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

   1 #include <assert.h>
   2 #include <errno.h>
   3 #include <netinet/in.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #include <unistd.h>
   7 #include <string>
   8 #include <vector>
   9
  10 #include "log.h"
  11 #include "metacube.h"
  12 #include "state.pb.h"
  13 #include "stream.h"
  14 #include "util.h"
  15
  16 using namespace std;
  17
  18 Stream::Stream(const string &stream_id, size_t backlog_size, Encoding encoding)
  19         : stream_id(stream_id),
  20           encoding(encoding),
  21           data_fd(make_tempfile("")),
  22           backlog_size(backlog_size),
  23           bytes_received(0),
  24           mark_pool(NULL)
  25 {
  26         if (data_fd == -1) {
  27                 exit(1);
  28         }
  29 }
  30
  31 Stream::~Stream()
  32 {
  33         if (data_fd != -1) {
  34                 int ret;
  35                 do {
  36                         ret = close(data_fd);
  37                 } while (ret == -1 && errno == EINTR);
  38                 if (ret == -1) {
  39                         log_perror("close");
  40                 }
  41         }
  42 }
  43
  44 Stream::Stream(const StreamProto &serialized, int data_fd)
  45         : stream_id(serialized.stream_id()),
  46           http_header(serialized.http_header()),
  47           stream_header(serialized.stream_header()),
  48           encoding(Stream::STREAM_ENCODING_RAW),  // Will be changed later.
  49           data_fd(data_fd),
  50           backlog_size(serialized.backlog_size()),
  51           bytes_received(serialized.bytes_received()),
  52           mark_pool(NULL)
  53 {
  54         if (data_fd == -1) {
  55                 exit(1);
  56         }
  57
  58         // Split old-style headers into HTTP and video headers.
  59         if (!serialized.header().empty()) {
  60                 string header = serialized.header();
  61                 size_t split = header.find("\r\n\r\n");
  62                 if (split == string::npos) {
  63                         http_header = header;
  64                         stream_header = "";
  65                 } else {
  66                         http_header = header.substr(0, split + 2);  // Split off the second \r\n.
  67                         stream_header = header.substr(split, string::npos);
  68                 }
  69         }
  70 }
  71
  72 StreamProto Stream::serialize()
  73 {
  74         StreamProto serialized;
  75         serialized.set_http_header(http_header);
  76         serialized.set_stream_header(stream_header);
  77         serialized.add_data_fds(data_fd);
  78         serialized.set_backlog_size(backlog_size);
  79         serialized.set_bytes_received(bytes_received);
  80         serialized.set_stream_id(stream_id);
  81         data_fd = -1;
  82         return serialized;
  83 }
  84
  85 void Stream::set_backlog_size(size_t new_size)
  86 {
  87         if (backlog_size == new_size) {
  88                 return;
  89         }
  90
  91         string existing_data;
  92         if (!read_tempfile_and_close(data_fd, &existing_data)) {
  93                 exit(1);
  94         }
  95
  96         // Unwrap the data so it's no longer circular.
  97         if (bytes_received <= backlog_size) {
  98                 existing_data.resize(bytes_received);
  99         } else {
 100                 size_t pos = bytes_received % backlog_size;
 101                 existing_data = existing_data.substr(pos, string::npos) +
 102                         existing_data.substr(0, pos);
 103         }
 104
 105         // See if we need to discard data.
 106         if (new_size < existing_data.size()) {
 107                 size_t to_discard = existing_data.size() - new_size;
 108                 existing_data = existing_data.substr(to_discard, string::npos);
 109         }
 110
 111         // Create a new, empty data file.
 112         data_fd = make_tempfile("");
 113         backlog_size = new_size;
 114
 115         // Now cheat a bit by rewinding, and adding all the old data back.
 116         bytes_received -= existing_data.size();
 117         add_data(existing_data.data(), existing_data.size());
 118 }
 119
 120 void Stream::put_client_to_sleep(Client *client)
 121 {
 122         sleeping_clients.push_back(client);
 123 }
 124
 125 void Stream::add_data(const char *data, ssize_t bytes)
 126 {
 127         if (encoding == Stream::STREAM_ENCODING_RAW) {
 128                 add_data_raw(data, bytes);
 129         } else if (encoding == STREAM_ENCODING_METACUBE) {
 130                 metacube_block_header hdr;
 131                 memcpy(hdr.sync, METACUBE_SYNC, sizeof(hdr.sync));
 132                 hdr.size = htonl(bytes);
 133                 hdr.flags = htonl(0);
 134
 135                 char *block = new char[bytes + sizeof(hdr)];
 136                 memcpy(block, &hdr, sizeof(hdr));
 137                 memcpy(block + sizeof(hdr), data, bytes);
 138                 add_data_raw(block, bytes + sizeof(hdr));
 139                 delete[] block;
 140         } else {
 141                 assert(false);
 142         }
 143 }
 144
 145 void Stream::add_data_raw(const char *data, ssize_t bytes)
 146 {
 147         size_t pos = bytes_received % backlog_size;
 148         bytes_received += bytes;
 149
 150         if (pos + bytes > backlog_size) {
 151                 ssize_t to_copy = backlog_size - pos;
 152                 while (to_copy > 0) {
 153                         int ret = pwrite(data_fd, data, to_copy, pos);
 154                         if (ret == -1 && errno == EINTR) {
 155                                 continue;
 156                         }
 157                         if (ret == -1) {
 158                                 log_perror("pwrite");
 159                                 // Dazed and confused, but trying to continue...
 160                                 break;
 161                         }
 162                         pos += ret;
 163                         data += ret;
 164                         to_copy -= ret;
 165                         bytes -= ret;
 166                 }
 167                 pos = 0;
 168         }
 169
 170         while (bytes > 0) {
 171                 int ret = pwrite(data_fd, data, bytes, pos);
 172                 if (ret == -1 && errno == EINTR) {
 173                         continue;
 174                 }
 175                 if (ret == -1) {
 176                         log_perror("pwrite");
 177                         // Dazed and confused, but trying to continue...
 178                         break;
 179                 }
 180                 pos += ret;
 181                 data += ret;
 182                 bytes -= ret;
 183         }
 184 }
 185
 186 void Stream::wake_up_all_clients()
 187 {
 188         if (to_process.empty()) {
 189                 swap(sleeping_clients, to_process);
 190         } else {
 191                 to_process.insert(to_process.end(), sleeping_clients.begin(), sleeping_clients.end());
 192                 sleeping_clients.clear();
 193         }
 194 }