On Fri, 2012-01-27 at 00:36 +1100, Bojan Smojver wrote:
> Thanks, will implement.
Attached. If nobody comes up with regressions or other problems with
this approach, I'll commit it to trunk.
Thanks everyone for their input.
--
Bojan
Index: tables/apr_hash.c
===================================================================
--- tables/apr_hash.c (revision 1235978)
+++ tables/apr_hash.c (working copy)
@@ -18,6 +18,7 @@
#include "apr_general.h"
#include "apr_pools.h"
+#include "apr_time.h"
#include "apr_hash.h"
@@ -75,7 +76,7 @@
apr_pool_t *pool;
apr_hash_entry_t **array;
apr_hash_index_t iterator; /* For apr_hash_first(NULL, ...) */
- unsigned int count, max;
+ unsigned int count, max, seed;
apr_hashfunc_t hash_func;
apr_hash_entry_t *free; /* List of recycled entries */
};
@@ -95,13 +96,18 @@
APR_DECLARE(apr_hash_t *) apr_hash_make(apr_pool_t *pool)
{
apr_hash_t *ht;
+ apr_time_t now = apr_time_now();
+
ht = apr_palloc(pool, sizeof(apr_hash_t));
ht->pool = pool;
ht->free = NULL;
ht->count = 0;
ht->max = INITIAL_MAX;
+ ht->seed = (unsigned int)((now >> 32) ^ now ^ (apr_uintptr_t)pool ^
+ (apr_uintptr_t)ht ^ (apr_uintptr_t)&now) - 1;
ht->array = alloc_array(ht, ht->max);
ht->hash_func = apr_hashfunc_default;
+
return ht;
}
@@ -280,7 +286,7 @@
apr_hash_entry_t **hep, *he;
unsigned int hash;
- hash = ht->hash_func(key, &klen);
+ hash = ht->seed ^ ht->hash_func(key, &klen);
/* scan linked list */
for (hep = &ht->array[hash & ht->max], he = *hep;
@@ -322,6 +328,7 @@
ht->free = NULL;
ht->count = orig->count;
ht->max = orig->max;
+ ht->seed = orig->seed;
ht->hash_func = orig->hash_func;
ht->array = (apr_hash_entry_t **)((char *)ht + sizeof(apr_hash_t));
@@ -419,7 +426,7 @@
apr_hash_entry_t *new_vals = NULL;
apr_hash_entry_t *iter;
apr_hash_entry_t *ent;
- unsigned int i,j,k;
+ unsigned int i, j, k, hash;
#if APR_POOL_DEBUG
/* we don't copy keys and values, so it's necessary that
@@ -447,6 +454,7 @@
if (base->count + overlay->count > res->max) {
res->max = res->max * 2 + 1;
}
+ res->seed = base->seed;
res->array = alloc_array(res, res->max);
if (base->count + overlay->count) {
new_vals = apr_palloc(p, sizeof(apr_hash_entry_t) *
@@ -468,7 +476,8 @@
for (k = 0; k <= overlay->max; k++) {
for (iter = overlay->array[k]; iter; iter = iter->next) {
- i = iter->hash & res->max;
+ hash = res->seed ^ res->hash_func(iter->key, &iter->klen);
+ i = hash & res->max;
for (ent = res->array[i]; ent; ent = ent->next) {
if ((ent->klen == iter->klen) &&
(memcmp(ent->key, iter->key, iter->klen) == 0)) {
@@ -486,7 +495,7 @@
new_vals[j].klen = iter->klen;
new_vals[j].key = iter->key;
new_vals[j].val = iter->val;
- new_vals[j].hash = iter->hash;
+ new_vals[j].hash = hash;
new_vals[j].next = res->array[i];
res->array[i] = &new_vals[j];
res->count++;
Index: test/testhash.c
===================================================================
--- test/testhash.c (revision 1235978)
+++ test/testhash.c (working copy)
@@ -438,6 +438,79 @@
ABTS_STR_EQUAL(tc, "#entries 5\n", StrArray[5]);
}
+static void overlay_fetch(abts_case *tc, void *data)
+{
+ apr_hash_t *base = NULL;
+ apr_hash_t *overlay = NULL;
+ apr_hash_t *result = NULL;
+ int count;
+
+ base = apr_hash_make(p);
+ overlay = apr_hash_make(p);
+ ABTS_PTR_NOTNULL(tc, base);
+ ABTS_PTR_NOTNULL(tc, overlay);
+
+ apr_hash_set(base, "base1", APR_HASH_KEY_STRING, "value1");
+ apr_hash_set(base, "base2", APR_HASH_KEY_STRING, "value2");
+ apr_hash_set(base, "base3", APR_HASH_KEY_STRING, "value3");
+ apr_hash_set(base, "base4", APR_HASH_KEY_STRING, "value4");
+ apr_hash_set(base, "base5", APR_HASH_KEY_STRING, "value5");
+
+ apr_hash_set(overlay, "overlay1", APR_HASH_KEY_STRING, "value1");
+ apr_hash_set(overlay, "overlay2", APR_HASH_KEY_STRING, "value2");
+ apr_hash_set(overlay, "overlay3", APR_HASH_KEY_STRING, "value3");
+ apr_hash_set(overlay, "overlay4", APR_HASH_KEY_STRING, "value4");
+ apr_hash_set(overlay, "overlay5", APR_HASH_KEY_STRING, "value5");
+
+ result = apr_hash_overlay(p, overlay, base);
+
+ count = apr_hash_count(result);
+ ABTS_INT_EQUAL(tc, 10, count);
+
+ ABTS_STR_EQUAL(tc, "value1",
+ apr_hash_get(result, "base1", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value2",
+ apr_hash_get(result, "base2", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value3",
+ apr_hash_get(result, "base3", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value4",
+ apr_hash_get(result, "base4", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value5",
+ apr_hash_get(result, "base5", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value1",
+ apr_hash_get(result, "overlay1", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value2",
+ apr_hash_get(result, "overlay2", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value3",
+ apr_hash_get(result, "overlay3", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value4",
+ apr_hash_get(result, "overlay4", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value5",
+ apr_hash_get(result, "overlay5", APR_HASH_KEY_STRING));
+
+ ABTS_STR_EQUAL(tc, "value1",
+ apr_hash_get(base, "base1", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value2",
+ apr_hash_get(base, "base2", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value3",
+ apr_hash_get(base, "base3", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value4",
+ apr_hash_get(base, "base4", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value5",
+ apr_hash_get(base, "base5", APR_HASH_KEY_STRING));
+
+ ABTS_STR_EQUAL(tc, "value1",
+ apr_hash_get(overlay, "overlay1", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value2",
+ apr_hash_get(overlay, "overlay2", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value3",
+ apr_hash_get(overlay, "overlay3", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value4",
+ apr_hash_get(overlay, "overlay4", APR_HASH_KEY_STRING));
+ ABTS_STR_EQUAL(tc, "value5",
+ apr_hash_get(overlay, "overlay5", APR_HASH_KEY_STRING));
+}
+
abts_suite *testhash(abts_suite *suite)
{
suite = ADD_SUITE(suite)
@@ -461,6 +534,7 @@
abts_run_test(suite, overlay_empty, NULL);
abts_run_test(suite, overlay_2unique, NULL);
abts_run_test(suite, overlay_same, NULL);
+ abts_run_test(suite, overlay_fetch, NULL);
return suite;
}
