qemu/qobject/qstring.c
Marc-André Lureau 164c374b75 qstring: add qstring_free()
Similar to g_string_free(), optionally return the underlying char*.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-10-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:13 +01:00

182 lines
4.1 KiB
C

/*
* QString 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/qstring.h"
/**
* qstring_new(): Create a new empty QString
*
* Return strong reference.
*/
QString *qstring_new(void)
{
return qstring_from_str("");
}
/**
* qstring_get_length(): Get the length of a QString
*/
size_t qstring_get_length(const QString *qstring)
{
return qstring->length;
}
/**
* qstring_from_substr(): Create a new QString from a C string substring
*
* Return string reference
*/
QString *qstring_from_substr(const char *str, size_t start, size_t end)
{
QString *qstring;
assert(start <= end);
qstring = g_malloc(sizeof(*qstring));
qobject_init(QOBJECT(qstring), QTYPE_QSTRING);
qstring->length = end - start;
qstring->capacity = qstring->length;
assert(qstring->capacity < SIZE_MAX);
qstring->string = g_malloc(qstring->capacity + 1);
memcpy(qstring->string, str + start, qstring->length);
qstring->string[qstring->length] = 0;
return qstring;
}
/**
* qstring_from_str(): Create a new QString from a regular C string
*
* Return strong reference.
*/
QString *qstring_from_str(const char *str)
{
return qstring_from_substr(str, 0, strlen(str));
}
static void capacity_increase(QString *qstring, size_t len)
{
if (qstring->capacity < (qstring->length + len)) {
assert(len <= SIZE_MAX - qstring->capacity);
qstring->capacity += len;
assert(qstring->capacity <= SIZE_MAX / 2);
qstring->capacity *= 2; /* use exponential growth */
qstring->string = g_realloc(qstring->string, qstring->capacity + 1);
}
}
/* qstring_append(): Append a C string to a QString
*/
void qstring_append(QString *qstring, const char *str)
{
size_t len = strlen(str);
capacity_increase(qstring, len);
memcpy(qstring->string + qstring->length, str, len);
qstring->length += len;
qstring->string[qstring->length] = 0;
}
void qstring_append_int(QString *qstring, int64_t value)
{
char num[32];
snprintf(num, sizeof(num), "%" PRId64, value);
qstring_append(qstring, num);
}
/**
* qstring_append_chr(): Append a C char to a QString
*/
void qstring_append_chr(QString *qstring, int c)
{
capacity_increase(qstring, 1);
qstring->string[qstring->length++] = c;
qstring->string[qstring->length] = 0;
}
/**
* qstring_get_str(): Return a pointer to the stored string
*
* NOTE: Should be used with caution, if the object is deallocated
* this pointer becomes invalid.
*/
const char *qstring_get_str(const QString *qstring)
{
return qstring->string;
}
/**
* qstring_get_try_str(): Return a pointer to the stored string
*
* NOTE: will return NULL if qstring is not provided.
*/
const char *qstring_get_try_str(const QString *qstring)
{
return qstring ? qstring_get_str(qstring) : NULL;
}
/**
* qobject_get_try_str(): Return a pointer to the corresponding string
*
* NOTE: the string will only be returned if the object is valid, and
* its type is QString, otherwise NULL is returned.
*/
const char *qobject_get_try_str(const QObject *qstring)
{
return qstring_get_try_str(qobject_to(QString, qstring));
}
/**
* qstring_is_equal(): Test whether the two QStrings are equal
*/
bool qstring_is_equal(const QObject *x, const QObject *y)
{
return !strcmp(qobject_to(QString, x)->string,
qobject_to(QString, y)->string);
}
/**
* qstring_free(): Free the memory allocated by a QString object
*
* Return: if @return_str, return the underlying string, to be
* g_free(), otherwise NULL is returned.
*/
char *qstring_free(QString *qstring, bool return_str)
{
char *rv = NULL;
if (return_str) {
rv = qstring->string;
} else {
g_free(qstring->string);
}
g_free(qstring);
return rv;
}
/**
* qstring_destroy_obj(): Free all memory allocated by a QString
* object
*/
void qstring_destroy_obj(QObject *obj)
{
assert(obj != NULL);
qstring_free(qobject_to(QString, obj), FALSE);
}