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1 : : /* GIO - GLib Input, Output and Streaming Library
2 : : *
3 : : * Copyright (C) 2009 Red Hat, Inc.
4 : : *
5 : : * SPDX-License-Identifier: LGPL-2.1-or-later
6 : : *
7 : : * This library is free software; you can redistribute it and/or
8 : : * modify it under the terms of the GNU Lesser General Public
9 : : * License as published by the Free Software Foundation; either
10 : : * version 2.1 of the License, or (at your option) any later version.
11 : : *
12 : : * This library is distributed in the hope that it will be useful,
13 : : * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 : : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 : : * Lesser General Public License for more details.
16 : : *
17 : : * You should have received a copy of the GNU Lesser General
18 : : * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
19 : : *
20 : : * Author: Alexander Larsson <alexl@redhat.com>
21 : : */
22 : :
23 : : #include "config.h"
24 : : #include "gconverter.h"
25 : : #include "glibintl.h"
26 : :
27 : :
28 : : /**
29 : : * GConverter:
30 : : *
31 : : * `GConverter` is an interface for streaming conversions.
32 : : *
33 : : * `GConverter` is implemented by objects that convert
34 : : * binary data in various ways. The conversion can be
35 : : * stateful and may fail at any place.
36 : : *
37 : : * Some example conversions are: character set conversion,
38 : : * compression, decompression and regular expression
39 : : * replace.
40 : : *
41 : : * Since: 2.24
42 : : */
43 : :
44 : :
45 : : typedef GConverterIface GConverterInterface;
46 [ + + + - : 180922 : G_DEFINE_INTERFACE (GConverter, g_converter, G_TYPE_OBJECT)
+ + ]
47 : :
48 : : static void
49 : 7 : g_converter_default_init (GConverterInterface *iface)
50 : : {
51 : 7 : }
52 : :
53 : : /**
54 : : * g_converter_convert:
55 : : * @converter: a #GConverter.
56 : : * @inbuf: (array length=inbuf_size) (element-type guint8): the buffer
57 : : * containing the data to convert.
58 : : * @inbuf_size: the number of bytes in @inbuf
59 : : * @outbuf: (element-type guint8) (array length=outbuf_size) (not nullable): a
60 : : * buffer to write converted data in.
61 : : * @outbuf_size: the number of bytes in @outbuf, must be at least one
62 : : * @flags: a #GConverterFlags controlling the conversion details
63 : : * @bytes_read: (out) (not nullable): will be set to the number of bytes read
64 : : * from @inbuf on success
65 : : * @bytes_written: (out) (not nullable): will be set to the number of bytes
66 : : * written to @outbuf on success
67 : : * @error: location to store the error occurring, or %NULL to ignore
68 : : *
69 : : * This is the main operation used when converting data. It is to be called
70 : : * multiple times in a loop, and each time it will do some work, i.e.
71 : : * producing some output (in @outbuf) or consuming some input (from @inbuf) or
72 : : * both. If its not possible to do any work an error is returned.
73 : : *
74 : : * Note that a single call may not consume all input (or any input at all).
75 : : * Also a call may produce output even if given no input, due to state stored
76 : : * in the converter producing output.
77 : : *
78 : : * If any data was either produced or consumed, and then an error happens, then
79 : : * only the successful conversion is reported and the error is returned on the
80 : : * next call.
81 : : *
82 : : * A full conversion loop involves calling this method repeatedly, each time
83 : : * giving it new input and space output space. When there is no more input
84 : : * data after the data in @inbuf, the flag %G_CONVERTER_INPUT_AT_END must be set.
85 : : * The loop will be (unless some error happens) returning %G_CONVERTER_CONVERTED
86 : : * each time until all data is consumed and all output is produced, then
87 : : * %G_CONVERTER_FINISHED is returned instead. Note, that %G_CONVERTER_FINISHED
88 : : * may be returned even if %G_CONVERTER_INPUT_AT_END is not set, for instance
89 : : * in a decompression converter where the end of data is detectable from the
90 : : * data (and there might even be other data after the end of the compressed data).
91 : : *
92 : : * When some data has successfully been converted @bytes_read and is set to
93 : : * the number of bytes read from @inbuf, and @bytes_written is set to indicate
94 : : * how many bytes was written to @outbuf. If there are more data to output
95 : : * or consume (i.e. unless the %G_CONVERTER_INPUT_AT_END is specified) then
96 : : * %G_CONVERTER_CONVERTED is returned, and if no more data is to be output
97 : : * then %G_CONVERTER_FINISHED is returned.
98 : : *
99 : : * On error %G_CONVERTER_ERROR is returned and @error is set accordingly.
100 : : * Some errors need special handling:
101 : : *
102 : : * %G_IO_ERROR_NO_SPACE is returned if there is not enough space
103 : : * to write the resulting converted data, the application should
104 : : * call the function again with a larger @outbuf to continue.
105 : : *
106 : : * %G_IO_ERROR_PARTIAL_INPUT is returned if there is not enough
107 : : * input to fully determine what the conversion should produce,
108 : : * and the %G_CONVERTER_INPUT_AT_END flag is not set. This happens for
109 : : * example with an incomplete multibyte sequence when converting text,
110 : : * or when a regexp matches up to the end of the input (and may match
111 : : * further input). It may also happen when @inbuf_size is zero and
112 : : * there is no more data to produce.
113 : : *
114 : : * When this happens the application should read more input and then
115 : : * call the function again. If further input shows that there is no
116 : : * more data call the function again with the same data but with
117 : : * the %G_CONVERTER_INPUT_AT_END flag set. This may cause the conversion
118 : : * to finish as e.g. in the regexp match case (or, to fail again with
119 : : * %G_IO_ERROR_PARTIAL_INPUT in e.g. a charset conversion where the
120 : : * input is actually partial).
121 : : *
122 : : * After g_converter_convert() has returned %G_CONVERTER_FINISHED the
123 : : * converter object is in an invalid state where its not allowed
124 : : * to call g_converter_convert() anymore. At this time you can only
125 : : * free the object or call g_converter_reset() to reset it to the
126 : : * initial state.
127 : : *
128 : : * If the flag %G_CONVERTER_FLUSH is set then conversion is modified
129 : : * to try to write out all internal state to the output. The application
130 : : * has to call the function multiple times with the flag set, and when
131 : : * the available input has been consumed and all internal state has
132 : : * been produced then %G_CONVERTER_FLUSHED (or %G_CONVERTER_FINISHED if
133 : : * really at the end) is returned instead of %G_CONVERTER_CONVERTED.
134 : : * This is somewhat similar to what happens at the end of the input stream,
135 : : * but done in the middle of the data.
136 : : *
137 : : * This has different meanings for different conversions. For instance
138 : : * in a compression converter it would mean that we flush all the
139 : : * compression state into output such that if you uncompress the
140 : : * compressed data you get back all the input data. Doing this may
141 : : * make the final file larger due to padding though. Another example
142 : : * is a regexp conversion, where if you at the end of the flushed data
143 : : * have a match, but there is also a potential longer match. In the
144 : : * non-flushed case we would ask for more input, but when flushing we
145 : : * treat this as the end of input and do the match.
146 : : *
147 : : * Flushing is not always possible (like if a charset converter flushes
148 : : * at a partial multibyte sequence). Converters are supposed to try
149 : : * to produce as much output as possible and then return an error
150 : : * (typically %G_IO_ERROR_PARTIAL_INPUT).
151 : : *
152 : : * Returns: a #GConverterResult, %G_CONVERTER_ERROR on error.
153 : : *
154 : : * Since: 2.24
155 : : **/
156 : : GConverterResult
157 : 90409 : g_converter_convert (GConverter *converter,
158 : : const void *inbuf,
159 : : gsize inbuf_size,
160 : : void *outbuf,
161 : : gsize outbuf_size,
162 : : GConverterFlags flags,
163 : : gsize *bytes_read,
164 : : gsize *bytes_written,
165 : : GError **error)
166 : : {
167 : : GConverterIface *iface;
168 : :
169 : 90409 : g_return_val_if_fail (G_IS_CONVERTER (converter), G_CONVERTER_ERROR);
170 : 90409 : g_return_val_if_fail (inbuf != NULL || inbuf_size == 0, G_CONVERTER_ERROR);
171 : 90409 : g_return_val_if_fail (outbuf != NULL, G_CONVERTER_ERROR);
172 : 90409 : g_return_val_if_fail (outbuf_size > 0, G_CONVERTER_ERROR);
173 : 90409 : g_return_val_if_fail (bytes_read != NULL, G_CONVERTER_ERROR);
174 : 90409 : g_return_val_if_fail (bytes_written != NULL, G_CONVERTER_ERROR);
175 : 90409 : g_return_val_if_fail (error == NULL || *error == NULL, G_CONVERTER_ERROR);
176 : :
177 : 90409 : *bytes_read = 0;
178 : 90409 : *bytes_written = 0;
179 : :
180 : 90409 : iface = G_CONVERTER_GET_IFACE (converter);
181 : :
182 : 90409 : return (* iface->convert) (converter,
183 : : inbuf, inbuf_size,
184 : : outbuf, outbuf_size,
185 : : flags,
186 : : bytes_read, bytes_written, error);
187 : : }
188 : :
189 : : /**
190 : : * g_converter_reset:
191 : : * @converter: a #GConverter.
192 : : *
193 : : * Resets all internal state in the converter, making it behave
194 : : * as if it was just created. If the converter has any internal
195 : : * state that would produce output then that output is lost.
196 : : *
197 : : * Since: 2.24
198 : : **/
199 : : void
200 : 19 : g_converter_reset (GConverter *converter)
201 : : {
202 : : GConverterIface *iface;
203 : :
204 : 19 : g_return_if_fail (G_IS_CONVERTER (converter));
205 : :
206 : 19 : iface = G_CONVERTER_GET_IFACE (converter);
207 : :
208 : 19 : (* iface->reset) (converter);
209 : : }
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