Utilities and helpers. More...

#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/file.h>
#include <sys/types.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <inttypes.h>
#include "utils.h"
#include "debug.h"

Include dependency graph for utils.c:

Macros
#define	swap2(d) d

Functions
gint64	janus_get_monotonic_time (void)
	Helper to retrieve the system monotonic time, as Glib's g_get_monotonic_time may not be available (only since 2.28) More...

gint64	janus_get_real_time (void)
	Helper to retrieve the system real time, as Glib's g_get_real_time may not be available (only since 2.28) More...

gboolean	janus_is_true (const char *value)
	Helper to parse yes/no\|true/false configuration values. More...

gboolean	janus_strcmp_const_time (const void str1, const void str2)
	Helper to compare strings in constant time. More...

guint32	janus_random_uint32 (void)
	Helper to generate random 32-bit unsigned integers (useful for SSRCs, etc.) More...

guint64	janus_random_uint64 (void)
	Helper to generate random 64-bit unsigned integers (useful for Janus IDs) More...

guint64 *	janus_uint64_dup (guint64 num)
	Helper to generate an allocated copy of a guint64 number. More...

void	janus_flags_reset (janus_flags *flags)
	Janus flags reset method. More...

void	janus_flags_set (janus_flags *flags, gsize flag)
	Janus flags set method. More...

void	janus_flags_clear (janus_flags *flags, gsize flag)
	Janus flags clear method. More...

gboolean	janus_flags_is_set (janus_flags *flags, gsize flag)
	Janus flags check method. More...

char *	janus_string_replace (char message, const char old_string, const char *new_string)
	Helper to replace strings. More...

int	janus_mkdir (const char *dir, mode_t mode)
	Helper to create a new directory, and recursively create parent directories if needed. More...

int	janus_get_codec_pt (const char sdp, const char codec)
	Ugly and dirty helper to quickly get the payload type associated with a codec in an SDP. More...

const char *	janus_get_codec_from_pt (const char *sdp, int pt)
	Ugly and dirty helper to quickly get the codec associated with a payload type in an SDP. More...

int	janus_pidfile_create (const char *file)
	Create and lock a PID file. More...

int	janus_pidfile_remove (void)
	Unlock and remove a previously created PID file. More...

void	janus_get_json_type_name (int jtype, unsigned int flags, char *type_name)
	Creates a string describing the JSON type and constraint. More...

gboolean	janus_json_is_valid (json_t *val, json_type jtype, unsigned int flags)
	Checks whether the JSON value matches the type and constraint. More...

gboolean	janus_vp8_is_keyframe (const char *buffer, int len)
	Helper method to check if a VP8 frame is a keyframe or not. More...

gboolean	janus_vp9_is_keyframe (const char *buffer, int len)
	Helper method to check if a VP9 frame is a keyframe or not. More...

gboolean	janus_h264_is_keyframe (const char *buffer, int len)
	Helper method to check if an H.264 frame is a keyframe or not. More...

int	janus_vp8_parse_descriptor (char buffer, int len, uint16_t picid, uint8_t tl0picidx, uint8_t tid, uint8_t y, uint8_t keyidx)
	Helper method to parse a VP8 payload descriptor for useful info (e.g., when simulcasting) More...

void	janus_vp8_simulcast_context_reset (janus_vp8_simulcast_context *context)
	Set (or reset) the context fields to their default values. More...

void	janus_vp8_simulcast_descriptor_update (char buffer, int len, janus_vp8_simulcast_context context, gboolean switched)
	Use the context info to update the RTP header of a packet, if needed. More...

int	janus_vp9_parse_svc (char buffer, int len, int found, int spatial_layer, int temporal_layer, uint8_t p, uint8_t d, uint8_t u, uint8_t b, uint8_t *e)
	Helper method to parse a VP9 payload descriptor for SVC-related info (e.g., when SVC is enabled) More...

guint32	janus_push_bits (guint32 word, size_t num, guint32 val)
	Helper method to push individual bits at the end of a word. More...

void	janus_set1 (guint8 *data, size_t i, guint8 val)
	Helper method to set one byte at a memory position. More...

void	janus_set2 (guint8 *data, size_t i, guint32 val)
	Helper method to set two bytes at a memory position. More...

void	janus_set3 (guint8 *data, size_t i, guint32 val)
	Helper method to set three bytes at a memory position. More...

void	janus_set4 (guint8 *data, size_t i, guint32 val)
	Helper method to set four bytes at a memory position. More...

Detailed Description

Utilities and helpers.

Author: Lorenzo Miniero loren.nosp@m.zo@m.nosp@m.eetec.nosp@m.ho.c.nosp@m.om

Copyright: GNU General Public License v3

Implementations of a few methods that may be of use here and there in the code.

Core

Macro Definition Documentation

#define swap2 ( d ) d

Function Documentation

void janus_flags_clear	(	janus_flags *	flags,
		gsize	flag
	)

Janus flags clear method.

Parameters

[in]	flags	The janus_flags instance to update
[in]	flag	The flag to clear

gboolean janus_flags_is_set	(	janus_flags *	flags,
		gsize	flag
	)

Janus flags check method.

Parameters

[in]	flags	The janus_flags instance to check
[in]	flag	The flag to check

Returns: true if the flag is set, false otherwise

void janus_flags_reset ( janus_flags * flags )

Janus flags reset method.

Parameters

[in] flags The janus_flags instance to reset

void janus_flags_set	(	janus_flags *	flags,
		gsize	flag
	)

Janus flags set method.

Parameters

[in]	flags	The janus_flags instance to update
[in]	flag	The flag to set

const char* janus_get_codec_from_pt	(	const char *	sdp,
		int	pt
	)

Ugly and dirty helper to quickly get the codec associated with a payload type in an SDP.

Parameters

sdp	The SDP to parse
pt	The payload type to look for

Returns: The codec name, if found, NULL otherwise

int janus_get_codec_pt	(	const char *	sdp,
		const char *	codec
	)

Ugly and dirty helper to quickly get the payload type associated with a codec in an SDP.

Parameters

sdp	The SDP to parse
codec	The codec to look for

Returns: The payload type, if found, -1 otherwise

void janus_get_json_type_name	(	int	jtype,
		unsigned int	flags,
		char *	type_name
	)

Creates a string describing the JSON type and constraint.

Parameters

	jtype	The JSON type, e.g., JANUS_JSON_STRING
	flags	Indicates constraints for the described type
[out]	type_name	The type description, e.g., "a positive integer"; required size is 19 characters

Returns: 0 if successful, a negative integer otherwise

gint64 janus_get_monotonic_time ( void )

Helper to retrieve the system monotonic time, as Glib's g_get_monotonic_time may not be available (only since 2.28)

Returns: The system monotonic time

gint64 janus_get_real_time ( void )

Helper to retrieve the system real time, as Glib's g_get_real_time may not be available (only since 2.28)

Returns: The system real time

gboolean janus_h264_is_keyframe	(	const char *	buffer,
		int	len
	)

Helper method to check if an H.264 frame is a keyframe or not.

Parameters

[in]	buffer	The RTP payload to process
[in]	len	The length of the RTP payload

Returns: TRUE if it's a keyframe, FALSE otherwise

gboolean janus_is_true ( const char * value )

Helper to parse yes/no|true/false configuration values.

Parameters

value The configuration value to parse

Returns: true if the value contains a "yes", "YES", "true", TRUE", "1", false otherwise

gboolean janus_json_is_valid	(	json_t *	val,
		json_type	jtype,
		unsigned int	flags
	)

Checks whether the JSON value matches the type and constraint.

Parameters

val	The JSON value to be checked
jtype	The JSON type, e.g., JANUS_JSON_STRING
flags	Indicates constraints for the described type

Returns: TRUE if the value is valid

int janus_mkdir	(	const char *	dir,
		mode_t	mode
	)

Helper to create a new directory, and recursively create parent directories if needed.

Parameters

dir	Path to the new folder to create
mode	File permissions for the new directory file

Returns: An integer like the regular mkdir does

Note: A failure may indicate that creating any of the subdirectories failed: some may still have been created

int janus_pidfile_create ( const char * file )

Create and lock a PID file.

Parameters

file	Path to the PID file to use

Returns: 0 if successful, a negative integer otherwise

int janus_pidfile_remove ( void )

Unlock and remove a previously created PID file.

Returns: 0 if successful, a negative integer otherwise

guint32 janus_push_bits	(	guint32	word,
		size_t	num,
		guint32	val
	)

inline

Helper method to push individual bits at the end of a word.

Parameters

[in]	word	Initial value of word
[in]	num	Number of bits to push
[in]	val	Value of bits to push

Returns: 0 New word value

guint32 janus_random_uint32 ( void )

Helper to generate random 32-bit unsigned integers (useful for SSRCs, etc.)

Note: Currently just wraps g_random_int()

Returns: A random 32-bit unsigned integer

guint64 janus_random_uint64 ( void )

Helper to generate random 64-bit unsigned integers (useful for Janus IDs)

Returns: A random 64-bit unsigned integer

void janus_set1	(	guint8 *	data,
		size_t	i,
		guint8	val
	)

inline

Helper method to set one byte at a memory position.

Parameters

[in]	data	memory data pointer
[in]	i	position in memory to change
[in]	val	value to write

void janus_set2	(	guint8 *	data,
		size_t	i,
		guint32	val
	)

inline

Helper method to set two bytes at a memory position.

Parameters

[in]	data	memory data pointer
[in]	i	position in memory to change
[in]	val	value to write

void janus_set3	(	guint8 *	data,
		size_t	i,
		guint32	val
	)

inline

Helper method to set three bytes at a memory position.

Parameters

[in]	data	memory data pointer
[in]	i	position in memory to change
[in]	val	value to write

void janus_set4	(	guint8 *	data,
		size_t	i,
		guint32	val
	)

inline

Helper method to set four bytes at a memory position.

Parameters

[in]	data	memory data pointer
[in]	i	position in memory to change
[in]	val	value to write

gboolean janus_strcmp_const_time	(	const void *	str1,
		const void *	str2
	)

Helper to compare strings in constant time.

Parameters

str1	The first string to compare
str2	The second string to compare

Returns: true if the strings are the same, false otherwise

char* janus_string_replace	(	char *	message,
		const char *	old_string,
		const char *	new_string
	)

Helper to replace strings.

Parameters

message	The string that contains the text to replace, which may be freed if it is too short
old_string	The old text to replace
new_string	The new text

Returns: A pointer to the updated text string (re-allocated or just updated)

guint64* janus_uint64_dup ( guint64 num )

Helper to generate an allocated copy of a guint64 number.

Note: While apparently silly, this is needed in order to make sure guint64 values used as keys in GHashTable operations are not lost: using temporary guint64 numbers in a g_hash_table_insert, for instance, will cause the key to contain garbage as soon as the temporary variable is lost, and all opererations on the key to fail

Parameters

num	The guint64 number to duplicate

Returns: A pointer to a guint64 number, if successful, NULL otherwise

gboolean janus_vp8_is_keyframe	(	const char *	buffer,
		int	len
	)

Helper method to check if a VP8 frame is a keyframe or not.

Parameters

[in]	buffer	The RTP payload to process
[in]	len	The length of the RTP payload

Returns: TRUE if it's a keyframe, FALSE otherwise

int janus_vp8_parse_descriptor	(	char *	buffer,
		int	len,
		uint16_t *	picid,
		uint8_t *	tl0picidx,
		uint8_t *	tid,
		uint8_t *	y,
		uint8_t *	keyidx
	)

Helper method to parse a VP8 payload descriptor for useful info (e.g., when simulcasting)

Parameters

[in]	buffer	The RTP payload to process
[in]	len	The length of the RTP payload
[out]	picid	The Picture ID
[out]	tl0picidx	Temporal level zero index
[out]	tid	Temporal-layer index
[out]	y	Layer sync bit
[out]	keyidx	Temporal key frame index

Returns: 0 in case of success, a negative integer otherwise

void janus_vp8_simulcast_context_reset ( janus_vp8_simulcast_context * context )

Set (or reset) the context fields to their default values.

Parameters

[in] context The context to (re)set

void janus_vp8_simulcast_descriptor_update	(	char *	buffer,
		int	len,
		janus_vp8_simulcast_context *	context,
		gboolean	switched
	)

Use the context info to update the RTP header of a packet, if needed.

Parameters

[in]	buffer	The RTP payload to process
[in]	len	The length of the RTP payload
[in]	context	The context to use as a reference
[in]	switched	Whether there has been a source switch or not (important to compute offsets)

gboolean janus_vp9_is_keyframe	(	const char *	buffer,
		int	len
	)

Helper method to check if a VP9 frame is a keyframe or not.

Parameters

[in]	buffer	The RTP payload to process
[in]	len	The length of the RTP payload

Returns: TRUE if it's a keyframe, FALSE otherwise

int janus_vp9_parse_svc	(	char *	buffer,
		int	len,
		int *	found,
		int *	spatial_layer,
		int *	temporal_layer,
		uint8_t *	p,
		uint8_t *	d,
		uint8_t *	u,
		uint8_t *	b,
		uint8_t *	e
	)

Helper method to parse a VP9 payload descriptor for SVC-related info (e.g., when SVC is enabled)

Parameters

[in]	buffer	The RTP payload to process
[in]	len	The length of the RTP payload
[out]	found	Whether any SVC related info has been found or not
[out]	spatial_layer	Spatial layer of the packet
[out]	temporal_layer	Temporal layer of the packet
[out]	p	Inter-picture predicted picture bit
[out]	d	Inter-layer dependency used bit
[out]	u	Switching up point bit
[out]	b	Start of a frame bit
[out]	e	End of a frame bit

Returns: 0 in case of success, a negative integer otherwise

Macros

Functions

Detailed Description

Macro Definition Documentation

Function Documentation