X-Git-Url: https://git.sesse.net/?p=cubemap;a=blobdiff_plain;f=server.cpp;h=3107ead689e0e35b287cf9a0a9a6e65772846e01;hp=1deb087b056dc2ff1bf3cf426d71fff8c090d29b;hb=c039416ed5102c0c37298334bc009dc891038db9;hpb=1135808bf9df44b879994e6dac07a31eb78c2fdb

diff --git a/server.cpp b/server.cpp
index 1deb087..3107ead 100644
--- a/server.cpp
+++ b/server.cpp
@@ -538,19 +538,27 @@ sending_header_or_short_response_again:
 		}
 
 		Stream *stream = client->stream;
-		if (client->stream_pos == size_t(-2)) {
+		if (client->stream_pos == Client::STREAM_POS_AT_START) {
 			// Start sending from the beginning of the backlog.
 			client->stream_pos = min<size_t>(
 			    stream->bytes_received - stream->backlog_size,
 			    0);
 			client->state = Client::SENDING_DATA;
 			goto sending_data;
+		} else if (client->stream_pos_end != Client::STREAM_POS_NO_END) {
+			// We're sending a fragment, and should have all of it,
+			// so start sending right away.
+			assert(client->stream_pos >= 0);
+			client->state = Client::SENDING_DATA;
+			goto sending_data;
 		} else if (stream->prebuffering_bytes == 0) {
 			// Start sending from the first keyframe we get. In other
 			// words, we won't send any of the backlog, but we'll start
 			// sending immediately as we get the next keyframe block.
 			// Note that this is functionally identical to the next if branch,
 			// except that we save a binary search.
+			assert(client->stream_pos == Client::STREAM_POS_AT_END);
+			assert(client->stream_pos_end == Client::STREAM_POS_NO_END);
 			client->stream_pos = stream->bytes_received;
 			client->state = Client::WAITING_FOR_KEYFRAME;
 		} else {
@@ -560,6 +568,8 @@ sending_header_or_short_response_again:
 			// so that we are conservative and never add extra latency over just
 			// waiting (assuming CBR or nearly so); otherwise, we could want e.g.
 			// 100 kB prebuffer but end up sending a 10 MB GOP.
+			assert(client->stream_pos == Client::STREAM_POS_AT_END);
+			assert(client->stream_pos_end == Client::STREAM_POS_NO_END);
 			deque<size_t>::const_iterator starting_point_it =
 				lower_bound(stream->suitable_starting_points.begin(),
 					    stream->suitable_starting_points.end(),
@@ -611,9 +621,24 @@ sending_data:
 		Stream *stream = client->stream;
 
 sending_data_again:
-		size_t bytes_to_send = stream->bytes_received - client->stream_pos;
+		size_t bytes_to_send;
+		if (client->stream_pos_end == Client::STREAM_POS_NO_END) {
+			 bytes_to_send = stream->bytes_received - client->stream_pos;
+		} else {
+			 bytes_to_send = client->stream_pos_end - client->stream_pos;
+		}
 		assert(bytes_to_send <= stream->backlog_size);
 		if (bytes_to_send == 0) {
+			if (client->stream_pos == client->stream_pos_end) {  // We have a definite end, and we're at it.
+				if (more_requests(client)) {
+					// We're done sending the fragment, but should keep on reading new requests.
+					goto read_request_again;
+				} else {
+					// We're done sending the fragment, so now close.
+					// This is postcondition #1.
+					close_client(client);
+				}
+			}
 			return;
 		}
 
@@ -645,13 +670,17 @@ sending_data_again:
 		client->stream_pos += ret;
 		client->bytes_sent += ret;
 
-		if (client->stream_pos == stream->bytes_received) {
+		assert(client->stream_pos_end == Client::STREAM_POS_NO_END || client->stream_pos <= client->stream_pos_end);
+		if (client->stream_pos == client->stream_pos_end) {
+			goto sending_data_again;  // Will see that bytes_to_send == 0 and end.
+		} else if (client->stream_pos == stream->bytes_received) {
 			// We don't have any more data for this client, so put it to sleep.
 			// This is postcondition #3.
 			stream->put_client_to_sleep(client);
 		} else if (more_data && size_t(ret) == bytes_to_send) {
 			goto sending_data_again;
 		}
+		// We'll also get here for postcondition #4 (similar to the EAGAIN path above).
 		break;
 	}
 	default:
@@ -797,9 +826,19 @@ void Server::skip_lost_data(Client *client)
 	size_t bytes_to_send = stream->bytes_received - client->stream_pos;
 	if (bytes_to_send > stream->backlog_size) {
 		size_t bytes_lost = bytes_to_send - stream->backlog_size;
-		client->stream_pos = stream->bytes_received - stream->backlog_size;
 		client->bytes_lost += bytes_lost;
 		++client->num_loss_events;
+		if (!client->close_after_response) {
+			assert(client->stream_pos_end != Client::STREAM_POS_NO_END);
+
+			// We've already sent a Content-length, so we can't just skip data.
+			// Close the connection immediately and hope the other side
+			// is able to figure out that there was an error and it needs to skip.
+			client->close_after_response = true;
+			client->stream_pos = client->stream_pos_end;
+		} else {
+			client->stream_pos = stream->bytes_received - stream->backlog_size;
+		}
 	}
 }
 
@@ -834,10 +873,46 @@ int Server::parse_request(Client *client)
 	string url = request_tokens[1];
 	client->url = url;
 	if (url.size() > 8 && url.find("?backlog") == url.size() - 8) {
-		client->stream_pos = -2;
+		client->stream_pos = Client::STREAM_POS_AT_START;
 		url = url.substr(0, url.size() - 8);
 	} else {
-		client->stream_pos = -1;
+		size_t pos = url.find("?frag=");
+		if (pos != string::npos) {
+			// Parse an endpoint of the type /stream.mp4?frag=1234-5678.
+			const char *ptr = url.c_str() + pos + 6;
+
+			// "?frag=header" is special.
+			if (strcmp(ptr, "header") == 0) {
+				client->stream_pos = Client::STREAM_POS_HEADER_ONLY;
+				client->stream_pos_end = -1;
+			} else {
+				char *endptr;
+				long long frag_start = strtol(ptr, &endptr, 10);
+				if (ptr == endptr || frag_start < 0 || frag_start == LLONG_MAX) {
+					return 400;  // Bad request.
+				}
+				if (*endptr != '-') {
+					return 400;  // Bad request.
+				}
+				ptr = endptr + 1;
+
+				long long frag_end = strtol(ptr, &endptr, 10);
+				if (ptr == endptr || frag_end < frag_start || frag_end == LLONG_MAX) {
+					return 400;  // Bad request.
+				}
+
+				if (*endptr != '\0') {
+					return 400;  // Bad request.
+				}
+
+				client->stream_pos = frag_start;
+				client->stream_pos_end = frag_end;
+			}
+			url = url.substr(0, pos);
+		} else {
+			client->stream_pos = -1;
+			client->stream_pos_end = -1;
+		}
 	}
 
 	// Figure out if we're supposed to close the socket after we've delivered the response.
@@ -873,11 +948,26 @@ int Server::parse_request(Client *client)
 		return 503;  // Service unavailable.
 	}
 
-	// Streams currently never end, so we don't have a content-length,
-	// and can just as well tell the client it's Connection: close
-	// (otherwise, we'd have to implement chunking TE for no good reason).
-	// When we start to support fragments, this will change.
-	client->close_after_response = true;
+	if (client->stream_pos_end == Client::STREAM_POS_NO_END) {
+		// This stream won't end, so we don't have a content-length,
+		// and can just as well tell the client it's Connection: close
+		// (otherwise, we'd have to implement chunking TE for no good reason).
+		client->close_after_response = true;
+	} else {
+		if (stream->encoding == Stream::STREAM_ENCODING_METACUBE) {
+			// This doesn't make any sense, and is hard to implement, too.
+			return 416;  // Range not satisfiable.
+		}
+
+		// Check that we have the requested fragment in our backlog.
+		size_t buffer_end = stream->bytes_received;
+		size_t buffer_start = (buffer_end <= stream->backlog_size) ? 0 : buffer_end - stream->backlog_size;
+
+		if (client->stream_pos_end > buffer_end ||
+		    client->stream_pos < buffer_start) {
+			return 416;  // Range not satisfiable.
+		}
+	}
 
 	client->stream = stream;
 	if (setsockopt(client->sock, SOL_SOCKET, SO_MAX_PACING_RATE, &client->stream->pacing_rate, sizeof(client->stream->pacing_rate)) == -1) {
@@ -894,6 +984,15 @@ void Server::construct_header(Client *client)
 {
 	Stream *stream = client->stream;
 	client->header_or_short_response = stream->http_header;
+	if (client->stream_pos == Client::STREAM_POS_HEADER_ONLY) {
+		char buf[64];
+		snprintf(buf, sizeof(buf), "Content-length: %zu\r\n", stream->stream_header.size());
+		client->header_or_short_response.append(buf);
+	} else if (client->stream_pos_end != Client::STREAM_POS_NO_END) {
+		char buf[64];
+		snprintf(buf, sizeof(buf), "Content-length: %zu\r\n", client->stream_pos_end - client->stream_pos);
+		client->header_or_short_response.append(buf);
+	}
 	if (client->http_11) {
 		assert(client->header_or_short_response.find("HTTP/1.0") == 0);
 		client->header_or_short_response[7] = '1';  // Change to HTTP/1.1.
@@ -921,10 +1020,17 @@ void Server::construct_header(Client *client)
 	} else {
 		assert(false);
 	}
-	client->header_or_short_response.append(stream->stream_header);
+	if (client->stream_pos == Client::STREAM_POS_HEADER_ONLY) {
+		client->state = Client::SENDING_SHORT_RESPONSE;
+		client->header_or_short_response.append(stream->stream_header);
+	} else {
+		client->state = Client::SENDING_HEADER;
+		if (client->stream_pos_end == Client::STREAM_POS_NO_END) {  // Fragments don't contain stream headers.
+			client->header_or_short_response.append(stream->stream_header);
+		}
+	}
 
 	// Switch states.
-	client->state = Client::SENDING_HEADER;
 	change_epoll_events(client, EPOLLOUT | EPOLLET | EPOLLRDHUP);
 }