diff options
| author | Quincey Koziol <koziol@hdfgroup.org> | 2007-12-20 20:36:08 (GMT) |
|---|---|---|
| committer | Quincey Koziol <koziol@hdfgroup.org> | 2007-12-20 20:36:08 (GMT) |
| commit | 6878261a432d9cc8c705aa6c4f85450b29b37150 (patch) | |
| tree | 765a4e072ef63bdda33320ca2c16938c5fa7a06f /src/H5checksum.c | |
| parent | 79a96581a64a4b2f8a6679100a7f369bb963ab94 (diff) | |
| download | hdf5-6878261a432d9cc8c705aa6c4f85450b29b37150.zip hdf5-6878261a432d9cc8c705aa6c4f85450b29b37150.tar.gz hdf5-6878261a432d9cc8c705aa6c4f85450b29b37150.tar.bz2 | |
[svn-r14353] Description:
- Add hash value for skip list string types, to reduce # of string
comparisons.
- Fixed bug with metadata/small data block aggregator adding size == 0
block into file free space list.
- Refactored metadata/small data block aggregator code into single set of
common routines.
- Changed block aggregator code to be smarter about releasing space in the
'other' block when the 'other' block has aggregated enough data.
Tested on:
FreeBSD/32 6.2 (duty) in debug mode
FreeBSD/64 6.2 (liberty) w/C++ & FORTRAN, in debug mode
Linux/32 2.6 (kagiso) w/PGI compilers, w/C++ & FORTRAN, w/threadsafe,
in debug mode
Linux/64-amd64 2.6 (smirom) w/default API=1.6.x, w/C++ & FORTRAN,
in production mode
Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
in production mode
Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
w/szip filter, in production mode
Mac OS X/32 10.4.10 (amazon) in debug mode
Linux/64-ia64 2.4 (tg-login3) w/parallel, w/FORTRAN, in production mode
Diffstat (limited to 'src/H5checksum.c')
| -rw-r--r-- | src/H5checksum.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/src/H5checksum.c b/src/H5checksum.c index f2e344d..e42f152 100644 --- a/src/H5checksum.c +++ b/src/H5checksum.c @@ -459,3 +459,36 @@ H5_checksum_metadata(const void *data, size_t len, uint32_t initval) FUNC_LEAVE_NOAPI(H5_checksum_lookup3(data, len, initval)) } /* end H5_checksum_metadata() */ + +/*------------------------------------------------------------------------- + * Function: H5_hash_string + * + * Purpose: Provide a simple & fast routine for hashing strings + * + * Note: This algorithm is the 'djb2' algorithm described on this page: + * http://www.cse.yorku.ca/~oz/hash.html + * + * Return: hash of input string (can't fail) + * + * Programmer: Quincey Koziol + * Tuesday, December 11, 2007 + * + *------------------------------------------------------------------------- + */ +uint32_t +H5_hash_string(const char *str) +{ + uint32_t hash = 5381; + int c; + + FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5_hash_string) + + /* Sanity check */ + HDassert(str); + + while(c = *str++) + hash = ((hash << 5) + hash) + c; /* hash * 33 + c */ + + FUNC_LEAVE_NOAPI(hash) +} /* end H5_hash_string() */ + |