output/recorder: convert to C++

src/output/RecorderOutputPlugin.cxx

@@ -0,0 +1,275 @@
+/*
+ * 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 "RecorderOutputPlugin.hxx"
+#include "output_api.h"
+#include "encoder_plugin.h"
+#include "encoder_list.h"
+#include "fd_util.h"
+#include "open.h"
+
+#include <assert.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "recorder"
+
+struct RecorderOutput {
+	struct audio_output base;
+
+	/**
+	 * The configured encoder plugin.
+	 */
+	struct encoder *encoder;
+
+	/**
+	 * The destination file name.
+	 */
+	const char *path;
+
+	/**
+	 * The destination file descriptor.
+	 */
+	int fd;
+
+	/**
+	 * The buffer for encoder_read().
+	 */
+	char buffer[32768];
+
+	bool Initialize(const config_param *param, GError **error_r) {
+		return ao_base_init(&base, &recorder_output_plugin, param,
+				    error_r);
+	}
+
+	void Deinitialize() {
+		ao_base_finish(&base);
+	}
+
+	bool Configure(const config_param *param, GError **error_r);
+
+	bool WriteToFile(const void *data, size_t length, GError **error_r);
+
+	/**
+	 * Writes pending data from the encoder to the output file.
+	 */
+	bool EncoderToFile(GError **error_r);
+};
+
+/**
+ * The quark used for GError.domain.
+ */
+static inline GQuark
+recorder_output_quark(void)
+{
+	return g_quark_from_static_string("recorder_output");
+}
+
+inline bool
+RecorderOutput::Configure(const config_param *param, GError **error_r)
+{
+	/* read configuration */
+
+	const char *encoder_name =
+		config_get_block_string(param, "encoder", "vorbis");
+	const struct encoder_plugin *encoder_plugin =
+		encoder_plugin_get(encoder_name);
+	if (encoder_plugin == nullptr) {
+		g_set_error(error_r, recorder_output_quark(), 0,
+			    "No such encoder: %s", encoder_name);
+		return false;
+	}
+
+	path = config_get_block_string(param, "path", nullptr);
+	if (path == nullptr) {
+		g_set_error(error_r, recorder_output_quark(), 0,
+			    "'path' not configured");
+		return false;
+	}
+
+	/* initialize encoder */
+
+	encoder = encoder_init(encoder_plugin, param, error_r);
+	if (encoder == nullptr)
+		return false;
+
+	return true;
+}
+
+static audio_output *
+recorder_output_init(const config_param *param, GError **error_r)
+{
+	RecorderOutput *recorder = new RecorderOutput();
+
+	if (!recorder->Initialize(param, error_r)) {
+		delete recorder;
+		return nullptr;
+	}
+
+	if (!recorder->Configure(param, error_r)) {
+		recorder->Deinitialize();
+		delete recorder;
+		return nullptr;
+	}
+
+	return &recorder->base;
+}
+
+static void
+recorder_output_finish(struct audio_output *ao)
+{
+	RecorderOutput *recorder = (RecorderOutput *)ao;
+
+	encoder_finish(recorder->encoder);
+	recorder->Deinitialize();
+	delete recorder;
+}
+
+inline bool
+RecorderOutput::WriteToFile(const void *_data, size_t length, GError **error_r)
+{
+	assert(length > 0);
+
+	const uint8_t *data = (const uint8_t *)_data, *end = data + length;
+
+	while (true) {
+		ssize_t nbytes = write(fd, data, end - data);
+		if (nbytes > 0) {
+			data += nbytes;
+			if (data == end)
+				return true;
+		} else if (nbytes == 0) {
+			/* shouldn't happen for files */
+			g_set_error(error_r, recorder_output_quark(), 0,
+				    "write() returned 0");
+			return false;
+		} else if (errno != EINTR) {
+			g_set_error(error_r, recorder_output_quark(), 0,
+				    "Failed to write to '%s': %s",
+				    path, g_strerror(errno));
+			return false;
+		}
+	}
+}
+
+inline bool
+RecorderOutput::EncoderToFile(GError **error_r)
+{
+	assert(fd >= 0);
+
+	while (true) {
+		/* read from the encoder */
+
+		size_t size = encoder_read(encoder, buffer, sizeof(buffer));
+		if (size == 0)
+			return true;
+
+		/* write everything into the file */
+
+		if (!WriteToFile(buffer, size, error_r))
+			return false;
+	}
+}
+
+static bool
+recorder_output_open(struct audio_output *ao,
+		     struct audio_format *audio_format,
+		     GError **error_r)
+{
+	RecorderOutput *recorder = (RecorderOutput *)ao;
+
+	/* create the output file */
+
+	recorder->fd = open_cloexec(recorder->path,
+				    O_CREAT|O_WRONLY|O_TRUNC|O_BINARY,
+				    0666);
+	if (recorder->fd < 0) {
+		g_set_error(error_r, recorder_output_quark(), 0,
+			    "Failed to create '%s': %s",
+			    recorder->path, g_strerror(errno));
+		return false;
+	}
+
+	/* open the encoder */
+
+	if (!encoder_open(recorder->encoder, audio_format, error_r)) {
+		close(recorder->fd);
+		unlink(recorder->path);
+		return false;
+	}
+
+	if (!recorder->EncoderToFile(error_r)) {
+		encoder_close(recorder->encoder);
+		close(recorder->fd);
+		unlink(recorder->path);
+		return false;
+	}
+
+	return true;
+}
+
+static void
+recorder_output_close(struct audio_output *ao)
+{
+	RecorderOutput *recorder = (RecorderOutput *)ao;
+
+	/* flush the encoder and write the rest to the file */
+
+	if (encoder_end(recorder->encoder, nullptr))
+		recorder->EncoderToFile(nullptr);
+
+	/* now really close everything */
+
+	encoder_close(recorder->encoder);
+
+	close(recorder->fd);
+}
+
+static size_t
+recorder_output_play(struct audio_output *ao, const void *chunk, size_t size,
+		     GError **error_r)
+{
+	RecorderOutput *recorder = (RecorderOutput *)ao;
+
+	return encoder_write(recorder->encoder, chunk, size, error_r) &&
+		recorder->EncoderToFile(error_r)
+		? size : 0;
+}
+
+const struct audio_output_plugin recorder_output_plugin = {
+	"recorder",
+	nullptr,
+	recorder_output_init,
+	recorder_output_finish,
+	nullptr,
+	nullptr,
+	recorder_output_open,
+	recorder_output_close,
+	nullptr,
+	nullptr,
+	recorder_output_play,
+	nullptr,
+	nullptr,
+	nullptr,
+	nullptr,
+};