qemu/qstring.c
Anthony Liguori d30ec846ed Allow strings to grow in size
This lets us use QString for building larger strings

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-17 08:49:38 -06:00

109 lines
2.3 KiB
C

/*
* QString 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 "qobject.h"
#include "qstring.h"
#include "qemu-common.h"
static void qstring_destroy_obj(QObject *obj);
static const QType qstring_type = {
.code = QTYPE_QSTRING,
.destroy = qstring_destroy_obj,
};
/**
* qstring_new(): Create a new empty QString
*
* Return strong reference.
*/
QString *qstring_new(void)
{
return qstring_from_str("");
}
/**
* qstring_from_str(): Create a new QString from a regular C string
*
* Return strong reference.
*/
QString *qstring_from_str(const char *str)
{
QString *qstring;
qstring = qemu_malloc(sizeof(*qstring));
qstring->length = strlen(str);
qstring->capacity = qstring->length;
qstring->string = qemu_malloc(qstring->capacity + 1);
memcpy(qstring->string, str, qstring->length);
qstring->string[qstring->length] = 0;
QOBJECT_INIT(qstring, &qstring_type);
return qstring;
}
/* qstring_append(): Append a C string to a QString
*/
void qstring_append(QString *qstring, const char *str)
{
size_t len = strlen(str);
if (qstring->capacity < (qstring->length + len)) {
qstring->capacity += len;
qstring->capacity *= 2; /* use exponential growth */
qstring->string = qemu_realloc(qstring->string, qstring->capacity + 1);
}
memcpy(qstring->string + qstring->length, str, len);
qstring->length += len;
qstring->string[qstring->length] = 0;
}
/**
* qobject_to_qstring(): Convert a QObject to a QString
*/
QString *qobject_to_qstring(const QObject *obj)
{
if (qobject_type(obj) != QTYPE_QSTRING)
return NULL;
return container_of(obj, QString, base);
}
/**
* 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_destroy_obj(): Free all memory allocated by a QString
* object
*/
static void qstring_destroy_obj(QObject *obj)
{
QString *qs;
assert(obj != NULL);
qs = qobject_to_qstring(obj);
qemu_free(qs->string);
qemu_free(qs);
}