feat(lnm): add logging framework

lnm/src/_include/lnm/log_internal.h

@@ -0,0 +1,26 @@
+#ifndef LNM_LOG_INTERNAL
+#define LNM_LOG_INTERNAL
+
+#include "lnm/log.h"
+
+typedef enum lnm_logger_stream_type {
+  lnm_logger_stream_type_file = 0
+} lnm_logger_stream_type;
+
+typedef struct lnm_logger_stream {
+  void *ptr;
+  lnm_logger_stream_type type;
+  lnm_log_level level;
+} lnm_logger_stream;
+
+struct lnm_logger {
+  struct {
+    lnm_logger_stream **arr;
+    size_t len;
+  } streams;
+};
+
+lnm_err lnm_logger_stream_register(lnm_logger *logger,
+                                   lnm_logger_stream *stream);
+
+#endif

lnm/src/lnm_log.c

@@ -0,0 +1,86 @@
+#include <stdio.h>
+#include <time.h>
+
+#include "lnm/common.h"
+#include "lnm/log_internal.h"
+
+const char *lnm_log_level_names[] = {"DEBUG   ", "INFO    ", "NOTICE  ",
+                                     "WARNING ", "ERROR   ", "CRITICAL"};
+
+lnm_logger *global_logger = NULL;
+
+lnm_err lnm_log_init_global() {
+  global_logger = calloc(1, sizeof(lnm_logger));
+
+  return global_logger == NULL ? lnm_err_failed_alloc : lnm_err_ok;
+}
+
+lnm_err lnm_logger_stream_register(lnm_logger *logger,
+                                   lnm_logger_stream *stream) {
+  lnm_logger_stream **new =
+      logger->streams.len == 0
+          ? malloc(sizeof(lnm_logger_stream *))
+          : realloc(logger->streams.arr,
+                    (logger->streams.len + 1) * sizeof(lnm_logger_stream *));
+
+  if (new == NULL) {
+    return lnm_err_failed_alloc;
+  }
+
+  new[logger->streams.len] = stream;
+  logger->streams.arr = new;
+  logger->streams.len++;
+
+  return lnm_err_ok;
+}
+
+lnm_err lnm_log_register_stdout(lnm_log_level level) {
+  lnm_logger_stream *stream = malloc(sizeof(lnm_logger_stream));
+
+  if (stream == NULL) {
+    return lnm_err_failed_alloc;
+  }
+
+  stream->type = lnm_logger_stream_type_file;
+  stream->ptr = stdout;
+  stream->level = level;
+
+  LNM_RES2(lnm_logger_stream_register(global_logger, stream), free(stream));
+
+  return lnm_err_ok;
+}
+
+void lnm_vlog(lnm_log_level level, const char *section, const char *fmt,
+              va_list ap) {
+  char date_str[32];
+
+  time_t now = time(NULL);
+  strftime(date_str, sizeof(date_str) - 1, "%Y-%m-%d %H:%M:%S",
+           localtime(&now));
+
+  for (size_t i = 0; i < global_logger->streams.len; i++) {
+    lnm_logger_stream *stream = global_logger->streams.arr[i];
+
+    if (level < stream->level) {
+      continue;
+    }
+
+    switch (stream->type) {
+    case lnm_logger_stream_type_file:
+      fprintf(stream->ptr, "[%s][%s][%s] ", date_str,
+              lnm_log_level_names[level], section);
+      vfprintf(stream->ptr, fmt, ap);
+      fprintf(stream->ptr, "\n");
+      break;
+    }
+
+    va_end(ap);
+  }
+}
+
+void lnm_log(lnm_log_level level, const char *section, const char *fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  lnm_vlog(level, section, fmt, ap);
+  va_end(ap);
+}