qemu

qdict.c (10661B)

---

 /*
  * QDict Module
  *
  * Copyright (C) 2009 Red Hat Inc.
  *
  * Authors:
  *  Luiz Capitulino <lcapitulino@redhat.com>
  *
  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
  * See the COPYING.LIB file in the top-level directory.
  */
 
 #include "qemu/osdep.h"
 #include "qapi/qmp/qnum.h"
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qbool.h"
 #include "qapi/qmp/qnull.h"
 #include "qapi/qmp/qstring.h"
 #include "qobject-internal.h"
 
 /**
  * qdict_new(): Create a new QDict
  *
  * Return strong reference.
  */
 QDict *qdict_new(void)
 {
     QDict *qdict;
 
     qdict = g_malloc0(sizeof(*qdict));
     qobject_init(QOBJECT(qdict), QTYPE_QDICT);
 
     return qdict;
 }
 
 /**
  * tdb_hash(): based on the hash algorithm 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 = g_malloc0(sizeof(*entry));
     entry->key = g_strdup(key);
     entry->value = value;
 
     return entry;
 }
 
 /**
  * qdict_entry_value(): Return qdict entry value
  *
  * Return weak reference.
  */
 QObject *qdict_entry_value(const QDictEntry *entry)
 {
     return entry->value;
 }
 
 /**
  * qdict_entry_key(): Return qdict entry key
  *
  * Return a *pointer* to the string, it has to be duplicated before being
  * stored.
  */
 const char *qdict_entry_key(const QDictEntry *entry)
 {
     return entry->key;
 }
 
 /**
  * qdict_find(): List lookup function
  */
 static QDictEntry *qdict_find(const QDict *qdict,
                               const char *key, unsigned int bucket)
 {
     QDictEntry *entry;
 
     QLIST_FOREACH(entry, &qdict->table[bucket], 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 bucket;
     QDictEntry *entry;
 
     bucket = tdb_hash(key) % QDICT_BUCKET_MAX;
     entry = qdict_find(qdict, key, bucket);
     if (entry) {
         /* replace key's value */
         qobject_unref(entry->value);
         entry->value = value;
     } else {
         /* allocate a new entry */
         entry = alloc_entry(key, value);
         QLIST_INSERT_HEAD(&qdict->table[bucket], entry, next);
         qdict->size++;
     }
 }
 
 void qdict_put_int(QDict *qdict, const char *key, int64_t value)
 {
     qdict_put(qdict, key, qnum_from_int(value));
 }
 
 void qdict_put_bool(QDict *qdict, const char *key, bool value)
 {
     qdict_put(qdict, key, qbool_from_bool(value));
 }
 
 void qdict_put_str(QDict *qdict, const char *key, const char *value)
 {
     qdict_put(qdict, key, qstring_from_str(value));
 }
 
 void qdict_put_null(QDict *qdict, const char *key)
 {
     qdict_put(qdict, key, qnull());
 }
 
 /**
  * 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_BUCKET_MAX);
     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 bucket = tdb_hash(key) % QDICT_BUCKET_MAX;
     return (qdict_find(qdict, key, bucket) == NULL ? 0 : 1);
 }
 
 /**
  * qdict_size(): Return the size of the dictionary
  */
 size_t qdict_size(const QDict *qdict)
 {
     return qdict->size;
 }
 
 /**
  * qdict_get_double(): Get an number mapped by 'key'
  *
  * This function assumes that 'key' exists and it stores a QNum.
  *
  * Return number mapped by 'key'.
  */
 double qdict_get_double(const QDict *qdict, const char *key)
 {
     return qnum_get_double(qobject_to(QNum, qdict_get(qdict, key)));
 }
 
 /**
  * qdict_get_int(): Get an integer mapped by 'key'
  *
  * This function assumes that 'key' exists and it stores a
  * QNum representable as int.
  *
  * Return integer mapped by 'key'.
  */
 int64_t qdict_get_int(const QDict *qdict, const char *key)
 {
     return qnum_get_int(qobject_to(QNum, qdict_get(qdict, key)));
 }
 
 /**
  * qdict_get_bool(): Get a bool mapped by 'key'
  *
  * This function assumes that 'key' exists and it stores a
  * QBool object.
  *
  * Return bool mapped by 'key'.
  */
 bool qdict_get_bool(const QDict *qdict, const char *key)
 {
     return qbool_get_bool(qobject_to(QBool, qdict_get(qdict, key)));
 }
 
 /**
  * qdict_get_qlist(): If @qdict maps @key to a QList, return it, else NULL.
  */
 QList *qdict_get_qlist(const QDict *qdict, const char *key)
 {
     return qobject_to(QList, qdict_get(qdict, key));
 }
 
 /**
  * qdict_get_qdict(): If @qdict maps @key to a QDict, return it, else NULL.
  */
 QDict *qdict_get_qdict(const QDict *qdict, const char *key)
 {
     return qobject_to(QDict, qdict_get(qdict, key));
 }
 
 /**
  * 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)
 {
     return qstring_get_str(qobject_to(QString, qdict_get(qdict, key)));
 }
 
 /**
  * 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 a QNum representing an
  * integer, 'def_value' will be returned.
  */
 int64_t qdict_get_try_int(const QDict *qdict, const char *key,
                           int64_t def_value)
 {
     QNum *qnum = qobject_to(QNum, qdict_get(qdict, key));
     int64_t val;
 
     if (!qnum || !qnum_get_try_int(qnum, &val)) {
         return def_value;
     }
 
     return val;
 }
 
 /**
  * qdict_get_try_bool(): Try to get a bool mapped by 'key'
  *
  * Return bool mapped by 'key', if it is not present in the
  * dictionary or if the stored object is not of QBool type
  * 'def_value' will be returned.
  */
 bool qdict_get_try_bool(const QDict *qdict, const char *key, bool def_value)
 {
     QBool *qbool = qobject_to(QBool, qdict_get(qdict, key));
 
     return qbool ? qbool_get_bool(qbool) : def_value;
 }
 
 /**
  * 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)
 {
     QString *qstr = qobject_to(QString, qdict_get(qdict, key));
 
     return qstr ? qstring_get_str(qstr) : NULL;
 }
 
 static QDictEntry *qdict_next_entry(const QDict *qdict, int first_bucket)
 {
     int i;
 
     for (i = first_bucket; i < QDICT_BUCKET_MAX; i++) {
         if (!QLIST_EMPTY(&qdict->table[i])) {
             return QLIST_FIRST(&qdict->table[i]);
         }
     }
 
     return NULL;
 }
 
 /**
  * qdict_first(): Return first qdict entry for iteration.
  */
 const QDictEntry *qdict_first(const QDict *qdict)
 {
     return qdict_next_entry(qdict, 0);
 }
 
 /**
  * qdict_next(): Return next qdict entry in an iteration.
  */
 const QDictEntry *qdict_next(const QDict *qdict, const QDictEntry *entry)
 {
     QDictEntry *ret;
 
     ret = QLIST_NEXT(entry, next);
     if (!ret) {
         unsigned int bucket = tdb_hash(entry->key) % QDICT_BUCKET_MAX;
         ret = qdict_next_entry(qdict, bucket + 1);
     }
 
     return ret;
 }
 
 /**
  * qdict_clone_shallow(): Clones a given QDict. Its entries are not copied, but
  * another reference is added.
  */
 QDict *qdict_clone_shallow(const QDict *src)
 {
     QDict *dest;
     QDictEntry *entry;
     int i;
 
     dest = qdict_new();
 
     for (i = 0; i < QDICT_BUCKET_MAX; i++) {
         QLIST_FOREACH(entry, &src->table[i], next) {
             qdict_put_obj(dest, entry->key, qobject_ref(entry->value));
         }
     }
 
     return dest;
 }
 
 /**
  * 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_unref(e->value);
     g_free(e->key);
     g_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_BUCKET_MAX);
     if (entry) {
         QLIST_REMOVE(entry, next);
         qentry_destroy(entry);
         qdict->size--;
     }
 }
 
 /**
  * qdict_is_equal(): Test whether the two QDicts are equal
  *
  * Here, equality means whether they contain the same keys and whether
  * the respective values are in turn equal (i.e. invoking
  * qobject_is_equal() on them yields true).
  */
 bool qdict_is_equal(const QObject *x, const QObject *y)
 {
     const QDict *dict_x = qobject_to(QDict, x);
     const QDict *dict_y = qobject_to(QDict, y);
     const QDictEntry *e;
 
     if (qdict_size(dict_x) != qdict_size(dict_y)) {
         return false;
     }
 
     for (e = qdict_first(dict_x); e; e = qdict_next(dict_x, e)) {
         const QObject *obj_x = qdict_entry_value(e);
         const QObject *obj_y = qdict_get(dict_y, qdict_entry_key(e));
 
         if (!qobject_is_equal(obj_x, obj_y)) {
             return false;
         }
     }
 
     return true;
 }
 
 /**
  * qdict_destroy_obj(): Free all the memory allocated by a QDict
  */
 void qdict_destroy_obj(QObject *obj)
 {
     int i;
     QDict *qdict;
 
     assert(obj != NULL);
     qdict = qobject_to(QDict, obj);
 
     for (i = 0; i < QDICT_BUCKET_MAX; i++) {
         QDictEntry *entry = QLIST_FIRST(&qdict->table[i]);
         while (entry) {
             QDictEntry *tmp = QLIST_NEXT(entry, next);
             QLIST_REMOVE(entry, next);
             qentry_destroy(entry);
             entry = tmp;
         }
     }
 
     g_free(qdict);
 }
 
 void qdict_unref(QDict *q)
 {
     qobject_unref(q);
 }