4c1f94bcb890526548e1702209625add432232e1
2 * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
19 /** \file filter_chain.c common helper functions for filter input/output */
27 DEFINE_FILTER_ARRAY(filters
);
30 * call the init function of each supported filter
32 * \param all_filters the array of all supported filters
35 void filter_init(struct filter
*all_filters
)
39 for (f
= all_filters
; f
->name
; f
++)
44 * close and destroy a filter callback
46 * \param fcb the filter callback to close
48 * This removes \a fcb from the list of filter callbacks and calls
49 * the close callback associated with \a fcb.
51 static void close_filter_callback(struct filter_callback
*fcb
)
53 PARA_NOTICE_LOG("closing filter_callback %p, data: %p\n", fcb
, fcb
->data
);
59 * close all callbacks of a filter node
61 * \param fn the filter node which contains the filter callbacks to be closed
63 * Call close_filter_callback() for each entry in the filter callback list
66 static void close_callbacks(struct filter_node
*fn
)
68 struct filter_callback
*fcb
, *tmp
;
70 list_for_each_entry_safe(fcb
, tmp
, &fn
->callbacks
, node
)
71 close_filter_callback(fcb
);
74 static void call_callbacks(struct filter_node
*fn
, char *inbuf
, size_t inlen
,
75 char *outbuf
, size_t outlen
)
77 struct filter_callback
*fcb
, *tmp
;
78 list_for_each_entry_safe(fcb
, tmp
, &fn
->callbacks
, node
) {
80 if (inlen
&& fcb
->input_cb
) {
81 ret
= fcb
->input_cb(inbuf
, inlen
, fcb
);
83 close_filter_callback(fcb
);
87 if (!outlen
|| !fcb
->output_cb
)
89 ret
= fcb
->output_cb(outbuf
, outlen
, fcb
);
91 close_filter_callback(fcb
);
96 * call the convert function of each filter
98 * \param fci the filter chain containing the list of filter nodes.
100 * This is the core function of the filter subsystem. It loops over the list of
101 * filter nodes determined by \a fci and calls the filter's convert function if
102 * there is input available for the filter node in question. If the convert
103 * function consumed some or all of its input data, all registered input
104 * callbacks are called. Similarly, if a convert function produced output, all
105 * registerd output callbacks get called.
107 * \return The sum of output bytes produced by the convert functions on success,
108 * negative return value on errors.
110 * \sa filter_node, filter#convert, filter_callback
112 int filter_io(struct filter_chain_info
*fci
)
114 struct filter_node
*fn
;
117 int conv
, conv_total
= 0;
120 loaded
= fci
->in_loaded
;
122 list_for_each_entry(fn
, &fci
->filters
, node
) {
124 if (*loaded
&& fn
->loaded
< fn
->bufsize
) {
125 size_t old_fn_loaded
= fn
->loaded
;
126 PARA_DEBUG_LOG("fc %p loaded: %zd, calling %s convert\n", fci
, *loaded
, fn
->filter
->name
);
127 ret
= fn
->filter
->convert(ib
, *loaded
, fn
);
133 call_callbacks(fn
, ib
, ret
, fn
->buf
+ old_fn_loaded
, fn
->loaded
- old_fn_loaded
);
136 if (*loaded
&& ret
) {
137 PARA_DEBUG_LOG("moving %zd bytes in input buffer for %s filter\n",
138 *loaded
, fn
->filter
->name
);
139 memmove(ib
, ib
+ ret
, *loaded
);
143 loaded
= &fn
->loaded
;
145 // PARA_DEBUG_LOG("loaded: %d\n", *loaded);
153 * close all filter nodes and its callbacks
155 * \param fci the filter chain to close
157 * For each filter node determined by \a fci, call the close function of each
158 * registered filter callback as well as the close function of the
159 * corresponding filter. Free all resources and destroy all callback lists and
160 * the filter node list.
162 * \sa filter::close, filter_callback::close
164 void close_filters(struct filter_chain_info
*fci
)
166 struct filter_node
*fn
, *tmp
;
170 PARA_DEBUG_LOG("closing filter chain %p\n", fci
);
171 list_for_each_entry_safe(fn
, tmp
, &fci
->filters
, node
) {
172 PARA_NOTICE_LOG("closing %s filter callbacks (fci %p, fn %p)\n", fn
->filter
->name
, fci
, fn
);
174 PARA_NOTICE_LOG("closing %s filter (fci %p, fn %p)\n", fn
->filter
->name
, fci
, fn
);
175 fn
->filter
->close(fn
);
182 * If the filter has a command line parser and options is not NULL, run it.
183 * Returns filter_num on success, negative on errors
185 static int parse_filter_args(int filter_num
, char *options
, void **conf
)
187 struct filter
*f
= &filters
[filter_num
];
191 // PARA_DEBUG_LOG("%s, options: %s, parser: %p\n", f->name,
192 // options? options : "(none)", f->parse_config);
193 if (!f
->parse_config
)
194 return strlen(options
)? -E_BAD_FILTER_OPTIONS
: filter_num
;
195 // PARA_DEBUG_LOG("options: %s\n", options);
196 argc
= split_args(options
, &argv
, " \t");
197 // PARA_DEBUG_LOG("argc = %d, argv[0]: %s\n", argc, argv[0]);
198 for (i
= argc
- 1; i
>= 0; i
--)
199 argv
[i
+ 1] = argv
[i
];
200 argv
[0] = para_strdup(f
->name
);
202 *conf
= f
->parse_config(argc
, argv
);
203 return *conf
? filter_num
: -E_BAD_FILTER_OPTIONS
;
207 * check the filter command line options
209 * \param fa the command line options
210 * \param conf points to the filter configuration upon successful return
212 * Check if \a fa starts with a the name of a supported filter, followed by
213 * a colon. If yes, call the command line parser of that filter.
215 * \return On success, the number of the filter is returned and \a conf
216 * is initialized to point to the filter configuration determined by \a fa.
217 * On errors, a negative value is returned.
219 * Note: If \a fa specifies a filter that has no command line parser success is
220 * returned, and \a conf is initialized to \p NULL.
222 * \sa filter::parse_config
224 int check_filter_arg(char *fa
, void **conf
)
229 // PARA_DEBUG_LOG("arg: %s\n", fa);
230 for (j
= 0; filters
[j
].name
; j
++) {
231 const char *name
= filters
[j
].name
;
232 size_t len
= strlen(name
);
234 if (strlen(fa
) < len
)
236 if (strncmp(name
, fa
, len
))
241 if (c
&& !filters
[j
].parse_config
)
242 return -E_BAD_FILTER_OPTIONS
;
243 return parse_filter_args(j
, c
? fa
+ len
+ 1 :
244 fa
+ strlen(fa
), conf
);
246 return -E_UNSUPPORTED_FILTER
;