LogInit: move backend code to LogBackend.cxx

src/LogBackend.cxx

@@ -18,37 +18,162 @@
  */
 
 #include "config.h"
+#include "LogBackend.hxx"
 #include "Log.hxx"
 #include "util/Domain.hxx"
+#include "util/CharUtil.hxx"
 
 #include <glib.h>
 
 #include <assert.h>
+#include <stdio.h>
+#include <string.h>
 
-static GLogLevelFlags
-ToGLib(LogLevel level)
+#ifdef HAVE_SYSLOG
+#include <syslog.h>
+#endif
+
+static LogLevel log_threshold = LogLevel::INFO;
+static const char *log_charset;
+
+static bool enable_timestamp;
+
+#ifdef HAVE_SYSLOG
+static bool enable_syslog;
+#endif
+
+void
+SetLogThreshold(LogLevel _threshold)
 {
-	switch (level) {
+	log_threshold = _threshold;
+}
+
+void
+SetLogCharset(const char *_charset)
+{
+	log_charset = _charset;
+}
+
+void
+EnableLogTimestamp()
+{
+#ifdef HAVE_SYSLOG
+	assert(!enable_syslog);
+#endif
+	assert(!enable_timestamp);
+
+	enable_timestamp = true;
+}
+
+static const char *log_date(void)
+{
+	static constexpr size_t LOG_DATE_BUF_SIZE = 16;
+	static char buf[LOG_DATE_BUF_SIZE];
+	time_t t = time(nullptr);
+	strftime(buf, LOG_DATE_BUF_SIZE, "%b %d %H:%M : ", localtime(&t));
+	return buf;
+}
+
+/**
+ * Determines the length of the string excluding trailing whitespace
+ * characters.
+ */
+static int
+chomp_length(const char *p)
+{
+	size_t length = strlen(p);
+
+	while (length > 0 && IsWhitespaceOrNull(p[length - 1]))
+		--length;
+
+	return (int)length;
+}
+
+#ifdef HAVE_SYSLOG
+
+static int
+ToSysLogLevel(LogLevel log_level)
+{
+	switch (log_level) {
 	case LogLevel::DEBUG:
-		return G_LOG_LEVEL_DEBUG;
+		return LOG_DEBUG;
 
 	case LogLevel::INFO:
-		return G_LOG_LEVEL_INFO;
+		return LOG_INFO;
 
 	case LogLevel::DEFAULT:
-		return G_LOG_LEVEL_MESSAGE;
+		return LOG_NOTICE;
 
 	case LogLevel::WARNING:
+		return LOG_WARNING;
+
 	case LogLevel::ERROR:
-		return G_LOG_LEVEL_WARNING;
+		return LOG_ERR;
 	}
 
 	assert(false);
 	gcc_unreachable();
 }
 
+static void
+SysLog(const Domain &domain, LogLevel log_level, const char *message)
+{
+	syslog(ToSysLogLevel(log_level), "%s: %.*s",
+	       domain.GetName(),
+	       chomp_length(message), message);
+}
+
+void
+LogInitSysLog()
+{
+	openlog(PACKAGE, 0, LOG_DAEMON);
+	enable_syslog = true;
+}
+
+void
+LogFinishSysLog()
+{
+	if (enable_syslog)
+		closelog();
+}
+
+#endif
+
+static void
+FileLog(const Domain &domain, const char *message)
+{
+	char *converted;
+
+	if (log_charset != nullptr) {
+		converted = g_convert_with_fallback(message, -1,
+						    log_charset, "utf-8",
+						    nullptr, nullptr,
+						    nullptr, nullptr);
+		if (converted != nullptr)
+			message = converted;
+	} else
+		converted = nullptr;
+
+	fprintf(stderr, "%s%s: %.*s\n",
+		enable_timestamp ? log_date() : "",
+		domain.GetName(),
+		chomp_length(message), message);
+
+	g_free(converted);
+}
+
 void
 Log(const Domain &domain, LogLevel level, const char *msg)
 {
-	g_log(domain.GetName(), ToGLib(level), "%s", msg);
+	if (level < log_threshold)
+		return;
+
+#ifdef HAVE_SYSLOG
+	if (enable_syslog) {
+		SysLog(domain, level, msg);
+		return;
+	}
+#endif
+
+	FileLog(domain, msg);
 }