output/fifo: convert to C++

1 files changed, 326 insertions, 0 deletions

diff --git a/src/output/FifoOutputPlugin.cxx b/src/output/FifoOutputPlugin.cxx
new file mode 100644
index 000000000..ebebc254f
--- /dev/null
+++ b/src/output/FifoOutputPlugin.cxx
@@ -0,0 +1,326 @@
+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * 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 Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "FifoOutputPlugin.hxx"
+#include "output_api.h"
+#include "timer.h"
+#include "fd_util.h"
+#include "open.h"
+
+#include <glib.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "fifo"
+
+#define FIFO_BUFFER_SIZE 65536 /* pipe capacity on Linux >= 2.6.11 */
+
+struct FifoOutput {
+	struct audio_output base;
+
+	char *path;
+	int input;
+	int output;
+	bool created;
+	struct timer *timer;
+
+	FifoOutput()
+		:path(nullptr), input(-1), output(-1), created(false) {}
+
+	~FifoOutput() {
+		g_free(path);
+	}
+
+	bool Initialize(const config_param *param, GError **error_r) {
+		return ao_base_init(&base, &fifo_output_plugin, param,
+				    error_r);
+	}
+
+	void Deinitialize() {
+		ao_base_finish(&base);
+	}
+
+	bool Create(GError **error_r);
+	bool Check(GError **error_r);
+	void Delete();
+
+	bool Open(GError **error_r);
+	void Close();
+};
+
+/**
+ * The quark used for GError.domain.
+ */
+static inline GQuark
+fifo_output_quark(void)
+{
+	return g_quark_from_static_string("fifo_output");
+}
+
+inline void
+FifoOutput::Delete()
+{
+	g_debug("Removing FIFO \"%s\"", path);
+
+	if (unlink(path) < 0) {
+		g_warning("Could not remove FIFO \"%s\": %s",
+			  path, g_strerror(errno));
+		return;
+	}
+
+	created = false;
+}
+
+void
+FifoOutput::Close()
+{
+	struct stat st;
+
+	if (input >= 0) {
+		close(input);
+		input = -1;
+	}
+
+	if (output >= 0) {
+		close(output);
+		output = -1;
+	}
+
+	if (created && (stat(path, &st) == 0))
+		Delete();
+}
+
+inline bool
+FifoOutput::Create(GError **error_r)
+{
+	if (mkfifo(path, 0666) < 0) {
+		g_set_error(error_r, fifo_output_quark(), errno,
+			    "Couldn't create FIFO \"%s\": %s",
+			    path, g_strerror(errno));
+		return false;
+	}
+
+	created = true;
+	return true;
+}
+
+inline bool
+FifoOutput::Check(GError **error_r)
+{
+	struct stat st;
+	if (stat(path, &st) < 0) {
+		if (errno == ENOENT) {
+			/* Path doesn't exist */
+			return Create(error_r);
+		}
+
+		g_set_error(error_r, fifo_output_quark(), errno,
+			    "Failed to stat FIFO \"%s\": %s",
+			    path, g_strerror(errno));
+		return false;
+	}
+
+	if (!S_ISFIFO(st.st_mode)) {
+		g_set_error(error_r, fifo_output_quark(), 0,
+			    "\"%s\" already exists, but is not a FIFO",
+			    path);
+		return false;
+	}
+
+	return true;
+}
+
+inline bool
+FifoOutput::Open(GError **error_r)
+{
+	if (!Check(error_r))
+		return false;
+
+	input = open_cloexec(path, O_RDONLY|O_NONBLOCK|O_BINARY, 0);
+	if (input < 0) {
+		g_set_error(error_r, fifo_output_quark(), errno,
+			    "Could not open FIFO \"%s\" for reading: %s",
+			    path, g_strerror(errno));
+		Close();
+		return false;
+	}
+
+	output = open_cloexec(path, O_WRONLY|O_NONBLOCK|O_BINARY, 0);
+	if (output < 0) {
+		g_set_error(error_r, fifo_output_quark(), errno,
+			    "Could not open FIFO \"%s\" for writing: %s",
+			    path, g_strerror(errno));
+		Close();
+		return false;
+	}
+
+	return true;
+}
+
+static bool
+fifo_open(FifoOutput *fd, GError **error_r)
+{
+	return fd->Open(error_r);
+}
+
+static struct audio_output *
+fifo_output_init(const config_param *param, GError **error_r)
+{
+	GError *error = nullptr;
+	char *path = config_dup_block_path(param, "path", &error);
+	if (!path) {
+		if (error != nullptr)
+			g_propagate_error(error_r, error);
+		else
+			g_set_error(error_r, fifo_output_quark(), 0,
+				    "No \"path\" parameter specified");
+		return nullptr;
+	}
+
+	FifoOutput *fd = new FifoOutput();
+	fd->path = path;
+
+	if (!fd->Initialize(param, error_r)) {
+		delete fd;
+		return nullptr;
+	}
+
+	if (!fifo_open(fd, error_r)) {
+		fd->Deinitialize();
+		delete fd;
+		return nullptr;
+	}
+
+	return &fd->base;
+}
+
+static void
+fifo_output_finish(struct audio_output *ao)
+{
+	FifoOutput *fd = (FifoOutput *)ao;
+
+	fd->Close();
+	fd->Deinitialize();
+	delete fd;
+}
+
+static bool
+fifo_output_open(struct audio_output *ao, struct audio_format *audio_format,
+		 G_GNUC_UNUSED GError **error)
+{
+	FifoOutput *fd = (FifoOutput *)ao;
+
+	fd->timer = timer_new(audio_format);
+
+	return true;
+}
+
+static void
+fifo_output_close(struct audio_output *ao)
+{
+	FifoOutput *fd = (FifoOutput *)ao;
+
+	timer_free(fd->timer);
+}
+
+static void
+fifo_output_cancel(struct audio_output *ao)
+{
+	FifoOutput *fd = (FifoOutput *)ao;
+	char buf[FIFO_BUFFER_SIZE];
+	int bytes = 1;
+
+	timer_reset(fd->timer);
+
+	while (bytes > 0 && errno != EINTR)
+		bytes = read(fd->input, buf, FIFO_BUFFER_SIZE);
+
+	if (bytes < 0 && errno != EAGAIN) {
+		g_warning("Flush of FIFO \"%s\" failed: %s",
+			  fd->path, g_strerror(errno));
+	}
+}
+
+static unsigned
+fifo_output_delay(struct audio_output *ao)
+{
+	FifoOutput *fd = (FifoOutput *)ao;
+
+	return fd->timer->started
+		? timer_delay(fd->timer)
+		: 0;
+}
+
+static size_t
+fifo_output_play(struct audio_output *ao, const void *chunk, size_t size,
+		 GError **error)
+{
+	FifoOutput *fd = (FifoOutput *)ao;
+	ssize_t bytes;
+
+	if (!fd->timer->started)
+		timer_start(fd->timer);
+	timer_add(fd->timer, size);
+
+	while (true) {
+		bytes = write(fd->output, chunk, size);
+		if (bytes > 0)
+			return (size_t)bytes;
+
+		if (bytes < 0) {
+			switch (errno) {
+			case EAGAIN:
+				/* The pipe is full, so empty it */
+				fifo_output_cancel(&fd->base);
+				continue;
+			case EINTR:
+				continue;
+			}
+
+			g_set_error(error, fifo_output_quark(), errno,
+				    "Failed to write to FIFO %s: %s",
+				    fd->path, g_strerror(errno));
+			return 0;
+		}
+	}
+}
+
+const struct audio_output_plugin fifo_output_plugin = {
+	"fifo",
+	nullptr,
+	fifo_output_init,
+	fifo_output_finish,
+	nullptr,
+	nullptr,
+	fifo_output_open,
+	fifo_output_close,
+	fifo_output_delay,
+	nullptr,
+	fifo_output_play,
+	nullptr,
+	fifo_output_cancel,
+	nullptr,
+	nullptr,
+};