greg/pcompress
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
61 commits 3 branches 21 tags 7.6 MiB
Commit graph

24 commits

Author SHA1 Message Date
Moinak Ghosh
2dadf411fa Reduce memory consumption and improve performance in dedupe 
Re-introduce crc64 for dedup blocks to avoid wasted memcpy-s
Restructe block array to be an array of pointers allocated on demand
Fix a corner case issue when splitting chunks at a dedup boundary
 2012-08-17 11:03:02 +05:30
Moinak Ghosh
55d0485d34 Improve Rabin computations using an irreducible polynomial 
Slight improvement to similarity computation
A simple mechanism to include DEBUG mode stats
Include stdint for common int types
 2012-08-15 20:13:40 +05:30
Moinak Ghosh
3150bdbed7 Implement secondary sketch based on character counts to refine similarity checksum. 
Proper checksum update for last block.
Update comments.
 2012-08-12 13:06:49 +05:30
Moinak Ghosh
f2ffcad2fd Compute and compare Mean sketch cksum to improve similarity comparison 
Fix optflags settings in Makefile
Small optimization in zero RLE encoder to avoid scanning during lookahead
Some minor fixes
 2012-08-09 23:57:24 +05:30
Moinak Ghosh
400d0bfa72 Bias fingerprint value with occurrence counts for a better sketch 
Fix latent bug when calling algo deinit in decompression code
Reduce diff threshold for slightly greater delta encoding
Limit similar buffer size difference for less wasted diffing
Change zlib compression wrapper to use faster deflateReset mechanism
Reduce optimization level for Dedupe code, it goes faster
 2012-08-08 22:40:58 +05:30
Moinak Ghosh
94563a7ecd Fix buffer size computation when allocating Rabin block array. 
Reduce memory usage of Rabin block array.
Add an SSE optimization for bsdiff.
Move integer hashing function to utils file.
More updates to README.
 2012-07-28 23:55:24 +05:30
Moinak Ghosh
c7cc7b469c Update chunk size computation to reduce memory usage. 
Implement runtime bypass of custom allocator.
Update README.
 2012-07-27 22:03:24 +05:30
Moinak Ghosh
962a2cae8a Compress Dedup index only if it is at least 90 bytes to avoid expansion. 
Some minor cleanup.
 2012-07-22 00:00:41 +05:30
Moinak Ghosh
e788eb43b8 Implement Delta Encoding based on modified bsdiff. 
Change to more accurate Sketch value computation approach.
 2012-07-19 21:41:07 +05:30
Moinak Ghosh
1da2c40888 Use a rolling checksum based sketch value for a rabin chunk instead of a CRC64 checksum. 
Avoids additional table-lookup memory access.
Reduce Rabin window size to avoid overflows in sketch value.
No need to maintain rolling checksum in Rabin context.
A few comment cleanups.
 2012-07-13 22:06:55 +05:30
Moinak Ghosh
a873f92e41 Fix crash when decompressing deduped archive. 
Ensure correct level is passed to lzma.
Avoid branch when wrapping rabin window position and check for rabin window size to be power of 2.
Update rabin parameters check for adaptive modes.
Add detection of 7-bit text/8-bit binary data for later use.
 2012-07-10 20:14:23 +05:30
Moinak Ghosh
010f49f412 Implement ability to partition chunks at the last rabin boundary instead of fixed size. 2012-07-08 21:44:08 +05:30
Moinak Ghosh
d3f5287ee5 Update License info to LGPLv3. 2012-07-07 22:18:29 +05:30
Moinak Ghosh
172432698e Adjust Rabin parameters for chunksize > LZMA window size. 2012-07-07 00:01:13 +05:30
Moinak Ghosh
ea923b84f0 Use different min block size and Rabin break pattern depending on compression algo. 
Cleanup some cruft.
 2012-07-06 23:24:12 +05:30
Moinak Ghosh
f5ce45b16e Techniques to better reduce Rabin Metadata. 
Fix wrong chunk sizing with dedup enabled.
 2012-07-06 00:16:02 +05:30
Moinak Ghosh
3f0e1952ef Fix compile warnings. 2012-07-04 23:20:10 +05:30
Moinak Ghosh
1eee08040f Use diferent average Rabin block sizes depending on compression algorithm. 
Misc cleanups.
 2012-07-03 22:47:24 +05:30
Moinak Ghosh
a13c61e926 Change rabin index encoding scheme for better metadata compression. 2012-07-02 22:08:03 +05:30
Moinak Ghosh
a1825a2305 Implement Parallel deduplication support. 
Restructure compression functions to take chunk flag as argument.
Add missing error flag printing in LZMA.
Only create enough threads as needed by chunk size and file size.
Minor cleanups and variable name changes.
 2012-07-01 21:44:02 +05:30
Moinak Ghosh
f9c3644459 Updates to Rabin based Dedup. 
Change command line option.
 2012-06-29 23:45:06 +05:30
Moinak Ghosh
cbf9728278 Implement Deduplication based on Rabin Fingerprinting: work in progress. 
Fix bug that prevented pipe mode from being used.
Allow building without specialized allocator.
Use basic optimize flag in debuig build.
 2012-06-29 18:23:55 +05:30
Moinak Ghosh
8f5f531967 Add license and other minor fixes. 2012-06-21 20:40:43 +05:30
Moinak Ghosh
733923cbf2 Add ability to adjust chunk boundary based on Rabin Fingerprinting to improve compression. 
Remove unnecessary checks in compression loop.
 2012-06-21 20:27:05 +05:30