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Slightly lower average traversal using a hash for comparison

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This commit is contained in:
Eric Fischer 2017-09-06 17:08:53 -07:00
parent 764a8ac17c
commit 93920d06e1
1 changed files with 18 additions and 22 deletions
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40
pool.cpp
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@ -7,31 +7,27 @@
#include "pool.hpp" #include "pool.hpp"
int swizzlecmp(const char *a, const char *b) { int swizzlecmp(const char *a, const char *b) {
ssize_t a1 = strlen(a) - 1; ssize_t alen = strlen(a);
ssize_t b1 = strlen(b) - 1; ssize_t blen = strlen(b);
while (a1 >= 0 || b1 >= 0) { if (strcmp(a, b) == 0) {
unsigned char ac = '\0', bc = '\0'; return 0;
if (a1 >= 0) {
ac = a[a1];
}
if (b1 >= 0) {
bc = b[b1];
}
int aa = ac;
int bb = bc;
int cmp = aa - bb;
if (cmp != 0) {
return cmp;
}
a1--;
b1--;
} }
return 0; unsigned int hash1 = 0, hash2 = 0;
for (ssize_t i = alen - 1; i >= 0; i--) {
hash1 = hash1 * 37 + a[i];
}
for (ssize_t i = blen - 1; i >= 0; i--) {
hash2 = hash2 * 37 + b[i];
}
int h1 = hash1, h2 = hash2;
if (h1 == h2) {
return strcmp(a, b);
}
return h1 - h2;
} }
long long addpool(struct memfile *poolfile, struct memfile *treefile, const char *s, char type) { long long addpool(struct memfile *poolfile, struct memfile *treefile, const char *s, char type) {