libsigrok/log.c

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/*
* This file is part of the sigrok project.
*
* Copyright (C) 2011-2012 Uwe Hermann <uwe@hermann-uwe.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdarg.h>
#include <stdio.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"
/**
* @file
*
* Controlling the libsigrok message logging functionality.
*/
/**
* @defgroup grp_logging Logging
*
* Controlling the libsigrok message logging functionality.
*
* @{
*/
/* Currently selected libsigrok loglevel. Default: SR_LOG_WARN. */
static int sr_loglevel = SR_LOG_WARN; /* Show errors+warnings per default. */
/* Function prototype. */
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static int sr_logv(void *cb_data, int loglevel, const char *format,
va_list args);
/* Pointer to the currently selected log callback. Default: sr_logv(). */
static sr_log_callback_t sr_log_callback = sr_logv;
/*
* Pointer to private data that can be passed to the log callback.
* This can be used (for example) by C++ GUIs to pass a "this" pointer.
*/
static void *sr_log_callback_data = NULL;
/* Log domain (a short string that is used as prefix for all messages). */
/** @cond PRIVATE */
#define LOGDOMAIN_MAXLEN 30
#define LOGDOMAIN_DEFAULT "sr: "
/** @endcond */
static char sr_log_domain[LOGDOMAIN_MAXLEN + 1] = LOGDOMAIN_DEFAULT;
/**
* Set the libsigrok loglevel.
*
* This influences the amount of log messages (debug messages, error messages,
* and so on) libsigrok will output. Using SR_LOG_NONE disables all messages.
*
* Note that this function itself will also output log messages. After the
* loglevel has changed, it will output a debug message with SR_LOG_DBG for
* example. Whether this message is shown depends on the (new) loglevel.
*
* @param loglevel The loglevel to set (SR_LOG_NONE, SR_LOG_ERR, SR_LOG_WARN,
* SR_LOG_INFO, SR_LOG_DBG, or SR_LOG_SPEW).
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid loglevel.
*
* @since 0.1.0
*/
SR_API int sr_log_loglevel_set(int loglevel)
{
if (loglevel < SR_LOG_NONE || loglevel > SR_LOG_SPEW) {
sr_err("Invalid loglevel %d.", loglevel);
return SR_ERR_ARG;
}
sr_loglevel = loglevel;
sr_dbg("libsigrok loglevel set to %d.", loglevel);
return SR_OK;
}
/**
* Get the libsigrok loglevel.
*
* @return The currently configured libsigrok loglevel.
*
* @since 0.1.0
*/
SR_API int sr_log_loglevel_get(void)
{
return sr_loglevel;
}
/**
* Set the libsigrok logdomain string.
*
* @param logdomain The string to use as logdomain for libsigrok log
* messages from now on. Must not be NULL. The maximum
* length of the string is 30 characters (this does not
* include the trailing NUL-byte). Longer strings are
* silently truncated.
* In order to not use a logdomain, pass an empty string.
* The function makes its own copy of the input string, i.e.
* the caller does not need to keep it around.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid logdomain.
*
* @since 0.1.0
*/
SR_API int sr_log_logdomain_set(const char *logdomain)
{
if (!logdomain) {
sr_err("log: %s: logdomain was NULL", __func__);
return SR_ERR_ARG;
}
/* TODO: Error handling. */
snprintf((char *)&sr_log_domain, LOGDOMAIN_MAXLEN, "%s", logdomain);
sr_dbg("Log domain set to '%s'.", (const char *)&sr_log_domain);
return SR_OK;
}
/**
* Get the currently configured libsigrok logdomain.
*
* @return A copy of the currently configured libsigrok logdomain
* string. The caller is responsible for g_free()ing the string when
* it is no longer needed.
*
* @since 0.1.0
*/
SR_API char *sr_log_logdomain_get(void)
{
return g_strdup((const char *)&sr_log_domain);
}
/**
* Set the libsigrok log callback to the specified function.
*
* @param cb Function pointer to the log callback function to use.
* Must not be NULL.
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* @param cb_data Pointer to private data to be passed on. This can be used by
* the caller to pass arbitrary data to the log functions. This
* pointer is only stored or passed on by libsigrok, and is
* never used or interpreted in any way. The pointer is allowed
* to be NULL if the caller doesn't need/want to pass any data.
*
* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments.
*
* @since 0.1.0
*/
SR_API int sr_log_callback_set(sr_log_callback_t cb, void *cb_data)
{
if (!cb) {
sr_err("log: %s: cb was NULL", __func__);
return SR_ERR_ARG;
}
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/* Note: 'cb_data' is allowed to be NULL. */
sr_log_callback = cb;
sr_log_callback_data = cb_data;
return SR_OK;
}
/**
* Set the libsigrok log callback to the default built-in one.
*
* Additionally, the internal 'sr_log_callback_data' pointer is set to NULL.
*
* @return SR_OK upon success, a negative error code otherwise.
*
* @since 0.1.0
*/
SR_API int sr_log_callback_set_default(void)
{
/*
* Note: No log output in this function, as it should safely work
* even if the currently set log callback is buggy/broken.
*/
sr_log_callback = sr_logv;
sr_log_callback_data = NULL;
return SR_OK;
}
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static int sr_logv(void *cb_data, int loglevel, const char *format, va_list args)
{
int ret;
/* This specific log callback doesn't need the void pointer data. */
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(void)cb_data;
/* Only output messages of at least the selected loglevel(s). */
if (loglevel > sr_loglevel)
return SR_OK; /* TODO? */
if (sr_log_domain[0] != '\0')
fprintf(stderr, "%s", sr_log_domain);
ret = vfprintf(stderr, format, args);
fprintf(stderr, "\n");
return ret;
}
/** @private */
SR_PRIV int sr_log(int loglevel, const char *format, ...)
{
int ret;
va_list args;
va_start(args, format);
ret = sr_log_callback(sr_log_callback_data, loglevel, format, args);
va_end(args);
return ret;
}
/** @private */
SR_PRIV int sr_spew(const char *format, ...)
{
int ret;
va_list args;
va_start(args, format);
ret = sr_log_callback(sr_log_callback_data, SR_LOG_SPEW, format, args);
va_end(args);
return ret;
}
/** @private */
SR_PRIV int sr_dbg(const char *format, ...)
{
int ret;
va_list args;
va_start(args, format);
ret = sr_log_callback(sr_log_callback_data, SR_LOG_DBG, format, args);
va_end(args);
return ret;
}
/** @private */
SR_PRIV int sr_info(const char *format, ...)
{
int ret;
va_list args;
va_start(args, format);
ret = sr_log_callback(sr_log_callback_data, SR_LOG_INFO, format, args);
va_end(args);
return ret;
}
/** @private */
SR_PRIV int sr_warn(const char *format, ...)
{
int ret;
va_list args;
va_start(args, format);
ret = sr_log_callback(sr_log_callback_data, SR_LOG_WARN, format, args);
va_end(args);
return ret;
}
/** @private */
SR_PRIV int sr_err(const char *format, ...)
{
int ret;
va_list args;
va_start(args, format);
ret = sr_log_callback(sr_log_callback_data, SR_LOG_ERR, format, args);
va_end(args);
return ret;
}
/** @} */