NAME¶
srf_index_hash - Adds a hash-table index to an SRF file.
SYNOPSIS¶
srf_index_hash [
-c] srf_archive
DESCRIPTION¶
srf_index_hash adds and index to an SRF file or replaces an existing
index with a new one. In the case of concatenated SRF files only the index at
the end of a file will be replaced, but internal indices will not be consulted
by SRF tools.
The index is a hash table indexing the sequence names only. The name itself does
not appear in the index, rather the top 7-bits of a 64-bit hash key are held
in the index along with N-bits used to determine the hash bucket. This reduces
the index size to around 10-15 bytes per sequence.
OPTIONS¶
- -c
- Check only. This requests that the index is not produced,
but the checks performed during the creation of an index (such as looking
for duplicate sequence names) are still performed.
AUTHOR¶
James Bonfield, Wellcome Trust Sanger Institute