log.cpp File Reference

#include <unistd.h>
#include <sys/uio.h>
#include <string.h>
#include <fcntl.h>
#include <inttypes.h>
#include "log.hpp"
#include "config.hpp"

Macros
#define	__STDC_FORMAT_MACROS
#define	LOG_MAX_SIZE   2048
#define	LOG_HEADER   "E/APPDYNAMICS: "
#define	LOG_HEADER_LEN   (sizeof(LOG_HEADER) - 1)
#define	ERROR_LOG_MSG   "<NULL Log Message>"

Functions
static void	log_write_to_stderr (const char *logmsg, size_t logmsg_len)
	Prefixes Log Message with timestamp and writes to stderr. More...
void	appd_iot_log (appd_iot_log_level_t log_level, const char *format,...)
	Reads log message, appends log header and triggers log write callback function. More...
const char *	appd_iot_error_code_to_str (appd_iot_error_code_t error_code)
	Convert error code to string. More...
const char *	appd_iot_sdk_state_to_str (appd_iot_sdk_state_t sdk_state)
	Convert sdk state to string. More...

Variables
static char	loglevel_c [APPD_IOT_MAX_LOG_LEVELS] = {'O', 'E', 'W', 'I', 'D', 'V', 'A'}
static const char *	error_code_to_str [APPD_IOT_MAX_ERROR_CODES]
static const char *	sdk_state_to_str [APPD_IOT_MAX_SDK_STATES]

Macro Definition Documentation

__STDC_FORMAT_MACROS

#define __STDC_FORMAT_MACROS

LOG_MAX_SIZE

#define LOG_MAX_SIZE   2048

LOG_HEADER

#define LOG_HEADER   "E/APPDYNAMICS: "

LOG_HEADER_LEN

#define LOG_HEADER_LEN   (sizeof(LOG_HEADER) - 1)

ERROR_LOG_MSG

#define ERROR_LOG_MSG   "<NULL Log Message>"

Function Documentation

log_write_to_stderr()

static void log_write_to_stderr ( const char *  logmsg, size_t  logmsg_len  )

static

Prefixes Log Message with timestamp and writes to stderr.

Parameters

logmsg	contains the log message without the newline char at the end
logmsg_len	contains the length of log message

{
  if (logmsg == NULL)
  {
    return;
  }

  int iovcnt;
  struct iovec iov[3];
  char timestamp[32];
  char eol = '\n';

  struct timeval tv;
  gettimeofday(&tv, NULL);

  int64_t time_in_ms = (int64_t)tv.tv_sec * 1000 + (int64_t)tv.tv_usec / 1000;
  size_t timestamp_len = snprintf(timestamp, sizeof(timestamp), "%" PRId64 " ", time_in_ms);

  if (timestamp_len >= sizeof(timestamp))
  {
    timestamp_len = sizeof(timestamp) - 1;
    timestamp[timestamp_len] = '\0';
  }

  iov[0].iov_base = (void*)timestamp;
  iov[0].iov_len = timestamp_len;

  iov[1].iov_base = (void*)logmsg;
  iov[1].iov_len = logmsg_len;

  iov[2].iov_base = (void*)(&eol);
  iov[2].iov_len = sizeof(eol);

  iovcnt = sizeof(iov) / sizeof(struct iovec);

  writev(STDERR_FILENO, iov, iovcnt);
}

appd_iot_log()

void appd_iot_log	(	appd_iot_log_level_t	log_level,
		const char *	format,
			...
	)

Reads log message, appends log header and triggers log write callback function.

Parameters

log_level	indicates log level listed in log_detail_t
format	Printf Format String

{
  //check for log level
  appd_iot_log_level_t configlog_level = appd_iot_get_log_level();

  if (log_level > configlog_level)
  {
    return;
  }

  if (log_level >= APPD_IOT_MAX_LOG_LEVELS)
  {
    log_level = APPD_IOT_LOG_ERROR;
  }

  //check for log write cb
  appd_iot_log_write_cb_t log_write_cb = appd_iot_get_log_write_cb();

  if (log_write_cb == NULL)
  {
    log_write_cb = &log_write_to_stderr;
  }

  //initilize logbuf with log header
  char logbuf[LOG_MAX_SIZE] = LOG_HEADER;
  size_t logmsg_len;

  //update log level in the log header
  logbuf[0] = loglevel_c[log_level];

  va_list args;

  //read log message
  va_start(args, format);
  int nchar = vsnprintf(logbuf + LOG_HEADER_LEN, (LOG_MAX_SIZE - LOG_HEADER_LEN), format, args);
  va_end(args);

  if (nchar < 0)
  {
    snprintf(logbuf + LOG_HEADER_LEN, sizeof(ERROR_LOG_MSG), ERROR_LOG_MSG);
    logmsg_len = LOG_HEADER_LEN + sizeof(ERROR_LOG_MSG) - 1;
  }
  else if (LOG_HEADER_LEN + nchar >= LOG_MAX_SIZE)
  {
    logmsg_len = LOG_MAX_SIZE - 1;
    logbuf[logmsg_len] = '\0';
  }
  else
  {
    logmsg_len = LOG_HEADER_LEN + nchar;
  }

  //trigger callback to write log msg
  log_write_cb(logbuf, logmsg_len);
}

appd_iot_error_code_to_str()

const char* appd_iot_error_code_to_str

(

appd_iot_error_code_t

error_code

)

Convert error code to string.

Parameters

error_code

that is to be converted to string

Returns

string representation of the error code

{
  return error_code_to_str[error_code];
}

appd_iot_sdk_state_to_str()

const char* appd_iot_sdk_state_to_str

(

appd_iot_sdk_state_t

sdk_state

)

Convert sdk state to string.

Parameters

sdk_state

that is to be converted to string

Returns

string representation of the sdk state

{
  return sdk_state_to_str[sdk_state];
}

Variable Documentation

loglevel_c

char loglevel_c[APPD_IOT_MAX_LOG_LEVELS] = {'O', 'E', 'W', 'I', 'D', 'V', 'A'}

static

error_code_to_str

const char* error_code_to_str[APPD_IOT_MAX_ERROR_CODES]

static

Initial value:

=
{
  
  "SUCCESS",
  
  "INVALID_INPUT",
  
  "MAX_LIMIT",
  
  "NETWORK_ERROR",
  
  "NETWORK_REJECT",
  
  "NETWORK_UNREACHABLE",
  
  "NETWORK_NOT_AVAILABLE",
  
  "NULL_PTR",
  
  "INTERNAL_ERROR",
  
  "NOT_SUPPORTED",
  
  "SDK_NOT_ENABLED",

}

sdk_state_to_str

const char* sdk_state_to_str[APPD_IOT_MAX_SDK_STATES]

static

Initial value:

=
{
  
  "SDK_UNINITIALIZED",
  
  "SDK_ENABLED",
  
  "SDK_DISABLED_KILL_SWITCH",
  
  "SDK_DISABLED_LICENSE_EXPIRED",
  
  "SDK_DISABLED_DATA_LIMIT_EXCEEDED"
}