xref: /openbmc/qemu/qobject/qstring.c (revision b11ce33f)
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/qobject.h"
15 #include "qapi/qmp/qstring.h"
16 #include "qemu-common.h"
17 
18 /**
19  * qstring_new(): Create a new empty QString
20  *
21  * Return strong reference.
22  */
23 QString *qstring_new(void)
24 {
25     return qstring_from_str("");
26 }
27 
28 /**
29  * qstring_get_length(): Get the length of a QString
30  */
31 size_t qstring_get_length(const QString *qstring)
32 {
33     return qstring->length;
34 }
35 
36 /**
37  * qstring_from_substr(): Create a new QString from a C string substring
38  *
39  * Return string reference
40  */
41 QString *qstring_from_substr(const char *str, int start, int end)
42 {
43     QString *qstring;
44 
45     qstring = g_malloc(sizeof(*qstring));
46     qobject_init(QOBJECT(qstring), QTYPE_QSTRING);
47 
48     qstring->length = end - start + 1;
49     qstring->capacity = qstring->length;
50 
51     qstring->string = g_malloc(qstring->capacity + 1);
52     memcpy(qstring->string, str + start, qstring->length);
53     qstring->string[qstring->length] = 0;
54 
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  */
64 QString *qstring_from_str(const char *str)
65 {
66     return qstring_from_substr(str, 0, strlen(str) - 1);
67 }
68 
69 static void capacity_increase(QString *qstring, size_t len)
70 {
71     if (qstring->capacity < (qstring->length + len)) {
72         qstring->capacity += len;
73         qstring->capacity *= 2; /* use exponential growth */
74 
75         qstring->string = g_realloc(qstring->string, qstring->capacity + 1);
76     }
77 }
78 
79 /* qstring_append(): Append a C string to a QString
80  */
81 void qstring_append(QString *qstring, const char *str)
82 {
83     size_t len = strlen(str);
84 
85     capacity_increase(qstring, len);
86     memcpy(qstring->string + qstring->length, str, len);
87     qstring->length += len;
88     qstring->string[qstring->length] = 0;
89 }
90 
91 void qstring_append_int(QString *qstring, int64_t value)
92 {
93     char num[32];
94 
95     snprintf(num, sizeof(num), "%" PRId64, value);
96     qstring_append(qstring, num);
97 }
98 
99 /**
100  * qstring_append_chr(): Append a C char to a QString
101  */
102 void qstring_append_chr(QString *qstring, int c)
103 {
104     capacity_increase(qstring, 1);
105     qstring->string[qstring->length++] = c;
106     qstring->string[qstring->length] = 0;
107 }
108 
109 /**
110  * qobject_to_qstring(): Convert a QObject to a QString
111  */
112 QString *qobject_to_qstring(const QObject *obj)
113 {
114     if (!obj || qobject_type(obj) != QTYPE_QSTRING) {
115         return NULL;
116     }
117     return container_of(obj, QString, base);
118 }
119 
120 /**
121  * qstring_get_str(): Return a pointer to the stored string
122  *
123  * NOTE: Should be used with caution, if the object is deallocated
124  * this pointer becomes invalid.
125  */
126 const char *qstring_get_str(const QString *qstring)
127 {
128     return qstring->string;
129 }
130 
131 /**
132  * qstring_is_equal(): Test whether the two QStrings are equal
133  */
134 bool qstring_is_equal(const QObject *x, const QObject *y)
135 {
136     return !strcmp(qobject_to_qstring(x)->string,
137                    qobject_to_qstring(y)->string);
138 }
139 
140 /**
141  * qstring_destroy_obj(): Free all memory allocated by a QString
142  * object
143  */
144 void qstring_destroy_obj(QObject *obj)
145 {
146     QString *qs;
147 
148     assert(obj != NULL);
149     qs = qobject_to_qstring(obj);
150     g_free(qs->string);
151     g_free(qs);
152 }
153