1 files changed, 342 insertions, 0 deletions
diff --git a/lib/isc/ht.c b/lib/isc/ht.c
new file mode 100644
index 0000000..07a36b4
--- /dev/null
+++ b/lib/isc/ht.c
@@ -0,0 +1,342 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#include <inttypes.h>
+#include <string.h>
+
+#include <isc/hash.h>
+#include <isc/ht.h>
+#include <isc/magic.h>
+#include <isc/mem.h>
+#include <isc/result.h>
+#include <isc/types.h>
+#include <isc/util.h>
+
+typedef struct isc_ht_node isc_ht_node_t;
+
+#define ISC_HT_MAGIC	 ISC_MAGIC('H', 'T', 'a', 'b')
+#define ISC_HT_VALID(ht) ISC_MAGIC_VALID(ht, ISC_HT_MAGIC)
+
+struct isc_ht_node {
+	void *value;
+	isc_ht_node_t *next;
+	size_t keysize;
+	unsigned char key[FLEXIBLE_ARRAY_MEMBER];
+};
+
+struct isc_ht {
+	unsigned int magic;
+	isc_mem_t *mctx;
+	size_t size;
+	size_t mask;
+	unsigned int count;
+	isc_ht_node_t **table;
+};
+
+struct isc_ht_iter {
+	isc_ht_t *ht;
+	size_t i;
+	isc_ht_node_t *cur;
+};
+
+void
+isc_ht_init(isc_ht_t **htp, isc_mem_t *mctx, uint8_t bits) {
+	isc_ht_t *ht = NULL;
+	size_t i;
+
+	REQUIRE(htp != NULL && *htp == NULL);
+	REQUIRE(mctx != NULL);
+	REQUIRE(bits >= 1 && bits <= (sizeof(size_t) * 8 - 1));
+
+	ht = isc_mem_get(mctx, sizeof(struct isc_ht));
+
+	ht->mctx = NULL;
+	isc_mem_attach(mctx, &ht->mctx);
+
+	ht->size = ((size_t)1 << bits);
+	ht->mask = ((size_t)1 << bits) - 1;
+	ht->count = 0;
+
+	ht->table = isc_mem_get(ht->mctx, ht->size * sizeof(isc_ht_node_t *));
+
+	for (i = 0; i < ht->size; i++) {
+		ht->table[i] = NULL;
+	}
+
+	ht->magic = ISC_HT_MAGIC;
+
+	*htp = ht;
+}
+
+void
+isc_ht_destroy(isc_ht_t **htp) {
+	isc_ht_t *ht;
+	size_t i;
+
+	REQUIRE(htp != NULL);
+
+	ht = *htp;
+	*htp = NULL;
+
+	REQUIRE(ISC_HT_VALID(ht));
+
+	ht->magic = 0;
+
+	for (i = 0; i < ht->size; i++) {
+		isc_ht_node_t *node = ht->table[i];
+		while (node != NULL) {
+			isc_ht_node_t *next = node->next;
+			ht->count--;
+			isc_mem_put(ht->mctx, node,
+				    offsetof(isc_ht_node_t, key) +
+					    node->keysize);
+			node = next;
+		}
+	}
+
+	INSIST(ht->count == 0);
+
+	isc_mem_put(ht->mctx, ht->table, ht->size * sizeof(isc_ht_node_t *));
+	isc_mem_putanddetach(&ht->mctx, ht, sizeof(struct isc_ht));
+}
+
+isc_result_t
+isc_ht_add(isc_ht_t *ht, const unsigned char *key, uint32_t keysize,
+	   void *value) {
+	isc_ht_node_t *node;
+	uint32_t hash;
+
+	REQUIRE(ISC_HT_VALID(ht));
+	REQUIRE(key != NULL && keysize > 0);
+
+	hash = isc_hash_function(key, keysize, true);
+	node = ht->table[hash & ht->mask];
+	while (node != NULL) {
+		if (keysize == node->keysize &&
+		    memcmp(key, node->key, keysize) == 0)
+		{
+			return (ISC_R_EXISTS);
+		}
+		node = node->next;
+	}
+
+	node = isc_mem_get(ht->mctx, offsetof(isc_ht_node_t, key) + keysize);
+
+	memmove(node->key, key, keysize);
+	node->keysize = keysize;
+	node->next = ht->table[hash & ht->mask];
+	node->value = value;
+
+	ht->count++;
+	ht->table[hash & ht->mask] = node;
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_ht_find(const isc_ht_t *ht, const unsigned char *key, uint32_t keysize,
+	    void **valuep) {
+	isc_ht_node_t *node;
+	uint32_t hash;
+
+	REQUIRE(ISC_HT_VALID(ht));
+	REQUIRE(key != NULL && keysize > 0);
+	REQUIRE(valuep == NULL || *valuep == NULL);
+
+	hash = isc_hash_function(key, keysize, true);
+	node = ht->table[hash & ht->mask];
+	while (node != NULL) {
+		if (keysize == node->keysize &&
+		    memcmp(key, node->key, keysize) == 0)
+		{
+			if (valuep != NULL) {
+				*valuep = node->value;
+			}
+			return (ISC_R_SUCCESS);
+		}
+		node = node->next;
+	}
+
+	return (ISC_R_NOTFOUND);
+}
+
+isc_result_t
+isc_ht_delete(isc_ht_t *ht, const unsigned char *key, uint32_t keysize) {
+	isc_ht_node_t *node, *prev;
+	uint32_t hash;
+
+	REQUIRE(ISC_HT_VALID(ht));
+	REQUIRE(key != NULL && keysize > 0);
+
+	prev = NULL;
+	hash = isc_hash_function(key, keysize, true);
+	node = ht->table[hash & ht->mask];
+	while (node != NULL) {
+		if (keysize == node->keysize &&
+		    memcmp(key, node->key, keysize) == 0)
+		{
+			if (prev == NULL) {
+				ht->table[hash & ht->mask] = node->next;
+			} else {
+				prev->next = node->next;
+			}
+			isc_mem_put(ht->mctx, node,
+				    offsetof(isc_ht_node_t, key) +
+					    node->keysize);
+			ht->count--;
+
+			return (ISC_R_SUCCESS);
+		}
+
+		prev = node;
+		node = node->next;
+	}
+	return (ISC_R_NOTFOUND);
+}
+
+void
+isc_ht_iter_create(isc_ht_t *ht, isc_ht_iter_t **itp) {
+	isc_ht_iter_t *it;
+
+	REQUIRE(ISC_HT_VALID(ht));
+	REQUIRE(itp != NULL && *itp == NULL);
+
+	it = isc_mem_get(ht->mctx, sizeof(isc_ht_iter_t));
+
+	it->ht = ht;
+	it->i = 0;
+	it->cur = NULL;
+
+	*itp = it;
+}
+
+void
+isc_ht_iter_destroy(isc_ht_iter_t **itp) {
+	isc_ht_iter_t *it;
+	isc_ht_t *ht;
+
+	REQUIRE(itp != NULL && *itp != NULL);
+
+	it = *itp;
+	*itp = NULL;
+	ht = it->ht;
+	isc_mem_put(ht->mctx, it, sizeof(isc_ht_iter_t));
+}
+
+isc_result_t
+isc_ht_iter_first(isc_ht_iter_t *it) {
+	REQUIRE(it != NULL);
+
+	it->i = 0;
+	while (it->i < it->ht->size && it->ht->table[it->i] == NULL) {
+		it->i++;
+	}
+
+	if (it->i == it->ht->size) {
+		return (ISC_R_NOMORE);
+	}
+
+	it->cur = it->ht->table[it->i];
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_ht_iter_next(isc_ht_iter_t *it) {
+	REQUIRE(it != NULL);
+	REQUIRE(it->cur != NULL);
+
+	it->cur = it->cur->next;
+	if (it->cur == NULL) {
+		do {
+			it->i++;
+		} while (it->i < it->ht->size && it->ht->table[it->i] == NULL);
+		if (it->i >= it->ht->size) {
+			return (ISC_R_NOMORE);
+		}
+		it->cur = it->ht->table[it->i];
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_ht_iter_delcurrent_next(isc_ht_iter_t *it) {
+	isc_result_t result = ISC_R_SUCCESS;
+	isc_ht_node_t *to_delete = NULL;
+	isc_ht_node_t *prev = NULL;
+	isc_ht_node_t *node = NULL;
+	uint32_t hash;
+	isc_ht_t *ht;
+	REQUIRE(it != NULL);
+	REQUIRE(it->cur != NULL);
+	to_delete = it->cur;
+	ht = it->ht;
+
+	it->cur = it->cur->next;
+	if (it->cur == NULL) {
+		do {
+			it->i++;
+		} while (it->i < ht->size && ht->table[it->i] == NULL);
+		if (it->i >= ht->size) {
+			result = ISC_R_NOMORE;
+		} else {
+			it->cur = ht->table[it->i];
+		}
+	}
+
+	hash = isc_hash_function(to_delete->key, to_delete->keysize, true);
+	node = ht->table[hash & ht->mask];
+	while (node != to_delete) {
+		prev = node;
+		node = node->next;
+		INSIST(node != NULL);
+	}
+
+	if (prev == NULL) {
+		ht->table[hash & ht->mask] = node->next;
+	} else {
+		prev->next = node->next;
+	}
+	isc_mem_put(ht->mctx, node,
+		    offsetof(isc_ht_node_t, key) + node->keysize);
+	ht->count--;
+
+	return (result);
+}
+
+void
+isc_ht_iter_current(isc_ht_iter_t *it, void **valuep) {
+	REQUIRE(it != NULL);
+	REQUIRE(it->cur != NULL);
+	REQUIRE(valuep != NULL && *valuep == NULL);
+
+	*valuep = it->cur->value;
+}
+
+void
+isc_ht_iter_currentkey(isc_ht_iter_t *it, unsigned char **key,
+		       size_t *keysize) {
+	REQUIRE(it != NULL);
+	REQUIRE(it->cur != NULL);
+	REQUIRE(key != NULL && *key == NULL);
+
+	*key = it->cur->key;
+	*keysize = it->cur->keysize;
+}
+
+unsigned int
+isc_ht_count(isc_ht_t *ht) {
+	REQUIRE(ISC_HT_VALID(ht));
+
+	return (ht->count);
+}