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)
  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(make_tempfile(serialized.data())),
  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         if (!read_tempfile(data_fd, serialized.mutable_data())) {  // Closes data_fd.
  77                 exit(1);
  78         }
  79         serialized.set_backlog_size(backlog_size);
  80         serialized.set_bytes_received(bytes_received);
  81         serialized.set_stream_id(stream_id);
  82         data_fd = -1;
  83         return serialized;
  84 }
  85
  86 void Stream::set_backlog_size(size_t new_size)
  87 {
  88         if (backlog_size == new_size) {
  89                 return;
  90         }
  91
  92         string existing_data;
  93         if (!read_tempfile(data_fd, &existing_data)) {  // Closes data_fd.
  94                 exit(1);
  95         }
  96
  97         // Unwrap the data so it's no longer circular.
  98         if (bytes_received <= backlog_size) {
  99                 existing_data.resize(bytes_received);
 100         } else {
 101                 size_t pos = bytes_received % backlog_size;
 102                 existing_data = existing_data.substr(pos, string::npos) +
 103                         existing_data.substr(0, pos);
 104         }
 105
 106         // See if we need to discard data.
 107         if (new_size < existing_data.size()) {
 108                 size_t to_discard = existing_data.size() - new_size;
 109                 existing_data = existing_data.substr(to_discard, string::npos);
 110         }
 111
 112         // Create a new, empty data file.
 113         data_fd = make_tempfile("");
 114         backlog_size = new_size;
 115
 116         // Now cheat a bit by rewinding, and adding all the old data back.
 117         bytes_received -= existing_data.size();
 118         add_data(existing_data.data(), existing_data.size());
 119 }
 120
 121 void Stream::put_client_to_sleep(Client *client)
 122 {
 123         sleeping_clients.push_back(client);
 124 }
 125
 126 void Stream::add_data(const char *data, ssize_t bytes)
 127 {
 128         if (encoding == Stream::STREAM_ENCODING_RAW) {
 129                 add_data_raw(data, bytes);
 130         } else if (encoding == STREAM_ENCODING_METACUBE) {
 131                 metacube_block_header hdr;
 132                 memcpy(hdr.sync, METACUBE_SYNC, sizeof(hdr.sync));
 133                 hdr.size = htonl(bytes);
 134                 hdr.flags = htonl(0);
 135
 136                 char *block = new char[bytes + sizeof(hdr)];
 137                 memcpy(block, &hdr, sizeof(hdr));
 138                 memcpy(block + sizeof(hdr), data, bytes);
 139                 add_data_raw(block, bytes + sizeof(hdr));
 140                 delete[] block;
 141         } else {
 142                 assert(false);
 143         }
 144 }
 145
 146 void Stream::add_data_raw(const char *data, ssize_t bytes)
 147 {
 148         size_t pos = bytes_received % backlog_size;
 149         bytes_received += bytes;
 150
 151         if (pos + bytes > backlog_size) {
 152                 ssize_t to_copy = backlog_size - pos;
 153                 while (to_copy > 0) {
 154                         int ret = pwrite(data_fd, data, to_copy, pos);
 155                         if (ret == -1 && errno == EINTR) {
 156                                 continue;
 157                         }
 158                         if (ret == -1) {
 159                                 log_perror("pwrite");
 160                                 // Dazed and confused, but trying to continue...
 161                                 break;
 162                         }
 163                         pos += ret;
 164                         data += ret;
 165                         to_copy -= ret;
 166                         bytes -= ret;
 167                 }
 168                 pos = 0;
 169         }
 170
 171         while (bytes > 0) {
 172                 int ret = pwrite(data_fd, data, bytes, pos);
 173                 if (ret == -1 && errno == EINTR) {
 174                         continue;
 175                 }
 176                 if (ret == -1) {
 177                         log_perror("pwrite");
 178                         // Dazed and confused, but trying to continue...
 179                         break;
 180                 }
 181                 pos += ret;
 182                 data += ret;
 183                 bytes -= ret;
 184         }
 185 }
 186
 187 void Stream::wake_up_all_clients()
 188 {
 189         if (to_process.empty()) {
 190                 swap(sleeping_clients, to_process);
 191         } else {
 192                 to_process.insert(to_process.end(), sleeping_clients.begin(), sleeping_clients.end());
 193                 sleeping_clients.clear();
 194         }
 195 }