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 16 /** 17 * qstring_new(): Create a new empty QString 18 * 19 * Return strong reference. 20 */ 21 QString *qstring_new(void) 22 { 23 return qstring_from_str(""); 24 } 25 26 /** 27 * qstring_get_length(): Get the length of a QString 28 */ 29 size_t qstring_get_length(const QString *qstring) 30 { 31 return qstring->length; 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, size_t start, size_t end) 40 { 41 QString *qstring; 42 43 assert(start <= end); 44 45 qstring = g_malloc(sizeof(*qstring)); 46 qobject_init(QOBJECT(qstring), QTYPE_QSTRING); 47 48 qstring->length = end - start; 49 qstring->capacity = qstring->length; 50 51 assert(qstring->capacity < SIZE_MAX); 52 qstring->string = g_malloc(qstring->capacity + 1); 53 memcpy(qstring->string, str + start, qstring->length); 54 qstring->string[qstring->length] = 0; 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)); 67 } 68 69 static void capacity_increase(QString *qstring, size_t len) 70 { 71 if (qstring->capacity < (qstring->length + len)) { 72 assert(len <= SIZE_MAX - qstring->capacity); 73 qstring->capacity += len; 74 assert(qstring->capacity <= SIZE_MAX / 2); 75 qstring->capacity *= 2; /* use exponential growth */ 76 77 qstring->string = g_realloc(qstring->string, qstring->capacity + 1); 78 } 79 } 80 81 /* qstring_append(): Append a C string to a QString 82 */ 83 void qstring_append(QString *qstring, const char *str) 84 { 85 size_t len = strlen(str); 86 87 capacity_increase(qstring, len); 88 memcpy(qstring->string + qstring->length, str, len); 89 qstring->length += len; 90 qstring->string[qstring->length] = 0; 91 } 92 93 void qstring_append_int(QString *qstring, int64_t value) 94 { 95 char num[32]; 96 97 snprintf(num, sizeof(num), "%" PRId64, value); 98 qstring_append(qstring, num); 99 } 100 101 /** 102 * qstring_append_chr(): Append a C char to a QString 103 */ 104 void qstring_append_chr(QString *qstring, int c) 105 { 106 capacity_increase(qstring, 1); 107 qstring->string[qstring->length++] = c; 108 qstring->string[qstring->length] = 0; 109 } 110 111 /** 112 * qstring_get_str(): Return a pointer to the stored string 113 * 114 * NOTE: Should be used with caution, if the object is deallocated 115 * this pointer becomes invalid. 116 */ 117 const char *qstring_get_str(const QString *qstring) 118 { 119 return qstring->string; 120 } 121 122 /** 123 * qstring_get_try_str(): Return a pointer to the stored string 124 * 125 * NOTE: will return NULL if qstring is not provided. 126 */ 127 const char *qstring_get_try_str(const QString *qstring) 128 { 129 return qstring ? qstring_get_str(qstring) : NULL; 130 } 131 132 /** 133 * qobject_get_try_str(): Return a pointer to the corresponding string 134 * 135 * NOTE: the string will only be returned if the object is valid, and 136 * its type is QString, otherwise NULL is returned. 137 */ 138 const char *qobject_get_try_str(const QObject *qstring) 139 { 140 return qstring_get_try_str(qobject_to(QString, qstring)); 141 } 142 143 /** 144 * qstring_is_equal(): Test whether the two QStrings are equal 145 */ 146 bool qstring_is_equal(const QObject *x, const QObject *y) 147 { 148 return !strcmp(qobject_to(QString, x)->string, 149 qobject_to(QString, y)->string); 150 } 151 152 /** 153 * qstring_free(): Free the memory allocated by a QString object 154 * 155 * Return: if @return_str, return the underlying string, to be 156 * g_free(), otherwise NULL is returned. 157 */ 158 char *qstring_free(QString *qstring, bool return_str) 159 { 160 char *rv = NULL; 161 162 if (return_str) { 163 rv = qstring->string; 164 } else { 165 g_free(qstring->string); 166 } 167 168 g_free(qstring); 169 170 return rv; 171 } 172 173 /** 174 * qstring_destroy_obj(): Free all memory allocated by a QString 175 * object 176 */ 177 void qstring_destroy_obj(QObject *obj) 178 { 179 assert(obj != NULL); 180 qstring_free(qobject_to(QString, obj), FALSE); 181 } 182