3 #include <netinet/in.h>
18 Stream::Stream(const string &url, size_t backlog_size, Encoding encoding)
21 data_fd(make_tempfile("")),
22 backlog_size(backlog_size),
38 Stream::Stream(const StreamProto &serialized, int data_fd)
39 : url(serialized.url()),
40 http_header(serialized.http_header()),
41 stream_header(serialized.stream_header()),
42 encoding(Stream::STREAM_ENCODING_RAW), // Will be changed later.
44 backlog_size(serialized.backlog_size()),
45 bytes_received(serialized.bytes_received()),
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) {
60 http_header = header.substr(0, split + 2); // Split off the second \r\n.
61 stream_header = header.substr(split, string::npos);
66 StreamProto Stream::serialize()
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_url(url);
79 void Stream::set_backlog_size(size_t new_size)
81 if (backlog_size == new_size) {
86 if (!read_tempfile_and_close(data_fd, &existing_data)) {
90 // Unwrap the data so it's no longer circular.
91 if (bytes_received <= backlog_size) {
92 existing_data.resize(bytes_received);
94 size_t pos = bytes_received % backlog_size;
95 existing_data = existing_data.substr(pos, string::npos) +
96 existing_data.substr(0, pos);
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);
105 // Create a new, empty data file.
106 data_fd = make_tempfile("");
110 backlog_size = new_size;
112 // Now cheat a bit by rewinding, and adding all the old data back.
113 bytes_received -= existing_data.size();
115 iov.iov_base = const_cast<char *>(existing_data.data());
116 iov.iov_len = existing_data.size();
123 void Stream::put_client_to_sleep(Client *client)
125 sleeping_clients.push_back(client);
128 // Return a new set of iovecs that contains only the first <bytes_wanted> bytes of <data>.
129 vector<iovec> collect_iovecs(const vector<iovec> &data, size_t bytes_wanted)
132 for (size_t i = 0; i < data.size() && bytes_wanted > 0; ++i) {
133 if (data[i].iov_len <= bytes_wanted) {
134 // Consume the entire iovec.
135 ret.push_back(data[i]);
136 bytes_wanted -= data[i].iov_len;
138 // Take only parts of this iovec.
140 iov.iov_base = data[i].iov_base;
141 iov.iov_len = bytes_wanted;
149 // Return a new set of iovecs that contains all of <data> except the first <bytes_wanted> bytes.
150 vector<iovec> remove_iovecs(const vector<iovec> &data, size_t bytes_wanted)
154 for (i = 0; i < data.size() && bytes_wanted > 0; ++i) {
155 if (data[i].iov_len <= bytes_wanted) {
156 // Consume the entire iovec.
157 bytes_wanted -= data[i].iov_len;
159 // Take only parts of this iovec.
161 iov.iov_base = reinterpret_cast<char *>(data[i].iov_base) + bytes_wanted;
162 iov.iov_len = data[i].iov_len - bytes_wanted;
168 // Add the rest of the iovecs unchanged.
169 ret.insert(ret.end(), data.begin() + i, data.end());
173 void Stream::add_data_raw(const vector<iovec> &orig_data)
175 vector<iovec> data = orig_data;
176 while (!data.empty()) {
177 size_t pos = bytes_received % backlog_size;
179 // Collect as many iovecs as we can before we hit the point
180 // where the circular buffer wraps around.
181 vector<iovec> to_write = collect_iovecs(data, backlog_size - pos);
184 ret = pwritev(data_fd, to_write.data(), to_write.size(), pos);
185 } while (ret == -1 && errno == EINTR);
188 log_perror("pwritev");
189 // Dazed and confused, but trying to continue...
192 bytes_received += ret;
194 // Remove the data that was actually written from the set of iovecs.
195 data = remove_iovecs(data, ret);
199 void Stream::add_data_deferred(const char *data, size_t bytes)
201 if (encoding == Stream::STREAM_ENCODING_METACUBE) {
202 // Add a Metacube block header before the data.
203 metacube_block_header hdr;
204 memcpy(hdr.sync, METACUBE_SYNC, sizeof(hdr.sync));
205 hdr.size = htonl(bytes);
206 hdr.flags = htonl(0);
209 iov.iov_base = new char[bytes + sizeof(hdr)];
210 iov.iov_len = bytes + sizeof(hdr);
212 memcpy(iov.iov_base, &hdr, sizeof(hdr));
213 memcpy(reinterpret_cast<char *>(iov.iov_base) + sizeof(hdr), data, bytes);
215 queued_data.push_back(iov);
216 } else if (encoding == Stream::STREAM_ENCODING_RAW) {
217 // Just add the data itself.
219 iov.iov_base = new char[bytes];
220 memcpy(iov.iov_base, data, bytes);
223 queued_data.push_back(iov);
229 void Stream::process_queued_data()
231 if (queued_data.empty()) {
235 add_data_raw(queued_data);
236 for (size_t i = 0; i < queued_data.size(); ++i) {
237 char *data = reinterpret_cast<char *>(queued_data[i].iov_base);
242 // We have more data, so wake up all clients.
243 if (to_process.empty()) {
244 swap(sleeping_clients, to_process);
246 to_process.insert(to_process.end(), sleeping_clients.begin(), sleeping_clients.end());
247 sleeping_clients.clear();