LXR qemu/qobject/qstring.c

   1/*
   2 * QString Module
   3 *
   4 * Copyright (C) 2009 Red Hat Inc.
   5 *
   6 * Authors:
   7 *  Luiz Capitulino <lcapitulino@redhat.com>
   8 *
   9 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
  10 * See the COPYING.LIB file in the top-level directory.
  11 */
  12
  13#include "qemu/osdep.h"
  14#include "qapi/qmp/qstring.h"
  15
  16/**
  17 * qstring_new(): Create a new empty QString
  18 *
  19 * Return strong reference.
  20 */
  21QString *qstring_new(void)
  22{
  23    return qstring_from_str("");
  24}
  25
  26/**
  27 * qstring_get_length(): Get the length of a QString
  28 */
  29size_t qstring_get_length(const QString *qstring)
  30{
  31    return qstring->length;
  32}
  33
  34/**
  35 * qstring_from_substr(): Create a new QString from a C string substring
  36 *
  37 * Return string reference
  38 */
  39QString *qstring_from_substr(const char *str, size_t start, size_t end)
  40{
  41    QString *qstring;
  42
  43    assert(start <= end);
  44
  45    qstring = g_malloc(sizeof(*qstring));
  46    qobject_init(QOBJECT(qstring), QTYPE_QSTRING);
  47
  48    qstring->length = end - start;
  49    qstring->capacity = qstring->length;
  50
  51    assert(qstring->capacity < SIZE_MAX);
  52    qstring->string = g_malloc(qstring->capacity + 1);
  53    memcpy(qstring->string, str + start, qstring->length);
  54    qstring->string[qstring->length] = 0;
  55
  56    return qstring;
  57}
  58
  59/**
  60 * qstring_from_str(): Create a new QString from a regular C string
  61 *
  62 * Return strong reference.
  63 */
  64QString *qstring_from_str(const char *str)
  65{
  66    return qstring_from_substr(str, 0, strlen(str));
  67}
  68
  69static void capacity_increase(QString *qstring, size_t len)
  70{
  71    if (qstring->capacity < (qstring->length + len)) {
  72        assert(len <= SIZE_MAX - qstring->capacity);
  73        qstring->capacity += len;
  74        assert(qstring->capacity <= SIZE_MAX / 2);
  75        qstring->capacity *= 2; /* use exponential growth */
  76
  77        qstring->string = g_realloc(qstring->string, qstring->capacity + 1);
  78    }
  79}
  80
  81/* qstring_append(): Append a C string to a QString
  82 */
  83void qstring_append(QString *qstring, const char *str)
  84{
  85    size_t len = strlen(str);
  86
  87    capacity_increase(qstring, len);
  88    memcpy(qstring->string + qstring->length, str, len);
  89    qstring->length += len;
  90    qstring->string[qstring->length] = 0;
  91}
  92
  93void qstring_append_int(QString *qstring, int64_t value)
  94{
  95    char num[32];
  96
  97    snprintf(num, sizeof(num), "%" PRId64, value);
  98    qstring_append(qstring, num);
  99}
 100
 101/**
 102 * qstring_append_chr(): Append a C char to a QString
 103 */
 104void qstring_append_chr(QString *qstring, int c)
 105{
 106    capacity_increase(qstring, 1);
 107    qstring->string[qstring->length++] = c;
 108    qstring->string[qstring->length] = 0;
 109}
 110
 111/**
 112 * qstring_get_str(): Return a pointer to the stored string
 113 *
 114 * NOTE: Should be used with caution, if the object is deallocated
 115 * this pointer becomes invalid.
 116 */
 117const char *qstring_get_str(const QString *qstring)
 118{
 119    return qstring->string;
 120}
 121
 122/**
 123 * qstring_get_try_str(): Return a pointer to the stored string
 124 *
 125 * NOTE: will return NULL if qstring is not provided.
 126 */
 127const char *qstring_get_try_str(const QString *qstring)
 128{
 129    return qstring ? qstring_get_str(qstring) : NULL;
 130}
 131
 132/**
 133 * qobject_get_try_str(): Return a pointer to the corresponding string
 134 *
 135 * NOTE: the string will only be returned if the object is valid, and
 136 * its type is QString, otherwise NULL is returned.
 137 */
 138const char *qobject_get_try_str(const QObject *qstring)
 139{
 140    return qstring_get_try_str(qobject_to(QString, qstring));
 141}
 142
 143/**
 144 * qstring_is_equal(): Test whether the two QStrings are equal
 145 */
 146bool qstring_is_equal(const QObject *x, const QObject *y)
 147{
 148    return !strcmp(qobject_to(QString, x)->string,
 149                   qobject_to(QString, y)->string);
 150}
 151
 152/**
 153 * qstring_destroy_obj(): Free all memory allocated by a QString
 154 * object
 155 */
 156void qstring_destroy_obj(QObject *obj)
 157{
 158    QString *qs;
 159
 160    assert(obj != NULL);
 161    qs = qobject_to(QString, obj);
 162    g_free(qs->string);
 163    g_free(qs);
 164}
 165