msg-decoder.h File Reference

#include "msg-types.h"
#include <stddef.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>

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Classes
struct	nexusrv_hw_cfg
	NexusRV Message decoder configuration. More...
struct	nexusrv_msg_decoder
	NexusRV Message decoder context. More...

Macros
#define	NEXUS_RV_MSG_MAX_BYTES   38

Typedefs
typedef struct nexusrv_hw_cfg	nexusrv_hw_cfg
	NexusRV Message decoder configuration. More...
typedef struct nexusrv_msg_decoder	nexusrv_msg_decoder
	NexusRV Message decoder context. More...

Functions
int	nexusrv_hwcfg_parse (nexusrv_msg_decoder *hwcfg, const char *str)
ssize_t	nexusrv_sync_forward (const uint8_t *buffer, size_t limit)
	Sync forward for the first full Message. More...
ssize_t	nexusrv_sync_backward (const uint8_t *buffer, size_t pos)
	Sync backward for the last full Message. More...
ssize_t	nexusrv_msg_decode (const nexusrv_hw_cfg *hwcfg, const uint8_t *buffer, size_t limit, nexusrv_msg *msg)
	Decode the full NexusRV Message from buffer into msg. More...
ssize_t	nexusrv_msg_decoder_next (nexusrv_msg_decoder *decoder, nexusrv_msg *msg)
	Iteratively decode the next Nexus Message from trace file. More...
uint8_t *	nexusrv_msg_decoder_lastmsg (nexusrv_msg_decoder *decoder)
	Get the pointer to the last successfully decoded Message bytes. More...
void	nexusrv_msg_decoder_rewind_last (nexusrv_msg_decoder *decoder)
	Rewind the decoder to the beginning of last Message. More...
int	nexusrv_print_msg (FILE *fp, const nexusrv_msg *msg)
	Print the msg in human readable form to fp. More...

Macro Definition Documentation

NEXUS_RV_MSG_MAX_BYTES

#define NEXUS_RV_MSG_MAX_BYTES   38

Maximum standard Message size in raw bytes

Typedef Documentation

nexusrv_hw_cfg

typedef struct nexusrv_hw_cfg nexusrv_hw_cfg

NexusRV Message decoder configuration.

This should be set to match the HW implementation

nexusrv_msg_decoder

typedef struct nexusrv_msg_decoder nexusrv_msg_decoder

NexusRV Message decoder context.

This should be initialized by nexusrv_msg_decoder_init before calling nexusrv_msg_next

Function Documentation

nexusrv_msg_decode()

ssize_t nexusrv_msg_decode	(	const nexusrv_hw_cfg *	hwcfg,
		const uint8_t *	buffer,
		size_t	limit,
		nexusrv_msg *	msg
	)

Decode the full NexusRV Message from buffer into msg.

Parameters

[in]	hwcfg	Must match the HW implementation that produced the trace
	buffer	The buffer that holds the Message
	limit	Should be set to the number of bytes in buffer
[out]	msg	Decoded Message

Return values

>0	the number of bytes consumed (a positive integer) on a success decoding of msg
-nexus_stream_truncate	if more bytes are expected from buffer
-nexus_msg_invalid	if decoded msg is invalid
-nexus_msg_missing_field	if decoded msg has missing fields

nexusrv_msg_decoder_lastmsg()

uint8_t* nexusrv_msg_decoder_lastmsg

(

nexusrv_msg_decoder *

decoder

)

Get the pointer to the last successfully decoded Message bytes.

Returns the pointer to bytes of last Message. It must be called after a successful return of nexusrv_msg_decoder_next, otherwise it returns NULL

Parameters

[in]

decoder

The same decoder used by nexusrv_msg_decoder_next

Returns

The pointer to the raw Message bytes

nexusrv_msg_decoder_next()

ssize_t nexusrv_msg_decoder_next	(	nexusrv_msg_decoder *	decoder,
		nexusrv_msg *	msg
	)

Iteratively decode the next Nexus Message from trace file.

It handles buffer fill and refill transparently, and caller is hence freed from dealing with -nexus_stream_truncate.

Parameters

[in]	decoder	Should be initialized by nexusrv_msg_decoder_init
[out]	msg	Decoded Message

Return values

==0	if no more Message to decode (EOF)
>0	the number of bytes consumed (a positive integer) on a success decoding of msg (same as nexusrv_msg_decode)
-nexus_stream_truncate	if EOF is already reached, and there's a partial Message at the end.
-nexus_stream_read_failed	if read decoder.fd has failed, error can be retrieved from errno
-nexus_buffer_too_small	if the size of decoder.buffer is too small to fit a single Message
-nexus_msg_invalid	if decoded msg is invalid
-nexus_msg_missing_field	if decoded msg has missing fields

nexusrv_msg_decoder_rewind_last()

void nexusrv_msg_decoder_rewind_last

(

nexusrv_msg_decoder *

decoder

)

Rewind the decoder to the beginning of last Message.

Rewind the decoder to point to the beginning of last Message, so it can be decoded again. This effectively "returns" the Message to the decoder. It does nothing if there's no previous invocation of nexusrv_msg_decoder_next, or it has already been called for the previous nexusrv_msg_decoder_next.

Parameters

[in]

decoder

The same decoder used by nexusrv_msg_decoder_next

nexusrv_print_msg()

int nexusrv_print_msg	(	FILE *	fp,
		const nexusrv_msg *	msg
	)

Print the msg in human readable form to fp.

Returns the total number of bytes written on success (as printf does), Or, on failure, the same return code of the first failed fprintf.

nexusrv_sync_backward()

ssize_t nexusrv_sync_backward	(	const uint8_t *	buffer,
		size_t	pos
	)

Sync backward for the last full Message.

It stops at the byte where the preceding byte has MSEO==3

Parameters

buffer	The buffer that holds Messages
pos	Should be set to the current position in buffer

Return values

>0	The position of the first full Message on success. The returned position can be equal to pos, which means the buffer contains a single Message, and we have just passed it.
-nexus_stream_truncate	If cannot find the beginning of the full Message in buffer

nexusrv_sync_forward()

ssize_t nexusrv_sync_forward	(	const uint8_t *	buffer,
		size_t	limit
	)

Sync forward for the first full Message.

It stops at the byte where the preceding byte has MSEO==3

Parameters

buffer	The buffer that holds Messages
limit	Should be set to the number of bytes in buffer

Return values

>0	The offset to the first full Message on success. The returned offset can be equal to limit, which means the buffer contains a single Message, and we have just passed it.
-nexus_stream_truncate	If cannot find the beginning of the full Message in buffer