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