diff options
Diffstat (limited to 'src/nodes.c')
-rw-r--r-- | src/nodes.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/src/nodes.c b/src/nodes.c new file mode 100644 index 00000000..7a200c9f --- /dev/null +++ b/src/nodes.c @@ -0,0 +1,137 @@ +/* + Copyright 2011-2018 David Robillard <http://drobilla.net> + + Permission to use, copy, modify, and/or distribute this software for any + purpose with or without fee is hereby granted, provided that the above + copyright notice and this permission notice appear in all copies. + + THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +*/ + +#include "node.h" + +#include "zix/common.h" +#include "zix/digest.h" +#include "zix/hash.h" + +#include <assert.h> +#include <stdlib.h> +#include <string.h> + +typedef struct { + size_t refs; + SerdNode* node; +} NodesEntry; + +typedef struct { + size_t refs; + const SerdNode* node; +} NodesSearchKey; + +struct SerdNodesImpl { + ZixHash* hash; +}; + +static uint32_t +nodes_hash(const void* n) +{ + const SerdNode* node = ((const NodesEntry*)n)->node; + uint32_t hash = zix_digest_start(); + hash = zix_digest_add(hash, node, serd_node_total_size(node)); + return hash; +} + +static bool +nodes_equal(const void* a, const void* b) +{ + const SerdNode* a_node = ((const NodesEntry*)a)->node; + const SerdNode* b_node = ((const NodesEntry*)b)->node; + const size_t a_size = serd_node_total_size(a_node); + const size_t b_size = serd_node_total_size(b_node); + return ((a_node == b_node) || + (a_size == b_size && !memcmp(a_node, b_node, a_size))); +} + +static void +free_entry(void* value, void* user_data) +{ + NodesEntry* entry = (NodesEntry*)value; + serd_node_free(entry->node); +} + +SerdNodes* +serd_nodes_new(void) +{ + SerdNodes* nodes = (SerdNodes*)calloc(1, sizeof(SerdNodes)); + nodes->hash = zix_hash_new(nodes_hash, nodes_equal, sizeof(NodesEntry)); + return nodes; +} + +void +serd_nodes_free(SerdNodes* nodes) +{ + zix_hash_foreach(nodes->hash, free_entry, nodes); + zix_hash_free(nodes->hash); + free(nodes); +} + +const SerdNode* +serd_nodes_intern(SerdNodes* nodes, const SerdNode* node) +{ + if (!node) { + return NULL; + } + + NodesSearchKey key = { 1, node }; + NodesEntry* inserted = NULL; + switch (zix_hash_insert(nodes->hash, &key, (const void**)&inserted)) { + case ZIX_STATUS_EXISTS: + assert(serd_node_equals(inserted->node, node)); + ++inserted->refs; + break; + case ZIX_STATUS_SUCCESS: + inserted->node = serd_node_copy(node); + default: break; + } + + return inserted ? inserted->node : NULL; +} + +const SerdNode* +serd_nodes_manage(SerdNodes* nodes, SerdNode* node) +{ + if (!node) { + return NULL; + } + + NodesSearchKey key = { 1, node }; + NodesEntry* inserted = NULL; + switch (zix_hash_insert(nodes->hash, &key, (const void**)&inserted)) { + case ZIX_STATUS_EXISTS: + assert(serd_node_equals(inserted->node, node)); + serd_node_free(node); + ++inserted->refs; + break; + default: break; + } + + return inserted ? inserted->node : NULL; +} + +void +serd_nodes_deref(SerdNodes* nodes, const SerdNode* node) +{ + NodesSearchKey key = { 1, node }; + NodesEntry* entry = (NodesEntry*)zix_hash_find(nodes->hash, &key); + if (entry && --entry->refs == 0) { + SerdNode* const intern_node = entry->node; + zix_hash_remove(nodes->hash, entry); + serd_node_free(intern_node); + } +} |