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-rw-r--r--libnetdata/dictionary/Makefile.am8
-rw-r--r--libnetdata/dictionary/README.md5
-rw-r--r--libnetdata/dictionary/dictionary.c329
-rw-r--r--libnetdata/dictionary/dictionary.h49
4 files changed, 391 insertions, 0 deletions
diff --git a/libnetdata/dictionary/Makefile.am b/libnetdata/dictionary/Makefile.am
new file mode 100644
index 0000000..161784b
--- /dev/null
+++ b/libnetdata/dictionary/Makefile.am
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+AUTOMAKE_OPTIONS = subdir-objects
+MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
+
+dist_noinst_DATA = \
+ README.md \
+ $(NULL)
diff --git a/libnetdata/dictionary/README.md b/libnetdata/dictionary/README.md
new file mode 100644
index 0000000..234ff18
--- /dev/null
+++ b/libnetdata/dictionary/README.md
@@ -0,0 +1,5 @@
+<!--
+custom_edit_url: https://github.com/netdata/netdata/edit/master/libnetdata/dictionary/README.md
+-->
+
+[![analytics](https://www.google-analytics.com/collect?v=1&aip=1&t=pageview&_s=1&ds=github&dr=https%3A%2F%2Fgithub.com%2Fnetdata%2Fnetdata&dl=https%3A%2F%2Fmy-netdata.io%2Fgithub%2Flibnetdata%2Fdictionary%2FREADME&_u=MAC~&cid=5792dfd7-8dc4-476b-af31-da2fdb9f93d2&tid=UA-64295674-3)](<>)
diff --git a/libnetdata/dictionary/dictionary.c b/libnetdata/dictionary/dictionary.c
new file mode 100644
index 0000000..cfcf1fb
--- /dev/null
+++ b/libnetdata/dictionary/dictionary.c
@@ -0,0 +1,329 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "../libnetdata.h"
+
+// ----------------------------------------------------------------------------
+// dictionary statistics
+
+static inline void NETDATA_DICTIONARY_STATS_INSERTS_PLUS1(DICTIONARY *dict) {
+ if(likely(dict->stats))
+ dict->stats->inserts++;
+}
+static inline void NETDATA_DICTIONARY_STATS_DELETES_PLUS1(DICTIONARY *dict) {
+ if(likely(dict->stats))
+ dict->stats->deletes++;
+}
+static inline void NETDATA_DICTIONARY_STATS_SEARCHES_PLUS1(DICTIONARY *dict) {
+ if(likely(dict->stats))
+ dict->stats->searches++;
+}
+static inline void NETDATA_DICTIONARY_STATS_ENTRIES_PLUS1(DICTIONARY *dict) {
+ if(likely(dict->stats))
+ dict->stats->entries++;
+}
+static inline void NETDATA_DICTIONARY_STATS_ENTRIES_MINUS1(DICTIONARY *dict) {
+ if(likely(dict->stats))
+ dict->stats->entries--;
+}
+
+
+// ----------------------------------------------------------------------------
+// dictionary locks
+
+static inline void dictionary_read_lock(DICTIONARY *dict) {
+ if(likely(dict->rwlock)) {
+ // debug(D_DICTIONARY, "Dictionary READ lock");
+ netdata_rwlock_rdlock(dict->rwlock);
+ }
+}
+
+static inline void dictionary_write_lock(DICTIONARY *dict) {
+ if(likely(dict->rwlock)) {
+ // debug(D_DICTIONARY, "Dictionary WRITE lock");
+ netdata_rwlock_wrlock(dict->rwlock);
+ }
+}
+
+static inline void dictionary_unlock(DICTIONARY *dict) {
+ if(likely(dict->rwlock)) {
+ // debug(D_DICTIONARY, "Dictionary UNLOCK lock");
+ netdata_rwlock_unlock(dict->rwlock);
+ }
+}
+
+
+// ----------------------------------------------------------------------------
+// avl index
+
+static int name_value_compare(void* a, void* b) {
+ if(((NAME_VALUE *)a)->hash < ((NAME_VALUE *)b)->hash) return -1;
+ else if(((NAME_VALUE *)a)->hash > ((NAME_VALUE *)b)->hash) return 1;
+ else return strcmp(((NAME_VALUE *)a)->name, ((NAME_VALUE *)b)->name);
+}
+
+static inline NAME_VALUE *dictionary_name_value_index_find_nolock(DICTIONARY *dict, const char *name, uint32_t hash) {
+ NAME_VALUE tmp;
+ tmp.hash = (hash)?hash:simple_hash(name);
+ tmp.name = (char *)name;
+
+ NETDATA_DICTIONARY_STATS_SEARCHES_PLUS1(dict);
+ return (NAME_VALUE *)avl_search(&(dict->values_index), (avl *) &tmp);
+}
+
+// ----------------------------------------------------------------------------
+// internal methods
+
+static NAME_VALUE *dictionary_name_value_create_nolock(DICTIONARY *dict, const char *name, void *value, size_t value_len, uint32_t hash) {
+ debug(D_DICTIONARY, "Creating name value entry for name '%s'.", name);
+
+ NAME_VALUE *nv = callocz(1, sizeof(NAME_VALUE));
+
+ if(dict->flags & DICTIONARY_FLAG_NAME_LINK_DONT_CLONE)
+ nv->name = (char *)name;
+ else {
+ nv->name = strdupz(name);
+ }
+
+ nv->hash = (hash)?hash:simple_hash(nv->name);
+
+ if(dict->flags & DICTIONARY_FLAG_VALUE_LINK_DONT_CLONE)
+ nv->value = value;
+ else {
+ nv->value = mallocz(value_len);
+ memcpy(nv->value, value, value_len);
+ }
+
+ // index it
+ NETDATA_DICTIONARY_STATS_INSERTS_PLUS1(dict);
+ if(unlikely(avl_insert(&((dict)->values_index), (avl *)(nv)) != (avl *)nv))
+ error("dictionary: INTERNAL ERROR: duplicate insertion to dictionary.");
+
+ NETDATA_DICTIONARY_STATS_ENTRIES_PLUS1(dict);
+
+ return nv;
+}
+
+static void dictionary_name_value_destroy_nolock(DICTIONARY *dict, NAME_VALUE *nv) {
+ debug(D_DICTIONARY, "Destroying name value entry for name '%s'.", nv->name);
+
+ NETDATA_DICTIONARY_STATS_DELETES_PLUS1(dict);
+ if(unlikely(avl_remove(&(dict->values_index), (avl *)(nv)) != (avl *)nv))
+ error("dictionary: INTERNAL ERROR: dictionary invalid removal of node.");
+
+ NETDATA_DICTIONARY_STATS_ENTRIES_MINUS1(dict);
+
+ if(!(dict->flags & DICTIONARY_FLAG_VALUE_LINK_DONT_CLONE)) {
+ debug(D_REGISTRY, "Dictionary freeing value of '%s'", nv->name);
+ freez(nv->value);
+ }
+
+ if(!(dict->flags & DICTIONARY_FLAG_NAME_LINK_DONT_CLONE)) {
+ debug(D_REGISTRY, "Dictionary freeing name '%s'", nv->name);
+ freez(nv->name);
+ }
+
+ freez(nv);
+}
+
+// ----------------------------------------------------------------------------
+// API - basic methods
+
+DICTIONARY *dictionary_create(uint8_t flags) {
+ debug(D_DICTIONARY, "Creating dictionary.");
+
+ DICTIONARY *dict = callocz(1, sizeof(DICTIONARY));
+
+ if(flags & DICTIONARY_FLAG_WITH_STATISTICS)
+ dict->stats = callocz(1, sizeof(struct dictionary_stats));
+
+ if(!(flags & DICTIONARY_FLAG_SINGLE_THREADED)) {
+ dict->rwlock = callocz(1, sizeof(netdata_rwlock_t));
+ netdata_rwlock_init(dict->rwlock);
+ }
+
+ avl_init(&dict->values_index, name_value_compare);
+ dict->flags = flags;
+
+ return dict;
+}
+
+void dictionary_destroy(DICTIONARY *dict) {
+ debug(D_DICTIONARY, "Destroying dictionary.");
+
+ dictionary_write_lock(dict);
+
+ while(dict->values_index.root)
+ dictionary_name_value_destroy_nolock(dict, (NAME_VALUE *)dict->values_index.root);
+
+ dictionary_unlock(dict);
+
+ if(dict->stats)
+ freez(dict->stats);
+
+ if(dict->rwlock) {
+ netdata_rwlock_destroy(dict->rwlock);
+ freez(dict->rwlock);
+ }
+
+ freez(dict);
+}
+
+// ----------------------------------------------------------------------------
+
+void *dictionary_set(DICTIONARY *dict, const char *name, void *value, size_t value_len) {
+ debug(D_DICTIONARY, "SET dictionary entry with name '%s'.", name);
+
+ uint32_t hash = simple_hash(name);
+
+ dictionary_write_lock(dict);
+
+ NAME_VALUE *nv = dictionary_name_value_index_find_nolock(dict, name, hash);
+ if(unlikely(!nv)) {
+ debug(D_DICTIONARY, "Dictionary entry with name '%s' not found. Creating a new one.", name);
+
+ nv = dictionary_name_value_create_nolock(dict, name, value, value_len, hash);
+ if(unlikely(!nv))
+ fatal("Cannot create name_value.");
+ }
+ else {
+ debug(D_DICTIONARY, "Dictionary entry with name '%s' found. Changing its value.", name);
+
+ if(dict->flags & DICTIONARY_FLAG_VALUE_LINK_DONT_CLONE) {
+ debug(D_REGISTRY, "Dictionary: linking value to '%s'", name);
+ nv->value = value;
+ }
+ else {
+ debug(D_REGISTRY, "Dictionary: cloning value to '%s'", name);
+
+ // copy the new value without breaking
+ // any other thread accessing the same entry
+ void *new = mallocz(value_len),
+ *old = nv->value;
+
+ memcpy(new, value, value_len);
+ nv->value = new;
+
+ debug(D_REGISTRY, "Dictionary: freeing old value of '%s'", name);
+ freez(old);
+ }
+ }
+
+ dictionary_unlock(dict);
+
+ return nv->value;
+}
+
+void *dictionary_get(DICTIONARY *dict, const char *name) {
+ debug(D_DICTIONARY, "GET dictionary entry with name '%s'.", name);
+
+ dictionary_read_lock(dict);
+ NAME_VALUE *nv = dictionary_name_value_index_find_nolock(dict, name, 0);
+ dictionary_unlock(dict);
+
+ if(unlikely(!nv)) {
+ debug(D_DICTIONARY, "Not found dictionary entry with name '%s'.", name);
+ return NULL;
+ }
+
+ debug(D_DICTIONARY, "Found dictionary entry with name '%s'.", name);
+ return nv->value;
+}
+
+int dictionary_del(DICTIONARY *dict, const char *name) {
+ int ret;
+
+ debug(D_DICTIONARY, "DEL dictionary entry with name '%s'.", name);
+
+ dictionary_write_lock(dict);
+
+ NAME_VALUE *nv = dictionary_name_value_index_find_nolock(dict, name, 0);
+ if(unlikely(!nv)) {
+ debug(D_DICTIONARY, "Not found dictionary entry with name '%s'.", name);
+ ret = -1;
+ }
+ else {
+ debug(D_DICTIONARY, "Found dictionary entry with name '%s'.", name);
+ dictionary_name_value_destroy_nolock(dict, nv);
+ ret = 0;
+ }
+
+ dictionary_unlock(dict);
+
+ return ret;
+}
+
+
+// ----------------------------------------------------------------------------
+// API - walk through the dictionary
+// the dictionary is locked for reading while this happens
+// do not user other dictionary calls while walking the dictionary - deadlock!
+
+static int dictionary_walker(avl *a, int (*callback)(void *entry, void *data), void *data) {
+ int total = 0, ret = 0;
+
+ if(a->avl_link[0]) {
+ ret = dictionary_walker(a->avl_link[0], callback, data);
+ if(ret < 0) return ret;
+ total += ret;
+ }
+
+ ret = callback(((NAME_VALUE *)a)->value, data);
+ if(ret < 0) return ret;
+ total += ret;
+
+ if(a->avl_link[1]) {
+ ret = dictionary_walker(a->avl_link[1], callback, data);
+ if (ret < 0) return ret;
+ total += ret;
+ }
+
+ return total;
+}
+
+int dictionary_get_all(DICTIONARY *dict, int (*callback)(void *entry, void *data), void *data) {
+ int ret = 0;
+
+ dictionary_read_lock(dict);
+
+ if(likely(dict->values_index.root))
+ ret = dictionary_walker(dict->values_index.root, callback, data);
+
+ dictionary_unlock(dict);
+
+ return ret;
+}
+
+static int dictionary_walker_name_value(avl *a, int (*callback)(char *name, void *entry, void *data), void *data) {
+ int total = 0, ret = 0;
+
+ if(a->avl_link[0]) {
+ ret = dictionary_walker_name_value(a->avl_link[0], callback, data);
+ if(ret < 0) return ret;
+ total += ret;
+ }
+
+ ret = callback(((NAME_VALUE *)a)->name, ((NAME_VALUE *)a)->value, data);
+ if(ret < 0) return ret;
+ total += ret;
+
+ if(a->avl_link[1]) {
+ ret = dictionary_walker_name_value(a->avl_link[1], callback, data);
+ if (ret < 0) return ret;
+ total += ret;
+ }
+
+ return total;
+}
+
+int dictionary_get_all_name_value(DICTIONARY *dict, int (*callback)(char *name, void *entry, void *data), void *data) {
+ int ret = 0;
+
+ dictionary_read_lock(dict);
+
+ if(likely(dict->values_index.root))
+ ret = dictionary_walker_name_value(dict->values_index.root, callback, data);
+
+ dictionary_unlock(dict);
+
+ return ret;
+}
diff --git a/libnetdata/dictionary/dictionary.h b/libnetdata/dictionary/dictionary.h
new file mode 100644
index 0000000..fc24ec2
--- /dev/null
+++ b/libnetdata/dictionary/dictionary.h
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_DICTIONARY_H
+#define NETDATA_DICTIONARY_H 1
+
+#include "../libnetdata.h"
+
+struct dictionary_stats {
+ unsigned long long inserts;
+ unsigned long long deletes;
+ unsigned long long searches;
+ unsigned long long entries;
+};
+
+typedef struct name_value {
+ avl avl_node; // the index - this has to be first!
+
+ uint32_t hash; // a simple hash to speed up searching
+ // we first compare hashes, and only if the hashes are equal we do string comparisons
+
+ char *name;
+ void *value;
+} NAME_VALUE;
+
+typedef struct dictionary {
+ avl_tree_type values_index;
+
+ uint8_t flags;
+
+ struct dictionary_stats *stats;
+ netdata_rwlock_t *rwlock;
+} DICTIONARY;
+
+#define DICTIONARY_FLAG_DEFAULT 0x00000000
+#define DICTIONARY_FLAG_SINGLE_THREADED 0x00000001
+#define DICTIONARY_FLAG_VALUE_LINK_DONT_CLONE 0x00000002
+#define DICTIONARY_FLAG_NAME_LINK_DONT_CLONE 0x00000004
+#define DICTIONARY_FLAG_WITH_STATISTICS 0x00000008
+
+extern DICTIONARY *dictionary_create(uint8_t flags);
+extern void dictionary_destroy(DICTIONARY *dict);
+extern void *dictionary_set(DICTIONARY *dict, const char *name, void *value, size_t value_len) NEVERNULL;
+extern void *dictionary_get(DICTIONARY *dict, const char *name);
+extern int dictionary_del(DICTIONARY *dict, const char *name);
+
+extern int dictionary_get_all(DICTIONARY *dict, int (*callback)(void *entry, void *d), void *data);
+extern int dictionary_get_all_name_value(DICTIONARY *dict, int (*callback)(char *name, void *entry, void *d), void *data);
+
+#endif /* NETDATA_DICTIONARY_H */
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