]> git.sesse.net Git - cubemap/blobdiff - stream.cpp
Remove std:: from all code in .cpp files, for consistency.
[cubemap] / stream.cpp
index 42edee95aae01176e94c3a63ab47704a95b19a36..64bf2e8053e7c0edd79b17f43ba12160a3dd8795 100644 (file)
@@ -2,33 +2,38 @@
 #include <errno.h>
 #include <limits.h>
 #include <netinet/in.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
+#include <algorithm>
 #include <string>
+#include <queue>
 #include <vector>
 
 #include "log.h"
 #include "metacube2.h"
+#include "mutexlock.h"
 #include "state.pb.h"
 #include "stream.h"
 #include "util.h"
 
 using namespace std;
 
-Stream::Stream(const string &url, size_t backlog_size, Encoding encoding)
+Stream::Stream(const string &url, size_t backlog_size, size_t prebuffering_bytes, Encoding encoding)
        : url(url),
          encoding(encoding),
          data_fd(make_tempfile("")),
           backlog_size(backlog_size),
+         prebuffering_bytes(prebuffering_bytes),
          bytes_received(0),
-         last_suitable_starting_point(-1),
-         mark_pool(NULL),
-         queued_data_last_starting_point(-1)
+         pacing_rate(~0U)
 {
        if (data_fd == -1) {
                exit(1);
        }
+
+       pthread_mutex_init(&queued_data_mutex, NULL);
 }
 
 Stream::~Stream()
@@ -45,33 +50,26 @@ Stream::Stream(const StreamProto &serialized, int data_fd)
          encoding(Stream::STREAM_ENCODING_RAW),  // Will be changed later.
          data_fd(data_fd),
          backlog_size(serialized.backlog_size()),
+         prebuffering_bytes(serialized.prebuffering_bytes()),
          bytes_received(serialized.bytes_received()),
-         mark_pool(NULL),
-         queued_data_last_starting_point(-1)
+         pacing_rate(~0U)
 {
        if (data_fd == -1) {
                exit(1);
        }
 
-       // Split old-style headers into HTTP and video headers.
-       if (!serialized.header().empty()) {
-               string header = serialized.header();
-               size_t split = header.find("\r\n\r\n");
-               if (split == string::npos) {
-                       http_header = header;
-                       stream_header = "";
-               } else {
-                       http_header = header.substr(0, split + 2);  // Split off the second \r\n.
-                       stream_header = header.substr(split, string::npos);
+       for (int i = 0; i < serialized.suitable_starting_point_size(); ++i) {
+               ssize_t point = serialized.suitable_starting_point(i);
+               if (point == -1) {
+                       // Can happen when upgrading from before 1.1.3,
+                       // where this was an optional field with -1 signifying
+                       // "no such point".
+                       continue;
                }
+               suitable_starting_points.push_back(point);
        }
 
-       // Older versions did not set last_suitable_starting_point.
-       if (serialized.has_last_suitable_starting_point()) {
-               last_suitable_starting_point = serialized.last_suitable_starting_point();
-       } else {
-               last_suitable_starting_point = bytes_received;
-       }
+       pthread_mutex_init(&queued_data_mutex, NULL);
 }
 
 StreamProto Stream::serialize()
@@ -81,8 +79,11 @@ StreamProto Stream::serialize()
        serialized.set_stream_header(stream_header);
        serialized.add_data_fds(data_fd);
        serialized.set_backlog_size(backlog_size);
+       serialized.set_prebuffering_bytes(prebuffering_bytes);
        serialized.set_bytes_received(bytes_received);
-       serialized.set_last_suitable_starting_point(last_suitable_starting_point);
+       for (size_t i = 0; i < suitable_starting_points.size(); ++i) {
+               serialized.add_suitable_starting_point(suitable_starting_points[i]);
+       }
        serialized.set_url(url);
        data_fd = -1;
        return serialized;
@@ -123,13 +124,15 @@ void Stream::set_backlog_size(size_t new_size)
 
        // Now cheat a bit by rewinding, and adding all the old data back.
        bytes_received -= existing_data.size();
-       iovec iov;
-       iov.iov_base = const_cast<char *>(existing_data.data());
-       iov.iov_len = existing_data.size();
-
-       vector<iovec> iovs;
-       iovs.push_back(iov);
-       add_data_raw(iovs);
+       DataElement data_element;
+       data_element.data.iov_base = const_cast<char *>(existing_data.data());
+       data_element.data.iov_len = existing_data.size();
+       data_element.suitable_for_stream_start = NOT_SUITABLE_FOR_STREAM_START;  // Ignored by add_data_raw().
+
+       vector<DataElement> data_elements;
+       data_elements.push_back(data_element);
+       add_data_raw(data_elements);
+       remove_obsolete_starting_points();
 }
 
 void Stream::put_client_to_sleep(Client *client)
@@ -138,20 +141,20 @@ void Stream::put_client_to_sleep(Client *client)
 }
 
 // Return a new set of iovecs that contains only the first <bytes_wanted> bytes of <data>.
-vector<iovec> collect_iovecs(const vector<iovec> &data, size_t bytes_wanted)
+vector<iovec> collect_iovecs(const vector<Stream::DataElement> &data, size_t bytes_wanted)
 {
        vector<iovec> ret;
-       size_t max_iovecs = std::min<size_t>(data.size(), IOV_MAX);
+       size_t max_iovecs = min<size_t>(data.size(), IOV_MAX);
        for (size_t i = 0; i < max_iovecs && bytes_wanted > 0; ++i) {
-               if (data[i].iov_len <= bytes_wanted) {
+               if (data[i].data.iov_len <= bytes_wanted) {
                        // Consume the entire iovec.
-                       ret.push_back(data[i]);
-                       bytes_wanted -= data[i].iov_len;
+                       ret.push_back(data[i].data);
+                       bytes_wanted -= data[i].data.iov_len;
                } else {
                        // Take only parts of this iovec.
                        iovec iov;
-                       iov.iov_base = data[i].iov_base;
-                       iov.iov_len = bytes_wanted;     
+                       iov.iov_base = data[i].data.iov_base;
+                       iov.iov_len = bytes_wanted;
                        ret.push_back(iov);
                        bytes_wanted = 0;
                }
@@ -160,20 +163,21 @@ vector<iovec> collect_iovecs(const vector<iovec> &data, size_t bytes_wanted)
 }
 
 // Return a new set of iovecs that contains all of <data> except the first <bytes_wanted> bytes.
-vector<iovec> remove_iovecs(const vector<iovec> &data, size_t bytes_wanted)
+vector<Stream::DataElement> remove_iovecs(const vector<Stream::DataElement> &data, size_t bytes_wanted)
 {
-       vector<iovec> ret;
+       vector<Stream::DataElement> ret;
        size_t i;
        for (i = 0; i < data.size() && bytes_wanted > 0; ++i) {
-               if (data[i].iov_len <= bytes_wanted) {
+               if (data[i].data.iov_len <= bytes_wanted) {
                        // Consume the entire iovec.
-                       bytes_wanted -= data[i].iov_len;
+                       bytes_wanted -= data[i].data.iov_len;
                } else {
                        // Take only parts of this iovec.
-                       iovec iov;
-                       iov.iov_base = reinterpret_cast<char *>(data[i].iov_base) + bytes_wanted;
-                       iov.iov_len = data[i].iov_len - bytes_wanted;
-                       ret.push_back(iov);
+                       Stream::DataElement data_element;
+                       data_element.data.iov_base = reinterpret_cast<char *>(data[i].data.iov_base) + bytes_wanted;
+                       data_element.data.iov_len = data[i].data.iov_len - bytes_wanted;
+                       data_element.suitable_for_stream_start = NOT_SUITABLE_FOR_STREAM_START;
+                       ret.push_back(data_element);
                        bytes_wanted = 0;
                }
        }
@@ -183,9 +187,9 @@ vector<iovec> remove_iovecs(const vector<iovec> &data, size_t bytes_wanted)
        return ret;
 }
 
-void Stream::add_data_raw(const vector<iovec> &orig_data)
+void Stream::add_data_raw(const vector<DataElement> &orig_data)
 {
-       vector<iovec> data = orig_data;
+       vector<DataElement> data = orig_data;
        while (!data.empty()) {
                size_t pos = bytes_received % backlog_size;
 
@@ -209,13 +213,24 @@ void Stream::add_data_raw(const vector<iovec> &orig_data)
        }
 }
 
+void Stream::remove_obsolete_starting_points()
+{
+       // We could do a binary search here (std::lower_bound), but it seems
+       // overkill for removing what's probably only a few points.
+       while (!suitable_starting_points.empty() &&
+              bytes_received - suitable_starting_points[0] > backlog_size) {
+               suitable_starting_points.pop_front();
+       }
+}
+
 void Stream::add_data_deferred(const char *data, size_t bytes, StreamStartSuitability suitable_for_stream_start)
 {
+       MutexLock lock(&queued_data_mutex);
        assert(suitable_for_stream_start == SUITABLE_FOR_STREAM_START ||
               suitable_for_stream_start == NOT_SUITABLE_FOR_STREAM_START);
-       if (suitable_for_stream_start == SUITABLE_FOR_STREAM_START) {
-               queued_data_last_starting_point = queued_data.size();
-       }
+
+       DataElement data_element;
+       data_element.suitable_for_stream_start = suitable_for_stream_start;
 
        if (encoding == Stream::STREAM_ENCODING_METACUBE) {
                // Add a Metacube block header before the data.
@@ -228,22 +243,20 @@ void Stream::add_data_deferred(const char *data, size_t bytes, StreamStartSuitab
                }
                hdr.csum = htons(metacube2_compute_crc(&hdr));
 
-               iovec iov;
-               iov.iov_base = new char[bytes + sizeof(hdr)];
-               iov.iov_len = bytes + sizeof(hdr);
+               data_element.data.iov_base = new char[bytes + sizeof(hdr)];
+               data_element.data.iov_len = bytes + sizeof(hdr);
 
-               memcpy(iov.iov_base, &hdr, sizeof(hdr));
-               memcpy(reinterpret_cast<char *>(iov.iov_base) + sizeof(hdr), data, bytes);
+               memcpy(data_element.data.iov_base, &hdr, sizeof(hdr));
+               memcpy(reinterpret_cast<char *>(data_element.data.iov_base) + sizeof(hdr), data, bytes);
 
-               queued_data.push_back(iov);
+               queued_data.push_back(data_element);
        } else if (encoding == Stream::STREAM_ENCODING_RAW) {
                // Just add the data itself.
-               iovec iov;
-               iov.iov_base = new char[bytes];
-               memcpy(iov.iov_base, data, bytes);
-               iov.iov_len = bytes;
+               data_element.data.iov_base = new char[bytes];
+               memcpy(data_element.data.iov_base, data, bytes);
+               data_element.data.iov_len = bytes;
 
-               queued_data.push_back(iov);
+               queued_data.push_back(data_element);
        } else {
                assert(false);
        }
@@ -251,27 +264,47 @@ void Stream::add_data_deferred(const char *data, size_t bytes, StreamStartSuitab
 
 void Stream::process_queued_data()
 {
-       if (queued_data.empty()) {
-               return;
+       vector<DataElement> queued_data_copy;
+
+       // Hold the lock for as short as possible, since add_data_raw() can possibly
+       // write to disk, which might disturb the input thread.
+       {
+               MutexLock lock(&queued_data_mutex);
+               if (queued_data.empty()) {
+                       return;
+               }
+
+               swap(queued_data, queued_data_copy);
        }
 
-       // Update the last suitable starting point for the stream,
-       // if the queued data contains such a starting point.
-       assert(queued_data_last_starting_point < ssize_t(queued_data.size()));
-       if (queued_data_last_starting_point >= 0) {
-               last_suitable_starting_point = bytes_received;
-               for (int i = 0; i < queued_data_last_starting_point; ++i) {
-                       last_suitable_starting_point += queued_data[i].iov_len;
+       // Add suitable starting points for the stream, if the queued data
+       // contains such starting points. Note that we drop starting points
+       // if they're less than 10 kB apart, so that we don't get a huge
+       // amount of them for e.g. each and every MPEG-TS 188-byte cell.
+       // The 10 kB value is somewhat arbitrary, but at least it should make
+       // the RAM cost of saving the position ~0.1% (or less) of the actual
+       // data, and 10 kB is a very fine granularity in most streams.
+       static const int minimum_start_point_distance = 10240;
+       size_t byte_position = bytes_received;
+       for (size_t i = 0; i < queued_data_copy.size(); ++i) {
+               if (queued_data_copy[i].suitable_for_stream_start == SUITABLE_FOR_STREAM_START) {
+                       size_t num_points = suitable_starting_points.size();
+                       if (num_points >= 2 &&
+                           suitable_starting_points[num_points - 1] - suitable_starting_points[num_points - 2] < minimum_start_point_distance) {
+                               // p[n-1] - p[n-2] < 10 kB, so drop p[n-1].
+                               suitable_starting_points.pop_back();
+                       }
+                       suitable_starting_points.push_back(byte_position);
                }
+               byte_position += queued_data_copy[i].data.iov_len;
        }
 
-       add_data_raw(queued_data);
-       for (size_t i = 0; i < queued_data.size(); ++i) {
-               char *data = reinterpret_cast<char *>(queued_data[i].iov_base);
+       add_data_raw(queued_data_copy);
+       remove_obsolete_starting_points();
+       for (size_t i = 0; i < queued_data_copy.size(); ++i) {
+               char *data = reinterpret_cast<char *>(queued_data_copy[i].data.iov_base);
                delete[] data;
        }
-       queued_data.clear();
-       queued_data_last_starting_point = -1;
 
        // We have more data, so wake up all clients.
        if (to_process.empty()) {