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().

4 files changed, 214 insertions, 3 deletions

diff --git a/Makefile.am b/Makefile.am
index 1c53631..8bb9aea 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -22,7 +22,7 @@ SUBDIRS = decoders
 
 lib_LTLIBRARIES = libsigrokdecode.la
 
-libsigrokdecode_la_SOURCES = controller.c decoder.c util.c
+libsigrokdecode_la_SOURCES = controller.c decoder.c log.c util.c
 
 libsigrokdecode_la_CPPFLAGS = $(CPPFLAGS_PYTHON) \
 			      -DDECODERS_DIR='"$(DECODERS_DIR)"'
@@ -30,6 +30,7 @@ libsigrokdecode_la_LDFLAGS = $(SIGROKDECODE_LT_LDFLAGS) \
 			     $(LDFLAGS_PYTHON)
 
 include_HEADERS = sigrokdecode.h
+noinst_HEADERS = sigrokdecode-internal.h
 
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = libsigrokdecode.pc
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;
+}
diff --git a/sigrokdecode-internal.h b/sigrokdecode-internal.h
new file mode 100644
index 0000000..94c0c49
--- /dev/null
+++ b/sigrokdecode-internal.h
@@ -0,0 +1,46 @@
+/*
+ * 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
+ */
+
+#ifndef SIGROKDECODE_SIGROKDECODE_INTERNAL_H
+#define SIGROKDECODE_SIGROKDECODE_INTERNAL_H
+
+// #include <stdarg.h>
+// #include <glib.h>
+
+/*--- Macros ----------------------------------------------------------------*/
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
+#endif
+
+#ifndef ARRAY_AND_SIZE
+#define ARRAY_AND_SIZE(a) (a), ARRAY_SIZE(a)
+#endif
+
+/*--- log.c -----------------------------------------------------------------*/
+
+int srd_log(int loglevel, const char *format, ...);
+int srd_spew(const char *format, ...);
+int srd_dbg(const char *format, ...);
+int srd_info(const char *format, ...);
+int srd_warn(const char *format, ...);
+int srd_err(const char *format, ...);
+
+#endif
diff --git a/sigrokdecode.h b/sigrokdecode.h
index 5afb90c..f7d93ac 100644
--- a/sigrokdecode.h
+++ b/sigrokdecode.h
@@ -53,6 +53,14 @@ extern "C" {
 #define SRD_ERR_PYTHON		-4 /**< Python C API error */
 #define SRD_ERR_DECODERS_DIR	-5 /**< Protocol decoder path invalid */
 
+/* libsigrokdecode loglevels. */
+#define SRD_LOG_NONE	0 /**< Output no messages at all. */
+#define SRD_LOG_ERR	1 /**< Output error messages. */
+#define SRD_LOG_WARN	2 /**< Output warnings. */
+#define SRD_LOG_INFO	3 /**< Output informational messages. */
+#define SRD_LOG_DBG	4 /**< Output debug messages. */
+#define SRD_LOG_SPEW	5 /**< Output very noisy debug messages. */
+
 /* TODO: Documentation. */
 struct srd_decoder {
 	/** The decoder ID. Must be non-NULL and unique for all decoders. */
@@ -101,6 +109,8 @@ struct srd_decoder_instance {
 	GSList *pd_output;
 };
 
+/*--- controller.c ----------------------------------------------------------*/
+
 int srd_init(void);
 int srd_exit(void);
 int set_modulepath(void);
@@ -113,7 +123,8 @@ int srd_session_start(const char *driver, int unitsize, uint64_t starttime,
 		uint64_t samplerate);
 int srd_session_feed(uint8_t *inbuf, uint64_t inbuflen);
 
-/* decoder.c */
+/*--- decoder.c -------------------------------------------------------------*/
+
 GSList *srd_list_decoders(void);
 struct srd_decoder *srd_get_decoder_by_id(const char *id);
 int srd_load_decoder(const char *name, struct srd_decoder **dec);
@@ -121,9 +132,14 @@ int srd_unload_decoder(struct srd_decoder *dec);
 int srd_load_all_decoders(void);
 int srd_unload_all_decoders(void);
 
-/* util.c */
+/*--- util.c ----------------------------------------------------------------*/
+
 int h_str(PyObject *py_res, PyObject *py_mod, const char *key, char **outstr);
 
+/*--- log.c -----------------------------------------------------------------*/
+
+int srd_set_loglevel(int loglevel);
+int srd_get_loglevel(void);
 
 #ifdef __cplusplus
 }