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),
29 queued_data_last_starting_point(-1)
35 pthread_mutex_init(&queued_data_mutex, NULL);
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 bytes_received(serialized.bytes_received()),
54 queued_data_last_starting_point(-1)
60 // Split old-style headers into HTTP and video headers.
61 if (!serialized.header().empty()) {
62 string header = serialized.header();
63 size_t split = header.find("\r\n\r\n");
64 if (split == string::npos) {
68 http_header = header.substr(0, split + 2); // Split off the second \r\n.
69 stream_header = header.substr(split, string::npos);
73 // Older versions did not set last_suitable_starting_point.
74 if (serialized.has_last_suitable_starting_point()) {
75 last_suitable_starting_point = serialized.last_suitable_starting_point();
77 last_suitable_starting_point = bytes_received;
80 pthread_mutex_init(&queued_data_mutex, NULL);
83 StreamProto Stream::serialize()
85 StreamProto serialized;
86 serialized.set_http_header(http_header);
87 serialized.set_stream_header(stream_header);
88 serialized.add_data_fds(data_fd);
89 serialized.set_backlog_size(backlog_size);
90 serialized.set_bytes_received(bytes_received);
91 serialized.set_last_suitable_starting_point(last_suitable_starting_point);
92 serialized.set_url(url);
97 void Stream::set_backlog_size(size_t new_size)
99 if (backlog_size == new_size) {
103 string existing_data;
104 if (!read_tempfile_and_close(data_fd, &existing_data)) {
108 // Unwrap the data so it's no longer circular.
109 if (bytes_received <= backlog_size) {
110 existing_data.resize(bytes_received);
112 size_t pos = bytes_received % backlog_size;
113 existing_data = existing_data.substr(pos, string::npos) +
114 existing_data.substr(0, pos);
117 // See if we need to discard data.
118 if (new_size < existing_data.size()) {
119 size_t to_discard = existing_data.size() - new_size;
120 existing_data = existing_data.substr(to_discard, string::npos);
123 // Create a new, empty data file.
124 data_fd = make_tempfile("");
128 backlog_size = new_size;
130 // Now cheat a bit by rewinding, and adding all the old data back.
131 bytes_received -= existing_data.size();
133 iov.iov_base = const_cast<char *>(existing_data.data());
134 iov.iov_len = existing_data.size();
141 void Stream::put_client_to_sleep(Client *client)
143 sleeping_clients.push_back(client);
146 // Return a new set of iovecs that contains only the first <bytes_wanted> bytes of <data>.
147 vector<iovec> collect_iovecs(const vector<iovec> &data, size_t bytes_wanted)
150 size_t max_iovecs = std::min<size_t>(data.size(), IOV_MAX);
151 for (size_t i = 0; i < max_iovecs && bytes_wanted > 0; ++i) {
152 if (data[i].iov_len <= bytes_wanted) {
153 // Consume the entire iovec.
154 ret.push_back(data[i]);
155 bytes_wanted -= data[i].iov_len;
157 // Take only parts of this iovec.
159 iov.iov_base = data[i].iov_base;
160 iov.iov_len = bytes_wanted;
168 // Return a new set of iovecs that contains all of <data> except the first <bytes_wanted> bytes.
169 vector<iovec> remove_iovecs(const vector<iovec> &data, size_t bytes_wanted)
173 for (i = 0; i < data.size() && bytes_wanted > 0; ++i) {
174 if (data[i].iov_len <= bytes_wanted) {
175 // Consume the entire iovec.
176 bytes_wanted -= data[i].iov_len;
178 // Take only parts of this iovec.
180 iov.iov_base = reinterpret_cast<char *>(data[i].iov_base) + bytes_wanted;
181 iov.iov_len = data[i].iov_len - bytes_wanted;
187 // Add the rest of the iovecs unchanged.
188 ret.insert(ret.end(), data.begin() + i, data.end());
192 void Stream::add_data_raw(const vector<iovec> &orig_data)
194 vector<iovec> data = orig_data;
195 while (!data.empty()) {
196 size_t pos = bytes_received % backlog_size;
198 // Collect as many iovecs as we can before we hit the point
199 // where the circular buffer wraps around.
200 vector<iovec> to_write = collect_iovecs(data, backlog_size - pos);
203 ret = pwritev(data_fd, to_write.data(), to_write.size(), pos);
204 } while (ret == -1 && errno == EINTR);
207 log_perror("pwritev");
208 // Dazed and confused, but trying to continue...
211 bytes_received += ret;
213 // Remove the data that was actually written from the set of iovecs.
214 data = remove_iovecs(data, ret);
218 void Stream::add_data_deferred(const char *data, size_t bytes, StreamStartSuitability suitable_for_stream_start)
220 MutexLock lock(&queued_data_mutex);
221 assert(suitable_for_stream_start == SUITABLE_FOR_STREAM_START ||
222 suitable_for_stream_start == NOT_SUITABLE_FOR_STREAM_START);
223 if (suitable_for_stream_start == SUITABLE_FOR_STREAM_START) {
224 queued_data_last_starting_point = queued_data.size();
227 if (encoding == Stream::STREAM_ENCODING_METACUBE) {
228 // Add a Metacube block header before the data.
229 metacube2_block_header hdr;
230 memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
231 hdr.size = htonl(bytes);
232 hdr.flags = htons(0);
233 if (suitable_for_stream_start == NOT_SUITABLE_FOR_STREAM_START) {
234 hdr.flags |= htons(METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START);
236 hdr.csum = htons(metacube2_compute_crc(&hdr));
239 iov.iov_base = new char[bytes + sizeof(hdr)];
240 iov.iov_len = bytes + sizeof(hdr);
242 memcpy(iov.iov_base, &hdr, sizeof(hdr));
243 memcpy(reinterpret_cast<char *>(iov.iov_base) + sizeof(hdr), data, bytes);
245 queued_data.push_back(iov);
246 } else if (encoding == Stream::STREAM_ENCODING_RAW) {
247 // Just add the data itself.
249 iov.iov_base = new char[bytes];
250 memcpy(iov.iov_base, data, bytes);
253 queued_data.push_back(iov);
259 void Stream::process_queued_data()
261 std::vector<iovec> queued_data_copy;
262 int queued_data_last_starting_point_copy = -1;
264 // Hold the lock for as short as possible, since add_data_raw() can possibly
265 // write to disk, which might disturb the input thread.
267 MutexLock lock(&queued_data_mutex);
268 if (queued_data.empty()) {
272 swap(queued_data, queued_data_copy);
273 swap(queued_data_last_starting_point, queued_data_last_starting_point_copy);
276 // Update the last suitable starting point for the stream,
277 // if the queued data contains such a starting point.
278 assert(queued_data_last_starting_point_copy < ssize_t(queued_data_copy.size()));
279 if (queued_data_last_starting_point_copy >= 0) {
280 last_suitable_starting_point = bytes_received;
281 for (int i = 0; i < queued_data_last_starting_point_copy; ++i) {
282 last_suitable_starting_point += queued_data_copy[i].iov_len;
286 add_data_raw(queued_data_copy);
287 for (size_t i = 0; i < queued_data_copy.size(); ++i) {
288 char *data = reinterpret_cast<char *>(queued_data_copy[i].iov_base);
292 // We have more data, so wake up all clients.
293 if (to_process.empty()) {
294 swap(sleeping_clients, to_process);
296 to_process.insert(to_process.end(), sleeping_clients.begin(), sleeping_clients.end());
297 sleeping_clients.clear();