2 * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file filter_common.c Common helper functions for filter input/output. */
20 /** The array of supported filters. */
21 struct filter filters
[NUM_SUPPORTED_FILTERS
] = {FILTER_ARRAY
};
24 * Call the init function of each supported filter.
26 * \param all_filters the array of all supported filters.
30 void filter_init(struct filter
*all_filters
)
34 FOR_EACH_SUPPORTED_FILTER(i
)
35 all_filters
[i
].init(all_filters
+ i
);
39 * Close and destroy a filter callback.
41 * \param fcb The filter callback to close.
43 * This removes \a fcb from the list of filter callbacks and calls
44 * the close callback associated with \a fcb.
46 static void close_filter_callback(struct filter_callback
*fcb
)
48 PARA_NOTICE_LOG("closing filter_callback %p, data: %p\n", fcb
, fcb
->data
);
54 * Close all callbacks of a filter node.
56 * \param fn The filter node which contains the filter callbacks to be closed.
58 * Call close_filter_callback() for each entry in the filter callback list
61 static void close_callbacks(struct filter_node
*fn
)
63 struct filter_callback
*fcb
, *tmp
;
65 list_for_each_entry_safe(fcb
, tmp
, &fn
->callbacks
, node
) {
66 PARA_INFO_LOG("closing %s filter callback\n",
67 filters
[fn
->filter_num
].name
);
68 close_filter_callback(fcb
);
72 static void call_callbacks(struct filter_node
*fn
, char *inbuf
, size_t inlen
,
73 char *outbuf
, size_t outlen
)
75 struct filter_callback
*fcb
, *tmp
;
76 list_for_each_entry_safe(fcb
, tmp
, &fn
->callbacks
, node
) {
78 if (inlen
&& fcb
->input_cb
) {
79 ret
= fcb
->input_cb(inbuf
, inlen
, fcb
);
81 close_filter_callback(fcb
);
85 if (!outlen
|| !fcb
->output_cb
)
87 ret
= fcb
->output_cb(outbuf
, outlen
, fcb
);
89 close_filter_callback(fcb
);
94 * Call the convert function of each filter.
97 * \param t The task identifying the filter chain.
99 * This is the core function of the filter subsystem. It loops over the list of
100 * filter nodes determined by \a t and calls the filter's convert function if
101 * there is input available for the filter node in question. If the convert
102 * function consumed some or all of its input data, all registered input
103 * callbacks are called. Similarly, if a convert function produced output, all
104 * registerd output callbacks get called.
106 * On errors a (negative) error code is stored in t->error.
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
= container_of(t
, struct filter_chain
, task
);
113 struct filter_node
*fn
;
116 int i
, conv
, conv_total
= 0;
118 if (fc
->output_error
&& *fc
->output_error
< 0) {
119 t
->error
= *fc
->output_error
;
124 loaded
= fc
->in_loaded
;
126 FOR_EACH_FILTER_NODE(fn
, fc
, i
) {
127 struct filter
*f
= filters
+ fn
->filter_num
;
128 if (fn
->loaded
< fn
->bufsize
) {
129 size_t size
, old_fn_loaded
= fn
->loaded
;
130 // PARA_DEBUG_LOG("fc %p loaded: %zd, calling %s convert\n",
131 // fc, *loaded, fn->filter->name);
132 t
->error
= f
->convert(ib
, *loaded
, fn
);
136 call_callbacks(fn
, ib
, size
, fn
->buf
+ old_fn_loaded
,
137 fn
->loaded
- old_fn_loaded
);
140 if (*loaded
&& size
) {
141 // PARA_DEBUG_LOG("moving %zd bytes in input "
142 // "buffer for %s filter\n",
143 // *loaded, fn->filter->name);
144 memmove(ib
, ib
+ size
, *loaded
);
148 loaded
= &fn
->loaded
;
151 // PARA_DEBUG_LOG("eof (in/out/fc): %d/%d/%d out_loaded: %zd, "
152 // "conv: %d, conv_total: %d\n", *fc->input_eof,
153 // fc->output_eof? *fc->output_eof : -42,
154 // fc->eof, *fc->out_loaded, conv, conv_total);
157 if (!*fc
->input_error
)
161 if (*fc
->in_loaded
&& conv_total
)
163 t
->error
= -E_FC_EOF
;
167 * Close all filter nodes and their 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
;
185 PARA_NOTICE_LOG("closing filter chain %p\n", fc
);
186 FOR_EACH_FILTER_NODE(fn
, fc
, i
) {
187 struct filter
*f
= filters
+ fn
->filter_num
;
189 PARA_INFO_LOG("closing %s filter\n", f
->name
);
192 free(fc
->filter_nodes
);
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
];
202 int ret
, i
, argc
= 2;
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 ret
= f
->parse_config(argc
, argv
, conf
);
219 return ret
< 0? ret
: filter_num
;
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_EACH_SUPPORTED_FILTER(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
;