git.sesse.net Git - cubemap/blob - stream.cpp

   1 #include <arpa/inet.h>
   2 #include <errno.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6 #include <string>
   7 #include <vector>
   8
   9 #include "state.pb.h"
  10 #include "log.h"
  11 #include "metacube.h"
  12 #include "stream.h"
  13 #include "util.h"
  14
  15 using namespace std;
  16
  17 Stream::Stream(const string &stream_id, size_t backlog_size, Encoding encoding)
  18         : stream_id(stream_id),
  19           encoding(encoding),
  20           data_fd(make_tempfile("")),
  21           backlog_size(backlog_size),
  22           bytes_received(0),
  23           mark_pool(NULL)
  24 {
  25         if (data_fd == -1) {
  26                 exit(1);
  27         }
  28 }
  29
  30 Stream::~Stream()
  31 {
  32         if (data_fd != -1) {
  33                 int ret;
  34                 do {
  35                         ret = close(data_fd);
  36                 } while (ret == -1 && errno == EINTR);
  37                 if (ret == -1) {
  38                         log_perror("close");
  39                 }
  40         }
  41 }
  42
  43 Stream::Stream(const StreamProto &serialized, int data_fd)
  44         : stream_id(serialized.stream_id()),
  45           http_header(serialized.http_header()),
  46           stream_header(serialized.stream_header()),
  47           encoding(Stream::STREAM_ENCODING_RAW),  // Will be changed later.
  48           data_fd(data_fd),
  49           backlog_size(serialized.backlog_size()),
  50           bytes_received(serialized.bytes_received()),
  51           mark_pool(NULL)
  52 {
  53         if (data_fd == -1) {
  54                 exit(1);
  55         }
  56
  57         // Split old-style headers into HTTP and video headers.
  58         if (!serialized.header().empty()) {
  59                 string header = serialized.header();
  60                 size_t split = header.find("\r\n\r\n");
  61                 if (split == string::npos) {
  62                         http_header = header;
  63                         stream_header = "";
  64                 } else {
  65                         http_header = header.substr(0, split + 2);  // Split off the second \r\n.
  66                         stream_header = header.substr(split, string::npos);
  67                 }
  68         }
  69 }
  70
  71 StreamProto Stream::serialize()
  72 {
  73         StreamProto serialized;
  74         serialized.set_http_header(http_header);
  75         serialized.set_stream_header(stream_header);
  76         serialized.add_data_fds(data_fd);
  77         serialized.set_backlog_size(backlog_size);
  78         serialized.set_bytes_received(bytes_received);
  79         serialized.set_stream_id(stream_id);
  80         data_fd = -1;
  81         return serialized;
  82 }
  83
  84 void Stream::set_backlog_size(size_t new_size)
  85 {
  86         if (backlog_size == new_size) {
  87                 return;
  88         }
  89
  90         string existing_data;
  91         if (!read_tempfile_and_close(data_fd, &existing_data)) {
  92                 exit(1);
  93         }
  94
  95         // Unwrap the data so it's no longer circular.
  96         if (bytes_received <= backlog_size) {
  97                 existing_data.resize(bytes_received);
  98         } else {
  99                 size_t pos = bytes_received % backlog_size;
 100                 existing_data = existing_data.substr(pos, string::npos) +
 101                         existing_data.substr(0, pos);
 102         }
 103
 104         // See if we need to discard data.
 105         if (new_size < existing_data.size()) {
 106                 size_t to_discard = existing_data.size() - new_size;
 107                 existing_data = existing_data.substr(to_discard, string::npos);
 108         }
 109
 110         // Create a new, empty data file.
 111         data_fd = make_tempfile("");
 112         backlog_size = new_size;
 113
 114         // Now cheat a bit by rewinding, and adding all the old data back.
 115         bytes_received -= existing_data.size();
 116         add_data(existing_data.data(), existing_data.size());
 117 }
 118
 119 void Stream::put_client_to_sleep(Client *client)
 120 {
 121         sleeping_clients.push_back(client);
 122 }
 123
 124 void Stream::add_data(const char *data, ssize_t bytes)
 125 {
 126         if (encoding == Stream::STREAM_ENCODING_RAW) {
 127                 add_data_raw(data, bytes);
 128         } else if (encoding == STREAM_ENCODING_METACUBE) {
 129                 metacube_block_header hdr;
 130                 memcpy(hdr.sync, METACUBE_SYNC, sizeof(hdr.sync));
 131                 hdr.size = htonl(bytes);
 132                 hdr.flags = htonl(0);
 133
 134                 char *block = new char[bytes + sizeof(hdr)];
 135                 memcpy(block, &hdr, sizeof(hdr));
 136                 memcpy(block + sizeof(hdr), data, bytes);
 137                 add_data_raw(block, bytes + sizeof(hdr));
 138                 delete[] block;
 139         } else {
 140                 assert(false);
 141         }
 142 }
 143
 144 void Stream::add_data_raw(const char *data, ssize_t bytes)
 145 {
 146         size_t pos = bytes_received % backlog_size;
 147         bytes_received += bytes;
 148
 149         if (pos + bytes > backlog_size) {
 150                 ssize_t to_copy = backlog_size - pos;
 151                 while (to_copy > 0) {
 152                         int ret = pwrite(data_fd, data, to_copy, pos);
 153                         if (ret == -1 && errno == EINTR) {
 154                                 continue;
 155                         }
 156                         if (ret == -1) {
 157                                 log_perror("pwrite");
 158                                 // Dazed and confused, but trying to continue...
 159                                 break;
 160                         }
 161                         pos += ret;
 162                         data += ret;
 163                         to_copy -= ret;
 164                         bytes -= ret;
 165                 }
 166                 pos = 0;
 167         }
 168
 169         while (bytes > 0) {
 170                 int ret = pwrite(data_fd, data, bytes, pos);
 171                 if (ret == -1 && errno == EINTR) {
 172                         continue;
 173                 }
 174                 if (ret == -1) {
 175                         log_perror("pwrite");
 176                         // Dazed and confused, but trying to continue...
 177                         break;
 178                 }
 179                 pos += ret;
 180                 data += ret;
 181                 bytes -= ret;
 182         }
 183 }
 184
 185 void Stream::wake_up_all_clients()
 186 {
 187         if (to_process.empty()) {
 188                 swap(sleeping_clients, to_process);
 189         } else {
 190                 to_process.insert(to_process.end(), sleeping_clients.begin(), sleeping_clients.end());
 191                 sleeping_clients.clear();
 192         }
 193 }