405,10 @@ static size_t encode_chunk_rle(const uint8 *src_buffer, uint8 *dst_buffer, size_
if (src == end_src - 1)count++;
if (count){
*dst++ = count - 1;
for (; count != 0; --count){
*dst++ = *src_norm_start++;
}
memcpy(dst, src_norm_start, count);
dst += count;
src_norm_start += count;
count = 0;
}
return dst - dst_buffer;
}
@@ -428,16 +431,17 @@ static size_t encode_chunk_repeat(const uint8 *src_buffer, uint8 *dst_buffer, si
// Iterate through remainder of the source buffer
for (i = 1; i < length; ) {
searchIndex = max(0, i - 32);
searchIndex = (i < 32) ? 0 : (i - 32);
searchEnd = i - 1;
bestRepeatCount = 0;
for (repeatIndex = searchIndex; repeatIndex <= searchEnd; repeatIndex++) {
repeatCount = 0;
maxRepeatCount = min(min(7, searchEnd - repeatIndex), length - i - 1);
// maxRepeatCount should not exceed length
assert(repeatIndex + maxRepeatCount < length);
assert(i + maxRepeatCount < length);
for (j = 0; j <= maxRepeatCount; j++) {
assert(repeatIndex + j < length);
assert(i + j < length);
if (src_buffer[repeatIndex + j] == src_buffer[i + j]) {
repeatCount++;
} else {