From 9438ef5f79fdac11080c3fa10c518e335fd7d8d6 Mon Sep 17 00:00:00 2001 From: Henri Beauchamp Date: Tue, 31 Jan 2023 17:42:51 +0100 Subject: SL-19110 Fast hashing classes for use in place of the slow LLMD5, where speed matters. (#64) This commit adds the HBXX64 and HBXX128 classes for use as a drop-in replacement for the slow LLMD5 hashing class, where speed matters and backward compatibility (with standard hashing algorithms) and/or cryptographic hashing qualities are not required. It also replaces LLMD5 with HBXX* in a few existing hot (well, ok, just "warm" for some) paths meeting the above requirements, while paving the way for future use cases, such as in the DRTVWR-559 and sibling branches where the slow LLMD5 is used (e.g. to hash materials and vertex buffer cache entries), and could be use such a (way) faster algorithm with very significant benefits and no negative impact. Here is the comment I added in indra/llcommon/hbxx.h: // HBXXH* classes are to be used where speed matters and cryptographic quality // is not required (no "one-way" guarantee, though they are likely not worst in // this respect than MD5 which got busted and is now considered too weak). The // xxHash code they are built upon is vectorized and about 50 times faster than // MD5. A 64 bits hash class is also provided for when 128 bits of entropy are // not needed. The hashes collision rate is similar to MD5's. // See https://github.com/Cyan4973/xxHash#readme for details. --- indra/cmake/LLCommon.cmake | 1 + 1 file changed, 1 insertion(+) (limited to 'indra/cmake/LLCommon.cmake') diff --git a/indra/cmake/LLCommon.cmake b/indra/cmake/LLCommon.cmake index 53871791fd..528b43c3fc 100644 --- a/indra/cmake/LLCommon.cmake +++ b/indra/cmake/LLCommon.cmake @@ -4,6 +4,7 @@ include(APR) include(Boost) include(EXPAT) include(Tracy) +include(xxHash) include(ZLIBNG) set(LLCOMMON_INCLUDE_DIRS -- cgit v1.3