/* GLIB - Library of useful routines for C programming * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald * * SPDX-License-Identifier: LGPL-2.1-or-later * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, see . */ /* * Modified by the GLib Team and others 1997-2000. See the AUTHORS * file for a list of people on the GLib Team. See the ChangeLog * files for a list of changes. These files are distributed with * GLib at ftp://ftp.gtk.org/pub/gtk/. */ /* * MT safe */ #include "config.h" #include /* memset */ #include "ghash.h" #include "gmacros.h" #include "glib-private.h" #include "gstrfuncs.h" #include "gatomic.h" #include "gtestutils.h" #include "gslice.h" #include "grefcount.h" #include "gvalgrind.h" /* The following #pragma is here so we can do this... * * #ifndef USE_SMALL_ARRAYS * is_big = TRUE; * #endif * return is_big ? *(((gpointer *) a) + index) : GUINT_TO_POINTER (*(((guint *) a) + index)); * * ...instead of this... * * #ifndef USE_SMALL_ARRAYS * return *(((gpointer *) a) + index); * #else * return is_big ? *(((gpointer *) a) + index) : GUINT_TO_POINTER (*(((guint *) a) + index)); * #endif * * ...and still compile successfully when -Werror=duplicated-branches is passed. */ #if defined(__GNUC__) && __GNUC__ > 6 #pragma GCC diagnostic ignored "-Wduplicated-branches" #endif /** * GHashTable: * * The #GHashTable struct is an opaque data structure to represent a * [Hash Table][glib-Hash-Tables]. It should only be accessed via the * following functions. */ /** * GHashFunc: * @key: a key * * Specifies the type of the hash function which is passed to * g_hash_table_new() when a #GHashTable is created. * * The function is passed a key and should return a #guint hash value. * The functions g_direct_hash(), g_int_hash() and g_str_hash() provide * hash functions which can be used when the key is a #gpointer, #gint*, * and #gchar* respectively. * * g_direct_hash() is also the appropriate hash function for keys * of the form `GINT_TO_POINTER (n)` (or similar macros). * * A good hash functions should produce * hash values that are evenly distributed over a fairly large range. * The modulus is taken with the hash table size (a prime number) to * find the 'bucket' to place each key into. The function should also * be very fast, since it is called for each key lookup. * * Note that the hash functions provided by GLib have these qualities, * but are not particularly robust against manufactured keys that * cause hash collisions. Therefore, you should consider choosing * a more secure hash function when using a GHashTable with keys * that originate in untrusted data (such as HTTP requests). * Using g_str_hash() in that situation might make your application * vulnerable to * [Algorithmic Complexity Attacks](https://lwn.net/Articles/474912/). * * The key to choosing a good hash is unpredictability. Even * cryptographic hashes are very easy to find collisions for when the * remainder is taken modulo a somewhat predictable prime number. There * must be an element of randomness that an attacker is unable to guess. * * Returns: the hash value corresponding to the key */ /** * GHFunc: * @key: a key * @value: the value corresponding to the key * @user_data: user data passed to g_hash_table_foreach() * * Specifies the type of the function passed to g_hash_table_foreach(). * It is called with each key/value pair, together with the @user_data * parameter which is passed to g_hash_table_foreach(). */ /** * GHRFunc: * @key: a key * @value: the value associated with the key * @user_data: user data passed to g_hash_table_remove() * * Specifies the type of the function passed to * g_hash_table_foreach_remove(). It is called with each key/value * pair, together with the @user_data parameter passed to * g_hash_table_foreach_remove(). It should return %TRUE if the * key/value pair should be removed from the #GHashTable. * * Returns: %TRUE if the key/value pair should be removed from the * #GHashTable */ /** * GEqualFunc: * @a: a value * @b: a value to compare with * * Specifies the type of a function used to test two values for * equality. The function should return %TRUE if both values are equal * and %FALSE otherwise. * * Returns: %TRUE if @a = @b; %FALSE otherwise */ /** * GHashTableIter: * * A GHashTableIter structure represents an iterator that can be used * to iterate over the elements of a #GHashTable. GHashTableIter * structures are typically allocated on the stack and then initialized * with g_hash_table_iter_init(). * * The iteration order of a #GHashTableIter over the keys/values in a hash * table is not defined. */ /** * g_hash_table_freeze: * @hash_table: a #GHashTable * * This function is deprecated and will be removed in the next major * release of GLib. It does nothing. */ /** * g_hash_table_thaw: * @hash_table: a #GHashTable * * This function is deprecated and will be removed in the next major * release of GLib. It does nothing. */ #define HASH_TABLE_MIN_SHIFT 3 /* 1 << 3 == 8 buckets */ #define UNUSED_HASH_VALUE 0 #define TOMBSTONE_HASH_VALUE 1 #define HASH_IS_UNUSED(h_) ((h_) == UNUSED_HASH_VALUE) #define HASH_IS_TOMBSTONE(h_) ((h_) == TOMBSTONE_HASH_VALUE) #define HASH_IS_REAL(h_) ((h_) >= 2) /* If int is smaller than void * on our arch, we start out with * int-sized keys and values and resize to pointer-sized entries as * needed. This saves a good amount of memory when the HT is being * used with e.g. GUINT_TO_POINTER(). */ #define BIG_ENTRY_SIZE (SIZEOF_VOID_P) #define SMALL_ENTRY_SIZE (SIZEOF_INT) /* NB: The USE_SMALL_ARRAYS code assumes pointers are at most 8 bytes. */ #if SMALL_ENTRY_SIZE < BIG_ENTRY_SIZE && BIG_ENTRY_SIZE <= 8 # define USE_SMALL_ARRAYS #endif struct _GHashTable { gsize size; gint mod; guint mask; guint nnodes; guint noccupied; /* nnodes + tombstones */ guint have_big_keys : 1; guint have_big_values : 1; gpointer keys; guint *hashes; gpointer values; GHashFunc hash_func; GEqualFunc key_equal_func; gatomicrefcount ref_count; #ifndef G_DISABLE_ASSERT /* * Tracks the structure of the hash table, not its contents: is only * incremented when a node is added or removed (is not incremented * when the key or data of a node is modified). */ int version; #endif GDestroyNotify key_destroy_func; GDestroyNotify value_destroy_func; }; typedef struct { GHashTable *hash_table; gpointer dummy1; gpointer dummy2; gint position; gboolean dummy3; gintptr version; } RealIter; G_STATIC_ASSERT (sizeof (GHashTableIter) == sizeof (RealIter)); G_STATIC_ASSERT (G_ALIGNOF (GHashTableIter) >= G_ALIGNOF (RealIter)); /* Each table size has an associated prime modulo (the first prime * lower than the table size) used to find the initial bucket. Probing * then works modulo 2^n. The prime modulo is necessary to get a * good distribution with poor hash functions. */ static const gint prime_mod [] = { 1, /* For 1 << 0 */ 2, 3, 7, 13, 31, 61, 127, 251, 509, 1021, 2039, 4093, 8191, 16381, 32749, 65521, /* For 1 << 16 */ 131071, 262139, 524287, 1048573, 2097143, 4194301, 8388593, 16777213, 33554393, 67108859, 134217689, 268435399, 536870909, 1073741789, 2147483647 /* For 1 << 31 */ }; static void g_hash_table_set_shift (GHashTable *hash_table, gint shift) { hash_table->size = 1 << shift; hash_table->mod = prime_mod [shift]; /* hash_table->size is always a power of two, so we can calculate the mask * by simply subtracting 1 from it. The leading assertion ensures that * we're really dealing with a power of two. */ g_assert ((hash_table->size & (hash_table->size - 1)) == 0); hash_table->mask = hash_table->size - 1; } static gint g_hash_table_find_closest_shift (gint n) { gint i; for (i = 0; n; i++) n >>= 1; return i; } static void g_hash_table_set_shift_from_size (GHashTable *hash_table, gint size) { gint shift; shift = g_hash_table_find_closest_shift (size); shift = MAX (shift, HASH_TABLE_MIN_SHIFT); g_hash_table_set_shift (hash_table, shift); } static inline gpointer g_hash_table_realloc_key_or_value_array (gpointer a, guint size, G_GNUC_UNUSED gboolean is_big) { #ifdef USE_SMALL_ARRAYS return g_realloc (a, size * (is_big ? BIG_ENTRY_SIZE : SMALL_ENTRY_SIZE)); #else return g_renew (gpointer, a, size); #endif } static inline gpointer g_hash_table_fetch_key_or_value (gpointer a, guint index, gboolean is_big) { #ifndef USE_SMALL_ARRAYS is_big = TRUE; #endif return is_big ? *(((gpointer *) a) + index) : GUINT_TO_POINTER (*(((guint *) a) + index)); } static inline void g_hash_table_assign_key_or_value (gpointer a, guint index, gboolean is_big, gpointer v) { #ifndef USE_SMALL_ARRAYS is_big = TRUE; #endif if (is_big) *(((gpointer *) a) + index) = v; else *(((guint *) a) + index) = GPOINTER_TO_UINT (v); } static inline gpointer g_hash_table_evict_key_or_value (gpointer a, guint index, gboolean is_big, gpointer v) { #ifndef USE_SMALL_ARRAYS is_big = TRUE; #endif if (is_big) { gpointer r = *(((gpointer *) a) + index); *(((gpointer *) a) + index) = v; return r; } else { gpointer r = GUINT_TO_POINTER (*(((guint *) a) + index)); *(((guint *) a) + index) = GPOINTER_TO_UINT (v); return r; } } static inline guint g_hash_table_hash_to_index (GHashTable *hash_table, guint hash) { /* Multiply the hash by a small prime before applying the modulo. This * prevents the table from becoming densely packed, even with a poor hash * function. A densely packed table would have poor performance on * workloads with many failed lookups or a high degree of churn. */ return (hash * 11) % hash_table->mod; } /* * g_hash_table_lookup_node: * @hash_table: our #GHashTable * @key: the key to look up against * @hash_return: key hash return location * * Performs a lookup in the hash table, preserving extra information * usually needed for insertion. * * This function first computes the hash value of the key using the * user's hash function. * * If an entry in the table matching @key is found then this function * returns the index of that entry in the table, and if not, the * index of an unused node (empty or tombstone) where the key can be * inserted. * * The computed hash value is returned in the variable pointed to * by @hash_return. This is to save insertions from having to compute * the hash record again for the new record. * * Returns: index of the described node */ static inline guint g_hash_table_lookup_node (GHashTable *hash_table, gconstpointer key, guint *hash_return) { guint node_index; guint node_hash; guint hash_value; guint first_tombstone = 0; gboolean have_tombstone = FALSE; guint step = 0; hash_value = hash_table->hash_func (key); if (G_UNLIKELY (!HASH_IS_REAL (hash_value))) hash_value = 2; *hash_return = hash_value; node_index = g_hash_table_hash_to_index (hash_table, hash_value); node_hash = hash_table->hashes[node_index]; while (!HASH_IS_UNUSED (node_hash)) { /* We first check if our full hash values * are equal so we can avoid calling the full-blown * key equality function in most cases. */ if (node_hash == hash_value) { gpointer node_key = g_hash_table_fetch_key_or_value (hash_table->keys, node_index, hash_table->have_big_keys); if (hash_table->key_equal_func) { if (hash_table->key_equal_func (node_key, key)) return node_index; } else if (node_key == key) { return node_index; } } else if (HASH_IS_TOMBSTONE (node_hash) && !have_tombstone) { first_tombstone = node_index; have_tombstone = TRUE; } step++; node_index += step; node_index &= hash_table->mask; node_hash = hash_table->hashes[node_index]; } if (have_tombstone) return first_tombstone; return node_index; } /* * g_hash_table_remove_node: * @hash_table: our #GHashTable * @node: pointer to node to remove * @notify: %TRUE if the destroy notify handlers are to be called * * Removes a node from the hash table and updates the node count. * The node is replaced by a tombstone. No table resize is performed. * * If @notify is %TRUE then the destroy notify functions are called * for the key and value of the hash node. */ static void g_hash_table_remove_node (GHashTable *hash_table, gint i, gboolean notify) { gpointer key; gpointer value; key = g_hash_table_fetch_key_or_value (hash_table->keys, i, hash_table->have_big_keys); value = g_hash_table_fetch_key_or_value (hash_table->values, i, hash_table->have_big_values); /* Erect tombstone */ hash_table->hashes[i] = TOMBSTONE_HASH_VALUE; /* Be GC friendly */ g_hash_table_assign_key_or_value (hash_table->keys, i, hash_table->have_big_keys, NULL); g_hash_table_assign_key_or_value (hash_table->values, i, hash_table->have_big_values, NULL); g_assert (hash_table->nnodes > 0); hash_table->nnodes--; if (notify && hash_table->key_destroy_func) hash_table->key_destroy_func (key); if (notify && hash_table->value_destroy_func) hash_table->value_destroy_func (value); } /* * g_hash_table_setup_storage: * @hash_table: our #GHashTable * * Initialise the hash table size, mask, mod, and arrays. */ static void g_hash_table_setup_storage (GHashTable *hash_table) { gboolean small = FALSE; /* We want to use small arrays only if: * - we are running on a system where that makes sense (64 bit); and * - we are not running under valgrind. */ #ifdef USE_SMALL_ARRAYS small = TRUE; # ifdef ENABLE_VALGRIND if (RUNNING_ON_VALGRIND) small = FALSE; # endif #endif g_hash_table_set_shift (hash_table, HASH_TABLE_MIN_SHIFT); hash_table->have_big_keys = !small; hash_table->have_big_values = !small; hash_table->keys = g_hash_table_realloc_key_or_value_array (NULL, hash_table->size, hash_table->have_big_keys); hash_table->values = hash_table->keys; hash_table->hashes = g_new0 (guint, hash_table->size); } /* * g_hash_table_remove_all_nodes: * @hash_table: our #GHashTable * @notify: %TRUE if the destroy notify handlers are to be called * * Removes all nodes from the table. * * If @notify is %TRUE then the destroy notify functions are called * for the key and value of the hash node. * * Since this may be a precursor to freeing the table entirely, we'd * ideally perform no resize, and we can indeed avoid that in some * cases. However: in the case that we'll be making callbacks to user * code (via destroy notifies) we need to consider that the user code * might call back into the table again. In this case, we setup a new * set of arrays so that any callers will see an empty (but valid) * table. */ static void g_hash_table_remove_all_nodes (GHashTable *hash_table, gboolean notify, gboolean destruction) { int i; gpointer key; gpointer value; gint old_size; gpointer *old_keys; gpointer *old_values; guint *old_hashes; gboolean old_have_big_keys; gboolean old_have_big_values; /* If the hash table is already empty, there is nothing to be done. */ if (hash_table->nnodes == 0) return; hash_table->nnodes = 0; hash_table->noccupied = 0; /* Easy case: no callbacks, so we just zero out the arrays */ if (!notify || (hash_table->key_destroy_func == NULL && hash_table->value_destroy_func == NULL)) { if (!destruction) { memset (hash_table->hashes, 0, hash_table->size * sizeof (guint)); #ifdef USE_SMALL_ARRAYS memset (hash_table->keys, 0, hash_table->size * (hash_table->have_big_keys ? BIG_ENTRY_SIZE : SMALL_ENTRY_SIZE)); memset (hash_table->values, 0, hash_table->size * (hash_table->have_big_values ? BIG_ENTRY_SIZE : SMALL_ENTRY_SIZE)); #else memset (hash_table->keys, 0, hash_table->size * sizeof (gpointer)); memset (hash_table->values, 0, hash_table->size * sizeof (gpointer)); #endif } return; } /* Hard case: we need to do user callbacks. There are two * possibilities here: * * 1) there are no outstanding references on the table and therefore * nobody should be calling into it again (destroying == true) * * 2) there are outstanding references, and there may be future * calls into the table, either after we return, or from the destroy * notifies that we're about to do (destroying == false) * * We handle both cases by taking the current state of the table into * local variables and replacing it with something else: in the "no * outstanding references" cases we replace it with a bunch of * null/zero values so that any access to the table will fail. In the * "may receive future calls" case, we reinitialise the struct to * appear like a newly-created empty table. * * In both cases, we take over the references for the current state, * freeing them below. */ old_size = hash_table->size; old_have_big_keys = hash_table->have_big_keys; old_have_big_values = hash_table->have_big_values; old_keys = g_steal_pointer (&hash_table->keys); old_values = g_steal_pointer (&hash_table->values); old_hashes = g_steal_pointer (&hash_table->hashes); if (!destruction) /* Any accesses will see an empty table */ g_hash_table_setup_storage (hash_table); else /* Will cause a quick crash on any attempted access */ hash_table->size = hash_table->mod = hash_table->mask = 0; /* Now do the actual destroy notifies */ for (i = 0; i < old_size; i++) { if (HASH_IS_REAL (old_hashes[i])) { key = g_hash_table_fetch_key_or_value (old_keys, i, old_have_big_keys); value = g_hash_table_fetch_key_or_value (old_values, i, old_have_big_values); old_hashes[i] = UNUSED_HASH_VALUE; g_hash_table_assign_key_or_value (old_keys, i, old_have_big_keys, NULL); g_hash_table_assign_key_or_value (old_values, i, old_have_big_values, NULL); if (hash_table->key_destroy_func != NULL) hash_table->key_destroy_func (key); if (hash_table->value_destroy_func != NULL) hash_table->value_destroy_func (value); } } /* Destroy old storage space. */ if (old_keys != old_values) g_free (old_values); g_free (old_keys); g_free (old_hashes); } static void realloc_arrays (GHashTable *hash_table, gboolean is_a_set) { hash_table->hashes = g_renew (guint, hash_table->hashes, hash_table->size); hash_table->keys = g_hash_table_realloc_key_or_value_array (hash_table->keys, hash_table->size, hash_table->have_big_keys); if (is_a_set) hash_table->values = hash_table->keys; else hash_table->values = g_hash_table_realloc_key_or_value_array (hash_table->values, hash_table->size, hash_table->have_big_values); } /* When resizing the table in place, we use a temporary bit array to keep * track of which entries have been assigned a proper location in the new * table layout. * * Each bit corresponds to a bucket. A bit is set if an entry was assigned * its corresponding location during the resize and thus should not be * evicted. The array starts out cleared to zero. */ static inline gboolean get_status_bit (const guint32 *bitmap, guint index) { return (bitmap[index / 32] >> (index % 32)) & 1; } static inline void set_status_bit (guint32 *bitmap, guint index) { bitmap[index / 32] |= 1U << (index % 32); } /* By calling dedicated resize functions for sets and maps, we avoid 2x * test-and-branch per key in the inner loop. This yields a small * performance improvement at the cost of a bit of macro gunk. */ #define DEFINE_RESIZE_FUNC(fname) \ static void fname (GHashTable *hash_table, guint old_size, guint32 *reallocated_buckets_bitmap) \ { \ guint i; \ \ for (i = 0; i < old_size; i++) \ { \ guint node_hash = hash_table->hashes[i]; \ gpointer key, value G_GNUC_UNUSED; \ \ if (!HASH_IS_REAL (node_hash)) \ { \ /* Clear tombstones */ \ hash_table->hashes[i] = UNUSED_HASH_VALUE; \ continue; \ } \ \ /* Skip entries relocated through eviction */ \ if (get_status_bit (reallocated_buckets_bitmap, i)) \ continue; \ \ hash_table->hashes[i] = UNUSED_HASH_VALUE; \ EVICT_KEYVAL (hash_table, i, NULL, NULL, key, value); \ \ for (;;) \ { \ guint hash_val; \ guint replaced_hash; \ guint step = 0; \ \ hash_val = g_hash_table_hash_to_index (hash_table, node_hash); \ \ while (get_status_bit (reallocated_buckets_bitmap, hash_val)) \ { \ step++; \ hash_val += step; \ hash_val &= hash_table->mask; \ } \ \ set_status_bit (reallocated_buckets_bitmap, hash_val); \ \ replaced_hash = hash_table->hashes[hash_val]; \ hash_table->hashes[hash_val] = node_hash; \ if (!HASH_IS_REAL (replaced_hash)) \ { \ ASSIGN_KEYVAL (hash_table, hash_val, key, value); \ break; \ } \ \ node_hash = replaced_hash; \ EVICT_KEYVAL (hash_table, hash_val, key, value, key, value); \ } \ } \ } #define ASSIGN_KEYVAL(ht, index, key, value) G_STMT_START{ \ g_hash_table_assign_key_or_value ((ht)->keys, (index), (ht)->have_big_keys, (key)); \ g_hash_table_assign_key_or_value ((ht)->values, (index), (ht)->have_big_values, (value)); \ }G_STMT_END #define EVICT_KEYVAL(ht, index, key, value, outkey, outvalue) G_STMT_START{ \ (outkey) = g_hash_table_evict_key_or_value ((ht)->keys, (index), (ht)->have_big_keys, (key)); \ (outvalue) = g_hash_table_evict_key_or_value ((ht)->values, (index), (ht)->have_big_values, (value)); \ }G_STMT_END DEFINE_RESIZE_FUNC (resize_map) #undef ASSIGN_KEYVAL #undef EVICT_KEYVAL #define ASSIGN_KEYVAL(ht, index, key, value) G_STMT_START{ \ g_hash_table_assign_key_or_value ((ht)->keys, (index), (ht)->have_big_keys, (key)); \ }G_STMT_END #define EVICT_KEYVAL(ht, index, key, value, outkey, outvalue) G_STMT_START{ \ (outkey) = g_hash_table_evict_key_or_value ((ht)->keys, (index), (ht)->have_big_keys, (key)); \ }G_STMT_END DEFINE_RESIZE_FUNC (resize_set) #undef ASSIGN_KEYVAL #undef EVICT_KEYVAL /* * g_hash_table_resize: * @hash_table: our #GHashTable * * Resizes the hash table to the optimal size based on the number of * nodes currently held. If you call this function then a resize will * occur, even if one does not need to occur. * Use g_hash_table_maybe_resize() instead. * * This function may "resize" the hash table to its current size, with * the side effect of cleaning up tombstones and otherwise optimizing * the probe sequences. */ static void g_hash_table_resize (GHashTable *hash_table) { guint32 *reallocated_buckets_bitmap; gsize old_size; gboolean is_a_set; old_size = hash_table->size; is_a_set = hash_table->keys == hash_table->values; /* The outer checks in g_hash_table_maybe_resize() will only consider * cleanup/resize when the load factor goes below .25 (1/4, ignoring * tombstones) or above .9375 (15/16, including tombstones). * * Once this happens, tombstones will always be cleaned out. If our * load sans tombstones is greater than .75 (1/1.333, see below), we'll * take this opportunity to grow the table too. * * Immediately after growing, the load factor will be in the range * .375 .. .469. After shrinking, it will be exactly .5. */ g_hash_table_set_shift_from_size (hash_table, hash_table->nnodes * 1.333); if (hash_table->size > old_size) { realloc_arrays (hash_table, is_a_set); memset (&hash_table->hashes[old_size], 0, (hash_table->size - old_size) * sizeof (guint)); reallocated_buckets_bitmap = g_new0 (guint32, (hash_table->size + 31) / 32); } else { reallocated_buckets_bitmap = g_new0 (guint32, (old_size + 31) / 32); } if (is_a_set) resize_set (hash_table, old_size, reallocated_buckets_bitmap); else resize_map (hash_table, old_size, reallocated_buckets_bitmap); g_free (reallocated_buckets_bitmap); if (hash_table->size < old_size) realloc_arrays (hash_table, is_a_set); hash_table->noccupied = hash_table->nnodes; } /* * g_hash_table_maybe_resize: * @hash_table: our #GHashTable * * Resizes the hash table, if needed. * * Essentially, calls g_hash_table_resize() if the table has strayed * too far from its ideal size for its number of nodes. */ static inline void g_hash_table_maybe_resize (GHashTable *hash_table) { gsize noccupied = hash_table->noccupied; gsize size = hash_table->size; if ((size > hash_table->nnodes * 4 && size > 1 << HASH_TABLE_MIN_SHIFT) || (size <= noccupied + (noccupied / 16))) g_hash_table_resize (hash_table); } #ifdef USE_SMALL_ARRAYS static inline gboolean entry_is_big (gpointer v) { return (((guintptr) v) >> ((BIG_ENTRY_SIZE - SMALL_ENTRY_SIZE) * 8)) != 0; } static inline gboolean g_hash_table_maybe_make_big_keys_or_values (gpointer *a_p, gpointer v, gint ht_size) { if (entry_is_big (v)) { guint *a = (guint *) *a_p; gpointer *a_new; gint i; a_new = g_new (gpointer, ht_size); for (i = 0; i < ht_size; i++) { a_new[i] = GUINT_TO_POINTER (a[i]); } g_free (a); *a_p = a_new; return TRUE; } return FALSE; } #endif static inline void g_hash_table_ensure_keyval_fits (GHashTable *hash_table, gpointer key, gpointer value) { gboolean is_a_set = (hash_table->keys == hash_table->values); #ifdef USE_SMALL_ARRAYS /* Convert from set to map? */ if (is_a_set) { if (hash_table->have_big_keys) { if (key != value) hash_table->values = g_memdup2 (hash_table->keys, sizeof (gpointer) * hash_table->size); /* Keys and values are both big now, so no need for further checks */ return; } else { if (key != value) { hash_table->values = g_memdup2 (hash_table->keys, sizeof (guint) * hash_table->size); is_a_set = FALSE; } } } /* Make keys big? */ if (!hash_table->have_big_keys) { hash_table->have_big_keys = g_hash_table_maybe_make_big_keys_or_values (&hash_table->keys, key, hash_table->size); if (is_a_set) { hash_table->values = hash_table->keys; hash_table->have_big_values = hash_table->have_big_keys; } } /* Make values big? */ if (!is_a_set && !hash_table->have_big_values) { hash_table->have_big_values = g_hash_table_maybe_make_big_keys_or_values (&hash_table->values, value, hash_table->size); } #else /* Just split if necessary */ if (is_a_set && key != value) hash_table->values = g_memdup2 (hash_table->keys, sizeof (gpointer) * hash_table->size); #endif } /** * g_hash_table_new: * @hash_func: a function to create a hash value from a key * @key_equal_func: a function to check two keys for equality * * Creates a new #GHashTable with a reference count of 1. * * Hash values returned by @hash_func are used to determine where keys * are stored within the #GHashTable data structure. The g_direct_hash(), * g_int_hash(), g_int64_hash(), g_double_hash() and g_str_hash() * functions are provided for some common types of keys. * If @hash_func is %NULL, g_direct_hash() is used. * * @key_equal_func is used when looking up keys in the #GHashTable. * The g_direct_equal(), g_int_equal(), g_int64_equal(), g_double_equal() * and g_str_equal() functions are provided for the most common types * of keys. If @key_equal_func is %NULL, keys are compared directly in * a similar fashion to g_direct_equal(), but without the overhead of * a function call. @key_equal_func is called with the key from the hash table * as its first parameter, and the user-provided key to check against as * its second. * * Returns: (transfer full): a new #GHashTable */ GHashTable * g_hash_table_new (GHashFunc hash_func, GEqualFunc key_equal_func) { return g_hash_table_new_full (hash_func, key_equal_func, NULL, NULL); } /** * g_hash_table_new_full: * @hash_func: a function to create a hash value from a key * @key_equal_func: a function to check two keys for equality * @key_destroy_func: (nullable): a function to free the memory allocated for the key * used when removing the entry from the #GHashTable, or %NULL * if you don't want to supply such a function. * @value_destroy_func: (nullable): a function to free the memory allocated for the * value used when removing the entry from the #GHashTable, or %NULL * if you don't want to supply such a function. * * Creates a new #GHashTable like g_hash_table_new() with a reference * count of 1 and allows to specify functions to free the memory * allocated for the key and value that get called when removing the * entry from the #GHashTable. * * Since version 2.42 it is permissible for destroy notify functions to * recursively remove further items from the hash table. This is only * permissible if the application still holds a reference to the hash table. * This means that you may need to ensure that the hash table is empty by * calling g_hash_table_remove_all() before releasing the last reference using * g_hash_table_unref(). * * Returns: (transfer full): a new #GHashTable */ GHashTable * g_hash_table_new_full (GHashFunc hash_func, GEqualFunc key_equal_func, GDestroyNotify key_destroy_func, GDestroyNotify value_destroy_func) { GHashTable *hash_table; hash_table = g_slice_new (GHashTable); g_atomic_ref_count_init (&hash_table->ref_count); hash_table->nnodes = 0; hash_table->noccupied = 0; hash_table->hash_func = hash_func ? hash_func : g_direct_hash; hash_table->key_equal_func = key_equal_func; #ifndef G_DISABLE_ASSERT hash_table->version = 0; #endif hash_table->key_destroy_func = key_destroy_func; hash_table->value_destroy_func = value_destroy_func; g_hash_table_setup_storage (hash_table); return hash_table; } /** * g_hash_table_new_similar: * @other_hash_table: (not nullable) (transfer none): Another #GHashTable * * Creates a new #GHashTable like g_hash_table_new_full() with a reference * count of 1. * * It inherits the hash function, the key equal function, the key destroy function, * as well as the value destroy function, from @other_hash_table. * * The returned hash table will be empty; it will not contain the keys * or values from @other_hash_table. * * Returns: (transfer full) (not nullable): a new #GHashTable * Since: 2.72 */ GHashTable * g_hash_table_new_similar (GHashTable *other_hash_table) { g_return_val_if_fail (other_hash_table, NULL); return g_hash_table_new_full (other_hash_table->hash_func, other_hash_table->key_equal_func, other_hash_table->key_destroy_func, other_hash_table->value_destroy_func); } /** * g_hash_table_iter_init: * @iter: an uninitialized #GHashTableIter * @hash_table: a #GHashTable * * Initializes a key/value pair iterator and associates it with * @hash_table. Modifying the hash table after calling this function * invalidates the returned iterator. * * The iteration order of a #GHashTableIter over the keys/values in a hash * table is not defined. * * |[ * GHashTableIter iter; * gpointer key, value; * * g_hash_table_iter_init (&iter, hash_table); * while (g_hash_table_iter_next (&iter, &key, &value)) * { * // do something with key and value * } * ]| * * Since: 2.16 */ void g_hash_table_iter_init (GHashTableIter *iter, GHashTable *hash_table) { RealIter *ri = (RealIter *) iter; g_return_if_fail (iter != NULL); g_return_if_fail (hash_table != NULL); ri->hash_table = hash_table; ri->position = -1; #ifndef G_DISABLE_ASSERT ri->version = hash_table->version; #endif } /** * g_hash_table_iter_next: * @iter: an initialized #GHashTableIter * @key: (out) (optional) (nullable): a location to store the key * @value: (out) (optional) (nullable): a location to store the value * * Advances @iter and retrieves the key and/or value that are now * pointed to as a result of this advancement. If %FALSE is returned, * @key and @value are not set, and the iterator becomes invalid. * * Returns: %FALSE if the end of the #GHashTable has been reached. * * Since: 2.16 */ gboolean g_hash_table_iter_next (GHashTableIter *iter, gpointer *key, gpointer *value) { RealIter *ri = (RealIter *) iter; gint position; g_return_val_if_fail (iter != NULL, FALSE); #ifndef G_DISABLE_ASSERT g_return_val_if_fail (ri->version == ri->hash_table->version, FALSE); #endif g_return_val_if_fail (ri->position < (gssize) ri->hash_table->size, FALSE); position = ri->position; do { position++; if (position >= (gssize) ri->hash_table->size) { ri->position = position; return FALSE; } } while (!HASH_IS_REAL (ri->hash_table->hashes[position])); if (key != NULL) *key = g_hash_table_fetch_key_or_value (ri->hash_table->keys, position, ri->hash_table->have_big_keys); if (value != NULL) *value = g_hash_table_fetch_key_or_value (ri->hash_table->values, position, ri->hash_table->have_big_values); ri->position = position; return TRUE; } /** * g_hash_table_iter_get_hash_table: * @iter: an initialized #GHashTableIter * * Returns the #GHashTable associated with @iter. * * Returns: (transfer none): the #GHashTable associated with @iter. * * Since: 2.16 */ GHashTable * g_hash_table_iter_get_hash_table (GHashTableIter *iter) { g_return_val_if_fail (iter != NULL, NULL); return ((RealIter *) iter)->hash_table; } static void iter_remove_or_steal (RealIter *ri, gboolean notify) { g_return_if_fail (ri != NULL); #ifndef G_DISABLE_ASSERT g_return_if_fail (ri->version == ri->hash_table->version); #endif g_return_if_fail (ri->position >= 0); g_return_if_fail ((gsize) ri->position < ri->hash_table->size); g_hash_table_remove_node (ri->hash_table, ri->position, notify); #ifndef G_DISABLE_ASSERT ri->version++; ri->hash_table->version++; #endif } /** * g_hash_table_iter_remove: * @iter: an initialized #GHashTableIter * * Removes the key/value pair currently pointed to by the iterator * from its associated #GHashTable. Can only be called after * g_hash_table_iter_next() returned %TRUE, and cannot be called * more than once for the same key/value pair. * * If the #GHashTable was created using g_hash_table_new_full(), * the key and value are freed using the supplied destroy functions, * otherwise you have to make sure that any dynamically allocated * values are freed yourself. * * It is safe to continue iterating the #GHashTable afterward: * |[ * while (g_hash_table_iter_next (&iter, &key, &value)) * { * if (condition) * g_hash_table_iter_remove (&iter); * } * ]| * * Since: 2.16 */ void g_hash_table_iter_remove (GHashTableIter *iter) { iter_remove_or_steal ((RealIter *) iter, TRUE); } /* * g_hash_table_insert_node: * @hash_table: our #GHashTable * @node_index: pointer to node to insert/replace * @key_hash: key hash * @key: (nullable): key to replace with, or %NULL * @value: value to replace with * @keep_new_key: whether to replace the key in the node with @key * @reusing_key: whether @key was taken out of the existing node * * Inserts a value at @node_index in the hash table and updates it. * * If @key has been taken out of the existing node (ie it is not * passed in via a g_hash_table_insert/replace) call, then @reusing_key * should be %TRUE. * * Returns: %TRUE if the key did not exist yet */ static gboolean g_hash_table_insert_node (GHashTable *hash_table, guint node_index, guint key_hash, gpointer new_key, gpointer new_value, gboolean keep_new_key, gboolean reusing_key) { gboolean already_exists; guint old_hash; gpointer key_to_free = NULL; gpointer key_to_keep = NULL; gpointer value_to_free = NULL; old_hash = hash_table->hashes[node_index]; already_exists = HASH_IS_REAL (old_hash); /* Proceed in three steps. First, deal with the key because it is the * most complicated. Then consider if we need to split the table in * two (because writing the value will result in the set invariant * becoming broken). Then deal with the value. * * There are three cases for the key: * * - entry already exists in table, reusing key: * free the just-passed-in new_key and use the existing value * * - entry already exists in table, not reusing key: * free the entry in the table, use the new key * * - entry not already in table: * use the new key, free nothing * * We update the hash at the same time... */ if (already_exists) { /* Note: we must record the old value before writing the new key * because we might change the value in the event that the two * arrays are shared. */ value_to_free = g_hash_table_fetch_key_or_value (hash_table->values, node_index, hash_table->have_big_values); if (keep_new_key) { key_to_free = g_hash_table_fetch_key_or_value (hash_table->keys, node_index, hash_table->have_big_keys); key_to_keep = new_key; } else { key_to_free = new_key; key_to_keep = g_hash_table_fetch_key_or_value (hash_table->keys, node_index, hash_table->have_big_keys); } } else { hash_table->hashes[node_index] = key_hash; key_to_keep = new_key; } /* Resize key/value arrays and split table as necessary */ g_hash_table_ensure_keyval_fits (hash_table, key_to_keep, new_value); g_hash_table_assign_key_or_value (hash_table->keys, node_index, hash_table->have_big_keys, key_to_keep); /* Step 3: Actually do the write */ g_hash_table_assign_key_or_value (hash_table->values, node_index, hash_table->have_big_values, new_value); /* Now, the bookkeeping... */ if (!already_exists) { hash_table->nnodes++; if (HASH_IS_UNUSED (old_hash)) { /* We replaced an empty node, and not a tombstone */ hash_table->noccupied++; g_hash_table_maybe_resize (hash_table); } #ifndef G_DISABLE_ASSERT hash_table->version++; #endif } if (already_exists) { if (hash_table->key_destroy_func && !reusing_key) (* hash_table->key_destroy_func) (key_to_free); if (hash_table->value_destroy_func) (* hash_table->value_destroy_func) (value_to_free); } return !already_exists; } /** * g_hash_table_iter_replace: * @iter: an initialized #GHashTableIter * @value: the value to replace with * * Replaces the value currently pointed to by the iterator * from its associated #GHashTable. Can only be called after * g_hash_table_iter_next() returned %TRUE. * * If you supplied a @value_destroy_func when creating the * #GHashTable, the old value is freed using that function. * * Since: 2.30 */ void g_hash_table_iter_replace (GHashTableIter *iter, gpointer value) { RealIter *ri; guint node_hash; gpointer key; ri = (RealIter *) iter; g_return_if_fail (ri != NULL); #ifndef G_DISABLE_ASSERT g_return_if_fail (ri->version == ri->hash_table->version); #endif g_return_if_fail (ri->position >= 0); g_return_if_fail ((gsize) ri->position < ri->hash_table->size); node_hash = ri->hash_table->hashes[ri->position]; key = g_hash_table_fetch_key_or_value (ri->hash_table->keys, ri->position, ri->hash_table->have_big_keys); g_hash_table_insert_node (ri->hash_table, ri->position, node_hash, key, value, TRUE, TRUE); #ifndef G_DISABLE_ASSERT ri->version++; ri->hash_table->version++; #endif } /** * g_hash_table_iter_steal: * @iter: an initialized #GHashTableIter * * Removes the key/value pair currently pointed to by the * iterator from its associated #GHashTable, without calling * the key and value destroy functions. Can only be called * after g_hash_table_iter_next() returned %TRUE, and cannot * be called more than once for the same key/value pair. * * Since: 2.16 */ void g_hash_table_iter_steal (GHashTableIter *iter) { iter_remove_or_steal ((RealIter *) iter, FALSE); } /** * g_hash_table_ref: * @hash_table: a valid #GHashTable * * Atomically increments the reference count of @hash_table by one. * This function is MT-safe and may be called from any thread. * * Returns: (transfer full): the passed in #GHashTable * * Since: 2.10 */ GHashTable * g_hash_table_ref (GHashTable *hash_table) { g_return_val_if_fail (hash_table != NULL, NULL); g_atomic_ref_count_inc (&hash_table->ref_count); return hash_table; } /** * g_hash_table_unref: * @hash_table: (transfer full): a valid #GHashTable * * Atomically decrements the reference count of @hash_table by one. * If the reference count drops to 0, all keys and values will be * destroyed, and all memory allocated by the hash table is released. * This function is MT-safe and may be called from any thread. * * Since: 2.10 */ void g_hash_table_unref (GHashTable *hash_table) { g_return_if_fail (hash_table != NULL); if (g_atomic_ref_count_dec (&hash_table->ref_count)) { g_hash_table_remove_all_nodes (hash_table, TRUE, TRUE); if (hash_table->keys != hash_table->values) g_free (hash_table->values); g_free (hash_table->keys); g_free (hash_table->hashes); g_slice_free (GHashTable, hash_table); } } /** * g_hash_table_destroy: * @hash_table: a #GHashTable * * Destroys all keys and values in the #GHashTable and decrements its * reference count by 1. If keys and/or values are dynamically allocated, * you should either free them first or create the #GHashTable with destroy * notifiers using g_hash_table_new_full(). In the latter case the destroy * functions you supplied will be called on all keys and values during the * destruction phase. */ void g_hash_table_destroy (GHashTable *hash_table) { g_return_if_fail (hash_table != NULL); g_hash_table_remove_all (hash_table); g_hash_table_unref (hash_table); } /** * g_hash_table_lookup: * @hash_table: a #GHashTable * @key: the key to look up * * Looks up a key in a #GHashTable. Note that this function cannot * distinguish between a key that is not present and one which is present * and has the value %NULL. If you need this distinction, use * g_hash_table_lookup_extended(). * * Returns: (nullable): the associated value, or %NULL if the key is not found */ gpointer g_hash_table_lookup (GHashTable *hash_table, gconstpointer key) { guint node_index; guint node_hash; g_return_val_if_fail (hash_table != NULL, NULL); node_index = g_hash_table_lookup_node (hash_table, key, &node_hash); return HASH_IS_REAL (hash_table->hashes[node_index]) ? g_hash_table_fetch_key_or_value (hash_table->values, node_index, hash_table->have_big_values) : NULL; } /** * g_hash_table_lookup_extended: * @hash_table: a #GHashTable * @lookup_key: the key to look up * @orig_key: (out) (optional): return location for the original key * @value: (out) (optional) (nullable): return location for the value associated * with the key * * Looks up a key in the #GHashTable, returning the original key and the * associated value and a #gboolean which is %TRUE if the key was found. This * is useful if you need to free the memory allocated for the original key, * for example before calling g_hash_table_remove(). * * You can actually pass %NULL for @lookup_key to test * whether the %NULL key exists, provided the hash and equal functions * of @hash_table are %NULL-safe. * * Returns: %TRUE if the key was found in the #GHashTable */ gboolean g_hash_table_lookup_extended (GHashTable *hash_table, gconstpointer lookup_key, gpointer *orig_key, gpointer *value) { guint node_index; guint node_hash; g_return_val_if_fail (hash_table != NULL, FALSE); node_index = g_hash_table_lookup_node (hash_table, lookup_key, &node_hash); if (!HASH_IS_REAL (hash_table->hashes[node_index])) { if (orig_key != NULL) *orig_key = NULL; if (value != NULL) *value = NULL; return FALSE; } if (orig_key) *orig_key = g_hash_table_fetch_key_or_value (hash_table->keys, node_index, hash_table->have_big_keys); if (value) *value = g_hash_table_fetch_key_or_value (hash_table->values, node_index, hash_table->have_big_values); return TRUE; } /* * g_hash_table_insert_internal: * @hash_table: our #GHashTable * @key: the key to insert * @value: the value to insert * @keep_new_key: if %TRUE and this key already exists in the table * then call the destroy notify function on the old key. If %FALSE * then call the destroy notify function on the new key. * * Implements the common logic for the g_hash_table_insert() and * g_hash_table_replace() functions. * * Do a lookup of @key. If it is found, replace it with the new * @value (and perhaps the new @key). If it is not found, create * a new node. * * Returns: %TRUE if the key did not exist yet */ static gboolean g_hash_table_insert_internal (GHashTable *hash_table, gpointer key, gpointer value, gboolean keep_new_key) { guint key_hash; guint node_index; g_return_val_if_fail (hash_table != NULL, FALSE); node_index = g_hash_table_lookup_node (hash_table, key, &key_hash); return g_hash_table_insert_node (hash_table, node_index, key_hash, key, value, keep_new_key, FALSE); } /** * g_hash_table_insert: * @hash_table: a #GHashTable * @key: a key to insert * @value: the value to associate with the key * * Inserts a new key and value into a #GHashTable. * * If the key already exists in the #GHashTable its current * value is replaced with the new value. If you supplied a * @value_destroy_func when creating the #GHashTable, the old * value is freed using that function. If you supplied a * @key_destroy_func when creating the #GHashTable, the passed * key is freed using that function. * * Starting from GLib 2.40, this function returns a boolean value to * indicate whether the newly added value was already in the hash table * or not. * * Returns: %TRUE if the key did not exist yet */ gboolean g_hash_table_insert (GHashTable *hash_table, gpointer key, gpointer value) { return g_hash_table_insert_internal (hash_table, key, value, FALSE); } /** * g_hash_table_replace: * @hash_table: a #GHashTable * @key: a key to insert * @value: the value to associate with the key * * Inserts a new key and value into a #GHashTable similar to * g_hash_table_insert(). The difference is that if the key * already exists in the #GHashTable, it gets replaced by the * new key. If you supplied a @value_destroy_func when creating * the #GHashTable, the old value is freed using that function. * If you supplied a @key_destroy_func when creating the * #GHashTable, the old key is freed using that function. * * Starting from GLib 2.40, this function returns a boolean value to * indicate whether the newly added value was already in the hash table * or not. * * Returns: %TRUE if the key did not exist yet */ gboolean g_hash_table_replace (GHashTable *hash_table, gpointer key, gpointer value) { return g_hash_table_insert_internal (hash_table, key, value, TRUE); } /** * g_hash_table_add: * @hash_table: a #GHashTable * @key: (transfer full): a key to insert * * This is a convenience function for using a #GHashTable as a set. It * is equivalent to calling g_hash_table_replace() with @key as both the * key and the value. * * In particular, this means that if @key already exists in the hash table, then * the old copy of @key in the hash table is freed and @key replaces it in the * table. * * When a hash table only ever contains keys that have themselves as the * corresponding value it is able to be stored more efficiently. See * the discussion in the section description. * * Starting from GLib 2.40, this function returns a boolean value to * indicate whether the newly added value was already in the hash table * or not. * * Returns: %TRUE if the key did not exist yet * * Since: 2.32 */ gboolean g_hash_table_add (GHashTable *hash_table, gpointer key) { return g_hash_table_insert_internal (hash_table, key, key, TRUE); } /** * g_hash_table_contains: * @hash_table: a #GHashTable * @key: a key to check * * Checks if @key is in @hash_table. * * Returns: %TRUE if @key is in @hash_table, %FALSE otherwise. * * Since: 2.32 **/ gboolean g_hash_table_contains (GHashTable *hash_table, gconstpointer key) { guint node_index; guint node_hash; g_return_val_if_fail (hash_table != NULL, FALSE); node_index = g_hash_table_lookup_node (hash_table, key, &node_hash); return HASH_IS_REAL (hash_table->hashes[node_index]); } /* * g_hash_table_remove_internal: * @hash_table: our #GHashTable * @key: the key to remove * @notify: %TRUE if the destroy notify handlers are to be called * Returns: %TRUE if a node was found and removed, else %FALSE * * Implements the common logic for the g_hash_table_remove() and * g_hash_table_steal() functions. * * Do a lookup of @key and remove it if it is found, calling the * destroy notify handlers only if @notify is %TRUE. */ static gboolean g_hash_table_remove_internal (GHashTable *hash_table, gconstpointer key, gboolean notify) { guint node_index; guint node_hash; g_return_val_if_fail (hash_table != NULL, FALSE); node_index = g_hash_table_lookup_node (hash_table, key, &node_hash); if (!HASH_IS_REAL (hash_table->hashes[node_index])) return FALSE; g_hash_table_remove_node (hash_table, node_index, notify); g_hash_table_maybe_resize (hash_table); #ifndef G_DISABLE_ASSERT hash_table->version++; #endif return TRUE; } /** * g_hash_table_remove: * @hash_table: a #GHashTable * @key: the key to remove * * Removes a key and its associated value from a #GHashTable. * * If the #GHashTable was created using g_hash_table_new_full(), the * key and value are freed using the supplied destroy functions, otherwise * you have to make sure that any dynamically allocated values are freed * yourself. * * Returns: %TRUE if the key was found and removed from the #GHashTable */ gboolean g_hash_table_remove (GHashTable *hash_table, gconstpointer key) { return g_hash_table_remove_internal (hash_table, key, TRUE); } /** * g_hash_table_steal: * @hash_table: a #GHashTable * @key: the key to remove * * Removes a key and its associated value from a #GHashTable without * calling the key and value destroy functions. * * Returns: %TRUE if the key was found and removed from the #GHashTable */ gboolean g_hash_table_steal (GHashTable *hash_table, gconstpointer key) { return g_hash_table_remove_internal (hash_table, key, FALSE); } /** * g_hash_table_steal_extended: * @hash_table: a #GHashTable * @lookup_key: the key to look up * @stolen_key: (out) (optional) (transfer full): return location for the * original key * @stolen_value: (out) (optional) (nullable) (transfer full): return location * for the value associated with the key * * Looks up a key in the #GHashTable, stealing the original key and the * associated value and returning %TRUE if the key was found. If the key was * not found, %FALSE is returned. * * If found, the stolen key and value are removed from the hash table without * calling the key and value destroy functions, and ownership is transferred to * the caller of this method, as with g_hash_table_steal(). That is the case * regardless whether @stolen_key or @stolen_value output parameters are * requested. * * You can pass %NULL for @lookup_key, provided the hash and equal functions * of @hash_table are %NULL-safe. * * The dictionary implementation optimizes for having all values identical to * their keys, for example by using g_hash_table_add(). When stealing both the * key and the value from such a dictionary, the value will be %NULL. * * Returns: %TRUE if the key was found in the #GHashTable * Since: 2.58 */ gboolean g_hash_table_steal_extended (GHashTable *hash_table, gconstpointer lookup_key, gpointer *stolen_key, gpointer *stolen_value) { guint node_index; guint node_hash; g_return_val_if_fail (hash_table != NULL, FALSE); node_index = g_hash_table_lookup_node (hash_table, lookup_key, &node_hash); if (!HASH_IS_REAL (hash_table->hashes[node_index])) { if (stolen_key != NULL) *stolen_key = NULL; if (stolen_value != NULL) *stolen_value = NULL; return FALSE; } if (stolen_key != NULL) { *stolen_key = g_hash_table_fetch_key_or_value (hash_table->keys, node_index, hash_table->have_big_keys); g_hash_table_assign_key_or_value (hash_table->keys, node_index, hash_table->have_big_keys, NULL); } if (stolen_value != NULL) { *stolen_value = g_hash_table_fetch_key_or_value (hash_table->values, node_index, hash_table->have_big_values); g_hash_table_assign_key_or_value (hash_table->values, node_index, hash_table->have_big_values, NULL); } g_hash_table_remove_node (hash_table, node_index, FALSE); g_hash_table_maybe_resize (hash_table); #ifndef G_DISABLE_ASSERT hash_table->version++; #endif return TRUE; } /** * g_hash_table_remove_all: * @hash_table: a #GHashTable * * Removes all keys and their associated values from a #GHashTable. * * If the #GHashTable was created using g_hash_table_new_full(), * the keys and values are freed using the supplied destroy functions, * otherwise you have to make sure that any dynamically allocated * values are freed yourself. * * Since: 2.12 */ void g_hash_table_remove_all (GHashTable *hash_table) { g_return_if_fail (hash_table != NULL); #ifndef G_DISABLE_ASSERT if (hash_table->nnodes != 0) hash_table->version++; #endif g_hash_table_remove_all_nodes (hash_table, TRUE, FALSE); g_hash_table_maybe_resize (hash_table); } /** * g_hash_table_steal_all: * @hash_table: a #GHashTable * * Removes all keys and their associated values from a #GHashTable * without calling the key and value destroy functions. * * Since: 2.12 */ void g_hash_table_steal_all (GHashTable *hash_table) { g_return_if_fail (hash_table != NULL); #ifndef G_DISABLE_ASSERT if (hash_table->nnodes != 0) hash_table->version++; #endif g_hash_table_remove_all_nodes (hash_table, FALSE, FALSE); g_hash_table_maybe_resize (hash_table); } /** * g_hash_table_steal_all_keys: (skip) * @hash_table: a #GHashTable * * Removes all keys and their associated values from a #GHashTable * without calling the key destroy functions, returning the keys * as a #GPtrArray with the free func set to the @hash_table key * destroy function. * * Returns: (transfer container): a #GPtrArray containing each key of * the table. Unref with with g_ptr_array_unref() when done. * * Since: 2.76 */ GPtrArray * g_hash_table_steal_all_keys (GHashTable *hash_table) { GPtrArray *array; GDestroyNotify key_destroy_func; g_return_val_if_fail (hash_table != NULL, NULL); array = g_hash_table_get_keys_as_ptr_array (hash_table); /* Ignore the key destroy notify calls during removal, and use it for the * array elements instead, but restore it after the hash table has been * cleared, so that newly added keys will continue using it. */ key_destroy_func = g_steal_pointer (&hash_table->key_destroy_func); g_ptr_array_set_free_func (array, key_destroy_func); g_hash_table_remove_all (hash_table); hash_table->key_destroy_func = g_steal_pointer (&key_destroy_func); return array; } /** * g_hash_table_steal_all_values: (skip) * @hash_table: a #GHashTable * * Removes all keys and their associated values from a #GHashTable * without calling the value destroy functions, returning the values * as a #GPtrArray with the free func set to the @hash_table value * destroy function. * * Returns: (transfer container): a #GPtrArray containing each value of * the table. Unref with with g_ptr_array_unref() when done. * * Since: 2.76 */ GPtrArray * g_hash_table_steal_all_values (GHashTable *hash_table) { GPtrArray *array; GDestroyNotify value_destroy_func; g_return_val_if_fail (hash_table != NULL, NULL); array = g_hash_table_get_values_as_ptr_array (hash_table); /* Ignore the value destroy notify calls during removal, and use it for the * array elements instead, but restore it after the hash table has been * cleared, so that newly added values will continue using it. */ value_destroy_func = g_steal_pointer (&hash_table->value_destroy_func); g_ptr_array_set_free_func (array, value_destroy_func); g_hash_table_remove_all (hash_table); hash_table->value_destroy_func = g_steal_pointer (&value_destroy_func); return array; } /* * g_hash_table_foreach_remove_or_steal: * @hash_table: a #GHashTable * @func: the user's callback function * @user_data: data for @func * @notify: %TRUE if the destroy notify handlers are to be called * * Implements the common logic for g_hash_table_foreach_remove() * and g_hash_table_foreach_steal(). * * Iterates over every node in the table, calling @func with the key * and value of the node (and @user_data). If @func returns %TRUE the * node is removed from the table. * * If @notify is true then the destroy notify handlers will be called * for each removed node. */ static guint g_hash_table_foreach_remove_or_steal (GHashTable *hash_table, GHRFunc func, gpointer user_data, gboolean notify) { guint deleted = 0; gsize i; #ifndef G_DISABLE_ASSERT gint version = hash_table->version; #endif for (i = 0; i < hash_table->size; i++) { guint node_hash = hash_table->hashes[i]; gpointer node_key = g_hash_table_fetch_key_or_value (hash_table->keys, i, hash_table->have_big_keys); gpointer node_value = g_hash_table_fetch_key_or_value (hash_table->values, i, hash_table->have_big_values); if (HASH_IS_REAL (node_hash) && (* func) (node_key, node_value, user_data)) { g_hash_table_remove_node (hash_table, i, notify); deleted++; } #ifndef G_DISABLE_ASSERT g_return_val_if_fail (version == hash_table->version, 0); #endif } g_hash_table_maybe_resize (hash_table); #ifndef G_DISABLE_ASSERT if (deleted > 0) hash_table->version++; #endif return deleted; } /** * g_hash_table_foreach_remove: * @hash_table: a #GHashTable * @func: (scope call): the function to call for each key/value pair * @user_data: user data to pass to the function * * Calls the given function for each key/value pair in the * #GHashTable. If the function returns %TRUE, then the key/value * pair is removed from the #GHashTable. If you supplied key or * value destroy functions when creating the #GHashTable, they are * used to free the memory allocated for the removed keys and values. * * See #GHashTableIter for an alternative way to loop over the * key/value pairs in the hash table. * * Returns: the number of key/value pairs removed */ guint g_hash_table_foreach_remove (GHashTable *hash_table, GHRFunc func, gpointer user_data) { g_return_val_if_fail (hash_table != NULL, 0); g_return_val_if_fail (func != NULL, 0); return g_hash_table_foreach_remove_or_steal (hash_table, func, user_data, TRUE); } /** * g_hash_table_foreach_steal: * @hash_table: a #GHashTable * @func: (scope call): the function to call for each key/value pair * @user_data: user data to pass to the function * * Calls the given function for each key/value pair in the * #GHashTable. If the function returns %TRUE, then the key/value * pair is removed from the #GHashTable, but no key or value * destroy functions are called. * * See #GHashTableIter for an alternative way to loop over the * key/value pairs in the hash table. * * Returns: the number of key/value pairs removed. */ guint g_hash_table_foreach_steal (GHashTable *hash_table, GHRFunc func, gpointer user_data) { g_return_val_if_fail (hash_table != NULL, 0); g_return_val_if_fail (func != NULL, 0); return g_hash_table_foreach_remove_or_steal (hash_table, func, user_data, FALSE); } /** * g_hash_table_foreach: * @hash_table: a #GHashTable * @func: (scope call): the function to call for each key/value pair * @user_data: user data to pass to the function * * Calls the given function for each of the key/value pairs in the * #GHashTable. The function is passed the key and value of each * pair, and the given @user_data parameter. The hash table may not * be modified while iterating over it (you can't add/remove * items). To remove all items matching a predicate, use * g_hash_table_foreach_remove(). * * The order in which g_hash_table_foreach() iterates over the keys/values in * the hash table is not defined. * * See g_hash_table_find() for performance caveats for linear * order searches in contrast to g_hash_table_lookup(). */ void g_hash_table_foreach (GHashTable *hash_table, GHFunc func, gpointer user_data) { gsize i; #ifndef G_DISABLE_ASSERT gint version; #endif g_return_if_fail (hash_table != NULL); g_return_if_fail (func != NULL); #ifndef G_DISABLE_ASSERT version = hash_table->version; #endif for (i = 0; i < hash_table->size; i++) { guint node_hash = hash_table->hashes[i]; gpointer node_key = g_hash_table_fetch_key_or_value (hash_table->keys, i, hash_table->have_big_keys); gpointer node_value = g_hash_table_fetch_key_or_value (hash_table->values, i, hash_table->have_big_values); if (HASH_IS_REAL (node_hash)) (* func) (node_key, node_value, user_data); #ifndef G_DISABLE_ASSERT g_return_if_fail (version == hash_table->version); #endif } } /** * g_hash_table_find: * @hash_table: a #GHashTable * @predicate: (scope call): function to test the key/value pairs for a certain property * @user_data: user data to pass to the function * * Calls the given function for key/value pairs in the #GHashTable * until @predicate returns %TRUE. The function is passed the key * and value of each pair, and the given @user_data parameter. The * hash table may not be modified while iterating over it (you can't * add/remove items). * * Note, that hash tables are really only optimized for forward * lookups, i.e. g_hash_table_lookup(). So code that frequently issues * g_hash_table_find() or g_hash_table_foreach() (e.g. in the order of * once per every entry in a hash table) should probably be reworked * to use additional or different data structures for reverse lookups * (keep in mind that an O(n) find/foreach operation issued for all n * values in a hash table ends up needing O(n*n) operations). * * Returns: (nullable): The value of the first key/value pair is returned, * for which @predicate evaluates to %TRUE. If no pair with the * requested property is found, %NULL is returned. * * Since: 2.4 */ gpointer g_hash_table_find (GHashTable *hash_table, GHRFunc predicate, gpointer user_data) { gsize i; #ifndef G_DISABLE_ASSERT gint version; #endif gboolean match; g_return_val_if_fail (hash_table != NULL, NULL); g_return_val_if_fail (predicate != NULL, NULL); #ifndef G_DISABLE_ASSERT version = hash_table->version; #endif match = FALSE; for (i = 0; i < hash_table->size; i++) { guint node_hash = hash_table->hashes[i]; gpointer node_key = g_hash_table_fetch_key_or_value (hash_table->keys, i, hash_table->have_big_keys); gpointer node_value = g_hash_table_fetch_key_or_value (hash_table->values, i, hash_table->have_big_values); if (HASH_IS_REAL (node_hash)) match = predicate (node_key, node_value, user_data); #ifndef G_DISABLE_ASSERT g_return_val_if_fail (version == hash_table->version, NULL); #endif if (match) return node_value; } return NULL; } /** * g_hash_table_size: * @hash_table: a #GHashTable * * Returns the number of elements contained in the #GHashTable. * * Returns: the number of key/value pairs in the #GHashTable. */ guint g_hash_table_size (GHashTable *hash_table) { g_return_val_if_fail (hash_table != NULL, 0); return hash_table->nnodes; } /** * g_hash_table_get_keys: * @hash_table: a #GHashTable * * Retrieves every key inside @hash_table. The returned data is valid * until changes to the hash release those keys. * * This iterates over every entry in the hash table to build its return value. * To iterate over the entries in a #GHashTable more efficiently, use a * #GHashTableIter. * * Returns: (transfer container): a #GList containing all the keys * inside the hash table. The content of the list is owned by the * hash table and should not be modified or freed. Use g_list_free() * when done using the list. * * Since: 2.14 */ GList * g_hash_table_get_keys (GHashTable *hash_table) { gsize i; GList *retval; g_return_val_if_fail (hash_table != NULL, NULL); retval = NULL; for (i = 0; i < hash_table->size; i++) { if (HASH_IS_REAL (hash_table->hashes[i])) retval = g_list_prepend (retval, g_hash_table_fetch_key_or_value (hash_table->keys, i, hash_table->have_big_keys)); } return retval; } /** * g_hash_table_get_keys_as_array: * @hash_table: a #GHashTable * @length: (out) (optional): the length of the returned array * * Retrieves every key inside @hash_table, as an array. * * The returned array is %NULL-terminated but may contain %NULL as a * key. Use @length to determine the true length if it's possible that * %NULL was used as the value for a key. * * Note: in the common case of a string-keyed #GHashTable, the return * value of this function can be conveniently cast to (const gchar **). * * This iterates over every entry in the hash table to build its return value. * To iterate over the entries in a #GHashTable more efficiently, use a * #GHashTableIter. * * You should always free the return result with g_free(). In the * above-mentioned case of a string-keyed hash table, it may be * appropriate to use g_strfreev() if you call g_hash_table_steal_all() * first to transfer ownership of the keys. * * Returns: (array length=length) (transfer container): a * %NULL-terminated array containing each key from the table. * * Since: 2.40 **/ gpointer * g_hash_table_get_keys_as_array (GHashTable *hash_table, guint *length) { gpointer *result; gsize i, j = 0; result = g_new (gpointer, hash_table->nnodes + 1); for (i = 0; i < hash_table->size; i++) { if (HASH_IS_REAL (hash_table->hashes[i])) result[j++] = g_hash_table_fetch_key_or_value (hash_table->keys, i, hash_table->have_big_keys); } g_assert (j == hash_table->nnodes); result[j] = NULL; if (length) *length = j; return result; } /** * g_hash_table_get_keys_as_ptr_array: (skip) * @hash_table: a #GHashTable * * Retrieves every key inside @hash_table, as a #GPtrArray. * The returned data is valid until changes to the hash release those keys. * * This iterates over every entry in the hash table to build its return value. * To iterate over the entries in a #GHashTable more efficiently, use a * #GHashTableIter. * * You should always unref the returned array with g_ptr_array_unref(). * * Returns: (transfer container): a #GPtrArray containing each key from * the table. Unref with with g_ptr_array_unref() when done. * * Since: 2.76 **/ GPtrArray * g_hash_table_get_keys_as_ptr_array (GHashTable *hash_table) { GPtrArray *array; g_return_val_if_fail (hash_table != NULL, NULL); array = g_ptr_array_sized_new (hash_table->size); for (gsize i = 0; i < hash_table->size; ++i) { if (HASH_IS_REAL (hash_table->hashes[i])) { g_ptr_array_add (array, g_hash_table_fetch_key_or_value ( hash_table->keys, i, hash_table->have_big_keys)); } } g_assert (array->len == hash_table->nnodes); return array; } /** * g_hash_table_get_values: * @hash_table: a #GHashTable * * Retrieves every value inside @hash_table. The returned data * is valid until @hash_table is modified. * * This iterates over every entry in the hash table to build its return value. * To iterate over the entries in a #GHashTable more efficiently, use a * #GHashTableIter. * * Returns: (transfer container): a #GList containing all the values * inside the hash table. The content of the list is owned by the * hash table and should not be modified or freed. Use g_list_free() * when done using the list. * * Since: 2.14 */ GList * g_hash_table_get_values (GHashTable *hash_table) { gsize i; GList *retval; g_return_val_if_fail (hash_table != NULL, NULL); retval = NULL; for (i = 0; i < hash_table->size; i++) { if (HASH_IS_REAL (hash_table->hashes[i])) retval = g_list_prepend (retval, g_hash_table_fetch_key_or_value (hash_table->values, i, hash_table->have_big_values)); } return retval; } /** * g_hash_table_get_values_as_ptr_array: (skip) * @hash_table: a #GHashTable * * Retrieves every value inside @hash_table, as a #GPtrArray. * The returned data is valid until changes to the hash release those values. * * This iterates over every entry in the hash table to build its return value. * To iterate over the entries in a #GHashTable more efficiently, use a * #GHashTableIter. * * You should always unref the returned array with g_ptr_array_unref(). * * Returns: (transfer container): a #GPtrArray containing each value from * the table. Unref with with g_ptr_array_unref() when done. * * Since: 2.76 **/ GPtrArray * g_hash_table_get_values_as_ptr_array (GHashTable *hash_table) { GPtrArray *array; g_return_val_if_fail (hash_table != NULL, NULL); array = g_ptr_array_sized_new (hash_table->size); for (gsize i = 0; i < hash_table->size; ++i) { if (HASH_IS_REAL (hash_table->hashes[i])) { g_ptr_array_add (array, g_hash_table_fetch_key_or_value ( hash_table->values, i, hash_table->have_big_values)); } } g_assert (array->len == hash_table->nnodes); return array; } /* Hash functions. */ /** * g_str_equal: * @v1: (not nullable): a key * @v2: (not nullable): a key to compare with @v1 * * Compares two strings for byte-by-byte equality and returns %TRUE * if they are equal. It can be passed to g_hash_table_new() as the * @key_equal_func parameter, when using non-%NULL strings as keys in a * #GHashTable. * * This function is typically used for hash table comparisons, but can be used * for general purpose comparisons of non-%NULL strings. For a %NULL-safe string * comparison function, see g_strcmp0(). * * Returns: %TRUE if the two keys match */ gboolean (g_str_equal) (gconstpointer v1, gconstpointer v2) { const gchar *string1 = v1; const gchar *string2 = v2; return strcmp (string1, string2) == 0; } /** * g_str_hash: * @v: (not nullable): a string key * * Converts a string to a hash value. * * This function implements the widely used "djb" hash apparently * posted by Daniel Bernstein to comp.lang.c some time ago. The 32 * bit unsigned hash value starts at 5381 and for each byte 'c' in * the string, is updated: `hash = hash * 33 + c`. This function * uses the signed value of each byte. * * It can be passed to g_hash_table_new() as the @hash_func parameter, * when using non-%NULL strings as keys in a #GHashTable. * * Note that this function may not be a perfect fit for all use cases. * For example, it produces some hash collisions with strings as short * as 2. * * Returns: a hash value corresponding to the key */ guint g_str_hash (gconstpointer v) { const signed char *p; guint32 h = 5381; for (p = v; *p != '\0'; p++) h = (h << 5) + h + *p; return h; } /** * g_direct_hash: * @v: (nullable): a #gpointer key * * Converts a gpointer to a hash value. * It can be passed to g_hash_table_new() as the @hash_func parameter, * when using opaque pointers compared by pointer value as keys in a * #GHashTable. * * This hash function is also appropriate for keys that are integers * stored in pointers, such as `GINT_TO_POINTER (n)`. * * Returns: a hash value corresponding to the key. */ guint g_direct_hash (gconstpointer v) { return GPOINTER_TO_UINT (v); } /** * g_direct_equal: * @v1: (nullable): a key * @v2: (nullable): a key to compare with @v1 * * Compares two #gpointer arguments and returns %TRUE if they are equal. * It can be passed to g_hash_table_new() as the @key_equal_func * parameter, when using opaque pointers compared by pointer value as * keys in a #GHashTable. * * This equality function is also appropriate for keys that are integers * stored in pointers, such as `GINT_TO_POINTER (n)`. * * Returns: %TRUE if the two keys match. */ gboolean g_direct_equal (gconstpointer v1, gconstpointer v2) { return v1 == v2; } /** * g_int_equal: * @v1: (not nullable): a pointer to a #gint key * @v2: (not nullable): a pointer to a #gint key to compare with @v1 * * Compares the two #gint values being pointed to and returns * %TRUE if they are equal. * It can be passed to g_hash_table_new() as the @key_equal_func * parameter, when using non-%NULL pointers to integers as keys in a * #GHashTable. * * Note that this function acts on pointers to #gint, not on #gint * directly: if your hash table's keys are of the form * `GINT_TO_POINTER (n)`, use g_direct_equal() instead. * * Returns: %TRUE if the two keys match. */ gboolean g_int_equal (gconstpointer v1, gconstpointer v2) { return *((const gint*) v1) == *((const gint*) v2); } /** * g_int_hash: * @v: (not nullable): a pointer to a #gint key * * Converts a pointer to a #gint to a hash value. * It can be passed to g_hash_table_new() as the @hash_func parameter, * when using non-%NULL pointers to integer values as keys in a #GHashTable. * * Note that this function acts on pointers to #gint, not on #gint * directly: if your hash table's keys are of the form * `GINT_TO_POINTER (n)`, use g_direct_hash() instead. * * Returns: a hash value corresponding to the key. */ guint g_int_hash (gconstpointer v) { return *(const gint*) v; } /** * g_uint_equal: * @v1: (not nullable): a pointer to a #guint key * @v2: (not nullable): a pointer to a #guint key to compare with @v1 * * Compares the two #guint values being pointed to and returns * %TRUE if they are equal. * It can be passed to g_hash_table_new() as the @key_equal_func * parameter, when using non-%NULL pointers to integers as keys in a * #GHashTable. * * Note that this function acts on pointers to #guint, not on #guint * directly: if your hash table's keys are of the form * `GUINT_TO_POINTER (n)`, use g_direct_equal() instead. * * Returns: %TRUE if the two keys match. */ gboolean g_uint_equal (gconstpointer v1, gconstpointer v2) { return *((const guint *) v1) == *((const guint *) v2); } /** * g_uint_hash: * @v: (not nullable): a pointer to a #guint key * * Converts a pointer to a #guint to a hash value. * It can be passed to g_hash_table_new() as the @hash_func parameter, * when using non-%NULL pointers to integer values as keys in a #GHashTable. * * Note that this function acts on pointers to #guint, not on #guint * directly: if your hash table's keys are of the form * `GUINT_TO_POINTER (n)`, use g_direct_hash() instead. * * Returns: a hash value corresponding to the key. */ guint g_uint_hash (gconstpointer v) { return *(const guint *) v; } /** * g_int64_equal: * @v1: (not nullable): a pointer to a #gint64 key * @v2: (not nullable): a pointer to a #gint64 key to compare with @v1 * * Compares the two #gint64 values being pointed to and returns * %TRUE if they are equal. * It can be passed to g_hash_table_new() as the @key_equal_func * parameter, when using non-%NULL pointers to 64-bit integers as keys in a * #GHashTable. * * Returns: %TRUE if the two keys match. * * Since: 2.22 */ gboolean g_int64_equal (gconstpointer v1, gconstpointer v2) { return *((const gint64*) v1) == *((const gint64*) v2); } /** * g_int64_hash: * @v: (not nullable): a pointer to a #gint64 key * * Converts a pointer to a #gint64 to a hash value. * * It can be passed to g_hash_table_new() as the @hash_func parameter, * when using non-%NULL pointers to 64-bit integer values as keys in a * #GHashTable. * * Returns: a hash value corresponding to the key. * * Since: 2.22 */ guint g_int64_hash (gconstpointer v) { const guint64 *bits = v; return (guint) ((*bits >> 32) ^ (*bits & 0xffffffffU)); } /** * g_double_equal: * @v1: (not nullable): a pointer to a #gdouble key * @v2: (not nullable): a pointer to a #gdouble key to compare with @v1 * * Compares the two #gdouble values being pointed to and returns * %TRUE if they are equal. * It can be passed to g_hash_table_new() as the @key_equal_func * parameter, when using non-%NULL pointers to doubles as keys in a * #GHashTable. * * Returns: %TRUE if the two keys match. * * Since: 2.22 */ gboolean g_double_equal (gconstpointer v1, gconstpointer v2) { return *((const gdouble*) v1) == *((const gdouble*) v2); } /** * g_double_hash: * @v: (not nullable): a pointer to a #gdouble key * * Converts a pointer to a #gdouble to a hash value. * It can be passed to g_hash_table_new() as the @hash_func parameter, * It can be passed to g_hash_table_new() as the @hash_func parameter, * when using non-%NULL pointers to doubles as keys in a #GHashTable. * * Returns: a hash value corresponding to the key. * * Since: 2.22 */ guint g_double_hash (gconstpointer v) { /* Same as g_int64_hash() */ const guint64 *bits = v; return (guint) ((*bits >> 32) ^ (*bits & 0xffffffffU)); }