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-rw-r--r--lib/nghttp2_map.c313
1 files changed, 313 insertions, 0 deletions
diff --git a/lib/nghttp2_map.c b/lib/nghttp2_map.c
new file mode 100644
index 0000000..e5db168
--- /dev/null
+++ b/lib/nghttp2_map.c
@@ -0,0 +1,313 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2017 ngtcp2 contributors
+ * Copyright (c) 2012 nghttp2 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include "nghttp2_map.h"
+
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+
+#include "nghttp2_helper.h"
+
+#define NGHTTP2_INITIAL_TABLE_LENBITS 8
+
+int nghttp2_map_init(nghttp2_map *map, nghttp2_mem *mem) {
+ map->mem = mem;
+ map->tablelen = 1 << NGHTTP2_INITIAL_TABLE_LENBITS;
+ map->tablelenbits = NGHTTP2_INITIAL_TABLE_LENBITS;
+ map->table =
+ nghttp2_mem_calloc(mem, map->tablelen, sizeof(nghttp2_map_bucket));
+ if (map->table == NULL) {
+ return NGHTTP2_ERR_NOMEM;
+ }
+
+ map->size = 0;
+
+ return 0;
+}
+
+void nghttp2_map_free(nghttp2_map *map) {
+ if (!map) {
+ return;
+ }
+
+ nghttp2_mem_free(map->mem, map->table);
+}
+
+void nghttp2_map_each_free(nghttp2_map *map, int (*func)(void *data, void *ptr),
+ void *ptr) {
+ uint32_t i;
+ nghttp2_map_bucket *bkt;
+
+ for (i = 0; i < map->tablelen; ++i) {
+ bkt = &map->table[i];
+
+ if (bkt->data == NULL) {
+ continue;
+ }
+
+ func(bkt->data, ptr);
+ }
+}
+
+int nghttp2_map_each(nghttp2_map *map, int (*func)(void *data, void *ptr),
+ void *ptr) {
+ int rv;
+ uint32_t i;
+ nghttp2_map_bucket *bkt;
+
+ for (i = 0; i < map->tablelen; ++i) {
+ bkt = &map->table[i];
+
+ if (bkt->data == NULL) {
+ continue;
+ }
+
+ rv = func(bkt->data, ptr);
+ if (rv != 0) {
+ return rv;
+ }
+ }
+
+ return 0;
+}
+
+static uint32_t hash(nghttp2_map_key_type key) {
+ return (uint32_t)key * 2654435769u;
+}
+
+static size_t h2idx(uint32_t hash, uint32_t bits) {
+ return hash >> (32 - bits);
+}
+
+static size_t distance(uint32_t tablelen, uint32_t tablelenbits,
+ nghttp2_map_bucket *bkt, size_t idx) {
+ return (idx - h2idx(bkt->hash, tablelenbits)) & (tablelen - 1);
+}
+
+static void map_bucket_swap(nghttp2_map_bucket *bkt, uint32_t *phash,
+ nghttp2_map_key_type *pkey, void **pdata) {
+ uint32_t h = bkt->hash;
+ nghttp2_map_key_type key = bkt->key;
+ void *data = bkt->data;
+
+ bkt->hash = *phash;
+ bkt->key = *pkey;
+ bkt->data = *pdata;
+
+ *phash = h;
+ *pkey = key;
+ *pdata = data;
+}
+
+static void map_bucket_set_data(nghttp2_map_bucket *bkt, uint32_t hash,
+ nghttp2_map_key_type key, void *data) {
+ bkt->hash = hash;
+ bkt->key = key;
+ bkt->data = data;
+}
+
+void nghttp2_map_print_distance(nghttp2_map *map) {
+ uint32_t i;
+ size_t idx;
+ nghttp2_map_bucket *bkt;
+
+ for (i = 0; i < map->tablelen; ++i) {
+ bkt = &map->table[i];
+
+ if (bkt->data == NULL) {
+ fprintf(stderr, "@%u <EMPTY>\n", i);
+ continue;
+ }
+
+ idx = h2idx(bkt->hash, map->tablelenbits);
+ fprintf(stderr, "@%u hash=%08x key=%d base=%zu distance=%zu\n", i,
+ bkt->hash, bkt->key, idx,
+ distance(map->tablelen, map->tablelenbits, bkt, idx));
+ }
+}
+
+static int insert(nghttp2_map_bucket *table, uint32_t tablelen,
+ uint32_t tablelenbits, uint32_t hash,
+ nghttp2_map_key_type key, void *data) {
+ size_t idx = h2idx(hash, tablelenbits);
+ size_t d = 0, dd;
+ nghttp2_map_bucket *bkt;
+
+ for (;;) {
+ bkt = &table[idx];
+
+ if (bkt->data == NULL) {
+ map_bucket_set_data(bkt, hash, key, data);
+ return 0;
+ }
+
+ dd = distance(tablelen, tablelenbits, bkt, idx);
+ if (d > dd) {
+ map_bucket_swap(bkt, &hash, &key, &data);
+ d = dd;
+ } else if (bkt->key == key) {
+ /* TODO This check is just a waste after first swap or if this
+ function is called from map_resize. That said, there is no
+ difference with or without this conditional in performance
+ wise. */
+ return NGHTTP2_ERR_INVALID_ARGUMENT;
+ }
+
+ ++d;
+ idx = (idx + 1) & (tablelen - 1);
+ }
+}
+
+/* new_tablelen must be power of 2 and new_tablelen == (1 <<
+ new_tablelenbits) must hold. */
+static int map_resize(nghttp2_map *map, uint32_t new_tablelen,
+ uint32_t new_tablelenbits) {
+ uint32_t i;
+ nghttp2_map_bucket *new_table;
+ nghttp2_map_bucket *bkt;
+ int rv;
+ (void)rv;
+
+ new_table =
+ nghttp2_mem_calloc(map->mem, new_tablelen, sizeof(nghttp2_map_bucket));
+ if (new_table == NULL) {
+ return NGHTTP2_ERR_NOMEM;
+ }
+
+ for (i = 0; i < map->tablelen; ++i) {
+ bkt = &map->table[i];
+ if (bkt->data == NULL) {
+ continue;
+ }
+ rv = insert(new_table, new_tablelen, new_tablelenbits, bkt->hash, bkt->key,
+ bkt->data);
+
+ assert(0 == rv);
+ }
+
+ nghttp2_mem_free(map->mem, map->table);
+ map->tablelen = new_tablelen;
+ map->tablelenbits = new_tablelenbits;
+ map->table = new_table;
+
+ return 0;
+}
+
+int nghttp2_map_insert(nghttp2_map *map, nghttp2_map_key_type key, void *data) {
+ int rv;
+
+ assert(data);
+
+ /* Load factor is 0.75 */
+ if ((map->size + 1) * 4 > map->tablelen * 3) {
+ rv = map_resize(map, map->tablelen * 2, map->tablelenbits + 1);
+ if (rv != 0) {
+ return rv;
+ }
+ }
+
+ rv = insert(map->table, map->tablelen, map->tablelenbits, hash(key), key,
+ data);
+ if (rv != 0) {
+ return rv;
+ }
+ ++map->size;
+ return 0;
+}
+
+void *nghttp2_map_find(nghttp2_map *map, nghttp2_map_key_type key) {
+ uint32_t h = hash(key);
+ size_t idx = h2idx(h, map->tablelenbits);
+ nghttp2_map_bucket *bkt;
+ size_t d = 0;
+
+ for (;;) {
+ bkt = &map->table[idx];
+
+ if (bkt->data == NULL ||
+ d > distance(map->tablelen, map->tablelenbits, bkt, idx)) {
+ return NULL;
+ }
+
+ if (bkt->key == key) {
+ return bkt->data;
+ }
+
+ ++d;
+ idx = (idx + 1) & (map->tablelen - 1);
+ }
+}
+
+int nghttp2_map_remove(nghttp2_map *map, nghttp2_map_key_type key) {
+ uint32_t h = hash(key);
+ size_t idx = h2idx(h, map->tablelenbits), didx;
+ nghttp2_map_bucket *bkt;
+ size_t d = 0;
+
+ for (;;) {
+ bkt = &map->table[idx];
+
+ if (bkt->data == NULL ||
+ d > distance(map->tablelen, map->tablelenbits, bkt, idx)) {
+ return NGHTTP2_ERR_INVALID_ARGUMENT;
+ }
+
+ if (bkt->key == key) {
+ map_bucket_set_data(bkt, 0, 0, NULL);
+
+ didx = idx;
+ idx = (idx + 1) & (map->tablelen - 1);
+
+ for (;;) {
+ bkt = &map->table[idx];
+ if (bkt->data == NULL ||
+ distance(map->tablelen, map->tablelenbits, bkt, idx) == 0) {
+ break;
+ }
+
+ map->table[didx] = *bkt;
+ map_bucket_set_data(bkt, 0, 0, NULL);
+ didx = idx;
+
+ idx = (idx + 1) & (map->tablelen - 1);
+ }
+
+ --map->size;
+
+ return 0;
+ }
+
+ ++d;
+ idx = (idx + 1) & (map->tablelen - 1);
+ }
+}
+
+void nghttp2_map_clear(nghttp2_map *map) {
+ memset(map->table, 0, sizeof(*map->table) * map->tablelen);
+ map->size = 0;
+}
+
+size_t nghttp2_map_size(nghttp2_map *map) { return map->size; }
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-29 13:47:06 +0000