/* * QDict data type. * * Copyright (C) 2009 Red Hat Inc. * * Authors: * Luiz Capitulino <lcapitulino@redhat.com> * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. */ #include "qint.h" #include "qdict.h" #include "qstring.h" #include "qobject.h" #include "sys-queue.h" #include "qemu-common.h" static void qdict_destroy_obj(QObject *obj); static const QType qdict_type = { .code = QTYPE_QDICT, .destroy = qdict_destroy_obj, }; /** * qdict_new(): Create a new QDict * * Return strong reference. */ QDict *qdict_new(void) { QDict *qdict; qdict = qemu_mallocz(sizeof(*qdict)); QOBJECT_INIT(qdict, &qdict_type); return qdict; } /** * qobject_to_qdict(): Convert a QObject into a QDict */ QDict *qobject_to_qdict(const QObject *obj) { if (qobject_type(obj) != QTYPE_QDICT) return NULL; return container_of(obj, QDict, base); } /** * tdb_hash(): based on the hash agorithm from gdbm, via tdb * (from module-init-tools) */ static unsigned int tdb_hash(const char *name) { unsigned value; /* Used to compute the hash value. */ unsigned i; /* Used to cycle through random values. */ /* Set the initial value from the key size. */ for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++) value = (value + (((const unsigned char *)name)[i] << (i*5 % 24))); return (1103515243 * value + 12345); } /** * alloc_entry(): allocate a new QDictEntry */ static QDictEntry *alloc_entry(const char *key, QObject *value) { QDictEntry *entry; entry = qemu_mallocz(sizeof(*entry)); entry->key = qemu_strdup(key); entry->value = value; return entry; } /** * qdict_find(): List lookup function */ static QDictEntry *qdict_find(const QDict *qdict, const char *key, unsigned int hash) { QDictEntry *entry; LIST_FOREACH(entry, &qdict->table[hash], next) if (!strcmp(entry->key, key)) return entry; return NULL; } /** * qdict_put_obj(): Put a new QObject into the dictionary * * Insert the pair 'key:value' into 'qdict', if 'key' already exists * its 'value' will be replaced. * * This is done by freeing the reference to the stored QObject and * storing the new one in the same entry. * * NOTE: ownership of 'value' is transferred to the QDict */ void qdict_put_obj(QDict *qdict, const char *key, QObject *value) { unsigned int hash; QDictEntry *entry; hash = tdb_hash(key) % QDICT_HASH_SIZE; entry = qdict_find(qdict, key, hash); if (entry) { /* replace key's value */ qobject_decref(entry->value); entry->value = value; } else { /* allocate a new entry */ entry = alloc_entry(key, value); LIST_INSERT_HEAD(&qdict->table[hash], entry, next); } qdict->size++; } /** * qdict_get(): Lookup for a given 'key' * * Return a weak reference to the QObject associated with 'key' if * 'key' is present in the dictionary, NULL otherwise. */ QObject *qdict_get(const QDict *qdict, const char *key) { QDictEntry *entry; entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_HASH_SIZE); return (entry == NULL ? NULL : entry->value); } /** * qdict_haskey(): Check if 'key' exists * * Return 1 if 'key' exists in the dict, 0 otherwise */ int qdict_haskey(const QDict *qdict, const char *key) { unsigned int hash = tdb_hash(key) % QDICT_HASH_SIZE; return (qdict_find(qdict, key, hash) == NULL ? 0 : 1); } /** * qdict_size(): Return the size of the dictionary */ size_t qdict_size(const QDict *qdict) { return qdict->size; } /** * qdict_get_obj(): Get a QObject of a specific type */ static QObject *qdict_get_obj(const QDict *qdict, const char *key, qtype_code type) { QObject *obj; obj = qdict_get(qdict, key); assert(obj != NULL); assert(qobject_type(obj) == type); return obj; } /** * qdict_get_int(): Get an integer mapped by 'key' * * This function assumes that 'key' exists and it stores a * QInt object. * * Return integer mapped by 'key'. */ int64_t qdict_get_int(const QDict *qdict, const char *key) { QObject *obj = qdict_get_obj(qdict, key, QTYPE_QINT); return qint_get_int(qobject_to_qint(obj)); } /** * qdict_get_str(): Get a pointer to the stored string mapped * by 'key' * * This function assumes that 'key' exists and it stores a * QString object. * * Return pointer to the string mapped by 'key'. */ const char *qdict_get_str(const QDict *qdict, const char *key) { QObject *obj = qdict_get_obj(qdict, key, QTYPE_QSTRING); return qstring_get_str(qobject_to_qstring(obj)); } /** * qdict_get_try_int(): Try to get integer mapped by 'key' * * Return integer mapped by 'key', if it is not present in * the dictionary or if the stored object is not of QInt type * 'err_value' will be returned. */ int64_t qdict_get_try_int(const QDict *qdict, const char *key, int64_t err_value) { QObject *obj; obj = qdict_get(qdict, key); if (!obj || qobject_type(obj) != QTYPE_QINT) return err_value; return qint_get_int(qobject_to_qint(obj)); } /** * qdict_get_try_str(): Try to get a pointer to the stored string * mapped by 'key' * * Return a pointer to the string mapped by 'key', if it is not present * in the dictionary or if the stored object is not of QString type * NULL will be returned. */ const char *qdict_get_try_str(const QDict *qdict, const char *key) { QObject *obj; obj = qdict_get(qdict, key); if (!obj || qobject_type(obj) != QTYPE_QSTRING) return NULL; return qstring_get_str(qobject_to_qstring(obj)); } /** * qentry_destroy(): Free all the memory allocated by a QDictEntry */ static void qentry_destroy(QDictEntry *e) { assert(e != NULL); assert(e->key != NULL); assert(e->value != NULL); qobject_decref(e->value); qemu_free(e->key); qemu_free(e); } /** * qdict_del(): Delete a 'key:value' pair from the dictionary * * This will destroy all data allocated by this entry. */ void qdict_del(QDict *qdict, const char *key) { QDictEntry *entry; entry = qdict_find(qdict, key, tdb_hash(key) % QDICT_HASH_SIZE); if (entry) { LIST_REMOVE(entry, next); qentry_destroy(entry); qdict->size--; } } /** * qdict_destroy_obj(): Free all the memory allocated by a QDict */ static void qdict_destroy_obj(QObject *obj) { int i; QDict *qdict; assert(obj != NULL); qdict = qobject_to_qdict(obj); for (i = 0; i < QDICT_HASH_SIZE; i++) { QDictEntry *entry = LIST_FIRST(&qdict->table[i]); while (entry) { QDictEntry *tmp = LIST_NEXT(entry, next); LIST_REMOVE(entry, next); qentry_destroy(entry); entry = tmp; } } qemu_free(qdict); }