/*
* 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/qint.h"
#include "qapi/qmp/qfloat.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qbool.h"
#include "qapi/qmp/qstring.h"
#include "qapi/qmp/qobject.h"
#include "qemu/queue.h"
#include "qemu-common.h"
#include "qemu/cutils.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;
}
/**
* qobject_to_qdict(): Convert a QObject into a QDict
*/
QDict *qobject_to_qdict(const QObject *obj)
{
if (!obj || 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 = 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_decref(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++;
}
}
/**
* 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_obj(): Get a QObject of a specific type
*/
static QObject *qdict_get_obj(const QDict *qdict, const char *key, QType type)
{
QObject *obj;
obj = qdict_get(qdict, key);
assert(obj != NULL);
assert(qobject_type(obj) == type);
return obj;
}
/**
* qdict_get_double(): Get an number mapped by 'key'
*
* This function assumes that 'key' exists and it stores a
* QFloat or QInt object.
*
* Return number mapped by 'key'.
*/
double qdict_get_double(const QDict *qdict, const char *key)
{
QObject *obj = qdict_get(qdict, key);
assert(obj);
switch (qobject_type(obj)) {
case QTYPE_QFLOAT:
return qfloat_get_double(qobject_to_qfloat(obj));
case QTYPE_QINT:
return qint_get_int(qobject_to_qint(obj));
default:
abort();
}
}
/**
* 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)
{
return qint_get_int(qobject_to_qint(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(): Get the QList mapped by 'key'
*
* This function assumes that 'key' exists and it stores a
* QList object.
*
* Return QList mapped by 'key'.
*/
QList *qdict_get_qlist(const QDict *qdict, const char *key)
{
return qobject_to_qlist(qdict_get_obj(qdict, key, QTYPE_QLIST));
}
/**
* qdict_get_qdict(): Get the QDict mapped by 'key'
*
* This function assumes that 'key' exists and it stores a
* QDict object.
*
* Return QDict mapped by 'key'.
*/
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 of QInt type
* 'def_value' will be returned.
*/
int64_t qdict_get_try_int(const QDict *qdict, const char *key,
int64_t def_value)
{
QInt *qint = qobject_to_qint(qdict_get(qdict, key));
return qint ? qint_get_int(qint) : def_value;
}
/**
* 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;
}
/**
* qdict_iter(): Iterate over all the dictionary's stored values.
*
* This function allows the user to provide an iterator, which will be
* called for each stored value in the dictionary.
*/
void qdict_iter(const QDict *qdict,
void (*iter)(const char *key, QObject *obj, void *opaque),
void *opaque)
{
int i;
QDictEntry *entry;
for (i = 0; i < QDICT_BUCKET_MAX; i++) {
QLIST_FOREACH(entry, &qdict->table[i], next)
iter(entry->key, entry->value, opaque);
}
}
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) {
qobject_incref(entry->value);
qdict_put_obj(dest, entry->key, 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_decref(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_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);
}
/**
* qdict_copy_default(): If no entry mapped by 'key' exists in 'dst' yet, the
* value of 'key' in 'src' is copied there (and the refcount increased
* accordingly).
*/
void qdict_copy_default(QDict *dst, QDict *src, const char *key)
{
QObject *val;
if (qdict_haskey(dst, key)) {
return;
}
val = qdict_get(src, key);
if (val) {
qobject_incref(val);
qdict_put_obj(dst, key, val);
}
}
/**
* qdict_set_default_str(): If no entry mapped by 'key' exists in 'dst' yet, a
* new QString initialised by 'val' is put there.
*/
void qdict_set_default_str(QDict *dst, const char *key, const char *val)
{
if (qdict_haskey(dst, key)) {
return;
}
qdict_put(dst, key, qstring_from_str(val));
}
static void qdict_flatten_qdict(QDict *qdict, QDict *target,
const char *prefix);
static void qdict_flatten_qlist(QList *qlist, QDict *target, const char *prefix)
{
QObject *value;
const QListEntry *entry;
char *new_key;
int i;
/* This function is never called with prefix == NULL, i.e., it is always
* called from within qdict_flatten_q(list|dict)(). Therefore, it does not
* need to remove list entries during the iteration (the whole list will be
* deleted eventually anyway from qdict_flatten_qdict()). */
assert(prefix);
entry = qlist_first(qlist);
for (i = 0; entry; entry = qlist_next(entry), i++) {
value = qlist_entry_obj(entry);
new_key = g_strdup_printf("%s.%i", prefix, i);
if (qobject_type(value) == QTYPE_QDICT) {
qdict_flatten_qdict(qobject_to_qdict(value), target, new_key);
} else if (qobject_type(value) == QTYPE_QLIST) {
qdict_flatten_qlist(qobject_to_qlist(value), target, new_key);
} else {
/* All other types are moved to the target unchanged. */
qobject_incref(value);
qdict_put_obj(target, new_key, value);
}
g_free(new_key);
}
}
static void qdict_flatten_qdict(QDict *qdict, QDict *target, const char *prefix)
{
QObject *value;
const QDictEntry *entry, *next;
char *new_key;
bool delete;
entry = qdict_first(qdict);
while (entry != NULL) {
next = qdict_next(qdict, entry);
value = qdict_entry_value(entry);
new_key = NULL;
delete = false;
if (prefix) {
new_key = g_strdup_printf("%s.%s", prefix, entry->key);
}
if (qobject_type(value) == QTYPE_QDICT) {
/* Entries of QDicts are processed recursively, the QDict object
* itself disappears. */
qdict_flatten_qdict(qobject_to_qdict(value), target,
new_key ? new_key : entry->key);
delete = true;
} else if (qobject_type(value) == QTYPE_QLIST) {
qdict_flatten_qlist(qobject_to_qlist(value), target,
new_key ? new_key : entry->key);
delete = true;
} else if (prefix) {
/* All other objects are moved to the target unchanged. */
qobject_incref(value);
qdict_put_obj(target, new_key, value);
delete = true;
}
g_free(new_key);
if (delete) {
qdict_del(qdict, entry->key);
/* Restart loop after modifying the iterated QDict */
entry = qdict_first(qdict);
continue;
}
entry = next;
}
}
/**
* qdict_flatten(): For each nested QDict with key x, all fields with key y
* are moved to this QDict and their key is renamed to "x.y". For each nested
* QList with key x, the field at index y is moved to this QDict with the key
* "x.y" (i.e., the reverse of what qdict_array_split() does).
* This operation is applied recursively for nested QDicts and QLists.
*/
void qdict_flatten(QDict *qdict)
{
qdict_flatten_qdict(qdict, qdict, NULL);
}
/* extract all the src QDict entries starting by start into dst */
void qdict_extract_subqdict(QDict *src, QDict **dst, const char *start)
{
const QDictEntry *entry, *next;
const char *p;
*dst = qdict_new();
entry = qdict_first(src);
while (entry != NULL) {
next = qdict_next(src, entry);
if (strstart(entry->key, start, &p)) {
qobject_incref(entry->value);
qdict_put_obj(*dst, p, entry->value);
qdict_del(src, entry->key);
}
entry = next;
}
}
static int qdict_count_prefixed_entries(const QDict *src, const char *start)
{
const QDictEntry *entry;
int count = 0;
for (entry = qdict_first(src); entry; entry = qdict_next(src, entry)) {
if (strstart(entry->key, start, NULL)) {
if (count == INT_MAX) {
return -ERANGE;
}
count++;
}
}
return count;
}
/**
* qdict_array_split(): This function moves array-like elements of a QDict into
* a new QList. Every entry in the original QDict with a key "%u" or one
* prefixed "%u.", where %u designates an unsigned integer starting at 0 and
* incrementally counting up, will be moved to a new QDict at index %u in the
* output QList with the key prefix removed, if that prefix is "%u.". If the
* whole key is just "%u", the whole QObject will be moved unchanged without
* creating a new QDict. The function terminates when there is no entry in the
* QDict with a prefix directly (incrementally) following the last one; it also
* returns if there are both entries with "%u" and "%u." for the same index %u.
* Example: {"0.a": 42, "0.b": 23, "1.x": 0, "4.y": 1, "o.o": 7, "2": 66}
* (or {"1.x": 0, "4.y": 1, "0.a": 42, "o.o": 7, "0.b": 23, "2": 66})
* => [{"a": 42, "b": 23}, {"x": 0}, 66]
* and {"4.y": 1, "o.o": 7} (remainder of the old QDict)
*/
void qdict_array_split(QDict *src, QList **dst)
{
unsigned i;
*dst = qlist_new();
for (i = 0; i < UINT_MAX; i++) {
QObject *subqobj;
bool is_subqdict;
QDict *subqdict;
char indexstr[32], prefix[32];
size_t snprintf_ret;
snprintf_ret = snprintf(indexstr, 32, "%u", i);
assert(snprintf_ret < 32);
subqobj = qdict_get(src, indexstr);
snprintf_ret = snprintf(prefix, 32, "%u.", i);
assert(snprintf_ret < 32);
/* Overflow is the same as positive non-zero results */
is_subqdict = qdict_count_prefixed_entries(src, prefix);
// There may be either a single subordinate object (named "%u") or
// multiple objects (each with a key prefixed "%u."), but not both.
if (!subqobj == !is_subqdict) {
break;
}
if (is_subqdict) {
qdict_extract_subqdict(src, &subqdict, prefix);
assert(qdict_size(subqdict) > 0);
} else {
qobject_incref(subqobj);
qdict_del(src, indexstr);
}
qlist_append_obj(*dst, subqobj ?: QOBJECT(subqdict));
}
}
/**
* qdict_array_entries(): Returns the number of direct array entries if the
* sub-QDict of src specified by the prefix in subqdict (or src itself for
* prefix == "") is valid as an array, i.e. the length of the created list if
* the sub-QDict would become empty after calling qdict_array_split() on it. If
* the array is not valid, -EINVAL is returned.
*/
int qdict_array_entries(QDict *src, const char *subqdict)
{
const QDictEntry *entry;
unsigned i;
unsigned entries = 0;
size_t subqdict_len = strlen(subqdict);
assert(!subqdict_len || subqdict[subqdict_len - 1] == '.');
/* qdict_array_split() loops until UINT_MAX, but as we want to return
* negative errors, we only have a signed return value here. Any additional
* entries will lead to -EINVAL. */
for (i = 0; i < INT_MAX; i++) {
QObject *subqobj;
int subqdict_entries;
char *prefix = g_strdup_printf("%s%u.", subqdict, i);
subqdict_entries = qdict_count_prefixed_entries(src, prefix);
/* Remove ending "." */
prefix[strlen(prefix) - 1] = 0;
subqobj = qdict_get(src, prefix);
g_free(prefix);
if (subqdict_entries < 0) {
return subqdict_entries;
}
/* There may be either a single subordinate object (named "%u") or
* multiple objects (each with a key prefixed "%u."), but not both. */
if (subqobj && subqdict_entries) {
return -EINVAL;
} else if (!subqobj && !subqdict_entries) {
break;
}
entries += subqdict_entries ? subqdict_entries : 1;
}
/* Consider everything handled that isn't part of the given sub-QDict */
for (entry = qdict_first(src); entry; entry = qdict_next(src, entry)) {
if (!strstart(qdict_entry_key(entry), subqdict, NULL)) {
entries++;
}
}
/* Anything left in the sub-QDict that wasn't handled? */
if (qdict_size(src) != entries) {
return -EINVAL;
}
return i;
}
/**
* qdict_join(): Absorb the src QDict into the dest QDict, that is, move all
* elements from src to dest.
*
* If an element from src has a key already present in dest, it will not be
* moved unless overwrite is true.
*
* If overwrite is true, the conflicting values in dest will be discarded and
* replaced by the corresponding values from src.
*
* Therefore, with overwrite being true, the src QDict will always be empty when
* this function returns. If overwrite is false, the src QDict will be empty
* iff there were no conflicts.
*/
void qdict_join(QDict *dest, QDict *src, bool overwrite)
{
const QDictEntry *entry, *next;
entry = qdict_first(src);
while (entry) {
next = qdict_next(src, entry);
if (overwrite || !qdict_haskey(dest, entry->key)) {
qobject_incref(entry->value);
qdict_put_obj(dest, entry->key, entry->value);
qdict_del(src, entry->key);
}
entry = next;
}
}
