greg/pcompress
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Improve check in E8E9 filter to avoid unnecessary encodes.

Browse source 
Allow small increase in output chunk size for transform preprocessing (E8E9).
Ensure chunk allocations always include oerhead size.
This commit is contained in:
Moinak Ghosh 2015-01-25 23:17:23 -08:00
parent 678a6a2da4
commit 30dee9a1a9
2 changed files with 20 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
filters/dispack/dis.cpp
View file

@ -957,14 +957,15 @@ int
Forward_E89(uint8_t *src, uint64_t sz)
{
uint32_t i;
uint32_t size;
uint32_t size, conversions;
if (sz > UINT32_MAX) {
if (sz > UINT32_MAX || sz < 25) {
return (-1);
}
size = sz;
i = 0;
conversions = 0;
while (i < size-4) {
if ((src[i] & 0xfe) == 0xe8 &&
(src[i+4] == 0 || src[i+4] == 0xff))
@ -979,11 +980,14 @@ Forward_E89(uint8_t *src, uint64_t sz)
src[i+1] = (uint8_t)(off >> 16);
src[i+2] = (uint8_t)(off >> 8);
src[i+3] = (uint8_t)off;
conversions++;
}
}
}
i++;
}
if (conversions < 10)
return (-1);
return (0);
}

21
pcompress.c
View file

@ -222,6 +222,7 @@ preproc_compress(pc_ctx_t *pctx, compress_func_ptr cmp_func, void *src, uint64_t
result = 0;
stype = PC_SUBTYPE(btype);
analyzed = 0;
if (btype == TYPE_UNKNOWN || stype == TYPE_ARCHIVE_TAR || stype == TYPE_PDF ||
PC_TYPE(btype) & TYPE_TEXT || interesting) {
analyze_buffer(src, srclen, &actx);
@ -469,7 +470,7 @@ preproc_decompress(pc_ctx_t *pctx, compress_func_ptr dec_func, void *src, uint64
}
if (!(type & (PREPROC_COMPRESSED|PREPROC_TYPE_DELTA2|PREPROC_TYPE_LZP|
PREPROC_TYPE_DISPACK|PREPROC_TYPE_DICT))
PREPROC_TYPE_DISPACK|PREPROC_TYPE_DICT|PREPROC_TYPE_E8E9))
&& type > 0) {
log_msg(LOG_ERR, 0, "Invalid preprocessing flags: %d", type);
return (-1);
@ -1631,12 +1632,8 @@ redo:
if (!tdat->compressed_chunk && tdat->len_cmp != METADATA_INDICATOR) {
tdat->compressed_chunk = (uchar_t *)slab_alloc(NULL,
compressed_chunksize);
if ((pctx->enable_rabin_scan || pctx->enable_fixed_scan))
tdat->uncompressed_chunk = (uchar_t *)slab_alloc(NULL,
compressed_chunksize);
else
tdat->uncompressed_chunk = (uchar_t *)slab_alloc(NULL,
chunksize);
if (!tdat->compressed_chunk || !tdat->uncompressed_chunk) {
log_msg(LOG_ERR, 0, "2: Out of memory");
UNCOMP_BAIL;
@ -1926,9 +1923,15 @@ plain_index:
* If at all compression expands/does not shrink data then the chunk
* will be left uncompressed. Also if the compression errored the
* chunk will be left uncompressed.
*
* HOWEVER, increased chunk size is allowed in preprocessing mode since
* there are unavoidable cases where an E8E9 filter is applied and then
* later on compression does not happen. So we have to retain information
* that E8E9 hapened, to recover the data correctly. In this corner case
* the chunk size is increased by 1 byte for the preproc header.
*/
tdat->len_cmp = _chunksize;
if (_chunksize >= tdat->rbytes || rv < 0) {
if ((_chunksize >= tdat->rbytes && !pctx->preprocess_mode) || rv < 0) {
if (!(pctx->enable_rabin_scan || pctx->enable_fixed_scan) || !tdat->rctx->valid)
memcpy(compressed_chunk, tdat->uncompressed_chunk, tdat->rbytes);
type = UNCOMPRESSED;
@ -2444,10 +2447,7 @@ start_compress(pc_ctx_t *pctx, const char *filename, uint64_t chunksize, int lev
log_msg(LOG_INFO, 0, "Scaling to 1 thread");
nprocs = pctx->nthreads;
dary = (struct cmp_data **)slab_calloc(NULL, nprocs, sizeof (struct cmp_data *));
if ((pctx->enable_rabin_scan || pctx->enable_fixed_scan))
cread_buf = (uchar_t *)slab_alloc(NULL, compressed_chunksize);
else
cread_buf = (uchar_t *)slab_alloc(NULL, chunksize);
if (!cread_buf) {
log_msg(LOG_ERR, 0, "3: Out of memory");
COMP_BAIL;
@ -2477,7 +2477,8 @@ start_compress(pc_ctx_t *pctx, const char *filename, uint64_t chunksize, int lev
if (single_chunk)
tdat->uncompressed_chunk = (uchar_t *)1;
else
tdat->uncompressed_chunk = (uchar_t *)slab_alloc(NULL, chunksize);
tdat->uncompressed_chunk = (uchar_t *)slab_alloc(NULL,
compressed_chunksize);
tdat->cmp_seg = (uchar_t *)slab_alloc(NULL, compressed_chunksize);
}
tdat->compressed_chunk = tdat->cmp_seg + COMPRESSED_CHUNKSZ +