Add 'instant_rehashing' type flag (non-incremental)

Signed-off-by: Viktor Söderqvist <viktor.soderqvist@est.tech>

src/hashtab.c

@@ -509,6 +509,9 @@ static inline void rehashStepOnWriteIfNeeded(hashtab *t) {
 static int resize(hashtab *t, size_t min_capacity, int *malloc_failed) {
     if (malloc_failed) *malloc_failed = 0;
 
+    /* Adjust mininum size. We don't resize to zero currently. */
+    if (min_capacity == 0) min_capacity = 1;
+
     /* Size of new table. */
     signed char exp = nextBucketExp(min_capacity);
     size_t num_buckets = numBuckets(exp);
@@ -549,6 +552,10 @@ static int resize(hashtab *t, size_t min_capacity, int *malloc_failed) {
     /* If the old table was empty, the rehashing is completed immediately. */
     if (t->tables[0] == NULL || t->used[0] == 0) {
         rehashingCompleted(t);
+    } else if (t->type->instant_rehashing) {
+        while (hashtabIsRehashing(t)) {
+            rehashStep(t);
+        }
     }
     return 1;
 }

src/hashtab.h

@@ -91,6 +91,8 @@ typedef struct {
     /* Allow a hashtab to carry extra caller-defined metadata. The extra memory
      * is initialized to 0. */
     size_t (*getMetadataSize)(void);
+    /* Flag to disable incremental rehashing */
+    unsigned instant_rehashing : 1;
     /* Allow the caller to store some data here in the type. It's useful for the
      * rehashingStarted and rehashingCompleted callbacks. */
     void *userdata;
@@ -128,15 +130,6 @@ typedef struct hashtabStats {
     unsigned long *clvector;
 } hashtabStats;
 
-/* TODO:
- *
- * - Type flag to disable incremental rehashing.
- *
- * Not needed: defrag functions (solved by emit_ref in scan) */
-
-
-/* --- Inline functions --- */
-
 /* --- Prototypes --- */
 
 /* Hash function (global seed) */

src/unit/test_files.h

@@ -24,6 +24,7 @@ int test_cursor(int argc, char **argv, int flags);
 int test_set_hash_function_seed(int argc, char **argv, int flags);
 int test_add_find_delete(int argc, char **argv, int flags);
 int test_add_find_delete_avoid_resize(int argc, char **argv, int flags);
+int test_instant_rehashing(int argc, char **argv, int flags);
 int test_probing_chain_length(int argc, char **argv, int flags);
 int test_two_phase_insert_and_pop(int argc, char **argv, int flags);
 int test_scan(int argc, char **argv, int flags);
@@ -152,7 +153,7 @@ unitTest __test_crc64_c[] = {{"test_crc64", test_crc64}, {NULL, NULL}};
 unitTest __test_crc64combine_c[] = {{"test_crc64combine", test_crc64combine}, {NULL, NULL}};
 unitTest __test_dict_c[] = {{"test_dictCreate", test_dictCreate}, {"test_dictAdd16Keys", test_dictAdd16Keys}, {"test_dictDisableResize", test_dictDisableResize}, {"test_dictAddOneKeyTriggerResize", test_dictAddOneKeyTriggerResize}, {"test_dictDeleteKeys", test_dictDeleteKeys}, {"test_dictDeleteOneKeyTriggerResize", test_dictDeleteOneKeyTriggerResize}, {"test_dictEmptyDirAdd128Keys", test_dictEmptyDirAdd128Keys}, {"test_dictDisableResizeReduceTo3", test_dictDisableResizeReduceTo3}, {"test_dictDeleteOneKeyTriggerResizeAgain", test_dictDeleteOneKeyTriggerResizeAgain}, {"test_dictBenchmark", test_dictBenchmark}, {NULL, NULL}};
 unitTest __test_endianconv_c[] = {{"test_endianconv", test_endianconv}, {NULL, NULL}};
-unitTest __test_hashtab_c[] = {{"test_cursor", test_cursor}, {"test_set_hash_function_seed", test_set_hash_function_seed}, {"test_add_find_delete", test_add_find_delete}, {"test_add_find_delete_avoid_resize", test_add_find_delete_avoid_resize}, {"test_probing_chain_length", test_probing_chain_length}, {"test_two_phase_insert_and_pop", test_two_phase_insert_and_pop}, {"test_scan", test_scan}, {"test_iterator", test_iterator}, {"test_safe_iterator", test_safe_iterator}, {"test_random_element", test_random_element}, {NULL, NULL}};
+unitTest __test_hashtab_c[] = {{"test_cursor", test_cursor}, {"test_set_hash_function_seed", test_set_hash_function_seed}, {"test_add_find_delete", test_add_find_delete}, {"test_add_find_delete_avoid_resize", test_add_find_delete_avoid_resize}, {"test_instant_rehashing", test_instant_rehashing}, {"test_probing_chain_length", test_probing_chain_length}, {"test_two_phase_insert_and_pop", test_two_phase_insert_and_pop}, {"test_scan", test_scan}, {"test_iterator", test_iterator}, {"test_safe_iterator", test_safe_iterator}, {"test_random_element", test_random_element}, {NULL, NULL}};
 unitTest __test_intset_c[] = {{"test_intsetValueEncodings", test_intsetValueEncodings}, {"test_intsetBasicAdding", test_intsetBasicAdding}, {"test_intsetLargeNumberRandomAdd", test_intsetLargeNumberRandomAdd}, {"test_intsetUpgradeFromint16Toint32", test_intsetUpgradeFromint16Toint32}, {"test_intsetUpgradeFromint16Toint64", test_intsetUpgradeFromint16Toint64}, {"test_intsetUpgradeFromint32Toint64", test_intsetUpgradeFromint32Toint64}, {"test_intsetStressLookups", test_intsetStressLookups}, {"test_intsetStressAddDelete", test_intsetStressAddDelete}, {NULL, NULL}};
 unitTest __test_kvstore_c[] = {{"test_kvstoreAdd16Keys", test_kvstoreAdd16Keys}, {"test_kvstoreIteratorRemoveAllKeysNoDeleteEmptyDict", test_kvstoreIteratorRemoveAllKeysNoDeleteEmptyDict}, {"test_kvstoreIteratorRemoveAllKeysDeleteEmptyDict", test_kvstoreIteratorRemoveAllKeysDeleteEmptyDict}, {"test_kvstoreDictIteratorRemoveAllKeysNoDeleteEmptyDict", test_kvstoreDictIteratorRemoveAllKeysNoDeleteEmptyDict}, {"test_kvstoreDictIteratorRemoveAllKeysDeleteEmptyDict", test_kvstoreDictIteratorRemoveAllKeysDeleteEmptyDict}, {NULL, NULL}};
 unitTest __test_listpack_c[] = {{"test_listpackCreateIntList", test_listpackCreateIntList}, {"test_listpackCreateList", test_listpackCreateList}, {"test_listpackLpPrepend", test_listpackLpPrepend}, {"test_listpackLpPrependInteger", test_listpackLpPrependInteger}, {"test_listpackGetELementAtIndex", test_listpackGetELementAtIndex}, {"test_listpackPop", test_listpackPop}, {"test_listpackGetELementAtIndex2", test_listpackGetELementAtIndex2}, {"test_listpackIterate0toEnd", test_listpackIterate0toEnd}, {"test_listpackIterate1toEnd", test_listpackIterate1toEnd}, {"test_listpackIterate2toEnd", test_listpackIterate2toEnd}, {"test_listpackIterateBackToFront", test_listpackIterateBackToFront}, {"test_listpackIterateBackToFrontWithDelete", test_listpackIterateBackToFrontWithDelete}, {"test_listpackDeleteWhenNumIsMinusOne", test_listpackDeleteWhenNumIsMinusOne}, {"test_listpackDeleteWithNegativeIndex", test_listpackDeleteWithNegativeIndex}, {"test_listpackDeleteInclusiveRange0_0", test_listpackDeleteInclusiveRange0_0}, {"test_listpackDeleteInclusiveRange0_1", test_listpackDeleteInclusiveRange0_1}, {"test_listpackDeleteInclusiveRange1_2", test_listpackDeleteInclusiveRange1_2}, {"test_listpackDeleteWitStartIndexOutOfRange", test_listpackDeleteWitStartIndexOutOfRange}, {"test_listpackDeleteWitNumOverflow", test_listpackDeleteWitNumOverflow}, {"test_listpackBatchDelete", test_listpackBatchDelete}, {"test_listpackDeleteFooWhileIterating", test_listpackDeleteFooWhileIterating}, {"test_listpackReplaceWithSameSize", test_listpackReplaceWithSameSize}, {"test_listpackReplaceWithDifferentSize", test_listpackReplaceWithDifferentSize}, {"test_listpackRegressionGt255Bytes", test_listpackRegressionGt255Bytes}, {"test_listpackCreateLongListAndCheckIndices", test_listpackCreateLongListAndCheckIndices}, {"test_listpackCompareStrsWithLpEntries", test_listpackCompareStrsWithLpEntries}, {"test_listpackLpMergeEmptyLps", test_listpackLpMergeEmptyLps}, {"test_listpackLpMergeLp1Larger", test_listpackLpMergeLp1Larger}, {"test_listpackLpMergeLp2Larger", test_listpackLpMergeLp2Larger}, {"test_listpackLpNextRandom", test_listpackLpNextRandom}, {"test_listpackLpNextRandomCC", test_listpackLpNextRandomCC}, {"test_listpackRandomPairWithOneElement", test_listpackRandomPairWithOneElement}, {"test_listpackRandomPairWithManyElements", test_listpackRandomPairWithManyElements}, {"test_listpackRandomPairsWithOneElement", test_listpackRandomPairsWithOneElement}, {"test_listpackRandomPairsWithManyElements", test_listpackRandomPairsWithManyElements}, {"test_listpackRandomPairsUniqueWithOneElement", test_listpackRandomPairsUniqueWithOneElement}, {"test_listpackRandomPairsUniqueWithManyElements", test_listpackRandomPairsUniqueWithManyElements}, {"test_listpackPushVariousEncodings", test_listpackPushVariousEncodings}, {"test_listpackLpFind", test_listpackLpFind}, {"test_listpackLpValidateIntegrity", test_listpackLpValidateIntegrity}, {"test_listpackNumberOfElementsExceedsLP_HDR_NUMELE_UNKNOWN", test_listpackNumberOfElementsExceedsLP_HDR_NUMELE_UNKNOWN}, {"test_listpackStressWithRandom", test_listpackStressWithRandom}, {"test_listpackSTressWithVariableSize", test_listpackSTressWithVariableSize}, {"test_listpackBenchmarkInit", test_listpackBenchmarkInit}, {"test_listpackBenchmarkLpAppend", test_listpackBenchmarkLpAppend}, {"test_listpackBenchmarkLpFindString", test_listpackBenchmarkLpFindString}, {"test_listpackBenchmarkLpFindNumber", test_listpackBenchmarkLpFindNumber}, {"test_listpackBenchmarkLpSeek", test_listpackBenchmarkLpSeek}, {"test_listpackBenchmarkLpValidateIntegrity", test_listpackBenchmarkLpValidateIntegrity}, {"test_listpackBenchmarkLpCompareWithString", test_listpackBenchmarkLpCompareWithString}, {"test_listpackBenchmarkLpCompareWithNumber", test_listpackBenchmarkLpCompareWithNumber}, {"test_listpackBenchmarkFree", test_listpackBenchmarkFree}, {NULL, NULL}};

src/unit/test_hashtab.c

@@ -168,6 +168,35 @@ int test_add_find_delete_avoid_resize(int argc, char **argv, int flags) {
     return 0;
 }
 
+int test_instant_rehashing(int argc, char **argv, int flags) {
+    UNUSED(argc);
+    UNUSED(argv);
+    UNUSED(flags);
+
+    long count = 200;
+
+    /* A set of longs, i.e. pointer-sized values. */
+    hashtabType type = {.instant_rehashing = 1};
+    hashtab *t = hashtabCreate(&type);
+    long j;
+
+    /* Populate and check that rehashing is never ongoing. */
+    for (j = 0; j < count; j++) {
+        assert(hashtabAdd(t, (void *)j));
+        assert(!hashtabIsRehashing(t));
+    }
+
+    /* Delete and check that rehashing is never ongoing. */
+    for (j = 0; j < count; j++) {
+        assert(hashtabDelete(t, (void *)j));
+        assert(!hashtabIsRehashing(t));
+    }
+
+    hashtabRelease(t);
+    return 0;
+}
+
+
 int test_probing_chain_length(int argc, char **argv, int flags) {
     UNUSED(argc);
     UNUSED(argv);