logging: Add a simple ring buffer for buffering log lines

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/Makefile.am b/Makefile.am
index 54cd4a97e73b95f48c5f2de9dcd8843d1779d820..4ed9b788f061b2f7849868f5a9ff79b842e99b3a 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -234,6 +234,7 @@ libpakfire_la_SOURCES = \
        src/libpakfire/job.c \
        src/libpakfire/key.c \
        src/libpakfire/linter.c \
+       src/libpakfire/log_buffer.c \
        src/libpakfire/logging.c \
        src/libpakfire/mirror.c \
        src/libpakfire/mirrorlist.c \
@@ -283,6 +284,7 @@ pkginclude_HEADERS += \
        src/libpakfire/include/pakfire/job.h \
        src/libpakfire/include/pakfire/key.h \
        src/libpakfire/include/pakfire/linter.h \
+       src/libpakfire/include/pakfire/log_buffer.h \
        src/libpakfire/include/pakfire/logging.h \
        src/libpakfire/include/pakfire/mirror.h \
        src/libpakfire/include/pakfire/mirrorlist.h \

diff --git a/src/libpakfire/include/pakfire/log_buffer.h b/src/libpakfire/include/pakfire/log_buffer.h
new file mode 100644 (file)
index 0000000..1480f7b
--- /dev/null
+++ b/src/libpakfire/include/pakfire/log_buffer.h
@@ -0,0 +1,42 @@
+/*#############################################################################
+#                                                                             #
+# Pakfire - The IPFire package management system                              #
+# Copyright (C) 2024 Pakfire development team                                 #
+#                                                                             #
+# 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 3 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, see <http://www.gnu.org/licenses/>.       #
+#                                                                             #
+#############################################################################*/
+
+#ifndef PAKFIRE_LOG_BUFFER_H
+#define PAKFIRE_LOG_BUFFER_H
+
+#ifdef PAKFIRE_PRIVATE
+
+#include <pakfire/ctx.h>
+
+/*
+       Ring buffer for log messages
+*/
+
+struct pakfire_log_buffer;
+
+int pakfire_log_buffer_create(struct pakfire_log_buffer** buffer, struct pakfire_ctx* ctx, size_t size);
+struct pakfire_log_buffer* pakfire_log_buffer_ref(struct pakfire_log_buffer* buffer);
+struct pakfire_log_buffer* pakfire_log_buffer_unref(struct pakfire_log_buffer* buffer);
+
+int pakfire_log_buffer_enqueue(struct pakfire_log_buffer* buffer, int priority, const char* line, ssize_t length);
+int pakfire_log_buffer_dequeue(struct pakfire_log_buffer* buffer, int* priority, char** line, size_t* length);
+
+#endif /* PAKFIRE_PRIVATE */
+#endif /* PAKFIRE_LOG_BUFFER_H */

diff --git a/src/libpakfire/log_buffer.c b/src/libpakfire/log_buffer.c
new file mode 100644 (file)
index 0000000..c525904
--- /dev/null
+++ b/src/libpakfire/log_buffer.c
@@ -0,0 +1,180 @@
+/*#############################################################################
+#                                                                             #
+# Pakfire - The IPFire package management system                              #
+# Copyright (C) 2024 Pakfire development team                                 #
+#                                                                             #
+# 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 3 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, see <http://www.gnu.org/licenses/>.       #
+#                                                                             #
+#############################################################################*/
+
+#include <errno.h>
+#include <string.h>
+#include <sys/queue.h>
+
+#include <pakfire/ctx.h>
+#include <pakfire/log_buffer.h>
+
+struct pakfire_log_line {
+       STAILQ_ENTRY(pakfire_log_line) nodes;
+
+       int priority;
+       char* line;
+       size_t length;
+};
+
+struct pakfire_log_buffer {
+       struct pakfire_ctx* ctx;
+       int nrefs;
+
+       STAILQ_HEAD(lines, pakfire_log_line) lines;
+
+       size_t max_length;
+};
+
+static void pakfire_log_line_free(struct pakfire_log_line* line) {
+       if (line->line)
+               free(line->line);
+       free(line);
+}
+
+static void pakfire_log_buffer_free(struct pakfire_log_buffer* buffer) {
+       if (buffer->ctx)
+               pakfire_ctx_unref(buffer->ctx);
+
+       free(buffer);
+}
+
+int pakfire_log_buffer_create(struct pakfire_log_buffer** buffer, struct pakfire_ctx* ctx, size_t max_length) {
+       struct pakfire_log_buffer* b = NULL;
+
+       // Allocate a new object
+       b = calloc(1, sizeof(*b));
+       if (!b)
+               return -errno;
+
+       // Initialize the reference counter
+       b->nrefs = 1;
+
+       // Store a reference to the context
+       b->ctx = pakfire_ctx_ref(ctx);
+
+       // Store the maximum length
+       b->max_length = max_length;
+
+       // Initialize lines
+       STAILQ_INIT(&b->lines);
+
+       // Return the pointer
+       *buffer = b;
+
+       return 0;
+}
+
+struct pakfire_log_buffer* pakfire_log_buffer_ref(struct pakfire_log_buffer* buffer) {
+       ++buffer->nrefs;
+
+       return buffer;
+}
+
+struct pakfire_log_buffer* pakfire_log_buffer_unref(struct pakfire_log_buffer* buffer) {
+       if (--buffer->nrefs > 0)
+               return buffer;
+
+       pakfire_log_buffer_free(buffer);
+       return NULL;
+}
+
+static size_t pakfire_log_buffer_length(struct pakfire_log_buffer* buffer) {
+       struct pakfire_log_line* line = NULL;
+       size_t length = 0;
+
+       STAILQ_FOREACH(line, &buffer->lines, nodes)
+               length++;
+
+       return length;
+}
+
+int pakfire_log_buffer_enqueue(struct pakfire_log_buffer* buffer, int priority, const char* line, ssize_t length) {
+       struct pakfire_log_line* l = NULL;
+
+       // Fail if the buffer is full
+       if (buffer->max_length > 0) {
+               if (pakfire_log_buffer_length(buffer) >= buffer->max_length)
+                       return -ENOSPC;
+       }
+
+       // Automatically determine the length
+       if (length < 0)
+               length = strlen(line);
+
+       // Allocate a new line
+       l = calloc(1, sizeof(*l));
+       if (!l)
+               return -errno;
+
+       // Store the priority
+       l->priority = priority;
+
+       // Store the line
+       l->line = strndup(line, length);
+       if (!l->line)
+               goto ERROR;
+
+       // Store the length
+       l->length = length;
+
+       // Append to the queue
+       STAILQ_INSERT_TAIL(&buffer->lines, l, nodes);
+
+       return 0;
+
+ERROR:
+       if (l)
+               pakfire_log_line_free(l);
+
+       return -errno;
+}
+
+int pakfire_log_buffer_dequeue(struct pakfire_log_buffer* buffer, int* priority, char** line, size_t* length) {
+       struct pakfire_log_line* l = NULL;
+
+       // Priority & Line must be set, length is optional
+       if (!priority || !line)
+               return -EINVAL;
+
+       // Fetch the first line
+       l = STAILQ_FIRST(&buffer->lines);
+       if (!l)
+               return 0;
+
+       // Return the priority
+       *priority = l->priority;
+
+       // Return the line
+       *line = strndup(l->line, l->length);
+       if (!*line)
+               return -errno;
+
+       // Return the length
+       if (length)
+               *length = l->length;
+
+       // Remove the line
+       STAILQ_REMOVE_HEAD(&buffer->lines, nodes);
+
+       // Free the line
+       pakfire_log_line_free(l);
+
+       return 0;
+}