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 */
29 DEFINE_FILTER_ARRAY(filters
);
32 * call the init function of each supported filter
34 * \param all_filters the array of all supported filters
37 void filter_init(struct filter
*all_filters
)
41 for (f
= all_filters
; f
->name
; f
++)
46 * close and destroy a filter callback
48 * \param fcb the filter callback to close
50 * This removes \a fcb from the list of filter callbacks and calls
51 * the close callback associated with \a fcb.
53 static void close_filter_callback(struct filter_callback
*fcb
)
55 PARA_NOTICE_LOG("closing filter_callback %p, data: %p\n", fcb
, fcb
->data
);
61 * close all callbacks of a filter node
63 * \param fn the filter node which contains the filter callbacks to be closed
65 * Call close_filter_callback() for each entry in the filter callback list
68 static void close_callbacks(struct filter_node
*fn
)
70 struct filter_callback
*fcb
, *tmp
;
72 list_for_each_entry_safe(fcb
, tmp
, &fn
->callbacks
, node
)
73 close_filter_callback(fcb
);
76 static void call_callbacks(struct filter_node
*fn
, char *inbuf
, size_t inlen
,
77 char *outbuf
, size_t outlen
)
79 struct filter_callback
*fcb
, *tmp
;
80 list_for_each_entry_safe(fcb
, tmp
, &fn
->callbacks
, node
) {
82 if (inlen
&& fcb
->input_cb
) {
83 ret
= fcb
->input_cb(inbuf
, inlen
, fcb
);
85 close_filter_callback(fcb
);
89 if (!outlen
|| !fcb
->output_cb
)
91 ret
= fcb
->output_cb(outbuf
, outlen
, fcb
);
93 close_filter_callback(fcb
);
98 * call the convert function of each filter
100 * This is the core function of the filter subsystem. It loops over the list of
101 * filter nodes determined by \a t 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
108 * success, negative return value on errors (the return value is stored in
111 * \sa filter_node, filter#convert, filter_callback
113 void filter_pre_select(__a_unused
struct sched
*s
, struct task
*t
)
115 struct filter_chain
*fc
= t
->private_data
;
116 struct filter_node
*fn
;
119 int conv
, conv_total
= 0;
126 loaded
= fc
->in_loaded
;
128 list_for_each_entry(fn
, &fc
->filters
, node
) {
129 if (*loaded
&& fn
->loaded
< fn
->bufsize
) {
130 size_t old_fn_loaded
= fn
->loaded
;
131 PARA_DEBUG_LOG("fc %p loaded: %zd, calling %s convert\n",
132 fc
, *loaded
, fn
->filter
->name
);
133 t
->ret
= fn
->filter
->convert(ib
, *loaded
, fn
);
136 call_callbacks(fn
, ib
, t
->ret
, fn
->buf
+ old_fn_loaded
,
137 fn
->loaded
- old_fn_loaded
);
140 if (*loaded
&& t
->ret
) {
141 PARA_DEBUG_LOG("moving %zd bytes in input buffer for %s filter\n",
142 *loaded
, fn
->filter
->name
);
143 memmove(ib
, ib
+ t
->ret
, *loaded
);
147 loaded
= &fn
->loaded
;
150 PARA_DEBUG_LOG("eof (in/out/fc): %d/%d/%d out_loaded: %d, conv: %d, conv_total: %d\n", *fc
->input_eof
,
151 *fc
->output_eof
, fc
->eof
, *fc
->out_loaded
, conv
, conv_total
);
159 if (*fc
->in_loaded
&& conv_total
)
167 * close all filter nodes and its callbacks
169 * \param fc the filter chain to close
171 * For each filter node determined by \a fc, call the close function of each
172 * registered filter callback as well as the close function of the
173 * corresponding filter. Free all resources and destroy all callback lists and
174 * the filter node list.
176 * \sa filter::close, filter_callback::close
178 void close_filters(struct filter_chain
*fc
)
180 struct filter_node
*fn
, *tmp
;
184 PARA_DEBUG_LOG("closing filter chain %p\n", fc
);
185 list_for_each_entry_safe(fn
, tmp
, &fc
->filters
, node
) {
186 PARA_NOTICE_LOG("closing %s filter callbacks (fc %p, fn %p)\n", fn
->filter
->name
, fc
, fn
);
188 PARA_NOTICE_LOG("closing %s filter (fc %p, fn %p)\n", fn
->filter
->name
, fc
, fn
);
189 fn
->filter
->close(fn
);
196 * If the filter has a command line parser and options is not NULL, run it.
197 * Returns filter_num on success, negative on errors
199 static int parse_filter_args(int filter_num
, char *options
, void **conf
)
201 struct filter
*f
= &filters
[filter_num
];
205 // PARA_DEBUG_LOG("%s, options: %s, parser: %p\n", f->name,
206 // options? options : "(none)", f->parse_config);
207 if (!f
->parse_config
)
208 return strlen(options
)? -E_BAD_FILTER_OPTIONS
: filter_num
;
209 // PARA_DEBUG_LOG("options: %s\n", options);
210 argc
= split_args(options
, &argv
, " \t");
211 // PARA_DEBUG_LOG("argc = %d, argv[0]: %s\n", argc, argv[0]);
212 for (i
= argc
- 1; i
>= 0; i
--)
213 argv
[i
+ 1] = argv
[i
];
214 argv
[0] = para_strdup(f
->name
);
216 *conf
= f
->parse_config(argc
, argv
);
217 return *conf
? filter_num
: -E_BAD_FILTER_OPTIONS
;
221 * check the filter command line options
223 * \param fa the command line options
224 * \param conf points to the filter configuration upon successful return
226 * Check if \a fa starts with a the name of a supported filter, followed by
227 * a colon. If yes, call the command line parser of that filter.
229 * \return On success, the number of the filter is returned and \a conf
230 * is initialized to point to the filter configuration determined by \a fa.
231 * On errors, a negative value is returned.
233 * Note: If \a fa specifies a filter that has no command line parser success is
234 * returned, and \a conf is initialized to \p NULL.
236 * \sa filter::parse_config
238 int check_filter_arg(char *fa
, void **conf
)
243 // PARA_DEBUG_LOG("arg: %s\n", fa);
244 for (j
= 0; filters
[j
].name
; j
++) {
245 const char *name
= filters
[j
].name
;
246 size_t len
= strlen(name
);
248 if (strlen(fa
) < len
)
250 if (strncmp(name
, fa
, len
))
255 if (c
&& !filters
[j
].parse_config
)
256 return -E_BAD_FILTER_OPTIONS
;
257 return parse_filter_args(j
, c
? fa
+ len
+ 1 :
258 fa
+ strlen(fa
), conf
);
260 return -E_UNSUPPORTED_FILTER
;