From: Michael Jeanson Date: Tue, 6 Apr 2021 23:22:08 +0000 (-0400) Subject: Move jhash.h to 'src/common/' X-Git-Tag: v2.13.0-rc1~117 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=e58e5ad5abb76f1d91d6b23ec77036ff1616f832;p=lttng-ust.git Move jhash.h to 'src/common/' Change-Id: I17031c461b8376e92900239aceac45258e8e3c1b Signed-off-by: Michael Jeanson Signed-off-by: Mathieu Desnoyers --- diff --git a/src/common/Makefile.am b/src/common/Makefile.am index d80172dd..ff2cfd71 100644 --- a/src/common/Makefile.am +++ b/src/common/Makefile.am @@ -15,6 +15,7 @@ noinst_HEADERS = \ dynamic-type.h \ elf.h \ events.h \ + jhash.h \ logging.h \ macros.h \ patient.h \ diff --git a/src/common/jhash.h b/src/common/jhash.h new file mode 100644 index 00000000..4941b945 --- /dev/null +++ b/src/common/jhash.h @@ -0,0 +1,229 @@ +/* + * SPDX-License-Identifier: LGPL-2.1-only + * + * Copyright (C) 2011 Mathieu Desnoyers + */ + +#ifndef _UST_COMMON_JHASH_H +#define _UST_COMMON_JHASH_H + +#include +#include +#include +#include + +/* + * Hash function + * Source: http://burtleburtle.net/bob/c/lookup3.c + * Originally Public Domain + */ + +#define rot(x, k) (((x) << (k)) | ((x) >> (32 - (k)))) + +#define mix(a, b, c) \ +do { \ + a -= c; a ^= rot(c, 4); c += b; \ + b -= a; b ^= rot(a, 6); a += c; \ + c -= b; c ^= rot(b, 8); b += a; \ + a -= c; a ^= rot(c, 16); c += b; \ + b -= a; b ^= rot(a, 19); a += c; \ + c -= b; c ^= rot(b, 4); b += a; \ +} while (0) + +#define final(a, b, c) \ +{ \ + c ^= b; c -= rot(b, 14); \ + a ^= c; a -= rot(c, 11); \ + b ^= a; b -= rot(a, 25); \ + c ^= b; c -= rot(b, 16); \ + a ^= c; a -= rot(c, 4);\ + b ^= a; b -= rot(a, 14); \ + c ^= b; c -= rot(b, 24); \ +} + +#if (BYTE_ORDER == LITTLE_ENDIAN) +#define HASH_LITTLE_ENDIAN 1 +#else +#define HASH_LITTLE_ENDIAN 0 +#endif + +/* + * + * hashlittle() -- hash a variable-length key into a 32-bit value + * k : the key (the unaligned variable-length array of bytes) + * length : the length of the key, counting by bytes + * initval : can be any 4-byte value + * Returns a 32-bit value. Every bit of the key affects every bit of + * the return value. Two keys differing by one or two bits will have + * totally different hash values. + * + * The best hash table sizes are powers of 2. There is no need to do + * mod a prime (mod is sooo slow!). If you need less than 32 bits, + * use a bitmask. For example, if you need only 10 bits, do + * h = (h & hashmask(10)); + * In which case, the hash table should have hashsize(10) elements. + * + * If you are hashing n strings (uint8_t **)k, do it like this: + * for (i = 0, h = 0; i < n; ++i) h = hashlittle(k[i], len[i], h); + * + * By Bob Jenkins, 2006. bob_jenkins@burtleburtle.net. You may use this + * code any way you wish, private, educational, or commercial. It's free. + * + * Use for hash table lookup, or anything where one collision in 2^^32 is + * acceptable. Do NOT use for cryptographic purposes. + */ +static +uint32_t hashlittle(const void *key, size_t length, uint32_t initval) +{ + uint32_t a, b, c; /* internal state */ + union { + const void *ptr; + size_t i; + } u; + + /* Set up the internal state */ + a = b = c = 0xdeadbeef + ((uint32_t)length) + initval; + + u.ptr = key; + if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) { + const uint32_t *k = (const uint32_t *) key; /* read 32-bit chunks */ + + /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */ + while (length > 12) { + a += k[0]; + b += k[1]; + c += k[2]; + mix(a, b, c); + length -= 12; + k += 3; + } + + /*----------------------------- handle the last (probably partial) block */ + /* + * The original jhash.h reads beyond the end of string, and implements + * a special code path for VALGRIND. It seems to make ASan unhappy too + * though, so considering that hashing event names is not a fast-path + * in lttng-ust, remove the "fast" code entirely and use the slower + * but verifiable VALGRIND version of the code which does not issue + * out-of-bound reads. + */ + { + const uint8_t *k8; + + k8 = (const uint8_t *) k; + switch (length) { + case 12: c+=k[2]; b+=k[1]; a+=k[0]; break; + case 11: c+=((uint32_t) k8[10])<<16; /* fall through */ + case 10: c+=((uint32_t) k8[9])<<8; /* fall through */ + case 9 : c+=k8[8]; /* fall through */ + case 8 : b+=k[1]; a+=k[0]; break; + case 7 : b+=((uint32_t) k8[6])<<16; /* fall through */ + case 6 : b+=((uint32_t) k8[5])<<8; /* fall through */ + case 5 : b+=k8[4]; /* fall through */ + case 4 : a+=k[0]; break; + case 3 : a+=((uint32_t) k8[2])<<16; /* fall through */ + case 2 : a+=((uint32_t) k8[1])<<8; /* fall through */ + case 1 : a+=k8[0]; break; + case 0 : return c; + } + } + + } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) { + const uint16_t *k = (const uint16_t *) key; /* read 16-bit chunks */ + const uint8_t *k8; + + /*--------------- all but last block: aligned reads and different mixing */ + while (length > 12) + { + a += k[0] + (((uint32_t) k[1])<<16); + b += k[2] + (((uint32_t) k[3])<<16); + c += k[4] + (((uint32_t) k[5])<<16); + mix(a, b, c); + length -= 12; + k += 6; + } + + /*----------------------------- handle the last (probably partial) block */ + k8 = (const uint8_t *) k; + switch(length) + { + case 12: c+=k[4]+(((uint32_t) k[5])<<16); + b+=k[2]+(((uint32_t) k[3])<<16); + a+=k[0]+(((uint32_t) k[1])<<16); + break; + case 11: c+=((uint32_t) k8[10])<<16; /* fall through */ + case 10: c+=k[4]; + b+=k[2]+(((uint32_t) k[3])<<16); + a+=k[0]+(((uint32_t) k[1])<<16); + break; + case 9 : c+=k8[8]; /* fall through */ + case 8 : b+=k[2]+(((uint32_t) k[3])<<16); + a+=k[0]+(((uint32_t) k[1])<<16); + break; + case 7 : b+=((uint32_t) k8[6])<<16; /* fall through */ + case 6 : b+=k[2]; + a+=k[0]+(((uint32_t) k[1])<<16); + break; + case 5 : b+=k8[4]; /* fall through */ + case 4 : a+=k[0]+(((uint32_t) k[1])<<16); + break; + case 3 : a+=((uint32_t) k8[2])<<16; /* fall through */ + case 2 : a+=k[0]; + break; + case 1 : a+=k8[0]; + break; + case 0 : return c; /* zero length requires no mixing */ + } + + } else { /* need to read the key one byte at a time */ + const uint8_t *k = (const uint8_t *)key; + + /*--------------- all but the last block: affect some 32 bits of (a, b, c) */ + while (length > 12) { + a += k[0]; + a += ((uint32_t) k[1])<<8; + a += ((uint32_t) k[2])<<16; + a += ((uint32_t) k[3])<<24; + b += k[4]; + b += ((uint32_t) k[5])<<8; + b += ((uint32_t) k[6])<<16; + b += ((uint32_t) k[7])<<24; + c += k[8]; + c += ((uint32_t) k[9])<<8; + c += ((uint32_t) k[10])<<16; + c += ((uint32_t) k[11])<<24; + mix(a,b,c); + length -= 12; + k += 12; + } + + /*-------------------------------- last block: affect all 32 bits of (c) */ + switch (length) { /* all the case statements fall through */ + case 12: c+=((uint32_t) k[11])<<24; /* fall through */ + case 11: c+=((uint32_t) k[10])<<16; /* fall through */ + case 10: c+=((uint32_t) k[9])<<8; /* fall through */ + case 9 : c+=k[8]; /* fall through */ + case 8 : b+=((uint32_t) k[7])<<24; /* fall through */ + case 7 : b+=((uint32_t) k[6])<<16; /* fall through */ + case 6 : b+=((uint32_t) k[5])<<8; /* fall through */ + case 5 : b+=k[4]; /* fall through */ + case 4 : a+=((uint32_t) k[3])<<24; /* fall through */ + case 3 : a+=((uint32_t) k[2])<<16; /* fall through */ + case 2 : a+=((uint32_t) k[1])<<8; /* fall through */ + case 1 : a+=k[0]; + break; + case 0 : return c; + } + } + + final(a, b, c); + return c; +} + +static inline +uint32_t jhash(const void *key, size_t length, uint32_t seed) +{ + return hashlittle(key, length, seed); +} + +#endif /* _UST_COMMON_JHASH_H */ diff --git a/src/lib/lttng-ust/Makefile.am b/src/lib/lttng-ust/Makefile.am index ef035a18..1d0e85f1 100644 --- a/src/lib/lttng-ust/Makefile.am +++ b/src/lib/lttng-ust/Makefile.am @@ -23,7 +23,6 @@ liblttng_ust_tracepoint_la_SOURCES = \ tracepoint-weak-test.c \ tracepoint-internal.h \ lttng-tracer-core.h \ - jhash.h \ error.h liblttng_ust_tracepoint_la_LIBADD = \ @@ -80,7 +79,6 @@ liblttng_ust_runtime_la_SOURCES = \ tracepoint-internal.h \ events.h \ clock.h \ - jhash.h \ lttng-ust-uuid.h \ error.h \ tracef.c \ diff --git a/src/lib/lttng-ust/jhash.h b/src/lib/lttng-ust/jhash.h deleted file mode 100644 index bd34cc59..00000000 --- a/src/lib/lttng-ust/jhash.h +++ /dev/null @@ -1,224 +0,0 @@ -/* - * SPDX-License-Identifier: LGPL-2.1-only - * - * Copyright (C) 2011 Mathieu Desnoyers - */ - -#include -#include -#include -#include - -/* - * Hash function - * Source: http://burtleburtle.net/bob/c/lookup3.c - * Originally Public Domain - */ - -#define rot(x, k) (((x) << (k)) | ((x) >> (32 - (k)))) - -#define mix(a, b, c) \ -do { \ - a -= c; a ^= rot(c, 4); c += b; \ - b -= a; b ^= rot(a, 6); a += c; \ - c -= b; c ^= rot(b, 8); b += a; \ - a -= c; a ^= rot(c, 16); c += b; \ - b -= a; b ^= rot(a, 19); a += c; \ - c -= b; c ^= rot(b, 4); b += a; \ -} while (0) - -#define final(a, b, c) \ -{ \ - c ^= b; c -= rot(b, 14); \ - a ^= c; a -= rot(c, 11); \ - b ^= a; b -= rot(a, 25); \ - c ^= b; c -= rot(b, 16); \ - a ^= c; a -= rot(c, 4);\ - b ^= a; b -= rot(a, 14); \ - c ^= b; c -= rot(b, 24); \ -} - -#if (BYTE_ORDER == LITTLE_ENDIAN) -#define HASH_LITTLE_ENDIAN 1 -#else -#define HASH_LITTLE_ENDIAN 0 -#endif - -/* - * - * hashlittle() -- hash a variable-length key into a 32-bit value - * k : the key (the unaligned variable-length array of bytes) - * length : the length of the key, counting by bytes - * initval : can be any 4-byte value - * Returns a 32-bit value. Every bit of the key affects every bit of - * the return value. Two keys differing by one or two bits will have - * totally different hash values. - * - * The best hash table sizes are powers of 2. There is no need to do - * mod a prime (mod is sooo slow!). If you need less than 32 bits, - * use a bitmask. For example, if you need only 10 bits, do - * h = (h & hashmask(10)); - * In which case, the hash table should have hashsize(10) elements. - * - * If you are hashing n strings (uint8_t **)k, do it like this: - * for (i = 0, h = 0; i < n; ++i) h = hashlittle(k[i], len[i], h); - * - * By Bob Jenkins, 2006. bob_jenkins@burtleburtle.net. You may use this - * code any way you wish, private, educational, or commercial. It's free. - * - * Use for hash table lookup, or anything where one collision in 2^^32 is - * acceptable. Do NOT use for cryptographic purposes. - */ -static -uint32_t hashlittle(const void *key, size_t length, uint32_t initval) -{ - uint32_t a, b, c; /* internal state */ - union { - const void *ptr; - size_t i; - } u; - - /* Set up the internal state */ - a = b = c = 0xdeadbeef + ((uint32_t)length) + initval; - - u.ptr = key; - if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) { - const uint32_t *k = (const uint32_t *) key; /* read 32-bit chunks */ - - /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */ - while (length > 12) { - a += k[0]; - b += k[1]; - c += k[2]; - mix(a, b, c); - length -= 12; - k += 3; - } - - /*----------------------------- handle the last (probably partial) block */ - /* - * The original jhash.h reads beyond the end of string, and implements - * a special code path for VALGRIND. It seems to make ASan unhappy too - * though, so considering that hashing event names is not a fast-path - * in lttng-ust, remove the "fast" code entirely and use the slower - * but verifiable VALGRIND version of the code which does not issue - * out-of-bound reads. - */ - { - const uint8_t *k8; - - k8 = (const uint8_t *) k; - switch (length) { - case 12: c+=k[2]; b+=k[1]; a+=k[0]; break; - case 11: c+=((uint32_t) k8[10])<<16; /* fall through */ - case 10: c+=((uint32_t) k8[9])<<8; /* fall through */ - case 9 : c+=k8[8]; /* fall through */ - case 8 : b+=k[1]; a+=k[0]; break; - case 7 : b+=((uint32_t) k8[6])<<16; /* fall through */ - case 6 : b+=((uint32_t) k8[5])<<8; /* fall through */ - case 5 : b+=k8[4]; /* fall through */ - case 4 : a+=k[0]; break; - case 3 : a+=((uint32_t) k8[2])<<16; /* fall through */ - case 2 : a+=((uint32_t) k8[1])<<8; /* fall through */ - case 1 : a+=k8[0]; break; - case 0 : return c; - } - } - - } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) { - const uint16_t *k = (const uint16_t *) key; /* read 16-bit chunks */ - const uint8_t *k8; - - /*--------------- all but last block: aligned reads and different mixing */ - while (length > 12) - { - a += k[0] + (((uint32_t) k[1])<<16); - b += k[2] + (((uint32_t) k[3])<<16); - c += k[4] + (((uint32_t) k[5])<<16); - mix(a, b, c); - length -= 12; - k += 6; - } - - /*----------------------------- handle the last (probably partial) block */ - k8 = (const uint8_t *) k; - switch(length) - { - case 12: c+=k[4]+(((uint32_t) k[5])<<16); - b+=k[2]+(((uint32_t) k[3])<<16); - a+=k[0]+(((uint32_t) k[1])<<16); - break; - case 11: c+=((uint32_t) k8[10])<<16; /* fall through */ - case 10: c+=k[4]; - b+=k[2]+(((uint32_t) k[3])<<16); - a+=k[0]+(((uint32_t) k[1])<<16); - break; - case 9 : c+=k8[8]; /* fall through */ - case 8 : b+=k[2]+(((uint32_t) k[3])<<16); - a+=k[0]+(((uint32_t) k[1])<<16); - break; - case 7 : b+=((uint32_t) k8[6])<<16; /* fall through */ - case 6 : b+=k[2]; - a+=k[0]+(((uint32_t) k[1])<<16); - break; - case 5 : b+=k8[4]; /* fall through */ - case 4 : a+=k[0]+(((uint32_t) k[1])<<16); - break; - case 3 : a+=((uint32_t) k8[2])<<16; /* fall through */ - case 2 : a+=k[0]; - break; - case 1 : a+=k8[0]; - break; - case 0 : return c; /* zero length requires no mixing */ - } - - } else { /* need to read the key one byte at a time */ - const uint8_t *k = (const uint8_t *)key; - - /*--------------- all but the last block: affect some 32 bits of (a, b, c) */ - while (length > 12) { - a += k[0]; - a += ((uint32_t) k[1])<<8; - a += ((uint32_t) k[2])<<16; - a += ((uint32_t) k[3])<<24; - b += k[4]; - b += ((uint32_t) k[5])<<8; - b += ((uint32_t) k[6])<<16; - b += ((uint32_t) k[7])<<24; - c += k[8]; - c += ((uint32_t) k[9])<<8; - c += ((uint32_t) k[10])<<16; - c += ((uint32_t) k[11])<<24; - mix(a,b,c); - length -= 12; - k += 12; - } - - /*-------------------------------- last block: affect all 32 bits of (c) */ - switch (length) { /* all the case statements fall through */ - case 12: c+=((uint32_t) k[11])<<24; /* fall through */ - case 11: c+=((uint32_t) k[10])<<16; /* fall through */ - case 10: c+=((uint32_t) k[9])<<8; /* fall through */ - case 9 : c+=k[8]; /* fall through */ - case 8 : b+=((uint32_t) k[7])<<24; /* fall through */ - case 7 : b+=((uint32_t) k[6])<<16; /* fall through */ - case 6 : b+=((uint32_t) k[5])<<8; /* fall through */ - case 5 : b+=k[4]; /* fall through */ - case 4 : a+=((uint32_t) k[3])<<24; /* fall through */ - case 3 : a+=((uint32_t) k[2])<<16; /* fall through */ - case 2 : a+=((uint32_t) k[1])<<8; /* fall through */ - case 1 : a+=k[0]; - break; - case 0 : return c; - } - } - - final(a, b, c); - return c; -} - -static inline -uint32_t jhash(const void *key, size_t length, uint32_t seed) -{ - return hashlittle(key, length, seed); -} diff --git a/src/lib/lttng-ust/lttng-context-provider.c b/src/lib/lttng-ust/lttng-context-provider.c index caeb387b..cc437067 100644 --- a/src/lib/lttng-ust/lttng-context-provider.c +++ b/src/lib/lttng-ust/lttng-context-provider.c @@ -16,7 +16,7 @@ #include "context-internal.h" #include "lttng-tracer-core.h" -#include "jhash.h" +#include "common/jhash.h" #include "context-provider-internal.h" #include "common/macros.h" diff --git a/src/lib/lttng-ust/lttng-events.c b/src/lib/lttng-ust/lttng-events.c index 13becb91..9ebd61dd 100644 --- a/src/lib/lttng-ust/lttng-events.c +++ b/src/lib/lttng-ust/lttng-events.c @@ -55,7 +55,7 @@ #include "common/ringbuffer/frontend_types.h" #include "common/ringbuffer/frontend.h" #include "common/counter/counter.h" -#include "jhash.h" +#include "common/jhash.h" #include #include "context-provider-internal.h" diff --git a/src/lib/lttng-ust/lttng-probes.c b/src/lib/lttng-ust/lttng-probes.c index 2dff30f4..b2e77e01 100644 --- a/src/lib/lttng-ust/lttng-probes.c +++ b/src/lib/lttng-ust/lttng-probes.c @@ -19,7 +19,7 @@ #include #include "lttng-tracer-core.h" -#include "jhash.h" +#include "common/jhash.h" #include "error.h" #include "lib/lttng-ust/events.h" diff --git a/src/lib/lttng-ust/lttng-ust-statedump.c b/src/lib/lttng-ust/lttng-ust-statedump.c index 1873fa4c..fa72e34b 100644 --- a/src/lib/lttng-ust/lttng-ust-statedump.c +++ b/src/lib/lttng-ust/lttng-ust-statedump.c @@ -20,7 +20,7 @@ #include "common/macros.h" #include "lttng-tracer-core.h" #include "lttng-ust-statedump.h" -#include "jhash.h" +#include "common/jhash.h" #include "common/getenv.h" #include "lib/lttng-ust/events.h" diff --git a/src/lib/lttng-ust/tracepoint.c b/src/lib/lttng-ust/tracepoint.c index 7042339b..e7f520ab 100644 --- a/src/lib/lttng-ust/tracepoint.c +++ b/src/lib/lttng-ust/tracepoint.c @@ -28,7 +28,7 @@ #include "tracepoint-internal.h" #include "lttng-tracer-core.h" -#include "jhash.h" +#include "common/jhash.h" #include "error.h" /* Test compiler support for weak symbols with hidden visibility. */ diff --git a/src/lib/lttng-ust/ust-core.c b/src/lib/lttng-ust/ust-core.c index 88330a1e..95a0a2a2 100644 --- a/src/lib/lttng-ust/ust-core.c +++ b/src/lib/lttng-ust/ust-core.c @@ -15,7 +15,7 @@ #include "lttng-tracer-core.h" #include "lttng-rb-clients.h" #include "lttng-counter-client.h" -#include "jhash.h" +#include "common/jhash.h" static CDS_LIST_HEAD(lttng_transport_list); static CDS_LIST_HEAD(lttng_counter_transport_list);