3 #include <netinet/in.h>
13 #include "metacube2.h"
14 #include "mutexlock.h"
21 Stream::Stream(const string &url, size_t backlog_size, Encoding encoding)
24 data_fd(make_tempfile("")),
25 backlog_size(backlog_size),
27 last_suitable_starting_point(-1),
30 queued_data_last_starting_point(-1)
36 pthread_mutex_init(&queued_data_mutex, NULL);
46 Stream::Stream(const StreamProto &serialized, int data_fd)
47 : url(serialized.url()),
48 http_header(serialized.http_header()),
49 stream_header(serialized.stream_header()),
50 encoding(Stream::STREAM_ENCODING_RAW), // Will be changed later.
52 backlog_size(serialized.backlog_size()),
53 bytes_received(serialized.bytes_received()),
56 queued_data_last_starting_point(-1)
62 // Split old-style headers into HTTP and video headers.
63 if (!serialized.header().empty()) {
64 string header = serialized.header();
65 size_t split = header.find("\r\n\r\n");
66 if (split == string::npos) {
70 http_header = header.substr(0, split + 2); // Split off the second \r\n.
71 stream_header = header.substr(split, string::npos);
75 // Older versions did not set last_suitable_starting_point.
76 if (serialized.has_last_suitable_starting_point()) {
77 last_suitable_starting_point = serialized.last_suitable_starting_point();
79 last_suitable_starting_point = bytes_received;
82 pthread_mutex_init(&queued_data_mutex, NULL);
85 StreamProto Stream::serialize()
87 StreamProto serialized;
88 serialized.set_http_header(http_header);
89 serialized.set_stream_header(stream_header);
90 serialized.add_data_fds(data_fd);
91 serialized.set_backlog_size(backlog_size);
92 serialized.set_bytes_received(bytes_received);
93 serialized.set_last_suitable_starting_point(last_suitable_starting_point);
94 serialized.set_url(url);
99 void Stream::set_backlog_size(size_t new_size)
101 if (backlog_size == new_size) {
105 string existing_data;
106 if (!read_tempfile_and_close(data_fd, &existing_data)) {
110 // Unwrap the data so it's no longer circular.
111 if (bytes_received <= backlog_size) {
112 existing_data.resize(bytes_received);
114 size_t pos = bytes_received % backlog_size;
115 existing_data = existing_data.substr(pos, string::npos) +
116 existing_data.substr(0, pos);
119 // See if we need to discard data.
120 if (new_size < existing_data.size()) {
121 size_t to_discard = existing_data.size() - new_size;
122 existing_data = existing_data.substr(to_discard, string::npos);
125 // Create a new, empty data file.
126 data_fd = make_tempfile("");
130 backlog_size = new_size;
132 // Now cheat a bit by rewinding, and adding all the old data back.
133 bytes_received -= existing_data.size();
135 iov.iov_base = const_cast<char *>(existing_data.data());
136 iov.iov_len = existing_data.size();
143 void Stream::put_client_to_sleep(Client *client)
145 sleeping_clients.push_back(client);
148 // Return a new set of iovecs that contains only the first <bytes_wanted> bytes of <data>.
149 vector<iovec> collect_iovecs(const vector<iovec> &data, size_t bytes_wanted)
152 size_t max_iovecs = std::min<size_t>(data.size(), IOV_MAX);
153 for (size_t i = 0; i < max_iovecs && bytes_wanted > 0; ++i) {
154 if (data[i].iov_len <= bytes_wanted) {
155 // Consume the entire iovec.
156 ret.push_back(data[i]);
157 bytes_wanted -= data[i].iov_len;
159 // Take only parts of this iovec.
161 iov.iov_base = data[i].iov_base;
162 iov.iov_len = bytes_wanted;
170 // Return a new set of iovecs that contains all of <data> except the first <bytes_wanted> bytes.
171 vector<iovec> remove_iovecs(const vector<iovec> &data, size_t bytes_wanted)
175 for (i = 0; i < data.size() && bytes_wanted > 0; ++i) {
176 if (data[i].iov_len <= bytes_wanted) {
177 // Consume the entire iovec.
178 bytes_wanted -= data[i].iov_len;
180 // Take only parts of this iovec.
182 iov.iov_base = reinterpret_cast<char *>(data[i].iov_base) + bytes_wanted;
183 iov.iov_len = data[i].iov_len - bytes_wanted;
189 // Add the rest of the iovecs unchanged.
190 ret.insert(ret.end(), data.begin() + i, data.end());
194 void Stream::add_data_raw(const vector<iovec> &orig_data)
196 vector<iovec> data = orig_data;
197 while (!data.empty()) {
198 size_t pos = bytes_received % backlog_size;
200 // Collect as many iovecs as we can before we hit the point
201 // where the circular buffer wraps around.
202 vector<iovec> to_write = collect_iovecs(data, backlog_size - pos);
205 ret = pwritev(data_fd, to_write.data(), to_write.size(), pos);
206 } while (ret == -1 && errno == EINTR);
209 log_perror("pwritev");
210 // Dazed and confused, but trying to continue...
213 bytes_received += ret;
215 // Remove the data that was actually written from the set of iovecs.
216 data = remove_iovecs(data, ret);
220 void Stream::add_data_deferred(const char *data, size_t bytes, StreamStartSuitability suitable_for_stream_start)
222 MutexLock lock(&queued_data_mutex);
223 assert(suitable_for_stream_start == SUITABLE_FOR_STREAM_START ||
224 suitable_for_stream_start == NOT_SUITABLE_FOR_STREAM_START);
225 if (suitable_for_stream_start == SUITABLE_FOR_STREAM_START) {
226 queued_data_last_starting_point = queued_data.size();
229 if (encoding == Stream::STREAM_ENCODING_METACUBE) {
230 // Add a Metacube block header before the data.
231 metacube2_block_header hdr;
232 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
233 hdr.size = htonl(bytes);
234 hdr.flags = htons(0);
235 if (suitable_for_stream_start == NOT_SUITABLE_FOR_STREAM_START) {
236 hdr.flags |= htons(METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START);
238 hdr.csum = htons(metacube2_compute_crc(&hdr));
241 iov.iov_base = new char[bytes + sizeof(hdr)];
242 iov.iov_len = bytes + sizeof(hdr);
244 memcpy(iov.iov_base, &hdr, sizeof(hdr));
245 memcpy(reinterpret_cast<char *>(iov.iov_base) + sizeof(hdr), data, bytes);
247 queued_data.push_back(iov);
248 } else if (encoding == Stream::STREAM_ENCODING_RAW) {
249 // Just add the data itself.
251 iov.iov_base = new char[bytes];
252 memcpy(iov.iov_base, data, bytes);
255 queued_data.push_back(iov);
261 void Stream::process_queued_data()
263 std::vector<iovec> queued_data_copy;
264 int queued_data_last_starting_point_copy = -1;
266 // Hold the lock for as short as possible, since add_data_raw() can possibly
267 // write to disk, which might disturb the input thread.
269 MutexLock lock(&queued_data_mutex);
270 if (queued_data.empty()) {
274 swap(queued_data, queued_data_copy);
275 swap(queued_data_last_starting_point, queued_data_last_starting_point_copy);
278 // Update the last suitable starting point for the stream,
279 // if the queued data contains such a starting point.
280 assert(queued_data_last_starting_point_copy < ssize_t(queued_data_copy.size()));
281 if (queued_data_last_starting_point_copy >= 0) {
282 last_suitable_starting_point = bytes_received;
283 for (int i = 0; i < queued_data_last_starting_point_copy; ++i) {
284 last_suitable_starting_point += queued_data_copy[i].iov_len;
288 add_data_raw(queued_data_copy);
289 for (size_t i = 0; i < queued_data_copy.size(); ++i) {
290 char *data = reinterpret_cast<char *>(queued_data_copy[i].iov_base);
294 // We have more data, so wake up all clients.
295 if (to_process.empty()) {
296 swap(sleeping_clients, to_process);
298 to_process.insert(to_process.end(), sleeping_clients.begin(), sleeping_clients.end());
299 sleeping_clients.clear();