2 * Copyright (C) 2005-2009 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. */
10 #include <sys/types.h>
19 #include "buffer_tree.h"
24 /** The array of supported filters. */
25 struct filter filters
[NUM_SUPPORTED_FILTERS
] = {FILTER_ARRAY
};
28 * Call the init function of each supported filter.
31 void filter_init(void)
35 FOR_EACH_SUPPORTED_FILTER(i
)
36 filters
[i
].init(filters
+ i
);
40 * Close and destroy a filter callback.
42 * \param fcb The filter callback to close.
44 * This removes \a fcb from the list of filter callbacks and calls
45 * the close callback associated with \a fcb.
47 static void close_filter_callback(struct filter_callback
*fcb
)
49 PARA_NOTICE_LOG("closing filter_callback %p\n", fcb
);
55 * Close all callbacks of a filter node.
57 * \param fn The filter node which contains the filter callbacks to be closed.
59 * Call close_filter_callback() for each entry in the filter callback list
62 static void close_callbacks(struct filter_node
*fn
)
64 struct filter_callback
*fcb
, *tmp
;
66 list_for_each_entry_safe(fcb
, tmp
, &fn
->callbacks
, node
) {
67 PARA_INFO_LOG("closing %s filter callback\n",
68 filters
[fn
->filter_num
].name
);
69 close_filter_callback(fcb
);
73 static void call_callbacks(struct filter_node
*fn
, char *inbuf
, size_t inlen
,
74 char *outbuf
, size_t outlen
)
76 struct filter_callback
*fcb
, *tmp
;
77 list_for_each_entry_safe(fcb
, tmp
, &fn
->callbacks
, node
) {
79 if (inlen
&& fcb
->input_cb
) {
80 ret
= fcb
->input_cb(inbuf
, inlen
, fcb
);
82 close_filter_callback(fcb
);
86 if (!outlen
|| !fcb
->output_cb
)
88 ret
= fcb
->output_cb(outbuf
, outlen
, fcb
);
90 close_filter_callback(fcb
);
95 * Call the convert function of each filter.
98 * \param t The task identifying the filter chain.
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 * registered output callbacks get called.
107 * On errors a (negative) error code is stored in t->error.
109 * \sa filter_node, filter#convert, filter_callback.
111 void filter_post_select(__a_unused
struct sched
*s
, struct task
*t
)
113 struct filter_chain
*fc
= container_of(t
, struct filter_chain
, task
);
114 struct filter_node
*fn
;
117 int i
, conv
, conv_total
= 0;
119 if (fc
->output_error
&& *fc
->output_error
< 0) {
120 t
->error
= *fc
->output_error
;
125 loaded
= fc
->in_loaded
;
127 FOR_EACH_FILTER_NODE(fn
, fc
, i
) {
128 struct filter
*f
= filters
+ fn
->filter_num
;
129 if (fn
->loaded
< fn
->bufsize
) {
130 size_t size
, old_fn_loaded
= fn
->loaded
;
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
);
138 conv
+= size
+ fn
->loaded
- old_fn_loaded
;
140 memmove(ib
, ib
+ size
, *loaded
);
143 loaded
= &fn
->loaded
;
148 if (*fc
->input_error
>= 0)
152 if (*fc
->in_loaded
&& conv_total
)
154 t
->error
= -E_FC_EOF
;
158 * Close all filter nodes and their callbacks.
160 * \param fc The filter chain to close.
162 * For each filter node determined by \a fc, call the close function of each
163 * registered filter callback as well as the close function of the
164 * corresponding filter. Free all resources and destroy all callback lists and
165 * the filter node list.
167 * \sa filter::close, filter_callback::close
169 void close_filters(struct filter_chain
*fc
)
171 struct filter_node
*fn
;
176 PARA_NOTICE_LOG("closing filter chain %p\n", fc
);
177 FOR_EACH_FILTER_NODE(fn
, fc
, i
) {
178 struct filter
*f
= filters
+ fn
->filter_num
;
180 PARA_INFO_LOG("closing %s filter\n", f
->name
);
183 free(fc
->filter_nodes
);
187 * If the filter has a command line parser and options is not NULL, run it.
188 * Returns filter_num on success, negative on errors
190 static int parse_filter_args(int filter_num
, char *options
, void **conf
)
192 struct filter
*f
= &filters
[filter_num
];
193 int ret
, i
, argc
= 2;
196 // PARA_DEBUG_LOG("%s, options: %s, parser: %p\n", f->name,
197 // options? options : "(none)", f->parse_config);
198 if (!f
->parse_config
)
199 return strlen(options
)? -E_BAD_FILTER_OPTIONS
: filter_num
;
200 // PARA_DEBUG_LOG("options: %s\n", options);
201 argc
= create_argv(options
, " \t", &argv
);
203 return -E_BAD_FILTER_OPTIONS
;
204 PARA_DEBUG_LOG("argc = %d, argv[0]: %s\n", argc
, argv
[0]);
205 for (i
= argc
- 1; i
>= 0; i
--)
206 argv
[i
+ 1] = argv
[i
];
207 argv
[0] = para_strdup(f
->name
);
209 ret
= f
->parse_config(argc
, argv
, conf
);
210 free(argv
[argc
- 1]);
211 argv
[argc
- 1] = NULL
;
213 return ret
< 0? ret
: filter_num
;
217 * Check the filter command line options.
219 * \param fa The command line options.
220 * \param conf Points to the filter configuration upon successful return.
222 * Check if \a fa starts with a the name of a supported filter, followed by
223 * a colon. If yes, call the command line parser of that filter.
225 * \return On success, the number of the filter is returned and \a conf
226 * is initialized to point to the filter configuration determined by \a fa.
227 * On errors, a negative value is returned.
229 * Note: If \a fa specifies a filter that has no command line parser success is
230 * returned, and \a conf is initialized to \p NULL.
232 * \sa filter::parse_config
234 int check_filter_arg(char *fa
, void **conf
)
239 // PARA_DEBUG_LOG("arg: %s\n", fa);
240 FOR_EACH_SUPPORTED_FILTER(j
) {
241 const char *name
= filters
[j
].name
;
242 size_t len
= strlen(name
);
244 if (strlen(fa
) < len
)
246 if (strncmp(name
, fa
, len
))
251 if (c
&& !filters
[j
].parse_config
)
252 return -E_BAD_FILTER_OPTIONS
;
253 return parse_filter_args(j
, c
? fa
+ len
+ 1 :
254 fa
+ strlen(fa
), conf
);
256 return -E_UNSUPPORTED_FILTER
;
259 void print_filter_helps(int detailed
)
263 printf_or_die("\nAvailable filters: \n\t");
264 FOR_EACH_SUPPORTED_FILTER(i
)
265 printf_or_die("%s%s", i
? " " : "", filters
[i
].name
);
266 printf_or_die("\n\n");
268 FOR_EACH_SUPPORTED_FILTER(i
) {
269 struct filter
*f
= filters
+ i
;
271 if (!f
->help
.short_help
)
273 printf_or_die("Options for %s:\n", f
->name
);
274 ggo_print_help(&f
->help
, detailed
);