Parse a slogger2 buffer
#include <slog2_parse.h>
int slog2_parse_dynamic_buffer( slog2_log_t log,
int buffer_index,
slog2_packet_info_t *packet_info,
slog2_packet_callback callback,
void *param );
int slog2_parse_static_buffer( slog2_log_t log,
int buffer_index,
slog2_packet_info_t *packet_info,
slog2_packet_callback callback,
void *param );
typedef int (*slog2_packet_callback)( slog2_packet_info_t *__info,
void *__payload,
void *__param );
that's called to process each packet in the buffer; see below.
The slog2_parse_dynamic_buffer() and slog2_parse_static_buffer() functions parse through a live or static slogger2 buffer (respectively) from beginning to end, finding valid packets and calling the given callback function for each packet. If the callback returns a nonzero value, then these functions return immediately.
The prototype of the callback function is:
int callback( slog2_packet_info_t *info,
void *payload,
void *param );
The arguments are:
The callback should return 0 on success, or a nonzero value on failure.
0 on success, or -1 on failure.
#include <stdlib.h>
#include <stdio.h>
#include <sys/slog2.h>
#include <slog2_parse.h>
int my_callback (slog2_packet_info_t *info, void *payload, void *param)
{
printf (" Processing packet %d of size %d\n", info->sequence_number,
info->data_size);
switch (info->severity)
{
case SLOG2_SHUTDOWN: printf (" SHUTDOWN: ");
break;
case SLOG2_CRITICAL: printf (" CRITICAL: ");
break;
case SLOG2_ERROR: printf (" ERROR: ");
break;
case SLOG2_WARNING: printf (" Warning: ");
break;
case SLOG2_NOTICE: printf (" Notice: ");
break;
case SLOG2_INFO: printf (" Info: ");
break;
case SLOG2_DEBUG1: printf (" debug1: ");
break;
case SLOG2_DEBUG2: printf (" debug2: ");
break;
default: printf (" Unknown: ");
}
printf ("%s\n", (char *)payload);
return 0;
}
int main(int argc, char *argv[]) {
char log_path[PATH_MAX] = "/dev/shmem/slogger2/slogger_two.184341";
slog2_log_t my_log;
slog2_log_info_t log_info = SLOG2_LOG_INFO_INIT;
int buffer_index;
slog2_packet_info_t packet_info = SLOG2_PACKET_INFO_INIT;
slog2_buffer_info_t buffer_info = SLOG2_BUFFER_INFO_INIT;
/* Open a log file */
my_log = slog2_open_log(log_path);
if (my_log == 0)
{
printf ("Couldn't open %s.\n", log_path);
return EXIT_FAILURE;
}
/* What do we know about the log? */
if (slog2_get_log_info(my_log, &log_info) == -1)
{
printf ("Couldn't get information about the log.\n");
return EXIT_FAILURE;
}
printf ("Log information:\n");
printf (" Num buffers: %d\n", log_info.num_buffers);
printf (" Owner: %d\n", log_info.owner_pid);
printf (" Buffer set name: %s\n", log_info.buffer_set_name);
printf (" Verbosity: %d\n", log_info.verbosity_level);
/* Parse the log file. */
printf ("\nBuffers:\n");
for (buffer_index = 0; buffer_index < log_info.num_buffers; buffer_index++)
{
if (slog2_get_buffer_info(my_log, buffer_index, &buffer_info) == -1)
{
printf ("Couldn't get info about buffer %d.\n", buffer_index);
return EXIT_FAILURE;
}
printf (" Buffer %d: size: %d Name: %s\n", buffer_index,
buffer_info.buffer_size, buffer_info.buffer_name);
if (slog2_parse_static_buffer( my_log, buffer_index, &packet_info,
my_callback, NULL) == -1)
{
printf ("slog2_parse_static_buffer() failed.\n");
return EXIT_FAILURE;
}
}
/* Close the log file. */
slog2_close_log( my_log);
return EXIT_SUCCESS;
}
When run on the log produced by the example for slog2_register(), this program produces the following output:
Log information:
Num buffers: 2
Owner: 184341
Buffer set name: slogger_two
Verbosity: 5
Buffers:
Buffer 0: size: 28672 Name: hi_rate_logging
Processing packet 0 of size 63
Info: Writing a formatted string into the buffer: ./root/slogger_two
Processing packet 1 of size 43
Info: Writing a constant string into the buffer.
Processing packet 2 of size 37
Warning: string:Hello world, some_number:5108
Buffer 1: size: 4096 Name: lo_rate_logging
Processing packet 3 of size 28
Notice: This string will be logged.
| Safety: | |
|---|---|
| Cancellation point | No |
| Interrupt handler | No |
| Signal handler | No |
| Thread | Yes |