/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/mem/alg.h"
#include "libc/intrin/bits.h"
#include "libc/intrin/likely.h"
#include "libc/mem/mem.h"
#include "libc/stdio/rand.h"
#include "libc/str/internal.h"
#include "libc/str/str.h"
#include "libc/testlib/ezbench.h"
#include "libc/testlib/hyperion.h"
#include "libc/testlib/testlib.h"
#define MakeMemory(SL) memcpy(malloc(sizeof(SL) - 1), SL, sizeof(SL) - 1)
void *memmem_naive(const void *haystk, size_t haystklen, //
const void *needle, size_t needlelen) {
size_t i, j;
if (!needlelen) return haystk;
if (needlelen > haystklen) return 0;
for (i = 0; i < haystklen; ++i) {
for (j = 0;; ++j) {
if (j == needlelen) return (/*unconst*/ char *)haystk + i;
if (i + j == haystklen) break;
if (((char *)haystk)[i + j] != ((char *)needle)[j]) break;
}
}
return 0;
}
TEST(memmem, special) {
EXPECT_EQ(0, memmem(0, 0, 0, 0));
EXPECT_EQ(0, memmem(0, 0, "", 1));
EXPECT_EQ("", memmem("", 1, 0, 0));
}
TEST(memmem, test) {
char *needle = MakeMemory("abcdefgh");
char *haystk = MakeMemory("acccccccbbbbbbbbabcdefghdddddddd");
EXPECT_BINEQ(u"abcdefghdddddddd", memmem(haystk, 32, needle, 8));
memcpy(needle, "aaaaaaaa", 8);
memcpy(haystk, "acccccccbbbbbbbbaaaaaaaadddddddd", 32);
EXPECT_BINEQ(u"aaaaaaaadddddddd", memmem(haystk, 32, needle, 8));
free(haystk);
free(needle);
}
TEST(memmem, testNoMatch) {
char *needle = MakeMemory("abcdefzh");
char *haystk = MakeMemory("acccccccbbbbbbbbabcdefghdddddddd");
EXPECT_EQ(NULL, memmem(haystk, 32, needle, 8));
free(haystk);
free(needle);
}
TEST(memmem, testStartOfMemory) {
char *needle = MakeMemory("acccc");
char *haystk = MakeMemory("acccccccbbbbbbbbabcdefghdddddddd");
EXPECT_EQ(&haystk[0], memmem(haystk, 32, needle, 5));
free(haystk);
free(needle);
}
TEST(memmem, testEndOfMemory) {
char *haystk = MakeMemory("abc123");
char *needle = MakeMemory("123");
EXPECT_EQ(&haystk[3], memmem(haystk, 6, needle, 3));
free(haystk);
free(needle);
}
TEST(memmem, testOneNo) {
char *needle = MakeMemory("z");
char *haystk = MakeMemory("abc123");
EXPECT_EQ(0, memmem(haystk, 6, needle, 1));
free(haystk);
free(needle);
}
TEST(memmem, testOneYes) {
char *needle = MakeMemory("3");
char *haystk = MakeMemory("abc123");
EXPECT_EQ(&haystk[5], memmem(haystk, 6, needle, 1));
free(haystk);
free(needle);
}
TEST(memmem, testCrossesSseRegister) {
char *haystk = MakeMemory("eeeeeeeeeeeeeeeeffffffffffffffffrrrrrrrrrrrrrrrr");
char *needle = MakeMemory("eeeeeeeeeeeeefffffffffffff");
EXPECT_EQ(&haystk[3], memmem(haystk, 16 * 3, needle, 26));
free(haystk);
free(needle);
}
TEST(memmem, testHasNulCharacters) {
char *needle = MakeMemory("eeeeeeeeeeeee\0ffffffffffff");
char *haystk =
MakeMemory("eeeeeeeeeeeeeeee\0fffffffffffffffrrrrrrrrrrrrrrrr");
EXPECT_EQ(&haystk[3], memmem(haystk, 16 * 3, needle, 26));
free(haystk);
free(needle);
}
TEST(memmem, testWeird) {
char *needle = MakeMemory("-*-+-+-+-+-+-+-+");
char *haystk = MakeMemory("-+-+-+-+-+-+-+-*-+-+-+-+-+-+-+-+");
EXPECT_EQ(14, (intptr_t)memmem(haystk, 32, needle, 16) - (intptr_t)haystk);
free(haystk);
free(needle);
}
TEST(memmem, testEmptyNeedle_matchesStartOfHaystack) {
char *needle = malloc(0);
char *haystk = MakeMemory("-+-+-+-+-+-+-+-*-+-+-+-+-+-+-+-+");
EXPECT_EQ(0, (intptr_t)memmem(haystk, 32, needle, 0) - (intptr_t)haystk);
free(haystk);
free(needle);
}
TEST(memmem, testEmptyHaystack_alwaysReturnsNull) {
char *needle = MakeMemory("-*-+-+-+-+-+-+-+");
char *haystk = malloc(0);
EXPECT_EQ(NULL, memmem(haystk, 0, needle, 16));
EXPECT_EQ(NULL, memmem(haystk, 0, needle, 1));
free(haystk);
free(needle);
}
TEST(memmem, testEmptyHaystackAndNeedle_returnsHaystack) {
char *needle = malloc(0);
char *haystk = malloc(0);
EXPECT_EQ(haystk, memmem(haystk, 0, needle, 0));
free(haystk);
free(needle);
}
TEST(memmem, testWut) {
ASSERT_STREQ("x", memmem("x", 1, "x", 1));
}
TEST(memmem, fuzz) {
int i, j, k, n, m;
char a[128], b[128], *p, *q;
for (i = 0; i < 10000; ++i) {
rngset(a, sizeof(a), lemur64, -1);
rngset(b, sizeof(b), lemur64, -1);
p = a + lemur64() % sizeof(a) / 2;
q = b + lemur64() % sizeof(b) / 2;
n = lemur64() % sizeof(a) / 2;
m = lemur64() % sizeof(b) / 2;
ASSERT_EQ(memmem_naive(p, n, q, m), memmem(p, n, q, m));
}
}
/*
* memmem naive l: 43,783c 14,142ns m: 31,285c 10,105ns
* memmem l: 2,597c 839ns m: 2,612c 844ns
* memmem l: 509c 164ns m: 599c 193ns
*
* strstr naive l: 103,057c 33,287ns m: 47,035c 15,192ns
* strstr l: 3,186c 1,029ns m: 3,218c 1,039ns
* strstr torture 1 l: 27c 9ns m: 61c 20ns
* strstr torture 2 l: 2,322c 750ns m: 2,362c 763ns
* strstr torture 4 l: 2,407c 777ns m: 2,448c 791ns
* strstr torture 8 l: 2,803c 905ns m: 2,862c 924ns
* strstr torture 16 l: 4,559c 1,473ns m: 3,614c 1,167ns
* strstr torture 32 l: 5,324c 1,720ns m: 5,577c 1,801ns
*
* strcasestr naive l: 129,908c 41,959ns m: 155,420c 50,200ns
* strcasestr l: 33,464c 10,809ns m: 31,636c 10,218ns
* strcasestr tort 1 l: 38c 12ns m: 69c 22ns
* strcasestr tort 2 l: 2,544c 822ns m: 2,580c 833ns
* strcasestr tort 4 l: 2,745c 887ns m: 2,767c 894ns
* strcasestr tort 8 l: 4,198c 1,356ns m: 4,216c 1,362ns
* strcasestr tort 16 l: 7,402c 2,391ns m: 7,487c 2,418ns
* strcasestr tort 32 l: 13,772c 4,448ns m: 12,945c 4,181ns
*/
BENCH(memmem, bench) {
EZBENCH2("memmem naive", donothing,
EXPROPRIATE(memmem_naive(kHyperion, kHyperionSize, "THE END", 7)));
EZBENCH2("memmem", donothing,
EXPROPRIATE(memmem(kHyperion, kHyperionSize, "THE END", 7)));
EZBENCH2("memmem", donothing,
EXPROPRIATE(memmem(
"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab",
62, "aaaaaab", 7)));
}