2 * Copyright (C) 2005-2008 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.
29 void filter_init(struct filter
*all_filters
)
33 for (f
= all_filters
; f
->name
; f
++)
38 * Close and destroy a filter callback.
40 * \param fcb The filter callback to close.
42 * This removes \a fcb from the list of filter callbacks and calls
43 * the close callback associated with \a fcb.
45 static void close_filter_callback(struct filter_callback
*fcb
)
47 PARA_NOTICE_LOG("closing filter_callback %p, data: %p\n", fcb
, fcb
->data
);
53 * Close all callbacks of a filter node.
55 * \param fn The filter node which contains the filter callbacks to be closed.
57 * Call close_filter_callback() for each entry in the filter callback list
60 static void close_callbacks(struct filter_node
*fn
)
62 struct filter_callback
*fcb
, *tmp
;
64 list_for_each_entry_safe(fcb
, tmp
, &fn
->callbacks
, node
) {
65 PARA_INFO_LOG("closing %s filter callback\n",
66 filters
[fn
->filter_num
].name
);
67 close_filter_callback(fcb
);
71 static void call_callbacks(struct filter_node
*fn
, char *inbuf
, size_t inlen
,
72 char *outbuf
, size_t outlen
)
74 struct filter_callback
*fcb
, *tmp
;
75 list_for_each_entry_safe(fcb
, tmp
, &fn
->callbacks
, node
) {
77 if (inlen
&& fcb
->input_cb
) {
78 ret
= fcb
->input_cb(inbuf
, inlen
, fcb
);
80 close_filter_callback(fcb
);
84 if (!outlen
|| !fcb
->output_cb
)
86 ret
= fcb
->output_cb(outbuf
, outlen
, fcb
);
88 close_filter_callback(fcb
);
93 * Call the convert function of each filter.
96 * \param t The task identifying the filter chain.
98 * This is the core function of the filter subsystem. It loops over the list of
99 * filter nodes determined by \a t and calls the filter's convert function if
100 * there is input available for the filter node in question. If the convert
101 * function consumed some or all of its input data, all registered input
102 * callbacks are called. Similarly, if a convert function produced output, all
103 * registerd output callbacks get called.
105 * On errors a (negative) error code is stored in t->error.
107 * \sa filter_node, filter#convert, filter_callback.
109 void filter_pre_select(__a_unused
struct sched
*s
, struct task
*t
)
111 struct filter_chain
*fc
= container_of(t
, struct filter_chain
, task
);
112 struct filter_node
*fn
;
115 int i
, conv
, conv_total
= 0;
117 if (fc
->output_error
&& *fc
->output_error
< 0) {
118 t
->error
= *fc
->output_error
;
123 loaded
= fc
->in_loaded
;
125 FOR_EACH_FILTER_NODE(fn
, fc
, i
) {
126 struct filter
*f
= filters
+ fn
->filter_num
;
127 if (*loaded
&& fn
->loaded
< fn
->bufsize
) {
128 size_t size
, old_fn_loaded
= fn
->loaded
;
129 // PARA_DEBUG_LOG("fc %p loaded: %zd, calling %s convert\n",
130 // fc, *loaded, fn->filter->name);
131 t
->error
= f
->convert(ib
, *loaded
, fn
);
135 call_callbacks(fn
, ib
, size
, fn
->buf
+ old_fn_loaded
,
136 fn
->loaded
- old_fn_loaded
);
139 if (*loaded
&& size
) {
140 // PARA_DEBUG_LOG("moving %zd bytes in input "
141 // "buffer for %s filter\n",
142 // *loaded, fn->filter->name);
143 memmove(ib
, ib
+ size
, *loaded
);
147 loaded
= &fn
->loaded
;
150 // PARA_DEBUG_LOG("eof (in/out/fc): %d/%d/%d out_loaded: %zd, "
151 // "conv: %d, conv_total: %d\n", *fc->input_eof,
152 // fc->output_eof? *fc->output_eof : -42,
153 // fc->eof, *fc->out_loaded, conv, conv_total);
156 if (!*fc
->input_error
)
160 if (*fc
->in_loaded
&& conv_total
)
162 t
->error
= -E_FC_EOF
;
166 * Close all filter nodes and their callbacks.
168 * \param fc The filter chain to close.
170 * For each filter node determined by \a fc, call the close function of each
171 * registered filter callback as well as the close function of the
172 * corresponding filter. Free all resources and destroy all callback lists and
173 * the filter node list.
175 * \sa filter::close, filter_callback::close
177 void close_filters(struct filter_chain
*fc
)
179 struct filter_node
*fn
;
184 PARA_NOTICE_LOG("closing filter chain %p\n", fc
);
185 FOR_EACH_FILTER_NODE(fn
, fc
, i
) {
186 struct filter
*f
= filters
+ fn
->filter_num
;
188 PARA_INFO_LOG("closing %s filter\n", f
->name
);
191 free(fc
->filter_nodes
);
195 * If the filter has a command line parser and options is not NULL, run it.
196 * Returns filter_num on success, negative on errors
198 static int parse_filter_args(int filter_num
, char *options
, void **conf
)
200 struct filter
*f
= &filters
[filter_num
];
204 // PARA_DEBUG_LOG("%s, options: %s, parser: %p\n", f->name,
205 // options? options : "(none)", f->parse_config);
206 if (!f
->parse_config
)
207 return strlen(options
)? -E_BAD_FILTER_OPTIONS
: filter_num
;
208 // PARA_DEBUG_LOG("options: %s\n", options);
209 argc
= split_args(options
, &argv
, " \t");
210 // PARA_DEBUG_LOG("argc = %d, argv[0]: %s\n", argc, argv[0]);
211 for (i
= argc
- 1; i
>= 0; i
--)
212 argv
[i
+ 1] = argv
[i
];
213 argv
[0] = para_strdup(f
->name
);
215 *conf
= f
->parse_config(argc
, argv
);
218 return *conf
? filter_num
: -E_BAD_FILTER_OPTIONS
;
222 * Check the filter command line options.
224 * \param fa The command line options.
225 * \param conf Points to the filter configuration upon successful return.
227 * Check if \a fa starts with a the name of a supported filter, followed by
228 * a colon. If yes, call the command line parser of that filter.
230 * \return On success, the number of the filter is returned and \a conf
231 * is initialized to point to the filter configuration determined by \a fa.
232 * On errors, a negative value is returned.
234 * Note: If \a fa specifies a filter that has no command line parser success is
235 * returned, and \a conf is initialized to \p NULL.
237 * \sa filter::parse_config
239 int check_filter_arg(char *fa
, void **conf
)
244 // PARA_DEBUG_LOG("arg: %s\n", fa);
245 for (j
= 0; filters
[j
].name
; j
++) {
246 const char *name
= filters
[j
].name
;
247 size_t len
= strlen(name
);
249 if (strlen(fa
) < len
)
251 if (strncmp(name
, fa
, len
))
256 if (c
&& !filters
[j
].parse_config
)
257 return -E_BAD_FILTER_OPTIONS
;
258 return parse_filter_args(j
, c
? fa
+ len
+ 1 :
259 fa
+ strlen(fa
), conf
);
261 return -E_UNSUPPORTED_FILTER
;