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                 safe_close(data_fd);
  35         }
  36 }
  37
  38 Stream::Stream(const StreamProto &serialized, int data_fd)
  39         : stream_id(serialized.stream_id()),
  40           http_header(serialized.http_header()),
  41           stream_header(serialized.stream_header()),
  42           encoding(Stream::STREAM_ENCODING_RAW),  // Will be changed later.
  43           data_fd(data_fd),
  44           backlog_size(serialized.backlog_size()),
  45           bytes_received(serialized.bytes_received()),
  46           mark_pool(NULL)
  47 {
  48         if (data_fd == -1) {
  49                 exit(1);
  50         }
  51
  52         // Split old-style headers into HTTP and video headers.
  53         if (!serialized.header().empty()) {
  54                 string header = serialized.header();
  55                 size_t split = header.find("\r\n\r\n");
  56                 if (split == string::npos) {
  57                         http_header = header;
  58                         stream_header = "";
  59                 } else {
  60                         http_header = header.substr(0, split + 2);  // Split off the second \r\n.
  61                         stream_header = header.substr(split, string::npos);
  62                 }
  63         }
  64 }
  65
  66 StreamProto Stream::serialize()
  67 {
  68         StreamProto serialized;
  69         serialized.set_http_header(http_header);
  70         serialized.set_stream_header(stream_header);
  71         serialized.add_data_fds(data_fd);
  72         serialized.set_backlog_size(backlog_size);
  73         serialized.set_bytes_received(bytes_received);
  74         serialized.set_stream_id(stream_id);
  75         data_fd = -1;
  76         return serialized;
  77 }
  78
  79 void Stream::set_backlog_size(size_t new_size)
  80 {
  81         if (backlog_size == new_size) {
  82                 return;
  83         }
  84
  85         string existing_data;
  86         if (!read_tempfile_and_close(data_fd, &existing_data)) {
  87                 exit(1);
  88         }
  89
  90         // Unwrap the data so it's no longer circular.
  91         if (bytes_received <= backlog_size) {
  92                 existing_data.resize(bytes_received);
  93         } else {
  94                 size_t pos = bytes_received % backlog_size;
  95                 existing_data = existing_data.substr(pos, string::npos) +
  96                         existing_data.substr(0, pos);
  97         }
  98
  99         // See if we need to discard data.
 100         if (new_size < existing_data.size()) {
 101                 size_t to_discard = existing_data.size() - new_size;
 102                 existing_data = existing_data.substr(to_discard, string::npos);
 103         }
 104
 105         // Create a new, empty data file.
 106         data_fd = make_tempfile("");
 107         if (data_fd == -1) {
 108                 exit(1);
 109         }
 110         backlog_size = new_size;
 111
 112         // Now cheat a bit by rewinding, and adding all the old data back.
 113         bytes_received -= existing_data.size();
 114         add_data_raw(existing_data.data(), existing_data.size());
 115 }
 116
 117 void Stream::put_client_to_sleep(Client *client)
 118 {
 119         sleeping_clients.push_back(client);
 120 }
 121
 122 void Stream::add_data_raw(const char *data, ssize_t bytes)
 123 {
 124         size_t pos = bytes_received % backlog_size;
 125         bytes_received += bytes;
 126
 127         if (pos + bytes > backlog_size) {
 128                 ssize_t to_copy = backlog_size - pos;
 129                 while (to_copy > 0) {
 130                         int ret = pwrite(data_fd, data, to_copy, pos);
 131                         if (ret == -1 && errno == EINTR) {
 132                                 continue;
 133                         }
 134                         if (ret == -1) {
 135                                 log_perror("pwrite");
 136                                 // Dazed and confused, but trying to continue...
 137                                 break;
 138                         }
 139                         pos += ret;
 140                         data += ret;
 141                         to_copy -= ret;
 142                         bytes -= ret;
 143                 }
 144                 pos = 0;
 145         }
 146
 147         while (bytes > 0) {
 148                 int ret = pwrite(data_fd, data, bytes, pos);
 149                 if (ret == -1 && errno == EINTR) {
 150                         continue;
 151                 }
 152                 if (ret == -1) {
 153                         log_perror("pwrite");
 154                         // Dazed and confused, but trying to continue...
 155                         break;
 156                 }
 157                 pos += ret;
 158                 data += ret;
 159                 bytes -= ret;
 160         }
 161 }
 162
 163 void Stream::add_data_deferred(const char *data, size_t bytes)
 164 {
 165         if (encoding == Stream::STREAM_ENCODING_RAW) {
 166                 queued_data.append(string(data, data + bytes));
 167         } else if (encoding == STREAM_ENCODING_METACUBE) {
 168                 metacube_block_header hdr;
 169                 memcpy(hdr.sync, METACUBE_SYNC, sizeof(hdr.sync));
 170                 hdr.size = htonl(bytes);
 171                 hdr.flags = htonl(0);
 172
 173                 char *block = new char[bytes + sizeof(hdr)];
 174                 memcpy(block, &hdr, sizeof(hdr));
 175                 memcpy(block + sizeof(hdr), data, bytes);
 176                 queued_data.append(string(block, block + bytes + sizeof(hdr)));
 177                 delete[] block;
 178         } else {
 179                 assert(false);
 180         }
 181 }
 182
 183 void Stream::process_queued_data()
 184 {
 185         if (queued_data.empty()) {
 186                 return;
 187         }
 188
 189         add_data_raw(queued_data.data(), queued_data.size());
 190         queued_data.clear();
 191
 192         // We have more data, so wake up all clients.
 193         if (to_process.empty()) {
 194                 swap(sleeping_clients, to_process);
 195         } else {
 196                 to_process.insert(to_process.end(), sleeping_clients.begin(), sleeping_clients.end());
 197                 sleeping_clients.clear();
 198         }
 199 }