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      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 "qobject.h"
     14 #include "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_from_substr(): Create a new QString from a C string substring
     36  *
     37  * Return string reference
     38  */
     39 QString *qstring_from_substr(const char *str, int start, int end)
     40 {
     41     QString *qstring;
     42 
     43     qstring = qemu_malloc(sizeof(*qstring));
     44 
     45     qstring->length = end - start + 1;
     46     qstring->capacity = qstring->length;
     47 
     48     qstring->string = qemu_malloc(qstring->capacity + 1);
     49     memcpy(qstring->string, str + start, qstring->length);
     50     qstring->string[qstring->length] = 0;
     51 
     52     QOBJECT_INIT(qstring, &qstring_type);
     53 
     54     return qstring;
     55 }
     56 
     57 /**
     58  * qstring_from_str(): Create a new QString from a regular C string
     59  *
     60  * Return strong reference.
     61  */
     62 QString *qstring_from_str(const char *str)
     63 {
     64     return qstring_from_substr(str, 0, strlen(str) - 1);
     65 }
     66 
     67 static void capacity_increase(QString *qstring, size_t len)
     68 {
     69     if (qstring->capacity < (qstring->length + len)) {
     70         qstring->capacity += len;
     71         qstring->capacity *= 2; /* use exponential growth */
     72 
     73         qstring->string = qemu_realloc(qstring->string, qstring->capacity + 1);
     74     }
     75 }
     76 
     77 /* qstring_append(): Append a C string to a QString
     78  */
     79 void qstring_append(QString *qstring, const char *str)
     80 {
     81     size_t len = strlen(str);
     82 
     83     capacity_increase(qstring, len);
     84     memcpy(qstring->string + qstring->length, str, len);
     85     qstring->length += len;
     86     qstring->string[qstring->length] = 0;
     87 }
     88 
     89 void qstring_append_int(QString *qstring, int64_t value)
     90 {
     91     char num[32];
     92 
     93     snprintf(num, sizeof(num), "%" PRId64, value);
     94     qstring_append(qstring, num);
     95 }
     96 
     97 /**
     98  * qstring_append_chr(): Append a C char to a QString
     99  */
    100 void qstring_append_chr(QString *qstring, int c)
    101 {
    102     capacity_increase(qstring, 1);
    103     qstring->string[qstring->length++] = c;
    104     qstring->string[qstring->length] = 0;
    105 }
    106 
    107 /**
    108  * qobject_to_qstring(): Convert a QObject to a QString
    109  */
    110 QString *qobject_to_qstring(const QObject *obj)
    111 {
    112     if (qobject_type(obj) != QTYPE_QSTRING)
    113         return NULL;
    114 
    115     return container_of(obj, QString, base);
    116 }
    117 
    118 /**
    119  * qstring_get_str(): Return a pointer to the stored string
    120  *
    121  * NOTE: Should be used with caution, if the object is deallocated
    122  * this pointer becomes invalid.
    123  */
    124 const char *qstring_get_str(const QString *qstring)
    125 {
    126     return qstring->string;
    127 }
    128 
    129 /**
    130  * qstring_destroy_obj(): Free all memory allocated by a QString
    131  * object
    132  */
    133 static void qstring_destroy_obj(QObject *obj)
    134 {
    135     QString *qs;
    136 
    137     assert(obj != NULL);
    138     qs = qobject_to_qstring(obj);
    139     qemu_free(qs->string);
    140     qemu_free(qs);
    141 }
    142