Log: new logging library API

Prepare to migrate away from GLib.  Currently, we're still using GLib
as a backend.

1 files changed, 90 insertions, 255 deletions

diff --git a/src/Log.cxx b/src/Log.cxx
index 869327d25..f36e68133 100644
--- a/src/Log.cxx
+++ b/src/Log.cxx
@@ -18,7 +18,7 @@
  */
 
 #include "config.h"
-#include "Log.hxx"
+#include "LogV.hxx"
 #include "ConfigData.hxx"
 #include "ConfigGlobal.hxx"
 #include "ConfigOption.hxx"
@@ -30,322 +30,157 @@
 #include "util/Domain.hxx"
 #include "system/FatalError.hxx"
 
+#include <glib.h>
+
 #include <assert.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <string.h>
-#include <stdarg.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 #include <unistd.h>
 #include <errno.h>
-#include <glib.h>
-
-#ifdef HAVE_SYSLOG
-#include <syslog.h>
-#endif
-
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "log"
 
-#define LOG_LEVEL_SECURE G_LOG_LEVEL_INFO
-
-#define LOG_DATE_BUF_SIZE 16
-#define LOG_DATE_LEN (LOG_DATE_BUF_SIZE - 1)
-
-static constexpr Domain log_domain("log");
-
-static GLogLevelFlags log_threshold = G_LOG_LEVEL_MESSAGE;
+static GLogLevelFlags
+ToGLib(LogLevel level)
+{
+	switch (level) {
+	case LogLevel::DEBUG:
+		return G_LOG_LEVEL_DEBUG;
 
-static const char *log_charset;
+	case LogLevel::INFO:
+		return G_LOG_LEVEL_MESSAGE;
 
-static bool stdout_mode = true;
-static int out_fd;
-static Path out_path = Path::Null();
+	case LogLevel::WARNING:
+	case LogLevel::ERROR:
+		return G_LOG_LEVEL_WARNING;
+	}
 
-static void redirect_logs(int fd)
-{
-	assert(fd >= 0);
-	if (dup2(fd, STDOUT_FILENO) < 0)
-		FatalSystemError("Failed to dup2 stdout");
-	if (dup2(fd, STDERR_FILENO) < 0)
-		FatalSystemError("Failed to dup2 stderr");
+	assert(false);
+	gcc_unreachable();
 }
 
-static const char *log_date(void)
+void
+Log(const Domain &domain, LogLevel level, const char *msg)
 {
-	static char buf[LOG_DATE_BUF_SIZE];
-	time_t t = time(NULL);
-	strftime(buf, LOG_DATE_BUF_SIZE, "%b %d %H:%M : ", localtime(&t));
-	return buf;
+	g_log(domain.GetName(), ToGLib(level), "%s", msg);
 }
 
-/**
- * Determines the length of the string excluding trailing whitespace
- * characters.
- */
-static int
-chomp_length(const char *p)
+void
+LogFormatV(const Domain &domain, LogLevel level, const char *fmt, va_list ap)
 {
-	size_t length = strlen(p);
-
-	while (length > 0 && g_ascii_isspace(p[length - 1]))
-		--length;
-
-	return (int)length;
+	g_logv(domain.GetName(), ToGLib(level), fmt, ap);
 }
 
-static void
-file_log_func(const gchar *domain,
-	      GLogLevelFlags log_level,
-	      const gchar *message, gcc_unused gpointer user_data)
+void
+LogFormat(const Domain &domain, LogLevel level, const char *fmt, ...)
 {
-	char *converted;
-
-	if (log_level > log_threshold)
-		return;
-
-	if (log_charset != NULL) {
-		converted = g_convert_with_fallback(message, -1,
-						    log_charset, "utf-8",
-						    NULL, NULL, NULL, NULL);
-		if (converted != NULL)
-			message = converted;
-	} else
-		converted = NULL;
-
-	if (domain == nullptr)
-		domain = "";
-
-	fprintf(stderr, "%s%s%s%.*s\n",
-		stdout_mode ? "" : log_date(),
-		domain, *domain == 0 ? "" : ": ",
-		chomp_length(message), message);
-
-	g_free(converted);
+	va_list ap;
+	va_start(ap, fmt);
+	LogFormatV(domain, level, fmt, ap);
+	va_end(ap);
 }
 
-static void
-log_init_stdout(void)
+void
+FormatDebug(const Domain &domain, const char *fmt, ...)
 {
-	g_log_set_default_handler(file_log_func, NULL);
+	va_list ap;
+	va_start(ap, fmt);
+	LogFormatV(domain, LogLevel::DEBUG, fmt, ap);
+	va_end(ap);
 }
 
-static int
-open_log_file(void)
+void
+FormatInfo(const Domain &domain, const char *fmt, ...)
 {
-	assert(!out_path.IsNull());
-
-	return OpenFile(out_path, O_CREAT | O_WRONLY | O_APPEND, 0666);
+	va_list ap;
+	va_start(ap, fmt);
+	LogFormatV(domain, LogLevel::INFO, fmt, ap);
+	va_end(ap);
 }
 
-static bool
-log_init_file(unsigned line, Error &error)
+void
+FormatWarning(const Domain &domain, const char *fmt, ...)
 {
-	assert(!out_path.IsNull());
-
-	out_fd = open_log_file();
-	if (out_fd < 0) {
-		const std::string out_path_utf8 = out_path.ToUTF8();
-		error.FormatErrno("failed to open log file \"%s\" (config line %u)",
-				  out_path_utf8.c_str(), line);
-		return false;
-	}
-
-	g_log_set_default_handler(file_log_func, NULL);
-	return true;
+	va_list ap;
+	va_start(ap, fmt);
+	LogFormatV(domain, LogLevel::WARNING, fmt, ap);
+	va_end(ap);
 }
 
-#ifdef HAVE_SYSLOG
-
-static int
-glib_to_syslog_level(GLogLevelFlags log_level)
+void
+FormatError(const Domain &domain, const char *fmt, ...)
 {
-	switch (log_level & G_LOG_LEVEL_MASK) {
-	case G_LOG_LEVEL_ERROR:
-	case G_LOG_LEVEL_CRITICAL:
-		return LOG_ERR;
-
-	case G_LOG_LEVEL_WARNING:
-		return LOG_WARNING;
-
-	case G_LOG_LEVEL_MESSAGE:
-		return LOG_NOTICE;
-
-	case G_LOG_LEVEL_INFO:
-		return LOG_INFO;
-
-	case G_LOG_LEVEL_DEBUG:
-		return LOG_DEBUG;
-
-	default:
-		return LOG_NOTICE;
-	}
+	va_list ap;
+	va_start(ap, fmt);
+	LogFormatV(domain, LogLevel::ERROR, fmt, ap);
+	va_end(ap);
 }
 
-static void
-syslog_log_func(const gchar *domain,
-		GLogLevelFlags log_level, const gchar *message,
-		gcc_unused gpointer user_data)
+void
+LogError(const Error &error)
 {
-	if (stdout_mode) {
-		/* fall back to the file log function during
-		   startup */
-		file_log_func(domain, log_level,
-			      message, user_data);
-		return;
-	}
-
-	if (log_level > log_threshold)
-		return;
-
-	if (domain == nullptr)
-		domain = "";
-
-	syslog(glib_to_syslog_level(log_level), "%s%s%.*s",
-	       domain, *domain == 0 ? "" : ": ",
-	       chomp_length(message), message);
+	Log(error.GetDomain(), LogLevel::ERROR, error.GetMessage());
 }
 
-static void
-log_init_syslog(void)
+void
+LogError(const Error &error, const char *msg)
 {
-	assert(out_path.IsNull());
-
-	openlog(PACKAGE, 0, LOG_DAEMON);
-	g_log_set_default_handler(syslog_log_func, NULL);
+	LogFormat(error.GetDomain(), LogLevel::ERROR, "%s: %s",
+		  msg, error.GetMessage());
 }
 
-#endif
-
-static inline GLogLevelFlags
-parse_log_level(const char *value, unsigned line)
+void
+FormatError(const Error &error, const char *fmt, ...)
 {
-	if (0 == strcmp(value, "default"))
-		return G_LOG_LEVEL_MESSAGE;
-	if (0 == strcmp(value, "secure"))
-		return LOG_LEVEL_SECURE;
-	else if (0 == strcmp(value, "verbose"))
-		return G_LOG_LEVEL_DEBUG;
-	else {
-		FormatFatalError("unknown log level \"%s\" at line %u",
-				 value, line);
-		return G_LOG_LEVEL_MESSAGE;
-	}
+	char msg[1024];
+	va_list ap;
+	va_start(ap, fmt);
+	vsnprintf(msg, sizeof(msg), fmt, ap);
+	va_end(ap);
+
+	LogError(error, msg);
 }
 
 void
-log_early_init(bool verbose)
+LogErrno(const Domain &domain, int e, const char *msg)
 {
-	if (verbose)
-		log_threshold = G_LOG_LEVEL_DEBUG;
-
-	log_init_stdout();
+	LogFormat(domain, LogLevel::ERROR, "%s: %s", msg, g_strerror(e));
 }
 
-bool
-log_init(bool verbose, bool use_stdout, Error &error)
+void
+LogErrno(const Domain &domain, const char *msg)
 {
-	const struct config_param *param;
-
-	g_get_charset(&log_charset);
-
-	if (verbose)
-		log_threshold = G_LOG_LEVEL_DEBUG;
-	else if ((param = config_get_param(CONF_LOG_LEVEL)) != NULL)
-		log_threshold = parse_log_level(param->value, param->line);
-
-	if (use_stdout) {
-		log_init_stdout();
-		return true;
-	} else {
-		param = config_get_param(CONF_LOG_FILE);
-		if (param == NULL) {
-#ifdef HAVE_SYSLOG
-			/* no configuration: default to syslog (if
-			   available) */
-			log_init_syslog();
-			return true;
-#else
-			error.Set(log_domain,
-				  "config parameter 'log_file' not found");
-			return false;
-#endif
-#ifdef HAVE_SYSLOG
-		} else if (strcmp(param->value, "syslog") == 0) {
-			log_init_syslog();
-			return true;
-#endif
-		} else {
-			out_path = config_get_path(CONF_LOG_FILE, error);
-			return !out_path.IsNull() &&
-				log_init_file(param->line, error);
-		}
-	}
+	LogErrno(domain, errno, msg);
 }
 
 static void
-close_log_files(void)
+FormatErrnoV(const Domain &domain, int e, const char *fmt, va_list ap)
 {
-	if (stdout_mode)
-		return;
+	char msg[1024];
+	vsnprintf(msg, sizeof(msg), fmt, ap);
 
-#ifdef HAVE_SYSLOG
-	if (out_path.IsNull())
-		closelog();
-#endif
+	LogErrno(domain, e, msg);
 }
 
 void
-log_deinit(void)
+FormatErrno(const Domain &domain, int e, const char *fmt, ...)
 {
-	close_log_files();
-	out_path = Path::Null();
+	va_list ap;
+	va_start(ap, fmt);
+	FormatErrnoV(domain, e, fmt, ap);
+	va_end(ap);
 }
 
-
-void setup_log_output(bool use_stdout)
-{
-	fflush(NULL);
-	if (!use_stdout) {
-#ifndef WIN32
-		if (out_path.IsNull())
-			out_fd = open("/dev/null", O_WRONLY);
-#endif
-
-		if (out_fd >= 0) {
-			redirect_logs(out_fd);
-			close(out_fd);
-		}
-
-		stdout_mode = false;
-		log_charset = NULL;
-	}
-}
-
-int cycle_log_files(void)
+void
+FormatErrno(const Domain &domain, const char *fmt, ...)
 {
-	int fd;
-
-	if (stdout_mode || out_path.IsNull())
-		return 0;
-
-	assert(!out_path.IsNull());
-
-	g_debug("Cycling log files...\n");
-	close_log_files();
-
-	fd = open_log_file();
-	if (fd < 0) {
-		const std::string out_path_utf8 = out_path.ToUTF8();
-		g_warning("error re-opening log file: %s",
-			  out_path_utf8.c_str());
-		return -1;
-	}
+	const int e = errno;
 
-	redirect_logs(fd);
-	g_debug("Done cycling log files\n");
-	return 0;
+	va_list ap;
+	va_start(ap, fmt);
+	FormatErrnoV(domain, e, fmt, ap);
+	va_end(ap);
 }