4 #include <netinet/in.h>
15 #include "metacube2.h"
16 #include "mutexlock.h"
23 Stream::Stream(const string &url, size_t backlog_size, size_t prebuffering_bytes, Encoding encoding, Encoding src_encoding)
26 src_encoding(src_encoding),
27 data_fd(make_tempfile("")),
28 backlog_size(backlog_size),
29 prebuffering_bytes(prebuffering_bytes)
35 pthread_mutex_init(&queued_data_mutex, nullptr);
45 Stream::Stream(const StreamProto &serialized, int data_fd)
46 : url(serialized.url()),
47 http_header(serialized.http_header()),
48 stream_header(serialized.stream_header()),
49 encoding(Stream::STREAM_ENCODING_RAW), // Will be changed later.
51 backlog_size(serialized.backlog_size()),
52 prebuffering_bytes(serialized.prebuffering_bytes()),
53 bytes_received(serialized.bytes_received())
59 for (ssize_t point : serialized.suitable_starting_point()) {
61 // Can happen when upgrading from before 1.1.3,
62 // where this was an optional field with -1 signifying
66 suitable_starting_points.push_back(point);
69 pthread_mutex_init(&queued_data_mutex, nullptr);
72 StreamProto Stream::serialize()
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_prebuffering_bytes(prebuffering_bytes);
80 serialized.set_bytes_received(bytes_received);
81 for (size_t point : suitable_starting_points) {
82 serialized.add_suitable_starting_point(point);
84 serialized.set_url(url);
89 void Stream::set_backlog_size(size_t new_size)
91 if (backlog_size == new_size) {
96 if (!read_tempfile_and_close(data_fd, &existing_data)) {
100 // Unwrap the data so it's no longer circular.
101 if (bytes_received <= backlog_size) {
102 existing_data.resize(bytes_received);
104 size_t pos = bytes_received % backlog_size;
105 existing_data = existing_data.substr(pos, string::npos) +
106 existing_data.substr(0, pos);
109 // See if we need to discard data.
110 if (new_size < existing_data.size()) {
111 size_t to_discard = existing_data.size() - new_size;
112 existing_data = existing_data.substr(to_discard, string::npos);
115 // Create a new, empty data file.
116 data_fd = make_tempfile("");
120 backlog_size = new_size;
122 // Now cheat a bit by rewinding, and adding all the old data back.
123 bytes_received -= existing_data.size();
124 DataElement data_element;
125 data_element.data.iov_base = const_cast<char *>(existing_data.data());
126 data_element.data.iov_len = existing_data.size();
127 data_element.metacube_flags = 0; // Ignored by add_data_raw().
129 vector<DataElement> data_elements;
130 data_elements.push_back(data_element);
131 add_data_raw(data_elements);
132 remove_obsolete_starting_points();
135 void Stream::put_client_to_sleep(Client *client)
137 sleeping_clients.push_back(client);
140 // Return a new set of iovecs that contains only the first <bytes_wanted> bytes of <data>.
141 vector<iovec> collect_iovecs(const vector<Stream::DataElement> &data, size_t bytes_wanted)
144 size_t max_iovecs = min<size_t>(data.size(), IOV_MAX);
145 for (size_t i = 0; i < max_iovecs && bytes_wanted > 0; ++i) {
146 if (data[i].data.iov_len <= bytes_wanted) {
147 // Consume the entire iovec.
148 ret.push_back(data[i].data);
149 bytes_wanted -= data[i].data.iov_len;
151 // Take only parts of this iovec.
153 iov.iov_base = data[i].data.iov_base;
154 iov.iov_len = bytes_wanted;
162 // Return a new set of iovecs that contains all of <data> except the first <bytes_wanted> bytes.
163 vector<Stream::DataElement> remove_iovecs(const vector<Stream::DataElement> &data, size_t bytes_wanted)
165 vector<Stream::DataElement> ret;
167 for (i = 0; i < data.size() && bytes_wanted > 0; ++i) {
168 if (data[i].data.iov_len <= bytes_wanted) {
169 // Consume the entire iovec.
170 bytes_wanted -= data[i].data.iov_len;
172 // Take only parts of this iovec.
173 Stream::DataElement data_element;
174 data_element.data.iov_base = reinterpret_cast<char *>(data[i].data.iov_base) + bytes_wanted;
175 data_element.data.iov_len = data[i].data.iov_len - bytes_wanted;
176 data_element.metacube_flags = METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START;
177 ret.push_back(data_element);
182 // Add the rest of the iovecs unchanged.
183 ret.insert(ret.end(), data.begin() + i, data.end());
187 void Stream::add_data_raw(const vector<DataElement> &orig_data)
189 vector<DataElement> data = orig_data;
190 while (!data.empty()) {
191 size_t pos = bytes_received % backlog_size;
193 // Collect as many iovecs as we can before we hit the point
194 // where the circular buffer wraps around.
195 vector<iovec> to_write = collect_iovecs(data, backlog_size - pos);
198 ret = pwritev(data_fd, to_write.data(), to_write.size(), pos);
199 } while (ret == -1 && errno == EINTR);
202 log_perror("pwritev");
203 // Dazed and confused, but trying to continue...
206 bytes_received += ret;
208 // Remove the data that was actually written from the set of iovecs.
209 data = remove_iovecs(data, ret);
213 void Stream::remove_obsolete_starting_points()
215 // We could do a binary search here (std::lower_bound), but it seems
216 // overkill for removing what's probably only a few points.
217 while (!suitable_starting_points.empty() &&
218 bytes_received - suitable_starting_points[0] > backlog_size) {
219 suitable_starting_points.pop_front();
223 void Stream::add_data_deferred(const char *data, size_t bytes, uint16_t metacube_flags)
225 // For regular output, we don't want to send the client twice
226 // (it's already sent out together with the HTTP header).
227 // However, for Metacube output, we need to send it so that
228 // the Cubemap instance in the other end has a chance to update it.
229 // It may come twice in its stream, but Cubemap doesn't care.
230 if (encoding == Stream::STREAM_ENCODING_RAW &&
231 (metacube_flags & METACUBE_FLAGS_HEADER) != 0) {
235 MutexLock lock(&queued_data_mutex);
237 DataElement data_element;
238 data_element.metacube_flags = metacube_flags;
240 if (encoding == Stream::STREAM_ENCODING_METACUBE) {
241 // Add a Metacube block header before the data.
242 metacube2_block_header hdr;
243 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
244 hdr.size = htonl(bytes);
245 hdr.flags = htons(metacube_flags);
246 hdr.csum = htons(metacube2_compute_crc(&hdr));
248 data_element.data.iov_base = new char[bytes + sizeof(hdr)];
249 data_element.data.iov_len = bytes + sizeof(hdr);
251 memcpy(data_element.data.iov_base, &hdr, sizeof(hdr));
252 memcpy(reinterpret_cast<char *>(data_element.data.iov_base) + sizeof(hdr), data, bytes);
254 queued_data.push_back(data_element);
255 } else if (encoding == Stream::STREAM_ENCODING_RAW) {
256 // Just add the data itself.
257 data_element.data.iov_base = new char[bytes];
258 memcpy(data_element.data.iov_base, data, bytes);
259 data_element.data.iov_len = bytes;
261 queued_data.push_back(data_element);
267 void Stream::process_queued_data()
269 vector<DataElement> queued_data_copy;
271 // Hold the lock for as short as possible, since add_data_raw() can possibly
272 // write to disk, which might disturb the input thread.
274 MutexLock lock(&queued_data_mutex);
275 if (queued_data.empty()) {
279 swap(queued_data, queued_data_copy);
282 // Add suitable starting points for the stream, if the queued data
283 // contains such starting points. Note that we drop starting points
284 // if they're less than 10 kB apart, so that we don't get a huge
285 // amount of them for e.g. each and every MPEG-TS 188-byte cell.
286 // The 10 kB value is somewhat arbitrary, but at least it should make
287 // the RAM cost of saving the position ~0.1% (or less) of the actual
288 // data, and 10 kB is a very fine granularity in most streams.
289 static const int minimum_start_point_distance = 10240;
290 size_t byte_position = bytes_received;
291 for (const DataElement &elem : queued_data_copy) {
292 if ((elem.metacube_flags & METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START) == 0) {
293 size_t num_points = suitable_starting_points.size();
294 if (num_points >= 2 &&
295 suitable_starting_points[num_points - 1] - suitable_starting_points[num_points - 2] < minimum_start_point_distance) {
296 // p[n-1] - p[n-2] < 10 kB, so drop p[n-1].
297 suitable_starting_points.pop_back();
299 suitable_starting_points.push_back(byte_position);
301 byte_position += elem.data.iov_len;
304 add_data_raw(queued_data_copy);
305 remove_obsolete_starting_points();
306 for (const DataElement &elem : queued_data_copy) {
307 char *data = reinterpret_cast<char *>(elem.data.iov_base);
311 // We have more data, so wake up all clients.
312 if (to_process.empty()) {
313 swap(sleeping_clients, to_process);
315 to_process.insert(to_process.end(), sleeping_clients.begin(), sleeping_clients.end());
316 sleeping_clients.clear();