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         if (data_fd == -1) {
 114                 exit(1);
 115         }
 116         backlog_size = new_size;
 117
 118         // Now cheat a bit by rewinding, and adding all the old data back.
 119         bytes_received -= existing_data.size();
 120         add_data(existing_data.data(), existing_data.size());
 121 }
 122
 123 void Stream::put_client_to_sleep(Client *client)
 124 {
 125         sleeping_clients.push_back(client);
 126 }
 127
 128 void Stream::add_data(const char *data, ssize_t bytes)
 129 {
 130         if (encoding == Stream::STREAM_ENCODING_RAW) {
 131                 add_data_raw(data, bytes);
 132         } else if (encoding == STREAM_ENCODING_METACUBE) {
 133                 metacube_block_header hdr;
 134                 memcpy(hdr.sync, METACUBE_SYNC, sizeof(hdr.sync));
 135                 hdr.size = htonl(bytes);
 136                 hdr.flags = htonl(0);
 137
 138                 char *block = new char[bytes + sizeof(hdr)];
 139                 memcpy(block, &hdr, sizeof(hdr));
 140                 memcpy(block + sizeof(hdr), data, bytes);
 141                 add_data_raw(block, bytes + sizeof(hdr));
 142                 delete[] block;
 143         } else {
 144                 assert(false);
 145         }
 146 }
 147
 148 void Stream::add_data_raw(const char *data, ssize_t bytes)
 149 {
 150         size_t pos = bytes_received % backlog_size;
 151         bytes_received += bytes;
 152
 153         if (pos + bytes > backlog_size) {
 154                 ssize_t to_copy = backlog_size - pos;
 155                 while (to_copy > 0) {
 156                         int ret = pwrite(data_fd, data, to_copy, pos);
 157                         if (ret == -1 && errno == EINTR) {
 158                                 continue;
 159                         }
 160                         if (ret == -1) {
 161                                 log_perror("pwrite");
 162                                 // Dazed and confused, but trying to continue...
 163                                 break;
 164                         }
 165                         pos += ret;
 166                         data += ret;
 167                         to_copy -= ret;
 168                         bytes -= ret;
 169                 }
 170                 pos = 0;
 171         }
 172
 173         while (bytes > 0) {
 174                 int ret = pwrite(data_fd, data, bytes, pos);
 175                 if (ret == -1 && errno == EINTR) {
 176                         continue;
 177                 }
 178                 if (ret == -1) {
 179                         log_perror("pwrite");
 180                         // Dazed and confused, but trying to continue...
 181                         break;
 182                 }
 183                 pos += ret;
 184                 data += ret;
 185                 bytes -= ret;
 186         }
 187 }
 188
 189 void Stream::wake_up_all_clients()
 190 {
 191         if (to_process.empty()) {
 192                 swap(sleeping_clients, to_process);
 193         } else {
 194                 to_process.insert(to_process.end(), sleeping_clients.begin(), sleeping_clients.end());
 195                 sleeping_clients.clear();
 196         }
 197 }