Home | History | Annotate | Download | only in qobject 
      1 /*
      2  * QString Module
      3  *
      4  * Copyright (C) 2009 Red Hat Inc.
      5  *
      6  * Authors:
      7  *  Luiz Capitulino <lcapitulino (at) 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 "qapi/qmp/qobject.h"
     14 #include "qapi/qmp/qstring.h"
     15 #include "qemu-common.h"
     16 
     17 static void qstring_destroy_obj(QObject *obj);
     18 
     19 static const QType qstring_type = {
     20     .code = QTYPE_QSTRING,
     21     .destroy = qstring_destroy_obj,
     22 };
     23 
     24 /**
     25  * qstring_new(): Create a new empty QString
     26  *
     27  * Return strong reference.
     28  */
     29 QString *qstring_new(void)
     30 {
     31     return qstring_from_str("");
     32 }
     33 
     34 /**
     35  * qstring_get_length(): Get the length of a QString
     36  */
     37 size_t qstring_get_length(const QString *qstring)
     38 {
     39     return qstring->length;
     40 }
     41 
     42 /**
     43  * qstring_from_substr(): Create a new QString from a C string substring
     44  *
     45  * Return string reference
     46  */
     47 QString *qstring_from_substr(const char *str, int start, int end)
     48 {
     49     QString *qstring;
     50 
     51     qstring = g_malloc(sizeof(*qstring));
     52 
     53     qstring->length = end - start + 1;
     54     qstring->capacity = qstring->length;
     55 
     56     qstring->string = g_malloc(qstring->capacity + 1);
     57     memcpy(qstring->string, str + start, qstring->length);
     58     qstring->string[qstring->length] = 0;
     59 
     60     QOBJECT_INIT(qstring, &qstring_type);
     61 
     62     return qstring;
     63 }
     64 
     65 /**
     66  * qstring_from_str(): Create a new QString from a regular C string
     67  *
     68  * Return strong reference.
     69  */
     70 QString *qstring_from_str(const char *str)
     71 {
     72     return qstring_from_substr(str, 0, strlen(str) - 1);
     73 }
     74 
     75 static void capacity_increase(QString *qstring, size_t len)
     76 {
     77     if (qstring->capacity < (qstring->length + len)) {
     78         qstring->capacity += len;
     79         qstring->capacity *= 2; /* use exponential growth */
     80 
     81         qstring->string = g_realloc(qstring->string, qstring->capacity + 1);
     82     }
     83 }
     84 
     85 /* qstring_append(): Append a C string to a QString
     86  */
     87 void qstring_append(QString *qstring, const char *str)
     88 {
     89     size_t len = strlen(str);
     90 
     91     capacity_increase(qstring, len);
     92     memcpy(qstring->string + qstring->length, str, len);
     93     qstring->length += len;
     94     qstring->string[qstring->length] = 0;
     95 }
     96 
     97 void qstring_append_int(QString *qstring, int64_t value)
     98 {
     99     char num[32];
    100 
    101     snprintf(num, sizeof(num), "%" PRId64, value);
    102     qstring_append(qstring, num);
    103 }
    104 
    105 /**
    106  * qstring_append_chr(): Append a C char to a QString
    107  */
    108 void qstring_append_chr(QString *qstring, int c)
    109 {
    110     capacity_increase(qstring, 1);
    111     qstring->string[qstring->length++] = c;
    112     qstring->string[qstring->length] = 0;
    113 }
    114 
    115 /**
    116  * qobject_to_qstring(): Convert a QObject to a QString
    117  */
    118 QString *qobject_to_qstring(const QObject *obj)
    119 {
    120     if (qobject_type(obj) != QTYPE_QSTRING)
    121         return NULL;
    122 
    123     return container_of(obj, QString, base);
    124 }
    125 
    126 /**
    127  * qstring_get_str(): Return a pointer to the stored string
    128  *
    129  * NOTE: Should be used with caution, if the object is deallocated
    130  * this pointer becomes invalid.
    131  */
    132 const char *qstring_get_str(const QString *qstring)
    133 {
    134     return qstring->string;
    135 }
    136 
    137 /**
    138  * qstring_destroy_obj(): Free all memory allocated by a QString
    139  * object
    140  */
    141 static void qstring_destroy_obj(QObject *obj)
    142 {
    143     QString *qs;
    144 
    145     assert(obj != NULL);
    146     qs = qobject_to_qstring(obj);
    147     g_free(qs->string);
    148     g_free(qs);
    149 }
    150