srd: Add logging framework.

This includes the (private) functions srd_err() and friends, the
(public) SRD_LOG_ERR macros and friends, and the (public) API functions
srd_set_loglevel() and srd_get_loglevel().

1 files changed, 148 insertions, 0 deletions

diff --git a/log.c b/log.c
new file mode 100644
index 0000000..a051a15
--- /dev/null
+++ b/log.c
@@ -0,0 +1,148 @@
+/*
+ * This file is part of the sigrok project.
+ *
+ * Copyright (C) 2011 Uwe Hermann <uwe@hermann-uwe.de>
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include "sigrokdecode.h"
+#include "sigrokdecode-internal.h"
+
+static int srd_loglevel = SRD_LOG_WARN; /* Show errors+warnings per default. */
+
+/**
+ * Set the libsigrokdecode loglevel.
+ *
+ * This influences the amount of log messages (debug messages, error messages,
+ * and so on) libsigrokdecode will output. Using SRD_LOG_NONE disables all
+ * messages.
+ *
+ * @param loglevel The loglevel to set (SRD_LOG_NONE, SRD_LOG_ERR,
+ *                 SRD_LOG_WARN, SRD_LOG_INFO, SRD_LOG_DBG, or SRD_LOG_SPEW).
+ * @return SRD_OK upon success, SRD_ERR_ARGS upon invalid loglevel.
+ */
+int srd_set_loglevel(int loglevel)
+{
+	if (loglevel < SRD_LOG_NONE || loglevel > SRD_LOG_SPEW) {
+		srd_err("log: %s: invalid loglevel %d", __func__, loglevel);
+		return SRD_ERR_ARGS;
+	}
+
+	srd_loglevel = loglevel;
+
+	srd_dbg("log: %s: libsigrokdecode loglevel set to %d",
+		__func__, loglevel);
+
+	return SRD_OK;
+}
+
+/**
+ * Get the libsigrokdecode loglevel.
+ *
+ * @return The currently configured libsigrokdecode loglevel.
+ */
+int srd_get_loglevel(void)
+{
+	return srd_loglevel;
+}
+
+static int srd_logv(int loglevel, const char *format, va_list args)
+{
+	int ret;
+
+	/* Only output messages of at least the selected loglevel(s). */
+	if (loglevel > srd_loglevel)
+		return SRD_OK; /* TODO? */
+
+	ret = vfprintf(stderr, format, args);
+	fprintf(stderr, "\n");
+
+	return ret;
+}
+
+int srd_log(int loglevel, const char *format, ...)
+{
+	int ret;
+	va_list args;
+
+	va_start(args, format);
+	ret = srd_logv(loglevel, format, args);
+	va_end(args);
+
+	return ret;
+}
+
+int srd_spew(const char *format, ...)
+{
+	int ret;
+	va_list args;
+
+	va_start(args, format);
+	ret = srd_logv(SRD_LOG_SPEW, format, args);
+	va_end(args);
+
+	return ret;
+}
+
+int srd_dbg(const char *format, ...)
+{
+	int ret;
+	va_list args;
+
+	va_start(args, format);
+	ret = srd_logv(SRD_LOG_DBG, format, args);
+	va_end(args);
+
+	return ret;
+}
+
+int srd_info(const char *format, ...)
+{
+	int ret;
+	va_list args;
+
+	va_start(args, format);
+	ret = srd_logv(SRD_LOG_INFO, format, args);
+	va_end(args);
+
+	return ret;
+}
+
+int srd_warn(const char *format, ...)
+{
+	int ret;
+	va_list args;
+
+	va_start(args, format);
+	ret = srd_logv(SRD_LOG_WARN, format, args);
+	va_end(args);
+
+	return ret;
+}
+
+int srd_err(const char *format, ...)
+{
+	int ret;
+	va_list args;
+
+	va_start(args, format);
+	ret = srd_logv(SRD_LOG_ERR, format, args);
+	va_end(args);
+
+	return ret;
+}