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Complements the documentation for pattern files and exclude files

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Guinness 2020-11-30 16:35:25 +01:00
parent 22c463f5c3
commit 076ade8c24
1 changed files with 2 additions and 2 deletions
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docs/internals/data-structures.rst
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@ -577,7 +577,7 @@ Chunks
The |project_name| chunker uses a rolling hash computed by the Buzhash_ algorithm.
It triggers (chunks) when the last HASH_MASK_BITS bits of the hash are zero,
producing chunks of 2^HASH_MASK_BITS Bytes on average.
producing chunks with a target size of 2^HASH_MASK_BITS Bytes.
Buzhash is **only** used for cutting the chunks at places defined by the
content, the buzhash value is **not** used as the deduplication criteria (we
@ -589,7 +589,7 @@ can be used to tune the chunker parameters, the default is:
- CHUNK_MIN_EXP = 19 (minimum chunk size = 2^19 B = 512 kiB)
- CHUNK_MAX_EXP = 23 (maximum chunk size = 2^23 B = 8 MiB)
- HASH_MASK_BITS = 21 (statistical medium chunk size ~= 2^21 B = 2 MiB)
- HASH_MASK_BITS = 21 (target chunk size ~= 2^21 B = 2 MiB)
- HASH_WINDOW_SIZE = 4095 [B] (`0xFFF`)
The buzhash table is altered by XORing it with a seed randomly generated once