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2013-02-24hash: dynamically grow hash tableStephen Hemminger
Dynamically grow the hash table index if the chains get too long. If expansion doesn't help keep chain length short, then stop expanding, to avoid bad behavior if there is a poor hash function. Not a new idea, based on concepts in uthash. Depends on my previous patch to restrict hash to power of 2. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> [profiling results: sum of cycles spent in hash_get/jhash with RIPE RIS test data (single simple BGP peer) improved to 69% of previously spent] Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
2013-02-24hash: force size to be a power of 2Stephen Hemminger
By forcing the hash table size to be a power of 2, a potentially expensive divide can be replaced by a mask operation. Almost all usage of the hash table was using default size of 1024. Only places with different size was thread library (1011) and bgp aspath. Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
2011-03-21lib: Better hashing of string values using Bernstein hashStephen Hemminger
* hash.{h,c}: (string_hash_make) Hash optimised for strings, current implementation using Bernstein hash, which offers a good compromise between distribution and performance. * distribute.c: (distribute_hash_make) use previous instead of additive string hash. * if_rmap.c: (if_rmap_hash_make) ditto
2008-08-22[lib] hash compare function arguments ought to be const qualifiedStephen Hemminger
2008-08-14 Stephen Hemminger <stephen.hemminger@vyatta.com> * lib/hash.h: (struct hash) Hash comparator callback really ought to treat storage behind arguments as constant - a compare function with side-effects would be evil. * */*.c: Adjust comparator functions similarly, thus fixing at least a few compiler warnings about const qualifier being dropped. Signed-off-by: Paul Jakma <paul@quagga.net>
2005-05-062005-05-06 Paul Jakma <paul@dishone.st>paul
* (general) extern and static'ification of functions in code and header. Cleanup any definitions with unspecified arguments. Add casts for callback assignments where the callback is defined, typically, as passing void *, but the function being assigned has some other pointer type defined as its argument, as gcc complains about casts from void * to X* via function arguments. Fix some old K&R style function argument definitions. Add noreturn gcc attribute to some functions, as appropriate. Add unused gcc attribute to some functions (eg ones meant to help while debugging) Add guard defines to headers which were missing them. * command.c: (install_node) add const qualifier, still doesnt shut up the warning though, because of the double pointer. (cmp_node) ditto * keychain.c: (key_str2time) Add GET_LONG_RANGE() macro, derived fromn vty.h ones to fix some of the (long) < 0 warnings. * thread.c: (various) use thread_empty (cpu_record_hash_key) should cast to uintptr_t, a stdint.h type * vty.h: Add VTY_GET_IPV4_ADDRESS and VTY_GET_IPV4_PREFIX so they removed from ospfd/ospf_vty.h * zebra.h: Move definition of ZEBRA_PORT to here, to remove dependence of lib on zebra/zserv.h
2002-12-13Initial revisionpaul