Mon Mar 20 08:20:25 2006

Asterisk developer's documentation

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chanspy.h File Reference

Asterisk PBX channel spy definitions. More...

#include "asterisk/linkedlists.h"

Go to the source code of this file.

Data Structures
struct	ast_channel_spy
struct	ast_channel_spy_queue
Enumerations
enum	chanspy_flags {   CHANSPY_MIXAUDIO = (1 << 0), CHANSPY_READ_VOLADJUST = (1 << 1), CHANSPY_WRITE_VOLADJUST = (1 << 2), CHANSPY_FORMAT_AUDIO = (1 << 3),   CHANSPY_TRIGGER_MODE = (3 << 4), CHANSPY_TRIGGER_READ = (1 << 4), CHANSPY_TRIGGER_WRITE = (2 << 4), CHANSPY_TRIGGER_NONE = (3 << 4),   CHANSPY_TRIGGER_FLUSH = (1 << 6) }
enum	chanspy_states { CHANSPY_NEW = 0, CHANSPY_RUNNING = 1, CHANSPY_DONE = 2, CHANSPY_STOP = 3 }
Functions
int	ast_channel_spy_add (struct ast_channel *chan, struct ast_channel_spy *spy)
	Adds a spy to a channel, to begin receiving copies of the channel's audio frames.
ast_frame *	ast_channel_spy_read_frame (struct ast_channel_spy *spy, unsigned int samples)
	Read one (or more) frames of audio from a channel being spied upon.
void	ast_channel_spy_remove (struct ast_channel *chan, struct ast_channel_spy *spy)
	Remove a spy from a channel.
void	ast_channel_spy_stop_by_type (struct ast_channel *chan, const char *type)
	Find all spies of a particular type on a channel and stop them.
void	ast_channel_spy_trigger_wait (struct ast_channel_spy *spy)
	Efficiently wait until audio is available for a spy, or an exception occurs.

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Detailed Description

Asterisk PBX channel spy definitions.

Definition in file chanspy.h.

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Enumeration Type Documentation

enum chanspy_flags

Enumeration values: CHANSPY_MIXAUDIO  CHANSPY_READ_VOLADJUST  CHANSPY_WRITE_VOLADJUST  CHANSPY_FORMAT_AUDIO  CHANSPY_TRIGGER_MODE  CHANSPY_TRIGGER_READ  CHANSPY_TRIGGER_WRITE  CHANSPY_TRIGGER_NONE  CHANSPY_TRIGGER_FLUSH  Definition at line 39 of file chanspy.h. { CHANSPY_MIXAUDIO = (1 << 0), CHANSPY_READ_VOLADJUST = (1 << 1), CHANSPY_WRITE_VOLADJUST = (1 << 2), CHANSPY_FORMAT_AUDIO = (1 << 3), CHANSPY_TRIGGER_MODE = (3 << 4), CHANSPY_TRIGGER_READ = (1 << 4), CHANSPY_TRIGGER_WRITE = (2 << 4), CHANSPY_TRIGGER_NONE = (3 << 4), CHANSPY_TRIGGER_FLUSH = (1 << 6), };

enum chanspy_states

Enumeration values: CHANSPY_NEW  spy not yet operating CHANSPY_RUNNING  normal operation, spy is still operating CHANSPY_DONE  spy is stopped and already removed from channel CHANSPY_STOP  spy requested to stop, still attached to channel Definition at line 32 of file chanspy.h. { CHANSPY_NEW = 0, /*!< spy not yet operating */ CHANSPY_RUNNING = 1, /*!< normal operation, spy is still operating */ CHANSPY_DONE = 2, /*!< spy is stopped and already removed from channel */ CHANSPY_STOP = 3, /*!< spy requested to stop, still attached to channel */ };

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Function Documentation

int ast_channel_spy_add (  struct ast_channel *  chan, struct ast_channel_spy *  spy )

Adds a spy to a channel, to begin receiving copies of the channel's audio frames. Parameters: chan  The channel to add the spy to. spy  A pointer to ast_channel_spy structure describing how the spy is to be used. Returns: 0 for success, non-zero for failure Note: This function performs no locking; you must hold the channel's lock before calling this function. Definition at line 965 of file channel.c. References ast_clear_flag, ast_cond_init(), ast_getformatname(), AST_LIST_HEAD_INIT_NOLOCK, AST_LIST_INSERT_HEAD, AST_LIST_INSERT_TAIL, ast_log(), ast_set_flag, ast_test_flag, calloc, CHANSPY_FORMAT_AUDIO, CHANSPY_MIXAUDIO, CHANSPY_READ_VOLADJUST, CHANSPY_TRIGGER_MODE, CHANSPY_TRIGGER_READ, CHANSPY_TRIGGER_WRITE, CHANSPY_WRITE_VOLADJUST, ast_channel_spy_queue::format, LOG_DEBUG, LOG_WARNING, ast_channel::name, ast_channel_spy::read_queue, ast_channel::spies, ast_channel_spy::trigger, ast_channel_spy::type, and ast_channel_spy::write_queue. Referenced by start_spying(), and startmon(). { if (!ast_test_flag(spy, CHANSPY_FORMAT_AUDIO)) { ast_log(LOG_WARNING, "Could not add channel spy '%s' to channel '%s', only audio format spies are supported.\n", spy->type, chan->name); return -1; } if (ast_test_flag(spy, CHANSPY_READ_VOLADJUST) && (spy->read_queue.format != AST_FORMAT_SLINEAR)) { ast_log(LOG_WARNING, "Cannot provide volume adjustment on '%s' format spies\n", ast_getformatname(spy->read_queue.format)); return -1; } if (ast_test_flag(spy, CHANSPY_WRITE_VOLADJUST) && (spy->write_queue.format != AST_FORMAT_SLINEAR)) { ast_log(LOG_WARNING, "Cannot provide volume adjustment on '%s' format spies\n", ast_getformatname(spy->write_queue.format)); return -1; } if (ast_test_flag(spy, CHANSPY_MIXAUDIO) && ((spy->read_queue.format != AST_FORMAT_SLINEAR) || (spy->write_queue.format != AST_FORMAT_SLINEAR))) { ast_log(LOG_WARNING, "Cannot provide audio mixing on '%s'-'%s' format spies\n", ast_getformatname(spy->read_queue.format), ast_getformatname(spy->write_queue.format)); return -1; } if (!chan->spies) { if (!(chan->spies = calloc(1, sizeof(*chan->spies)))) { ast_log(LOG_WARNING, "Memory allocation failure\n"); return -1; } AST_LIST_HEAD_INIT_NOLOCK(&chan->spies->list); AST_LIST_INSERT_HEAD(&chan->spies->list, spy, list); } else { AST_LIST_INSERT_TAIL(&chan->spies->list, spy, list); } if (ast_test_flag(spy, CHANSPY_TRIGGER_MODE) != CHANSPY_TRIGGER_NONE) { ast_cond_init(&spy->trigger, NULL); ast_set_flag(spy, CHANSPY_TRIGGER_READ); ast_clear_flag(spy, CHANSPY_TRIGGER_WRITE); } ast_log(LOG_DEBUG, "Spy %s added to channel %s\n", spy->type, chan->name); return 0; }

struct ast_frame* ast_channel_spy_read_frame (  struct ast_channel_spy *  spy, unsigned int  samples )

Read one (or more) frames of audio from a channel being spied upon. Parameters: spy  The spy to operate on samples  The number of audio samples to read Returns: NULL for failure, one ast_frame pointer, or a chain of ast_frame pointers This function can return multiple frames if the spy structure needs to be 'flushed' due to mismatched queue lengths, or if the spy structure is configured to return unmixed audio (in which case each call to this function will return a frame of audio from each side of channel). Note: This function performs no locking; you must hold the spy's lock before calling this function. You must not hold the channel's lock at the same time. Definition at line 3862 of file channel.c. References ast_clear_flag, ast_codec_get_len(), ast_frame_adjust_volume(), ast_frame_slinear_sum(), ast_frdup(), ast_frfree(), ast_test_flag, CHANSPY_MIXAUDIO, CHANSPY_READ_VOLADJUST, CHANSPY_TRIGGER_FLUSH, CHANSPY_WRITE_VOLADJUST, copy_data_from_queue(), ast_channel_spy_queue::format, ast_frame::frametype, ast_channel_spy_queue::head, ast_frame::next, ast_channel_spy::read_queue, ast_channel_spy::read_vol_adjustment, result, ast_frame::samples, ast_channel_spy_queue::samples, ast_frame::subclass, ast_channel_spy::write_queue, and ast_channel_spy::write_vol_adjustment. Referenced by mixmonitor_thread(), and spy_generate(). { struct ast_frame *result; /* buffers are allocated to hold SLINEAR, which is the largest format */ short read_buf[samples]; short write_buf[samples]; struct ast_frame *read_frame; struct ast_frame *write_frame; int need_dup; struct ast_frame stack_read_frame = { .frametype = AST_FRAME_VOICE, .subclass = spy->read_queue.format, .data = read_buf, .samples = samples, .datalen = ast_codec_get_len(spy->read_queue.format, samples), }; struct ast_frame stack_write_frame = { .frametype = AST_FRAME_VOICE, .subclass = spy->write_queue.format, .data = write_buf, .samples = samples, .datalen = ast_codec_get_len(spy->write_queue.format, samples), }; /* if a flush has been requested, dump everything in whichever queue is larger */ if (ast_test_flag(spy, CHANSPY_TRIGGER_FLUSH)) { if (spy->read_queue.samples > spy->write_queue.samples) { if (ast_test_flag(spy, CHANSPY_READ_VOLADJUST)) { for (result = spy->read_queue.head; result; result = result->next) ast_frame_adjust_volume(result, spy->read_vol_adjustment); } result = spy->read_queue.head; spy->read_queue.head = NULL; spy->read_queue.samples = 0; ast_clear_flag(spy, CHANSPY_TRIGGER_FLUSH); return result; } else { if (ast_test_flag(spy, CHANSPY_WRITE_VOLADJUST)) { for (result = spy->write_queue.head; result; result = result->next) ast_frame_adjust_volume(result, spy->write_vol_adjustment); } result = spy->write_queue.head; spy->write_queue.head = NULL; spy->write_queue.samples = 0; ast_clear_flag(spy, CHANSPY_TRIGGER_FLUSH); return result; } } if ((spy->read_queue.samples < samples) || (spy->write_queue.samples < samples)) return NULL; /* short-circuit if both head frames have exactly what we want */ if ((spy->read_queue.head->samples == samples) && (spy->write_queue.head->samples == samples)) { read_frame = spy->read_queue.head; spy->read_queue.head = read_frame->next; read_frame->next = NULL; write_frame = spy->write_queue.head; spy->write_queue.head = write_frame->next; write_frame->next = NULL; spy->read_queue.samples -= samples; spy->write_queue.samples -= samples; need_dup = 0; } else { copy_data_from_queue(&spy->read_queue, read_buf, samples); copy_data_from_queue(&spy->write_queue, write_buf, samples); read_frame = &stack_read_frame; write_frame = &stack_write_frame; need_dup = 1; } if (ast_test_flag(spy, CHANSPY_READ_VOLADJUST)) ast_frame_adjust_volume(read_frame, spy->read_vol_adjustment); if (ast_test_flag(spy, CHANSPY_WRITE_VOLADJUST)) ast_frame_adjust_volume(write_frame, spy->write_vol_adjustment); if (ast_test_flag(spy, CHANSPY_MIXAUDIO)) { ast_frame_slinear_sum(read_frame, write_frame); if (need_dup) result = ast_frdup(read_frame); else { result = read_frame; ast_frfree(write_frame); } } else { if (need_dup) { result = ast_frdup(read_frame); result->next = ast_frdup(write_frame); } else { result = read_frame; result->next = write_frame; } } return result; }

void ast_channel_spy_remove (  struct ast_channel *  chan, struct ast_channel_spy *  spy )

Remove a spy from a channel. Parameters: chan  The channel to remove the spy from spy  The spy to be removed Returns: nothing Note: This function performs no locking; you must hold the channel's lock before calling this function. Definition at line 1040 of file channel.c. References ast_cond_destroy(), ast_frfree(), AST_LIST_EMPTY, AST_LIST_REMOVE, ast_log(), ast_mutex_lock(), ast_mutex_unlock(), ast_test_flag, ast_translator_free_path(), CHANSPY_TRIGGER_MODE, free, ast_channel_spy_queue::head, ast_channel_spy::lock, LOG_DEBUG, ast_channel::name, ast_frame::next, channel_spy_trans::path, ast_channel_spy::read_queue, ast_channel_spy_list::read_translator, ast_channel::spies, ast_channel_spy::trigger, ast_channel_spy::type, ast_channel_spy::write_queue, and ast_channel_spy_list::write_translator. Referenced by detach_spies(), stop_spying(), and stopmon(). { struct ast_frame *f; if (!chan->spies) return; AST_LIST_REMOVE(&chan->spies->list, spy, list); ast_mutex_lock(&spy->lock); for (f = spy->read_queue.head; f; f = spy->read_queue.head) { spy->read_queue.head = f->next; ast_frfree(f); } for (f = spy->write_queue.head; f; f = spy->write_queue.head) { spy->write_queue.head = f->next; ast_frfree(f); } if (ast_test_flag(spy, CHANSPY_TRIGGER_MODE) != CHANSPY_TRIGGER_NONE) ast_cond_destroy(&spy->trigger); ast_mutex_unlock(&spy->lock); ast_log(LOG_DEBUG, "Spy %s removed from channel %s\n", spy->type, chan->name); if (AST_LIST_EMPTY(&chan->spies->list)) { if (chan->spies->read_translator.path) ast_translator_free_path(chan->spies->read_translator.path); if (chan->spies->write_translator.path) ast_translator_free_path(chan->spies->write_translator.path); free(chan->spies); chan->spies = NULL; } }

void ast_channel_spy_stop_by_type (  struct ast_channel *  chan, const char *  type )

Find all spies of a particular type on a channel and stop them. Parameters: chan  The channel to operate on type  A character string identifying the type of spies to be stopped Returns: nothing Note: This function performs no locking; you must hold the channel's lock before calling this function. Definition at line 1017 of file channel.c. References ast_cond_signal(), AST_LIST_TRAVERSE, ast_mutex_lock(), ast_mutex_unlock(), ast_test_flag, CHANSPY_TRIGGER_MODE, ast_channel_spy::lock, ast_channel::spies, ast_channel_spy::trigger, and ast_channel_spy::type. Referenced by mixmonitor_cli(). { struct ast_channel_spy *spy; if (!chan->spies) return; AST_LIST_TRAVERSE(&chan->spies->list, spy, list) { ast_mutex_lock(&spy->lock); if ((spy->type == type) && (spy->status == CHANSPY_RUNNING)) { spy->status = CHANSPY_STOP; if (ast_test_flag(spy, CHANSPY_TRIGGER_MODE) != CHANSPY_TRIGGER_NONE) ast_cond_signal(&spy->trigger); } ast_mutex_unlock(&spy->lock); } }

void ast_channel_spy_trigger_wait (  struct ast_channel_spy *  spy  )

Efficiently wait until audio is available for a spy, or an exception occurs. Parameters: spy  The spy to wait on Returns: nothing Note: The locking rules for this function are non-obvious... first, you must not hold the channel's lock when calling this function. Second, you must hold the spy's lock before making the function call; while the function runs the lock will be released, and when the trigger event occurs, the lock will be re-obtained. This means that when control returns to your code, you will again hold the spy's lock. Definition at line 1035 of file channel.c. References ast_cond_wait(), ast_channel_spy::lock, and ast_channel_spy::trigger. Referenced by mixmonitor_thread(). { ast_cond_wait(&spy->trigger, &spy->lock); }

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