From: Dragan Dosen <ddosen@haproxy.com>
Date: Tue, 22 Dec 2020 20:44:33 +0000 (+0100)
Subject: MINOR: sample: add the xxh3 converter
X-Git-Tag: v2.4-dev5~81
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=04bf0cc086bda50dcace47b225aaeb7533c758b7;p=thirdparty%2Fhaproxy.git

MINOR: sample: add the xxh3 converter

This patch adds support for the XXH3 variant of hash function that
generates a 64-bit hash.
---

diff --git a/doc/configuration.txt b/doc/configuration.txt
index 95b020c03f..ca4c581db4 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -16356,6 +16356,15 @@ xor(<value>)
   This prefix is followed by a name. The separator is a '.'. The name may only
   contain characters 'a-z', 'A-Z', '0-9', '.' and '_'.
 
+xxh3([<seed>])
+  Hashes a binary input sample into a signed 64-bit quantity using the XXH3
+  64-bit variant of the XXhash hash function. This hash supports a seed which
+  defaults to zero but a different value maybe passed as the <seed> argument.
+  This hash is known to be very good and very fast so it can be used to hash
+  URLs and/or URL parameters for use as stick-table keys to collect statistics
+  with a low collision rate, though care must be taken as the algorithm is not
+  considered as cryptographically secure.
+
 xxh32([<seed>])
   Hashes a binary input sample into an unsigned 32-bit quantity using the 32-bit
   variant of the XXHash hash function. This hash supports a seed which defaults
diff --git a/src/sample.c b/src/sample.c
index d1941ce839..f70797dae2 100644
--- a/src/sample.c
+++ b/src/sample.c
@@ -2099,6 +2099,20 @@ static int sample_conv_xxh64(const struct arg *arg_p, struct sample *smp, void *
 	return 1;
 }
 
+static int sample_conv_xxh3(const struct arg *arg_p, struct sample *smp, void *private)
+{
+	unsigned long long int seed;
+
+	if (arg_p && arg_p->data.sint)
+		seed = (unsigned long long int)arg_p->data.sint;
+	else
+		seed = 0;
+	smp->data.u.sint = (long long int)XXH3(smp->data.u.str.area,
+	                                       smp->data.u.str.data, seed);
+	smp->data.type = SMP_T_SINT;
+	return 1;
+}
+
 /* hashes the binary input into a 32-bit unsigned int */
 static int sample_conv_crc32(const struct arg *arg_p, struct sample *smp, void *private)
 {
@@ -3959,6 +3973,7 @@ static struct sample_conv_kw_list sample_conv_kws = {ILH, {
 	{ "djb2",   sample_conv_djb2,      ARG1(0,SINT), NULL, SMP_T_BIN,  SMP_T_SINT  },
 	{ "sdbm",   sample_conv_sdbm,      ARG1(0,SINT), NULL, SMP_T_BIN,  SMP_T_SINT  },
 	{ "wt6",    sample_conv_wt6,       ARG1(0,SINT), NULL, SMP_T_BIN,  SMP_T_SINT  },
+	{ "xxh3",   sample_conv_xxh3,      ARG1(0,SINT), NULL, SMP_T_BIN,  SMP_T_SINT  },
 	{ "xxh32",  sample_conv_xxh32,     ARG1(0,SINT), NULL, SMP_T_BIN,  SMP_T_SINT  },
 	{ "xxh64",  sample_conv_xxh64,     ARG1(0,SINT), NULL, SMP_T_BIN,  SMP_T_SINT  },
 	{ "json",   sample_conv_json,      ARG1(1,STR),  sample_conv_json_check, SMP_T_STR,  SMP_T_STR },