xref: /openbmc/qemu/qobject/qstring.c (revision fe7f9b8e)
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  */
22 QString *qstring_new(void)
23 {
24     return qstring_from_str("");
25 }
26 
27 /**
28  * qstring_get_length(): Get the length of a QString
29  */
30 size_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  */
40 QString *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  */
63 QString *qstring_from_str(const char *str)
64 {
65     return qstring_from_substr(str, 0, strlen(str) - 1);
66 }
67 
68 static 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  */
80 void 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 
90 void 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  */
101 void 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  */
114 const 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  */
124 const 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  */
135 const 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  */
143 bool 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  */
153 void 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