Merging upstream version 1.45.3+dfsg.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 333 insertions, 0 deletions

diff --git a/src/libnetdata/dictionary/dictionary.h b/src/libnetdata/dictionary/dictionary.h
new file mode 100644
index 000000000..231fbfebd
--- /dev/null
+++ b/src/libnetdata/dictionary/dictionary.h
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+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_DICTIONARY_H
+#define NETDATA_DICTIONARY_H 1
+
+#include "../libnetdata.h"
+
+
+/*
+ * Netdata DICTIONARY features:
+ *
+ * CLONE or LINK
+ * Names and Values in the dictionary can be cloned or linked.
+ * In clone mode, the dictionary does all the memory management.
+ * The default is clone for both names and values.
+ * Set DICT_OPTION_NAME_LINK_DONT_CLONE to link names.
+ * Set DICT_OPTION_VALUE_LINK_DONT_CLONE to link names.
+ *
+ * ORDERED
+ * Items are ordered in the order they are added (new items are appended at the end).
+ * You may reverse the order by setting the flag DICT_OPTION_ADD_IN_FRONT.
+ *
+ * LOOKUP
+ * The dictionary uses JudyHS to maintain a very fast randomly accessible hash table.
+ *
+ * MULTI-THREADED and SINGLE-THREADED
+ * Each dictionary may be single threaded (no locks), or multi-threaded (multiple readers or one writer).
+ * The default is multi-threaded. Add the flag DICT_OPTION_SINGLE_THREADED for single-threaded.
+ *
+ * WALK-THROUGH and FOREACH traversal
+ * The dictionary can be traversed on read or write mode, either with a callback (walkthrough) or with
+ * a loop (foreach).
+ *
+ * In write mode traversal, the caller may delete only the current item, but may add as many items as needed.
+ *
+ */
+
+#ifdef NETDATA_INTERNAL_CHECKS
+#define DICT_WITH_STATS 1
+#endif
+
+#ifdef DICTIONARY_INTERNALS
+#define DICTFE_CONST
+#define DICT_ITEM_CONST
+#else
+#define DICTFE_CONST const
+#define DICT_ITEM_CONST const
+#endif
+
+typedef struct dictionary DICTIONARY;
+typedef struct dictionary_item DICTIONARY_ITEM;
+
+typedef enum __attribute__((packed)) dictionary_options {
+    DICT_OPTION_NONE                    = 0,        // the default is the opposite of all below
+    DICT_OPTION_SINGLE_THREADED         = (1 << 0), // don't use any locks (default: use locks)
+    DICT_OPTION_VALUE_LINK_DONT_CLONE   = (1 << 1), // don't copy the value, just point to the one provided (default: copy)
+    DICT_OPTION_NAME_LINK_DONT_CLONE    = (1 << 2), // don't copy the name, just point to the one provided (default: copy)
+    DICT_OPTION_DONT_OVERWRITE_VALUE    = (1 << 3), // don't overwrite values of dictionary items (default: overwrite)
+    DICT_OPTION_ADD_IN_FRONT            = (1 << 4), // add dictionary items at the front of the linked list (default: at the end)
+    DICT_OPTION_FIXED_SIZE              = (1 << 5), // the items of the dictionary have a fixed size
+    DICT_OPTION_INDEX_JUDY              = (1 << 6), // the default, if no other indexing is set
+    DICT_OPTION_INDEX_HASHTABLE         = (1 << 7), // use SIMPLE_HASHTABLE for indexing
+} DICT_OPTIONS;
+
+struct dictionary_stats {
+    const char *name;               // the name of the category
+
+    struct {
+        size_t active;              // the number of active dictionaries
+        size_t deleted;             // the number of dictionaries queued for destruction
+    } dictionaries;
+
+    struct {
+        long entries;               // active items in the dictionary
+        long pending_deletion;      // pending deletion items in the dictionary
+        long referenced;            // referenced items in the dictionary
+    } items;
+
+    struct {
+        size_t creations;           // dictionary creations
+        size_t destructions;        // dictionary destructions
+        size_t flushes;             // dictionary flushes
+        size_t traversals;          // dictionary foreach
+        size_t walkthroughs;        // dictionary walkthrough
+        size_t garbage_collections; // dictionary garbage collections
+        size_t searches;            // item searches
+        size_t inserts;             // item inserts
+        size_t resets;              // item resets
+        size_t deletes;             // item deletes
+    } ops;
+
+    struct {
+        size_t inserts;             // number of times the insert callback is called
+        size_t conflicts;           // number of times the conflict callback is called
+        size_t reacts;              // number of times the react callback is called
+        size_t deletes;             // number of times the delete callback is called
+    } callbacks;
+
+    // memory
+    struct {
+        long index;                 // bytes of keys indexed (indication of the index size)
+        long values;                // bytes of caller structures
+        long dict;                  // bytes of the structures dictionary needs
+    } memory;
+
+    // spin locks
+    struct {
+        size_t use_spins;           // number of times a reference to item had to spin to acquire it or ignore it
+        size_t search_spins;        // number of times a successful search result had to be thrown away
+        size_t insert_spins;        // number of times an insertion to the hash table had to be repeated
+        size_t delete_spins;        // number of times a deletion had to spin to get a decision
+    } spin_locks;
+};
+
+// Create a dictionary
+#ifdef NETDATA_INTERNAL_CHECKS
+#define dictionary_create(options) dictionary_create_advanced_with_trace(options, NULL, 0, __FUNCTION__, __LINE__, __FILE__)
+#define dictionary_create_advanced(options, stats, fixed_size) dictionary_create_advanced_with_trace(options, stats, fixed_size, __FUNCTION__, __LINE__, __FILE__)
+DICTIONARY *dictionary_create_advanced_with_trace(DICT_OPTIONS options, struct dictionary_stats *stats, size_t fixed_size, const char *function, size_t line, const char *file);
+#else
+#define dictionary_create(options) dictionary_create_advanced(options, NULL, 0)
+DICTIONARY *dictionary_create_advanced(DICT_OPTIONS options, struct dictionary_stats *stats, size_t fixed_size);
+#endif
+
+// Create a view on a dictionary
+#ifdef NETDATA_INTERNAL_CHECKS
+#define dictionary_create_view(master) dictionary_create_view_with_trace(master, __FUNCTION__, __LINE__, __FILE__)
+DICTIONARY *dictionary_create_view_with_trace(DICTIONARY *master, const char *function, size_t line, const char *file);
+#else
+DICTIONARY *dictionary_create_view(DICTIONARY *master);
+#endif
+
+// an insert callback to be called just after an item is added to the dictionary
+// this callback is called while the dictionary is write locked!
+typedef void (*dict_cb_insert_t)(const DICTIONARY_ITEM *item, void *value, void *data);
+void dictionary_register_insert_callback(DICTIONARY *dict, dict_cb_insert_t insert_callback, void *data);
+
+// a delete callback to be called just before an item is deleted forever
+// this callback is called while the dictionary is write locked!
+typedef void (*dict_cb_delete_t)(const DICTIONARY_ITEM *item, void *value, void *data);
+void dictionary_register_delete_callback(DICTIONARY *dict, dict_cb_delete_t delete_callback, void *data);
+
+// a merge callback to be called when DICT_OPTION_DONT_OVERWRITE_VALUE
+// and an item is already found in the dictionary - the dictionary does nothing else in this case
+// the old_value will remain in the dictionary - the new_value is ignored
+// The callback should return true if the value has been updated (it increases the dictionary version).
+typedef bool (*dict_cb_conflict_t)(const DICTIONARY_ITEM *item, void *old_value, void *new_value, void *data);
+void dictionary_register_conflict_callback(DICTIONARY *dict, dict_cb_conflict_t conflict_callback, void *data);
+
+// a reaction callback to be called after every item insertion or conflict
+// after the constructors have finished and the items are fully available for use
+// and the dictionary is not write locked anymore
+typedef void (*dict_cb_react_t)(const DICTIONARY_ITEM *item, void *value, void *data);
+void dictionary_register_react_callback(DICTIONARY *dict, dict_cb_react_t react_callback, void *data);
+
+// Destroy a dictionary
+// Returns the number of bytes freed
+// The returned value will not include name/key sizes
+// Registered delete callbacks will be run for each item in the dictionary.
+size_t dictionary_destroy(DICTIONARY *dict);
+
+// Empties a dictionary
+// Referenced items will survive, but are not offered anymore.
+// Registered delete callbacks will be run for each item in the dictionary.
+void dictionary_flush(DICTIONARY *dict);
+
+void dictionary_version_increment(DICTIONARY *dict);
+
+void dictionary_garbage_collect(DICTIONARY *dict);
+
+void cleanup_destroyed_dictionaries(void);
+
+// ----------------------------------------------------------------------------
+// Set an item in the dictionary
+//
+// - if an item with the same name does not exist, create one
+// - if an item with the same name exists, then:
+//        a) if DICT_OPTION_DONT_OVERWRITE_VALUE is set, just return the existing value (ignore the new value)
+//   else b) reset the value to the new value passed at the call
+//
+// When DICT_OPTION_VALUE_LINK_DONT_CLONE is set, the value is linked, otherwise it is copied
+// When DICT_OPTION_NAME_LINK_DONT_CLONE is set, the name is linked, otherwise it is copied
+//
+// When neither DICT_OPTION_VALUE_LINK_DONT_CLONE nor DICT_OPTION_NAME_LINK_DONT_CLONE are set, all the
+// memory management for names and values is done by the dictionary.
+//
+// Passing NULL as value, the dictionary will callocz() the newly allocated value, otherwise it will copy it.
+// Passing 0 as value_len, the dictionary will set the value to NULL (no allocations for value will be made).
+#define dictionary_set(dict, name, value, value_len) dictionary_set_advanced(dict, name, -1, value, value_len, NULL)
+void *dictionary_set_advanced(DICTIONARY *dict, const char *name, ssize_t name_len, void *value, size_t value_len, void *constructor_data);
+
+#define dictionary_set_and_acquire_item(dict, name, value, value_len) dictionary_set_and_acquire_item_advanced(dict, name, -1, value, value_len, NULL)
+DICT_ITEM_CONST DICTIONARY_ITEM *dictionary_set_and_acquire_item_advanced(DICTIONARY *dict, const char *name, ssize_t name_len, void *value, size_t value_len, void *constructor_data);
+
+// set an item in a dictionary view
+#define dictionary_view_set_and_acquire_item(dict, name, master_item) dictionary_view_set_and_acquire_item_advanced(dict, name, -1, master_item)
+DICT_ITEM_CONST DICTIONARY_ITEM *dictionary_view_set_and_acquire_item_advanced(DICTIONARY *dict, const char *name, ssize_t name_len, DICTIONARY_ITEM *master_item);
+#define dictionary_view_set(dict, name, master_item) dictionary_view_set_advanced(dict, name, -1, master_item)
+void *dictionary_view_set_advanced(DICTIONARY *dict, const char *name, ssize_t name_len, DICT_ITEM_CONST DICTIONARY_ITEM *master_item);
+
+// ----------------------------------------------------------------------------
+// Get an item from the dictionary
+// If it returns NULL, the item is not found
+
+#define dictionary_get(dict, name) dictionary_get_advanced(dict, name, -1)
+void *dictionary_get_advanced(DICTIONARY *dict, const char *name, ssize_t name_len);
+
+#define dictionary_get_and_acquire_item(dict, name) dictionary_get_and_acquire_item_advanced(dict, name, -1)
+DICT_ITEM_CONST DICTIONARY_ITEM *dictionary_get_and_acquire_item_advanced(DICTIONARY *dict, const char *name, ssize_t name_len);
+
+
+// ----------------------------------------------------------------------------
+// Delete an item from the dictionary
+// returns true if the item was found and has been deleted
+// returns false if the item was not found in the index
+
+#define dictionary_del(dict, name) dictionary_del_advanced(dict, name, -1)
+bool dictionary_del_advanced(DICTIONARY *dict, const char *name, ssize_t name_len);
+
+// ----------------------------------------------------------------------------
+// reference counters management
+
+void dictionary_acquired_item_release(DICTIONARY *dict, DICT_ITEM_CONST DICTIONARY_ITEM *item);
+
+DICT_ITEM_CONST DICTIONARY_ITEM *dictionary_acquired_item_dup(DICTIONARY *dict, DICT_ITEM_CONST DICTIONARY_ITEM *item);
+
+const char *dictionary_acquired_item_name(DICT_ITEM_CONST DICTIONARY_ITEM *item);
+void *dictionary_acquired_item_value(DICT_ITEM_CONST DICTIONARY_ITEM *item);
+
+size_t dictionary_acquired_item_references(DICT_ITEM_CONST DICTIONARY_ITEM *item);
+
+// ----------------------------------------------------------------------------
+// Traverse (walk through) the items of the dictionary.
+// The order of traversal is currently the order of insertion.
+//
+// The callback function may return a negative number to stop the traversal,
+// in which case that negative value is returned to the caller.
+//
+// If all callback calls return zero or positive numbers, the sum of all of
+// them is returned to the caller.
+//
+// You cannot alter the dictionary from inside a dictionary_walkthrough_read() - deadlock!
+// You can only delete the current item from inside a dictionary_walkthrough_write() - you can add as many as you want.
+//
+typedef int (*dict_walkthrough_callback_t)(const DICTIONARY_ITEM *item, void *value, void *data);
+
+#define dictionary_walkthrough_read(dict, callback, data) dictionary_walkthrough_rw(dict, 'r', callback, data)
+#define dictionary_walkthrough_write(dict, callback, data) dictionary_walkthrough_rw(dict, 'w', callback, data)
+int dictionary_walkthrough_rw(DICTIONARY *dict, char rw, dict_walkthrough_callback_t walkthrough_callback, void *data);
+
+typedef int (*dict_item_comparator_t)(const DICTIONARY_ITEM **item1, const DICTIONARY_ITEM **item2);
+
+#define dictionary_sorted_walkthrough_read(dict, callback, data) dictionary_sorted_walkthrough_rw(dict, 'r', callback, data, NULL)
+#define dictionary_sorted_walkthrough_write(dict, callback, data) dictionary_sorted_walkthrough_rw(dict, 'w', callback, data, NULL)
+int dictionary_sorted_walkthrough_rw(DICTIONARY *dict, char rw, dict_walkthrough_callback_t walkthrough_callback, void *data, dict_item_comparator_t item_comparator_callback);
+
+// ----------------------------------------------------------------------------
+// Traverse with foreach
+//
+// Use like this:
+//
+//  DICTFE dfe = {};
+//  for(MY_ITEM *item = dfe_start_read(&dfe, dict); item ; item = dfe_next(&dfe)) {
+//     // do things with the item and its dfe.name
+//  }
+//  dfe_done(&dfe);
+//
+// You cannot alter the dictionary from within a dfe_read_start() - deadlock!
+// You can only delete the current item from inside a dfe_start_write() - you can add as many as you want.
+//
+
+#define DICTIONARY_LOCK_READ      'r'
+#define DICTIONARY_LOCK_WRITE     'w'
+#define DICTIONARY_LOCK_REENTRANT 'z'
+
+void dictionary_write_lock(DICTIONARY *dict);
+void dictionary_write_unlock(DICTIONARY *dict);
+
+typedef DICTFE_CONST struct dictionary_foreach {
+    DICTIONARY *dict; // the dictionary upon we work
+
+    DICTIONARY_ITEM *item;      // the item we work on, to remember the position we are at
+                                // this can be used with dictionary_acquired_item_dup() to
+                                // acquire the currently working item.
+
+    const char *name;           // the dictionary name of the last item used
+    void *value;                // the dictionary value of the last item used
+                                // same as the return value of dictfe_start() and dictfe_next()
+
+    size_t counter;             // counts the number of iterations made, starting from zero
+
+    char rw;                    // the lock mode 'r' or 'w'
+    bool locked;                // true when the dictionary is locked
+} DICTFE;
+
+#define dfe_start_read(dict, value) dfe_start_rw(dict, value, DICTIONARY_LOCK_READ)
+#define dfe_start_write(dict, value) dfe_start_rw(dict, value, DICTIONARY_LOCK_WRITE)
+#define dfe_start_reentrant(dict, value) dfe_start_rw(dict, value, DICTIONARY_LOCK_REENTRANT)
+
+#define dfe_start_rw(dict, value, mode)                                                             \
+        do {                                                                                        \
+            DICTFE value ## _dfe = {};                                                              \
+            (void)(value); /* needed to avoid warning when looping without using this */            \
+            for((value) = dictionary_foreach_start_rw(&value ## _dfe, (dict), (mode));              \
+                (value ## _dfe.item) || (value) ;                                                   \
+                (value) = dictionary_foreach_next(&value ## _dfe))                                  \
+            {
+
+#define dfe_done(value)                                                                             \
+            }                                                                                       \
+            dictionary_foreach_done(&value ## _dfe);                                                \
+        } while(0)
+
+#define dfe_unlock(value) dictionary_foreach_unlock(&value ## _dfe)
+
+void *dictionary_foreach_start_rw(DICTFE *dfe, DICTIONARY *dict, char rw);
+void *dictionary_foreach_next(DICTFE *dfe);
+void  dictionary_foreach_done(DICTFE *dfe);
+void  dictionary_foreach_unlock(DICTFE *dfe);
+
+// ----------------------------------------------------------------------------
+// Get statistics about the dictionary
+
+size_t dictionary_version(DICTIONARY *dict);
+size_t dictionary_entries(DICTIONARY *dict);
+size_t dictionary_referenced_items(DICTIONARY *dict);
+
+// for all cases that the caller does not provide a stats structure, this is where they are accumulated.
+extern struct dictionary_stats dictionary_stats_category_other;
+
+int dictionary_unittest(size_t entries);
+
+#endif /* NETDATA_DICTIONARY_H */