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