output/httpd: convert to C++

1 files changed, 570 insertions, 0 deletions

diff --git a/src/output/HttpdOutputPlugin.cxx b/src/output/HttpdOutputPlugin.cxx
new file mode 100644
index 000000000..c686104c1
--- /dev/null
+++ b/src/output/HttpdOutputPlugin.cxx
@@ -0,0 +1,570 @@
+/*
+ * 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 "HttpdOutputPlugin.hxx"
+#include "HttpdInternal.hxx"
+#include "HttpdClient.hxx"
+#include "output_api.h"
+#include "encoder_plugin.h"
+#include "encoder_list.h"
+#include "resolver.h"
+#include "page.h"
+#include "icy_server.h"
+#include "fd_util.h"
+#include "server_socket.h"
+
+#include <assert.h>
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+
+#ifdef HAVE_LIBWRAP
+#include <sys/socket.h> /* needed for AF_UNIX */
+#include <tcpd.h>
+#endif
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "httpd_output"
+
+/**
+ * The quark used for GError.domain.
+ */
+static inline GQuark
+httpd_output_quark(void)
+{
+	return g_quark_from_static_string("httpd_output");
+}
+
+/**
+ * Check whether there is at least one client.
+ *
+ * Caller must lock the mutex.
+ */
+G_GNUC_PURE
+static bool
+httpd_output_has_clients(const httpd_output *httpd)
+{
+	return !httpd->clients.empty();
+}
+
+/**
+ * Check whether there is at least one client.
+ */
+G_GNUC_PURE
+static bool
+httpd_output_lock_has_clients(const httpd_output *httpd)
+{
+	const ScopeLock protect(httpd->mutex);
+	return httpd_output_has_clients(httpd);
+}
+
+static void
+httpd_listen_in_event(int fd, const struct sockaddr *address,
+		      size_t address_length, int uid, void *ctx);
+
+static bool
+httpd_output_bind(httpd_output *httpd, GError **error_r)
+{
+	httpd->open = false;
+
+	const ScopeLock protect(httpd->mutex);
+	return server_socket_open(httpd->server_socket, error_r);
+}
+
+static void
+httpd_output_unbind(httpd_output *httpd)
+{
+	assert(!httpd->open);
+
+	const ScopeLock protect(httpd->mutex);
+	server_socket_close(httpd->server_socket);
+}
+
+static struct audio_output *
+httpd_output_init(const struct config_param *param,
+		  GError **error)
+{
+	httpd_output *httpd = new httpd_output();
+	if (!ao_base_init(&httpd->base, &httpd_output_plugin, param, error)) {
+		g_free(httpd);
+		return NULL;
+	}
+
+	/* read configuration */
+	httpd->name =
+		config_get_block_string(param, "name", "Set name in config");
+	httpd->genre =
+		config_get_block_string(param, "genre", "Set genre in config");
+	httpd->website =
+		config_get_block_string(param, "website", "Set website in config");
+
+	guint port = config_get_block_unsigned(param, "port", 8000);
+
+	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 == NULL) {
+		g_set_error(error, httpd_output_quark(), 0,
+			    "No such encoder: %s", encoder_name);
+		ao_base_finish(&httpd->base);
+		g_free(httpd);
+		return NULL;
+	}
+
+	httpd->clients_max = config_get_block_unsigned(param,"max_clients", 0);
+
+	/* set up bind_to_address */
+
+	httpd->server_socket = server_socket_new(httpd_listen_in_event, httpd);
+
+	const char *bind_to_address =
+		config_get_block_string(param, "bind_to_address", NULL);
+	bool success = bind_to_address != NULL &&
+		strcmp(bind_to_address, "any") != 0
+		? server_socket_add_host(httpd->server_socket, bind_to_address,
+					 port, error)
+		: server_socket_add_port(httpd->server_socket, port, error);
+	if (!success) {
+		ao_base_finish(&httpd->base);
+		g_free(httpd);
+		return NULL;
+	}
+
+	/* initialize metadata */
+	httpd->metadata = NULL;
+	httpd->unflushed_input = 0;
+
+	/* initialize encoder */
+
+	httpd->encoder = encoder_init(encoder_plugin, param, error);
+	if (httpd->encoder == NULL) {
+		ao_base_finish(&httpd->base);
+		g_free(httpd);
+		return NULL;
+	}
+
+	/* determine content type */
+	httpd->content_type = encoder_get_mime_type(httpd->encoder);
+	if (httpd->content_type == NULL) {
+		httpd->content_type = "application/octet-stream";
+	}
+
+	return &httpd->base;
+}
+
+static void
+httpd_output_finish(struct audio_output *ao)
+{
+	httpd_output *httpd = (httpd_output *)ao;
+
+	if (httpd->metadata)
+		page_unref(httpd->metadata);
+
+	encoder_finish(httpd->encoder);
+	server_socket_free(httpd->server_socket);
+	ao_base_finish(&httpd->base);
+	delete httpd;
+}
+
+/**
+ * Creates a new #HttpdClient object and adds it into the
+ * httpd_output.clients linked list.
+ */
+static void
+httpd_client_add(httpd_output *httpd, int fd)
+{
+	httpd->clients.emplace_front(httpd, fd,
+				     httpd->encoder->plugin->tag == NULL);
+	httpd->clients_cnt++;
+
+	/* pass metadata to client */
+	if (httpd->metadata)
+		httpd->clients.front().PushMetaData(httpd->metadata);
+}
+
+static void
+httpd_listen_in_event(int fd, const struct sockaddr *address,
+		      size_t address_length, G_GNUC_UNUSED int uid, void *ctx)
+{
+	httpd_output *httpd = (httpd_output *)ctx;
+
+	/* the listener socket has become readable - a client has
+	   connected */
+
+#ifdef HAVE_LIBWRAP
+	if (address->sa_family != AF_UNIX) {
+		char *hostaddr = sockaddr_to_string(address, address_length, NULL);
+		const char *progname = g_get_prgname();
+
+		struct request_info req;
+		request_init(&req, RQ_FILE, fd, RQ_DAEMON, progname, 0);
+
+		fromhost(&req);
+
+		if (!hosts_access(&req)) {
+			/* tcp wrappers says no */
+			g_warning("libwrap refused connection (libwrap=%s) from %s",
+			      progname, hostaddr);
+			g_free(hostaddr);
+			close_socket(fd);
+			return;
+		}
+
+		g_free(hostaddr);
+	}
+#else
+	(void)address;
+	(void)address_length;
+#endif	/* HAVE_WRAP */
+
+	const ScopeLock protect(httpd->mutex);
+
+	if (fd >= 0) {
+		/* can we allow additional client */
+		if (httpd->open &&
+		    (httpd->clients_max == 0 ||
+		     httpd->clients_cnt < httpd->clients_max))
+			httpd_client_add(httpd, fd);
+		else
+			close_socket(fd);
+	} else if (fd < 0 && errno != EINTR) {
+		g_warning("accept() failed: %s", g_strerror(errno));
+	}
+}
+
+/**
+ * Reads data from the encoder (as much as available) and returns it
+ * as a new #page object.
+ */
+static struct page *
+httpd_output_read_page(httpd_output *httpd)
+{
+	if (httpd->unflushed_input >= 65536) {
+		/* we have fed a lot of input into the encoder, but it
+		   didn't give anything back yet - flush now to avoid
+		   buffer underruns */
+		encoder_flush(httpd->encoder, NULL);
+		httpd->unflushed_input = 0;
+	}
+
+	size_t size = 0;
+	do {
+		size_t nbytes = encoder_read(httpd->encoder,
+					     httpd->buffer + size,
+					     sizeof(httpd->buffer) - size);
+		if (nbytes == 0)
+			break;
+
+		httpd->unflushed_input = 0;
+
+		size += nbytes;
+	} while (size < sizeof(httpd->buffer));
+
+	if (size == 0)
+		return NULL;
+
+	return page_new_copy(httpd->buffer, size);
+}
+
+static bool
+httpd_output_encoder_open(httpd_output *httpd,
+			  struct audio_format *audio_format,
+			  GError **error)
+{
+	if (!encoder_open(httpd->encoder, audio_format, error))
+		return false;
+
+	/* we have to remember the encoder header, i.e. the first
+	   bytes of encoder output after opening it, because it has to
+	   be sent to every new client */
+	httpd->header = httpd_output_read_page(httpd);
+
+	httpd->unflushed_input = 0;
+
+	return true;
+}
+
+static bool
+httpd_output_enable(struct audio_output *ao, GError **error_r)
+{
+	httpd_output *httpd = (httpd_output *)ao;
+
+	return httpd_output_bind(httpd, error_r);
+}
+
+static void
+httpd_output_disable(struct audio_output *ao)
+{
+	httpd_output *httpd = (httpd_output *)ao;
+
+	httpd_output_unbind(httpd);
+}
+
+static bool
+httpd_output_open(struct audio_output *ao, struct audio_format *audio_format,
+		  GError **error)
+{
+	httpd_output *httpd = (httpd_output *)ao;
+
+	assert(httpd->clients.empty());
+
+	const ScopeLock protect(httpd->mutex);
+
+	/* open the encoder */
+
+	if (!httpd_output_encoder_open(httpd, audio_format, error))
+		return false;
+
+	/* initialize other attributes */
+
+	httpd->clients_cnt = 0;
+	httpd->timer = timer_new(audio_format);
+
+	httpd->open = true;
+
+	return true;
+}
+
+static void
+httpd_output_close(struct audio_output *ao)
+{
+	httpd_output *httpd = (httpd_output *)ao;
+
+	const ScopeLock protect(httpd->mutex);
+
+	httpd->open = false;
+
+	timer_free(httpd->timer);
+
+	httpd->clients.clear();
+
+	if (httpd->header != NULL)
+		page_unref(httpd->header);
+
+	encoder_close(httpd->encoder);
+}
+
+void
+httpd_output_remove_client(httpd_output *httpd, HttpdClient *client)
+{
+	assert(httpd != NULL);
+	assert(httpd->clients_cnt > 0);
+	assert(client != NULL);
+
+	for (auto prev = httpd->clients.before_begin(), i = std::next(prev);;
+	     prev = i, i = std::next(prev)) {
+		assert(i != httpd->clients.end());
+		if (&*i == client) {
+			httpd->clients.erase_after(prev);
+			httpd->clients_cnt--;
+			break;
+		}
+	}
+}
+
+void
+httpd_output_send_header(httpd_output *httpd, HttpdClient *client)
+{
+	if (httpd->header != NULL)
+		client->PushPage(httpd->header);
+}
+
+static unsigned
+httpd_output_delay(struct audio_output *ao)
+{
+	httpd_output *httpd = (httpd_output *)ao;
+
+	if (!httpd_output_lock_has_clients(httpd) && httpd->base.pause) {
+		/* if there's no client and this output is paused,
+		   then httpd_output_pause() will not do anything, it
+		   will not fill the buffer and it will not update the
+		   timer; therefore, we reset the timer here */
+		timer_reset(httpd->timer);
+
+		/* some arbitrary delay that is long enough to avoid
+		   consuming too much CPU, and short enough to notice
+		   new clients quickly enough */
+		return 1000;
+	}
+
+	return httpd->timer->started
+		? timer_delay(httpd->timer)
+		: 0;
+}
+
+/**
+ * Broadcasts a page struct to all clients.
+ */
+static void
+httpd_output_broadcast_page(httpd_output *httpd, struct page *page)
+{
+	assert(page != NULL);
+
+	const ScopeLock protect(httpd->mutex);
+	for (auto &client : httpd->clients)
+		client.PushPage(page);
+}
+
+/**
+ * Broadcasts data from the encoder to all clients.
+ */
+static void
+httpd_output_encoder_to_clients(httpd_output *httpd)
+{
+	httpd->mutex.lock();
+	for (auto &client : httpd->clients) {
+		if (client.GetQueueSize() > 256 * 1024) {
+			g_debug("client is too slow, flushing its queue");
+			client.CancelQueue();
+		}
+	}
+	httpd->mutex.unlock();
+
+	struct page *page;
+	while ((page = httpd_output_read_page(httpd)) != NULL) {
+		httpd_output_broadcast_page(httpd, page);
+		page_unref(page);
+	}
+}
+
+static bool
+httpd_output_encode_and_play(httpd_output *httpd,
+			     const void *chunk, size_t size, GError **error)
+{
+	if (!encoder_write(httpd->encoder, chunk, size, error))
+		return false;
+
+	httpd->unflushed_input += size;
+
+	httpd_output_encoder_to_clients(httpd);
+
+	return true;
+}
+
+static size_t
+httpd_output_play(struct audio_output *ao, const void *chunk, size_t size,
+		  GError **error_r)
+{
+	httpd_output *httpd = (httpd_output *)ao;
+
+	if (httpd_output_lock_has_clients(httpd)) {
+		if (!httpd_output_encode_and_play(httpd, chunk, size, error_r))
+			return 0;
+	}
+
+	if (!httpd->timer->started)
+		timer_start(httpd->timer);
+	timer_add(httpd->timer, size);
+
+	return size;
+}
+
+static bool
+httpd_output_pause(struct audio_output *ao)
+{
+	httpd_output *httpd = (httpd_output *)ao;
+
+	if (httpd_output_lock_has_clients(httpd)) {
+		static const char silence[1020] = { 0 };
+		return httpd_output_play(ao, silence, sizeof(silence),
+					 NULL) > 0;
+	} else {
+		return true;
+	}
+}
+
+static void
+httpd_output_tag(struct audio_output *ao, const struct tag *tag)
+{
+	httpd_output *httpd = (httpd_output *)ao;
+
+	assert(tag != NULL);
+
+	if (httpd->encoder->plugin->tag != NULL) {
+		/* embed encoder tags */
+
+		/* flush the current stream, and end it */
+
+		encoder_pre_tag(httpd->encoder, NULL);
+		httpd_output_encoder_to_clients(httpd);
+
+		/* send the tag to the encoder - which starts a new
+		   stream now */
+
+		encoder_tag(httpd->encoder, tag, NULL);
+
+		/* the first page generated by the encoder will now be
+		   used as the new "header" page, which is sent to all
+		   new clients */
+
+		struct page *page = httpd_output_read_page(httpd);
+		if (page != NULL) {
+			if (httpd->header != NULL)
+				page_unref(httpd->header);
+			httpd->header = page;
+			httpd_output_broadcast_page(httpd, page);
+		}
+	} else {
+		/* use Icy-Metadata */
+
+		if (httpd->metadata != NULL)
+			page_unref (httpd->metadata);
+
+		httpd->metadata =
+			icy_server_metadata_page(tag, TAG_ALBUM,
+						 TAG_ARTIST, TAG_TITLE,
+						 TAG_NUM_OF_ITEM_TYPES);
+		if (httpd->metadata != NULL) {
+			const ScopeLock protect(httpd->mutex);
+			for (auto &client : httpd->clients)
+				client.PushMetaData(httpd->metadata);
+		}
+	}
+}
+
+static void
+httpd_output_cancel(struct audio_output *ao)
+{
+	httpd_output *httpd = (httpd_output *)ao;
+
+	const ScopeLock protect(httpd->mutex);
+	for (auto &client : httpd->clients)
+		client.CancelQueue();
+}
+
+const struct audio_output_plugin httpd_output_plugin = {
+	"httpd",
+	nullptr,
+	httpd_output_init,
+	httpd_output_finish,
+	httpd_output_enable,
+	httpd_output_disable,
+	httpd_output_open,
+	httpd_output_close,
+	httpd_output_delay,
+	httpd_output_tag,
+	httpd_output_play,
+	nullptr,
+	httpd_output_cancel,
+	httpd_output_pause,
+	nullptr,
+};