Archipelago » qemu

/*

 * 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 "qemu-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;

    QLIST_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);

        QLIST_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) {

        QLIST_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 = QLIST_FIRST(&qdict->table[i]);

        while (entry) {

            QDictEntry *tmp = QLIST_NEXT(entry, next);

            QLIST_REMOVE(entry, next);

            qentry_destroy(entry);

            entry = tmp;

        }

    }

    qemu_free(qdict);

}