2 * Copyright (C) 2005-2007 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file filter_chain.c common helper functions for filter input/output */
20 DEFINE_FILTER_ARRAY(filters
);
23 * call the init function of each supported filter
25 * \param all_filters the array of all supported filters
28 void filter_init(struct filter
*all_filters
)
32 for (f
= all_filters
; f
->name
; f
++)
37 * close and destroy a filter callback
39 * \param fcb the filter callback to close
41 * This removes \a fcb from the list of filter callbacks and calls
42 * the close callback associated with \a fcb.
44 static void close_filter_callback(struct filter_callback
*fcb
)
46 PARA_NOTICE_LOG("closing filter_callback %p, data: %p\n", fcb
, fcb
->data
);
52 * close all callbacks of a filter node
54 * \param fn the filter node which contains the filter callbacks to be closed
56 * Call close_filter_callback() for each entry in the filter callback list
59 static void close_callbacks(struct filter_node
*fn
)
61 struct filter_callback
*fcb
, *tmp
;
63 list_for_each_entry_safe(fcb
, tmp
, &fn
->callbacks
, node
) {
64 PARA_INFO_LOG("closing %s filter callback\n",
66 close_filter_callback(fcb
);
70 static void call_callbacks(struct filter_node
*fn
, char *inbuf
, size_t inlen
,
71 char *outbuf
, size_t outlen
)
73 struct filter_callback
*fcb
, *tmp
;
74 list_for_each_entry_safe(fcb
, tmp
, &fn
->callbacks
, node
) {
76 if (inlen
&& fcb
->input_cb
) {
77 ret
= fcb
->input_cb(inbuf
, inlen
, fcb
);
79 close_filter_callback(fcb
);
83 if (!outlen
|| !fcb
->output_cb
)
85 ret
= fcb
->output_cb(outbuf
, outlen
, fcb
);
87 close_filter_callback(fcb
);
92 * call the convert function of each filter
95 * \param t the task containing the filter chain
97 * This is the core function of the filter subsystem. It loops over the list of
98 * filter nodes determined by \a t and calls the filter's convert function if
99 * there is input available for the filter node in question. If the convert
100 * function consumed some or all of its input data, all registered input
101 * callbacks are called. Similarly, if a convert function produced output, all
102 * registerd output callbacks get called.
104 * \return The sum of output bytes produced by the convert functions on
105 * success, negative return value on errors (the return value is stored in
108 * \sa filter_node, filter#convert, filter_callback
110 void filter_pre_select(__a_unused
struct sched
*s
, struct task
*t
)
112 struct filter_chain
*fc
= t
->private_data
;
113 struct filter_node
*fn
;
116 int conv
, conv_total
= 0;
119 if (fc
->output_eof
&& *fc
->output_eof
)
123 loaded
= fc
->in_loaded
;
125 list_for_each_entry(fn
, &fc
->filters
, node
) {
126 if (*loaded
&& fn
->loaded
< fn
->bufsize
) {
127 size_t size
, old_fn_loaded
= fn
->loaded
;
128 // PARA_DEBUG_LOG("fc %p loaded: %zd, calling %s convert\n",
129 // fc, *loaded, fn->filter->name);
130 t
->ret
= fn
->filter
->convert(ib
, *loaded
, fn
);
134 call_callbacks(fn
, ib
, size
, fn
->buf
+ old_fn_loaded
,
135 fn
->loaded
- old_fn_loaded
);
138 if (*loaded
&& size
) {
139 // PARA_DEBUG_LOG("moving %zd bytes in input "
140 // "buffer for %s filter\n",
141 // *loaded, fn->filter->name);
142 memmove(ib
, ib
+ size
, *loaded
);
146 loaded
= &fn
->loaded
;
149 // PARA_DEBUG_LOG("eof (in/out/fc): %d/%d/%d out_loaded: %zd, "
150 // "conv: %d, conv_total: %d\n", *fc->input_eof,
151 // fc->output_eof? *fc->output_eof : -42,
152 // fc->eof, *fc->out_loaded, conv, conv_total);
160 if (*fc
->in_loaded
&& conv_total
)
168 * close all filter nodes and its callbacks
170 * \param fc the filter chain to close
172 * For each filter node determined by \a fc, call the close function of each
173 * registered filter callback as well as the close function of the
174 * corresponding filter. Free all resources and destroy all callback lists and
175 * the filter node list.
177 * \sa filter::close, filter_callback::close
179 void close_filters(struct filter_chain
*fc
)
181 struct filter_node
*fn
, *tmp
;
185 PARA_NOTICE_LOG("closing filter chain %p\n", fc
);
186 list_for_each_entry_safe(fn
, tmp
, &fc
->filters
, node
) {
188 PARA_INFO_LOG("closing %s filter\n", fn
->filter
->name
);
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
);
219 return *conf
? filter_num
: -E_BAD_FILTER_OPTIONS
;
223 * check the filter command line options
225 * \param fa the command line options
226 * \param conf points to the filter configuration upon successful return
228 * Check if \a fa starts with a the name of a supported filter, followed by
229 * a colon. If yes, call the command line parser of that filter.
231 * \return On success, the number of the filter is returned and \a conf
232 * is initialized to point to the filter configuration determined by \a fa.
233 * On errors, a negative value is returned.
235 * Note: If \a fa specifies a filter that has no command line parser success is
236 * returned, and \a conf is initialized to \p NULL.
238 * \sa filter::parse_config
240 int check_filter_arg(char *fa
, void **conf
)
245 // PARA_DEBUG_LOG("arg: %s\n", fa);
246 for (j
= 0; filters
[j
].name
; j
++) {
247 const char *name
= filters
[j
].name
;
248 size_t len
= strlen(name
);
250 if (strlen(fa
) < len
)
252 if (strncmp(name
, fa
, len
))
257 if (c
&& !filters
[j
].parse_config
)
258 return -E_BAD_FILTER_OPTIONS
;
259 return parse_filter_args(j
, c
? fa
+ len
+ 1 :
260 fa
+ strlen(fa
), conf
);
262 return -E_UNSUPPORTED_FILTER
;