Add logging infrastructure.

Signed-off-by: Angus Salkeld <asalkeld@redhat.com>

docs/Makefile.am

@@ -26,7 +26,7 @@ inc_dir = $(top_srcdir)/include/qb
 dependant_headers = $(wildcard $(inc_dir)/qb*.h)
 dist_man_MANS = man3/qbipcc.h.3 man3/qbipcs.h.3 man3/qbatomic.h.3 \
 		man3/qbhdb.h.3 man3/qbipc_common.h.3 man3/qblist.h.3 \
-	       	man3/qbloop.h.3 man3/qbutil.h.3 man3/qbarray.h.3
+	       	man3/qbloop.h.3 man3/qbutil.h.3 man3/qbarray.h.3 man3/qblog.h
 
 
 $(dist_man_MANS): man.dox $(dependant_headers)

docs/mainpage.h

@@ -51,6 +51,12 @@
  * @see qbloop.h
  */
 
+/**
+ * @page qb_log_overview Logging
+ * @copydoc qblog.h
+ * @see qblog.h
+ */
+
 /**
  * @page qb_ipc_overview IPC Overview
  *

include/qb/qbdefs.h

@@ -47,6 +47,16 @@ extern "C" {
 #define	QB_FALSE		0
 #define	QB_TRUE			(!QB_FALSE)
 
+/*
+ * bit manipulation
+ */
+#define qb_bit_value(bit) (1 << (bit))
+#define qb_bit_set(barray, bit) (barray |= qb_bit_value(bit))
+#define qb_bit_clear(barray, bit) (barray &= ~(qb_bit_value(bit)))
+#define qb_bit_is_set(barray, bit) (barray & qb_bit_value(bit))
+#define qb_bit_is_clear(barray, bit) (!(barray & qb_bit_value(bit)))
+
+
 /*
  * handy time based converters.
  */

include/qb/qblog.h

@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2010 Red Hat, Inc.
+ *
+ * All rights reserved.
+ *
+ * Author: Angus Salkeld <asalkeld@redhat.com>
+ *
+ * libqb is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * libqb 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libqb.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef QB_LOG_H_DEFINED
+#define QB_LOG_H_DEFINED
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <syslog.h>
+
+/**
+ * @file qblog.h
+ * This is a the logging API.
+ */
+
+
+/*
+ * An instance of this structure is created in a special
+ * ELF section at every dynamic debug callsite.  At runtime,
+ * the special section is treated as an array of these.
+ */
+struct qb_log_callsite {
+        const char *function;
+        const char *filename;
+        const char *format;
+	uint8_t priority;
+        uint32_t lineno;
+	uint32_t tags;
+} __attribute__((aligned(8)));
+
+
+typedef struct qb_log_filter qb_log_filter_t;
+
+typedef void (*qb_log_logger_fn)(struct qb_log_callsite *cs,
+				 const char *msg);
+
+/* will be assigned by ld linker magic */
+extern struct qb_log_callsite __start___verbose[];
+extern struct qb_log_callsite __stop___verbose[];
+
+/**
+ * Internal function use qb_log()
+ */
+void qb_log_real_(struct qb_log_callsite *cs,
+		  int32_t error_number, ...);
+
+/**
+ * This is the main function to generate a log message.
+ *
+ * @param priority this takes syslog priorities.
+ * @param fmt usual printf style format specifiers
+ * @param args usual printf style args
+ */
+#define qb_log(priority, fmt, args...) do {			\
+	static struct qb_log_callsite descriptor		\
+	__attribute__((section("__verbose"), aligned(8))) =	\
+	{ __func__, __FILE__, fmt, priority, __LINE__, 0 };	\
+	qb_log_real_(&descriptor, 0, ##args);			\
+    } while(0)
+
+/**
+ * Create a filter to tag the callsites.
+ */
+qb_log_filter_t* qb_log_filter_create(void);
+
+/**
+ * destroy a filter.
+ */
+void qb_log_filter_destroy(struct qb_log_filter* flt);
+
+/**
+ * Set the priority on the filter
+ */
+int32_t qb_log_filter_priority_set(qb_log_filter_t* flt, uint8_t priority);
+
+/**
+ * add a chunk of code to a filter.
+ */
+void qb_log_filter_file_add(struct qb_log_filter* flt,
+			    const char* filename,
+			    int32_t start, int32_t end);
+
+/**
+ * tag the callsites defined by the filter.
+ */
+void qb_log_tag(struct qb_log_filter* flt, int32_t is_set, int32_t tag_bit);
+
+/**
+ * set your log handling function.
+ */
+void qb_log_handler_set(qb_log_logger_fn logger_fn);
+
+
+#endif /* QB_LOG_H_DEFINED */

lib/Makefile.am

@@ -40,7 +40,8 @@ libqb_la_CPPFLAGS	= -I$(top_builddir)/include -I$(top_srcdir)/include
 libqb_la_LDFLAGS	= -version-info 4:1:4
 source_to_lint		= util.c hdb.c ringbuffer.c ringbuffer_helper.c array.c \
 			  loop.c loop_poll.c loop_job.c \
-			  ipcc.c ipcs.c ipc_posix_mq.c ipc_sysv_mq.c ipc_shm.c ipc_us.c
+			  ipcc.c ipcs.c ipc_posix_mq.c ipc_sysv_mq.c ipc_shm.c ipc_us.c \
+			  log.c
 libqb_la_SOURCES	= $(source_to_lint)
 if USE_TIMERFD
 else

lib/log.c

@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2011 Red Hat, Inc.
+ *
+ * All rights reserved.
+ *
+ * Author: Angus Salkeld <asalkeld@redhat.com>
+ *
+ * libqb is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * libqb 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libqb.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <config.h>
+
+#include "os_base.h"
+#include <ctype.h>
+#include <stdarg.h>
+#include <qb/qbdefs.h>
+#include <qb/qblist.h>
+#include <qb/qblog.h>
+
+struct qb_log_filter_file {
+	char *filename;
+	int32_t start;
+	int32_t end;
+	struct qb_list_head list;
+};
+
+struct qb_log_filter {
+	uint8_t priority;
+	struct qb_list_head files_head;
+};
+
+struct qb_log_destination {
+	qb_log_logger_fn logger;
+};
+
+#define COMBINE_BUFFER_SIZE 256
+static struct qb_log_destination destination;
+
+
+void qb_log_real_(struct qb_log_callsite *cs,
+		  int32_t error_number, ...)
+{
+	va_list ap;
+	char buf[COMBINE_BUFFER_SIZE];
+	size_t len;
+	static int32_t in_logger = 0;
+
+	if (destination.logger == NULL) {
+		return;
+	}
+	if (in_logger) {
+		return;
+	}
+	in_logger = 1;
+
+	va_start(ap, error_number);
+	len = vsnprintf(buf, COMBINE_BUFFER_SIZE, cs->format, ap);
+	va_end(ap);
+
+	if (buf[len - 1] == '\n') {
+		buf[len - 1] = '\0';
+		len -= 1;
+	}
+
+	destination.logger(cs, buf);
+	in_logger = 0;
+}
+
+qb_log_filter_t* qb_log_filter_create(void)
+{
+	struct qb_log_filter *flt = calloc(1, sizeof(struct qb_log_filter));
+	qb_list_init(&flt->files_head);
+	flt->priority = LOG_INFO;
+	return flt;
+}
+
+void qb_log_filter_destroy(struct qb_log_filter* flt)
+{
+	struct qb_log_filter_file *ff;
+	struct qb_list_head *item;
+	struct qb_list_head *next;
+
+	qb_list_for_each_safe(item, next, &flt->files_head) {
+		ff = qb_list_entry(item, struct qb_log_filter_file, list);
+		qb_list_del(item);
+		free(ff);
+	}
+
+	free(flt);
+}
+
+int32_t qb_log_filter_priority_set(struct qb_log_filter* flt, uint8_t priority)
+{
+	flt->priority = priority;
+	return 0;
+}
+
+void qb_log_filter_file_add(struct qb_log_filter* flt,
+			    const char* filename,
+			    int32_t start, int32_t end)
+{
+	struct qb_log_filter_file *ff = calloc(1, sizeof(struct qb_log_filter_file));
+	qb_list_init(&ff->list);
+	ff->filename = (char*)filename;
+	ff->start = start;
+	ff->end = end;
+	qb_list_add(&ff->list, &flt->files_head);
+}
+
+void qb_log_tag(struct qb_log_filter* flt, int32_t is_set, int32_t tag_bit)
+{
+	struct qb_log_callsite *cs;
+	struct qb_log_filter_file *ff;
+	int32_t match;
+
+	for (cs = __start___verbose; cs < __stop___verbose; cs++) {
+		if (cs->priority > flt->priority)
+			continue;
+		match = QB_FALSE;
+		qb_list_for_each_entry(ff, &flt->files_head, list) {
+			if (ff->start <= cs->lineno &&
+			    ff->end >= cs->lineno &&
+			    strcmp(ff->filename, cs->filename) == 0) {
+				match = QB_TRUE;
+			}
+		}
+		if (match || qb_list_empty(&flt->files_head)) {
+			if (is_set) {
+				qb_bit_set(cs->tags, tag_bit);
+			} else {
+				qb_bit_clear(cs->tags, tag_bit);
+			}
+#if 0
+			printf("matched: %-12s %20s:%u fmt:<%d>%s\n",
+				cs->function, cs->filename, cs->lineno,
+				cs->priority, cs->format);
+#endif
+		}
+	}
+
+}
+
+void qb_log_handler_set(qb_log_logger_fn logger_fn)
+{
+	destination.logger = NULL;
+	qb_log(LOG_DEBUG, " ");
+	destination.logger = logger_fn;
+}
+

tests/.gitignore

@@ -8,3 +8,4 @@ bms
 rbreader
 rbwriter
 loop
+simple-log

tests/Makefile.am

@@ -18,7 +18,7 @@
 # along with libqb.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-noinst_PROGRAMS = bmc bmcpt bms rbwriter rbreader loop
+noinst_PROGRAMS = bmc bmcpt bms rbwriter rbreader loop simple-log
 
 bmc_SOURCES = bmc.c $(top_builddir)/include/qb/qbipcc.h
 bmc_CPPFLAGS = -I$(top_builddir)/include -I$(top_srcdir)/include
@@ -44,6 +44,10 @@ loop_SOURCES = loop.c $(top_builddir)/include/qb/qbloop.h
 loop_CPPFLAGS = -I$(top_builddir)/include -I$(top_srcdir)/include
 loop_LDADD = -lrt $(top_builddir)/lib/libqb.la
 
+simple_log_SOURCES = simple-log.c $(top_builddir)/include/qb/qblog.h
+simple_log_CPPFLAGS = -I$(top_builddir)/include -I$(top_srcdir)/include
+simple_log_LDADD = -lrt $(top_builddir)/lib/libqb.la
+
 
 if HAVE_CHECK
 EXTRA_DIST = check_resources.sh

tests/simple-log.c

@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2011 Red Hat, Inc.
+ *
+ * All rights reserved.
+ *
+ * Author: Angus Salkeld <asalkeld@redhat.com>
+ *
+ * libqb is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * libqb 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libqb.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "os_base.h"
+#include <signal.h>
+#include <syslog.h>
+
+#include <qb/qbdefs.h>
+#include <qb/qblog.h>
+
+static void func_one(void) {
+	qb_log(LOG_DEBUG, "hello");
+	qb_log(LOG_CRIT, "hello");
+	qb_log(LOG_ERR, "hello");
+	qb_log(LOG_INFO, "hello");
+}
+
+static void func_two(void) {
+	qb_log(LOG_DEBUG, "arrrg!");
+	qb_log(LOG_CRIT,  "arrrg!");
+	qb_log(LOG_ERR,   "arrrg!");
+	qb_log(LOG_INFO,  "arrrg!");
+}
+
+static void show_usage(const char *name)
+{
+	printf("usage: \n");
+	printf("%s <options>\n", name);
+	printf("\n");
+	printf("  options:\n");
+	printf("\n");
+	printf("  -v             verbose\n");
+	printf("  -h             show this help text\n");
+	printf("\n");
+}
+
+#define MY_STDOUT_TAG 1
+#define MY_LOG_TAG 2
+
+static void my_log_writer(struct qb_log_callsite *cs, const char *msg)
+{
+	if (qb_bit_is_set(cs->tags, MY_STDOUT_TAG)) {
+		fprintf(stdout, "[%s:%d] <%d> %s\n", cs->filename, cs->lineno, cs->priority, msg);
+	}
+	if (qb_bit_is_set(cs->tags, MY_LOG_TAG)) {
+		syslog(cs->priority, "%s", msg);
+	}
+}
+
+int32_t main(int32_t argc, char *argv[])
+{
+	const char *options = "vh";
+	int32_t opt;
+	uint8_t priority = LOG_NOTICE;
+	qb_log_filter_t* ls1;
+	qb_log_filter_t* ls2;
+
+	while ((opt = getopt(argc, argv, options)) != -1) {
+		switch (opt) {
+		case 'v':
+			priority++;
+			break;
+		case 'h':
+		default:
+			show_usage(argv[0]);
+			exit(0);
+			break;
+		}
+	}
+
+	qb_log_handler_set(my_log_writer);
+
+	/* stdout logging */
+	ls1 = qb_log_filter_create();
+	qb_log_filter_priority_set(ls1, priority);
+	qb_log_filter_file_add(ls1, __FILE__, 1, 33); // line 1 to 33
+	qb_log_filter_file_add(ls1, __FILE__, 75, INT32_MAX); // line 75 to EOF
+	qb_log_tag(ls1, QB_TRUE, MY_STDOUT_TAG);
+
+	/* syslog */
+	ls2 = qb_log_filter_create();
+	qb_log_filter_priority_set(ls2, LOG_WARNING);
+	qb_log_tag(ls2, QB_TRUE, MY_LOG_TAG);
+
+	qb_log(LOG_DEBUG, "hello");
+	qb_log(LOG_INFO, "hello");
+	qb_log(LOG_NOTICE, "hello");
+	func_one();
+	func_two();
+	qb_log_tag(ls2, QB_FALSE, MY_LOG_TAG);
+	qb_log(LOG_WARNING, "no syslog");
+	qb_log(LOG_ERR, "no syslog");
+
+	qb_log_filter_destroy(ls1);
+	qb_log_filter_destroy(ls2);
+
+	return 0;
+}
+