src/utils/log.h: add new aubio_log_set_function

diff --git a/src/utils/log.c b/src/utils/log.c
new file mode 100644 (file)
index 0000000..0f6ef81
--- /dev/null
+++ b/src/utils/log.c
@@ -0,0 +1,76 @@
+#include "config.h"
+#include "aubio_priv.h"
+#include "log.h"
+
+/** array of pointers to logging functions, one per level */
+static aubio_log_function_t aubio_log_function[AUBIO_LOG_LAST_LEVEL];
+/** array of pointers to closure passed to logging functions, one per level */
+static void* aubio_log_user_data[AUBIO_LOG_LAST_LEVEL];
+/** buffer for logging messages */
+static char aubio_log_buffer[512];
+
+/** private function used by default by logging functions */
+void
+aubio_default_log(sint_t level, const char_t *message, void * data UNUSED)
+{
+  FILE *out;
+  out = stdout;
+  if (level == AUBIO_LOG_DBG || level == AUBIO_LOG_ERR) {
+    out = stderr;
+  }
+  if (data != NULL) {
+    fprintf(out, "%s", (char_t *)data);
+  }
+  fprintf(out, "%s", message);
+  //fflush(out);
+}
+
+uint_t
+aubio_log(sint_t level, const char_t *fmt, ...)
+{
+  aubio_log_function_t fun = NULL;
+
+  va_list args;
+  va_start(args, fmt);
+  vsnprintf(aubio_log_buffer, sizeof(aubio_log_buffer), fmt, args);
+  va_end(args);
+
+  if ((level >= 0) && (level < AUBIO_LOG_LAST_LEVEL)) {
+    fun = aubio_log_function[level];
+    if (fun != NULL) {
+      (*fun)(level, aubio_log_buffer, aubio_log_user_data[level]);
+    } else {
+      aubio_default_log(level, aubio_log_buffer, NULL);
+    }
+  }
+  return AUBIO_FAIL;
+}
+
+void
+aubio_log_reset(void)
+{
+  uint_t i = 0;
+  for (i = 0; i < AUBIO_LOG_LAST_LEVEL; i++) {
+    aubio_log_set_level_function(i, aubio_default_log, NULL);
+  }
+}
+
+aubio_log_function_t
+aubio_log_set_level_function(sint_t level, aubio_log_function_t fun, void * data)
+{
+  aubio_log_function_t old = NULL;
+  if ((level >= 0) && (level < AUBIO_LOG_LAST_LEVEL)) {
+    old = aubio_log_function[level];
+    aubio_log_function[level] = fun;
+    aubio_log_user_data[level] = data;
+  }
+  return old;
+}
+
+void
+aubio_log_set_function(aubio_log_function_t fun, void * data) {
+  uint_t i = 0;
+  for (i = 0; i < AUBIO_LOG_LAST_LEVEL; i++) {
+    aubio_log_set_level_function(i, fun, data);
+  }
+}

diff --git a/src/utils/log.h b/src/utils/log.h
new file mode 100644 (file)
index 0000000..ee2606c
--- /dev/null
+++ b/src/utils/log.h
@@ -0,0 +1,98 @@
+/*
+  Copyright (C) 2016 Paul Brossier <piem@aubio.org>
+
+  This file is part of aubio.
+
+  aubio 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 3 of the License, or
+  (at your option) any later version.
+
+  aubio 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 aubio.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+#ifndef AUBIO_LOG_H
+#define AUBIO_LOG_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** \file
+
+  Logging features
+
+  This file specifies ::aubio_log_set_function and
+  ::aubio_log_set_level_function, which let you define one or several custom
+  logging functions to redirect warnings and errors from aubio to your
+  application. The custom function should have the prototype defined in
+  ::aubio_log_function_t.
+
+  After a call to ::aubio_log_set_level_function, ::aubio_log_reset can be used
+  to reset each logging functions to the default ones.
+
+  \example utils/test-log.c
+
+*/
+
+/** list of logging levels */
+enum aubio_log_level {
+  AUBIO_LOG_ERR, /**< critical errors */
+  AUBIO_LOG_WRN, /**< warnings */
+  AUBIO_LOG_MSG, /**< general messages */
+  AUBIO_LOG_DBG, /**< debug messages */
+  AUBIO_LOG_LAST_LEVEL, /**< number of valid levels */
+};
+
+/** Logging function prototype, to be passed to ::aubio_log_set_function
+
+  \param level log level
+  \param message text to log
+  \param data optional closure used by the callback
+
+  See @ref utils/test-log.c for an example of logging function.
+
+ */
+typedef void (*aubio_log_function_t)(sint_t level, const char_t *message, void
+    *data);
+
+/** Set logging function for all levels
+
+  \param fun the function to be used to log, of type ::aubio_log_function_t
+  \param data optional closure to be passed to the function (can be NULL if
+  nothing to pass)
+
+ */
+void aubio_log_set_function(aubio_log_function_t fun, void* data);
+
+/** Set logging function for a given level
+
+  \param level the level for which to set the logging function
+  \param fun the function to be used to log, of type ::aubio_log_function_t
+  \param data optional closure to be passed to the function (can be NULL if
+  nothing to pass)
+
+*/
+aubio_log_function_t aubio_log_set_level_function(sint_t level,
+    aubio_log_function_t fun, void* data);
+
+/** Reset all logging functions to the default one
+
+ After calling this function, the default logging function will be used to
+ print error, warning, normal, and debug messages to `stdout` or `stderr`.
+
+ */
+void aubio_log_reset(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* AUBIO_LOG_H */