souphttpsrc: reduce reading latency by using non-blocking read

Non-blocking read will return the amount of data available without
blocking to wait for the full requested size.

The downside is that now it souphttpsrc needs to have a waiting
mechanism in case there is no data available yet to avoid busy
looping arond the inputstream.
This commit is contained in:
Thiago Santos 2016-05-14 11:09:33 -03:00
parent fe34f46f32
commit 8816764112
2 changed files with 103 additions and 16 deletions

View file

@ -77,6 +77,7 @@
#endif
#include <gst/gstelement.h>
#include <gst/gst-i18n-plugin.h>
#include <gio/gio.h>
#include <libsoup/soup.h>
#include "gstsouphttpsrc.h"
#include "gstsouputils.h"
@ -175,6 +176,7 @@ static void gst_soup_http_src_got_headers (GstSoupHTTPSrc * src,
static void gst_soup_http_src_authenticate_cb (SoupSession * session,
SoupMessage * msg, SoupAuth * auth, gboolean retrying,
GstSoupHTTPSrc * src);
static void gst_soup_http_src_destroy_input_stream (GstSoupHTTPSrc * src);
#define gst_soup_http_src_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstSoupHTTPSrc, gst_soup_http_src, GST_TYPE_PUSH_SRC,
@ -439,10 +441,7 @@ gst_soup_http_src_reset (GstSoupHTTPSrc * src)
src->ret = GST_FLOW_OK;
g_cancellable_reset (src->cancellable);
if (src->input_stream) {
g_object_unref (src->input_stream);
src->input_stream = NULL;
}
gst_soup_http_src_destroy_input_stream (src);
gst_caps_replace (&src->src_caps, NULL);
g_free (src->iradio_name);
@ -461,6 +460,7 @@ gst_soup_http_src_init (GstSoupHTTPSrc * src)
g_mutex_init (&src->mutex);
g_cond_init (&src->have_headers_cond);
src->cancellable = g_cancellable_new ();
src->poll_context = g_main_context_new ();
src->location = NULL;
src->redirection_uri = NULL;
src->automatic_redirect = TRUE;
@ -515,6 +515,7 @@ gst_soup_http_src_finalize (GObject * gobject)
g_mutex_clear (&src->mutex);
g_cond_clear (&src->have_headers_cond);
g_object_unref (src->cancellable);
g_main_context_unref (src->poll_context);
g_free (src->location);
g_free (src->redirection_uri);
g_free (src->user_agent);
@ -764,6 +765,21 @@ gst_soup_http_src_unicodify (const gchar * str)
return gst_tag_freeform_string_to_utf8 (str, -1, env_vars);
}
static void
gst_soup_http_src_destroy_input_stream (GstSoupHTTPSrc * src)
{
if (src->input_stream) {
if (src->poll_source) {
g_source_destroy (src->poll_source);
g_source_unref (src->poll_source);
src->poll_source = NULL;
}
g_input_stream_close (src->input_stream, src->cancellable, NULL);
g_object_unref (src->input_stream);
src->input_stream = NULL;
}
}
static void
gst_soup_http_src_cancel_message (GstSoupHTTPSrc * src)
{
@ -1355,11 +1371,25 @@ gst_soup_http_src_build_message (GstSoupHTTPSrc * src, const gchar * method)
return TRUE;
}
static void
gst_soup_http_src_check_input_stream_interfaces (GstSoupHTTPSrc * src)
{
if (!src->input_stream)
return;
src->has_pollable_interface = G_IS_POLLABLE_INPUT_STREAM (src->input_stream)
&& g_pollable_input_stream_can_poll ((GPollableInputStream *)
src->input_stream);
}
static GstFlowReturn
gst_soup_http_src_send_message (GstSoupHTTPSrc * src)
{
g_return_val_if_fail (src->msg != NULL, GST_FLOW_ERROR);
g_assert (src->input_stream == NULL);
g_assert (src->poll_source == NULL);
/* FIXME We are ignoring the GError here, might be useful to debug */
src->input_stream =
soup_session_send (src->session, src->msg, src->cancellable, NULL);
@ -1380,6 +1410,8 @@ gst_soup_http_src_send_message (GstSoupHTTPSrc * src)
return GST_FLOW_ERROR;
}
gst_soup_http_src_check_input_stream_interfaces (src);
return GST_FLOW_OK;
}
@ -1448,6 +1480,38 @@ gst_soup_http_src_update_position (GstSoupHTTPSrc * src, gint64 bytes_read)
}
}
static gboolean
_gst_soup_http_src_data_available_callback (GObject * pollable_stream,
gpointer udata)
{
GstSoupHTTPSrc *src = udata;
src->have_data = TRUE;
return TRUE;
}
/* Need to wait on a gsource to know when data is available */
static gboolean
gst_soup_http_src_wait_for_data (GstSoupHTTPSrc * src)
{
src->have_data = FALSE;
if (!src->poll_source) {
src->poll_source =
g_pollable_input_stream_create_source ((GPollableInputStream *)
src->input_stream, src->cancellable);
g_source_set_callback (src->poll_source,
(GSourceFunc) _gst_soup_http_src_data_available_callback, src, NULL);
g_source_attach (src->poll_source, src->poll_context);
}
while (!src->have_data && !g_cancellable_is_cancelled (src->cancellable)) {
g_main_context_iteration (src->poll_context, TRUE);
}
return src->have_data;
}
static GstFlowReturn
gst_soup_http_src_read_buffer (GstSoupHTTPSrc * src, GstBuffer ** outbuf)
{
@ -1455,6 +1519,7 @@ gst_soup_http_src_read_buffer (GstSoupHTTPSrc * src, GstBuffer ** outbuf)
GstMapInfo mapinfo;
GstBaseSrc *bsrc;
GstFlowReturn ret;
GError *err = NULL;
bsrc = GST_BASE_SRC_CAST (src);
@ -1469,9 +1534,34 @@ gst_soup_http_src_read_buffer (GstSoupHTTPSrc * src, GstBuffer ** outbuf)
return GST_FLOW_ERROR;
}
read_bytes =
g_input_stream_read (src->input_stream, mapinfo.data, mapinfo.size,
src->cancellable, NULL);
if (src->has_pollable_interface) {
while (1) {
read_bytes =
g_pollable_input_stream_read_nonblocking ((GPollableInputStream *)
src->input_stream, mapinfo.data, mapinfo.size, src->cancellable,
&err);
if (read_bytes == -1) {
if (err && g_error_matches (err, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK)) {
g_error_free (err);
err = NULL;
/* no data yet, wait */
if (gst_soup_http_src_wait_for_data (src))
/* retry */
continue;
}
}
break;
}
} else {
read_bytes =
g_input_stream_read (src->input_stream, mapinfo.data, mapinfo.size,
src->cancellable, NULL);
}
if (err)
g_error_free (err);
GST_DEBUG_OBJECT (src, "Read %" G_GSSIZE_FORMAT " bytes from http input",
read_bytes);
@ -1518,11 +1608,7 @@ retry:
/* Check for pending position change */
if (src->request_position != src->read_position) {
if (src->input_stream) {
g_input_stream_close (src->input_stream, src->cancellable, NULL);
g_object_unref (src->input_stream);
src->input_stream = NULL;
}
gst_soup_http_src_destroy_input_stream (src);
}
if (g_cancellable_is_cancelled (src->cancellable)) {
@ -1559,10 +1645,7 @@ done:
gst_event_unref (http_headers_event);
g_mutex_lock (&src->mutex);
if (src->input_stream) {
g_object_unref (src->input_stream);
src->input_stream = NULL;
}
gst_soup_http_src_destroy_input_stream (src);
g_mutex_unlock (&src->mutex);
if (ret == GST_FLOW_CUSTOM_ERROR)
goto retry;

View file

@ -89,6 +89,10 @@ struct _GstSoupHTTPSrc {
GCancellable *cancellable;
GInputStream *input_stream;
gboolean has_pollable_interface;
gboolean have_data;
GMainContext *poll_context;
GSource *poll_source;
/* Shoutcast/icecast metadata extraction handling. */
gboolean iradio_mode;