As a PFIF subcontractor, I am requesting correction assistance: In MS-OXCRPC, 3.1.7.2.1.2 is claims "2. Find the longest match in the window for the lookahead buffer." in the "Using the compression algorithm".
But it looks Microsoft implementation has an unexpected behavior regarding the above line. Actually, I've implemented both decompression and compression of (LZ77+DIRECT2) algorithm and it works well. But the problem I have is my compression function doesn't return the same output has MSFT does. The routine I've implemented to find the longest match in the window for the lookahead buffer returns a longer length than MSFT implementation. My compression routine returns: string found at uncompressed_position 0x00000052 [ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ] comp[00000035] = 00BF = Metadata (len,offset) = (22, 00000017) - uncomp_pos: 00000052 bestlen < 25 comp[00000037] = 0C (shared byte) Comparaison of the compressed chunk: comp_chunk_by_microsoft[00000035] 32 != BF mycomp[00000035] comp_chunk_by_microsoft[00000036] 00 == 00 mycomp[00000036] comp_chunk_by_microsoft[00000037] 07 != DC mycomp[00000037] As you can see, MSFT implementation encode a 0x0032 metadata at offset 0x35 which means size of 5 (2 + 3) at position -6, and my implementation encode a three bytes metadata at offset 0x35. Here, http://www.msuiche.net/samba/debug_lzxpress.zip, you can found debug outputs and concerned file. All files concern only one chunk. Could you please describe the exact process to retrieve the longest match in the window for the lookahead buffer? Regards, -- Matthieu Suiche _______________________________________________ cifs-protocol mailing list [email protected] https://lists.samba.org/mailman/listinfo/cifs-protocol
