add some dependencies and test code

src/logger/sc_log.h

@@ -0,0 +1,146 @@
+/*
+ * BSD-3-Clause
+ *
+ * Copyright 2021 Ozan Tezcan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
+ * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef SC_LOG_H
+#define SC_LOG_H
+
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define SC_LOG_VERSION "2.0.0"
+
+enum sc_log_level
+{
+	SC_LOG_DEBUG,
+	SC_LOG_INFO,
+	SC_LOG_WARN,
+	SC_LOG_ERROR,
+	SC_LOG_OFF,
+};
+
+// clang-format off
+static const struct sc_log_level_pair
+{
+    const enum sc_log_level id;
+    const char *str;
+} sc_log_levels[] = {
+        {SC_LOG_DEBUG, "DEBUG"},
+        {SC_LOG_INFO,  "INFO" },
+        {SC_LOG_WARN,  "WARN" },
+        {SC_LOG_ERROR, "ERROR"},
+        {SC_LOG_OFF,   "OFF"  },
+};
+// clang-format on
+
+// Internal function
+int sc_log_log(enum sc_log_level level, const char *fmt, ...);
+
+// Max file size to rotate, should not be more than 4 GB.
+#define SC_LOG_FILE_SIZE (2 * 1024 * 1024)
+
+// Define SC_LOG_PRINT_FILE_NAME to print file name and line no in the log line.
+#ifdef SC_LOG_PRINT_FILE_NAME
+#define sc_log_ap(fmt, ...)                                                    \
+	"(%s:%d) " fmt, strrchr("/" __FILE__, '/') + 1, __LINE__, __VA_ARGS__
+#else
+#define sc_log_ap(fmt, ...) fmt, __VA_ARGS__
+#endif
+
+/**
+ * sc_log_init() call once in your application before using log functions.
+ * sc_log_term() call once to clean up, you must not use logger after this call.
+ * These functions are not thread-safe, should be called from a single thread.
+ *
+ * @return '0' on success, negative value on error, errno will be set.
+ */
+int sc_log_init(void);
+int sc_log_term(void);
+
+/**
+ * Set thread name.
+ *
+ * Call once from each thread if you want to set thread name.
+ * @param name  Thread name
+ */
+void sc_log_set_thread_name(const char *name);
+
+/**
+ * Set log level.
+ *
+ * @param level  One of "DEBUG", "INFO", "WARN", "ERROR", "OFF"
+ * @return       '0' on success, negative value on invalid level string
+ */
+int sc_log_set_level(const char *level);
+
+/**
+ * Enable stdout logging.
+ *
+ * @param enable 'true' to enable, 'false' to disable logging to stdout.
+ */
+void sc_log_set_stdout(bool enable);
+
+/**
+ * Enable file logging.
+ *
+ * Log files will be rotated to prevent generating very big files. Once current
+ * log file reaches 'SC_LOG_FILE_SIZE' (see definition above), it will be
+ * renamed as `prev` and the latest logs will always be in the 'current' file.
+ *
+ * e.g., sc_log_set_file("/tmp/log.0.txt", "/tmp/log-latest.txt");
+ *
+ * To disable logging into file: sc_log_set_file(NULL, NULL);
+ *
+ * @param prev     file path for previous log file, 'NULL' to disable
+ * @param current  file path for latest log file, 'NULL' to disable
+ * @return         0 on success, -1 on error, errno will be set.
+ */
+int sc_log_set_file(const char *prev, const char *current);
+
+/**
+ * Enabled logging to callback.
+ *
+ * @param arg user arg to callback.
+ * @param cb  log callback.
+ */
+void sc_log_set_callback(void *arg,
+			 int (*cb)(void *arg, enum sc_log_level level,
+				   const char *fmt, va_list va));
+
+// e.g., sc_log_error("Errno: %d, reason: %s", errno, strerror(errno));
+#define sc_log_debug(...) (sc_log_log(SC_LOG_DEBUG, sc_log_ap(__VA_ARGS__, "")))
+#define sc_log_info(...) (sc_log_log(SC_LOG_INFO, sc_log_ap(__VA_ARGS__, "")))
+#define sc_log_warn(...) (sc_log_log(SC_LOG_WARN, sc_log_ap(__VA_ARGS__, "")))
+#define sc_log_error(...) (sc_log_log(SC_LOG_ERROR, sc_log_ap(__VA_ARGS__, "")))
+
+#endif