X-Git-Url: https://git.sesse.net/?p=cubemap;a=blobdiff_plain;f=stream.cpp;h=42edee95aae01176e94c3a63ab47704a95b19a36;hp=109d2fd4a90116398e8b638816872cabf06b22ce;hb=74cd48ffef90d7d0752e37a4515e4ecfb68f7c9d;hpb=534764f026b82b144e974882c8e53c4cd8d21b68

diff --git a/stream.cpp b/stream.cpp
index 109d2fd..42edee9 100644
--- a/stream.cpp
+++ b/stream.cpp
@@ -1,26 +1,30 @@
-#include <arpa/inet.h>
+#include <assert.h>
 #include <errno.h>
-#include <stdio.h>
+#include <limits.h>
+#include <netinet/in.h>
 #include <stdlib.h>
-#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
 #include <string>
 #include <vector>
 
-#include "state.pb.h"
 #include "log.h"
-#include "metacube.h"
+#include "metacube2.h"
+#include "state.pb.h"
 #include "stream.h"
 #include "util.h"
 
 using namespace std;
 
-Stream::Stream(const string &stream_id, size_t backlog_size, Encoding encoding)
-	: stream_id(stream_id),
+Stream::Stream(const string &url, size_t backlog_size, Encoding encoding)
+	: url(url),
 	  encoding(encoding),
 	  data_fd(make_tempfile("")),
           backlog_size(backlog_size),
 	  bytes_received(0),
-	  mark_pool(NULL)
+	  last_suitable_starting_point(-1),
+	  mark_pool(NULL),
+	  queued_data_last_starting_point(-1)
 {
 	if (data_fd == -1) {
 		exit(1);
@@ -30,25 +34,20 @@ Stream::Stream(const string &stream_id, size_t backlog_size, Encoding encoding)
 Stream::~Stream()
 {
 	if (data_fd != -1) {
-		int ret;
-		do {
-			ret = close(data_fd);
-		} while (ret == -1 && errno == EINTR);
-		if (ret == -1) {
-			log_perror("close");
-		}
+		safe_close(data_fd);
 	}
 }
 
 Stream::Stream(const StreamProto &serialized, int data_fd)
-	: stream_id(serialized.stream_id()),
+	: url(serialized.url()),
 	  http_header(serialized.http_header()),
 	  stream_header(serialized.stream_header()),
 	  encoding(Stream::STREAM_ENCODING_RAW),  // Will be changed later.
 	  data_fd(data_fd),
 	  backlog_size(serialized.backlog_size()),
 	  bytes_received(serialized.bytes_received()),
-	  mark_pool(NULL)
+	  mark_pool(NULL),
+	  queued_data_last_starting_point(-1)
 {
 	if (data_fd == -1) {
 		exit(1);
@@ -66,6 +65,13 @@ Stream::Stream(const StreamProto &serialized, int data_fd)
 			stream_header = header.substr(split, string::npos);
 		}
 	}
+
+	// Older versions did not set last_suitable_starting_point.
+	if (serialized.has_last_suitable_starting_point()) {
+		last_suitable_starting_point = serialized.last_suitable_starting_point();
+	} else {
+		last_suitable_starting_point = bytes_received;
+	}
 }
 
 StreamProto Stream::serialize()
@@ -76,7 +82,8 @@ StreamProto Stream::serialize()
 	serialized.add_data_fds(data_fd);
 	serialized.set_backlog_size(backlog_size);
 	serialized.set_bytes_received(bytes_received);
-	serialized.set_stream_id(stream_id);
+	serialized.set_last_suitable_starting_point(last_suitable_starting_point);
+	serialized.set_url(url);
 	data_fd = -1;
 	return serialized;
 }
@@ -109,11 +116,20 @@ void Stream::set_backlog_size(size_t new_size)
 
 	// Create a new, empty data file.
 	data_fd = make_tempfile("");
+	if (data_fd == -1) {
+		exit(1);
+	}
 	backlog_size = new_size;
 
 	// Now cheat a bit by rewinding, and adding all the old data back.
 	bytes_received -= existing_data.size();
-	add_data(existing_data.data(), existing_data.size());
+	iovec iov;
+	iov.iov_base = const_cast<char *>(existing_data.data());
+	iov.iov_len = existing_data.size();
+
+	vector<iovec> iovs;
+	iovs.push_back(iov);
+	add_data_raw(iovs);
 }
 
 void Stream::put_client_to_sleep(Client *client)
@@ -121,69 +137,143 @@ void Stream::put_client_to_sleep(Client *client)
 	sleeping_clients.push_back(client);
 }
 
-void Stream::add_data(const char *data, ssize_t bytes)
+// Return a new set of iovecs that contains only the first <bytes_wanted> bytes of <data>.
+vector<iovec> collect_iovecs(const vector<iovec> &data, size_t bytes_wanted)
 {
-	if (encoding == Stream::STREAM_ENCODING_RAW) {
-		add_data_raw(data, bytes);
-	} else if (encoding == STREAM_ENCODING_METACUBE) {
-		metacube_block_header hdr;
-		memcpy(hdr.sync, METACUBE_SYNC, sizeof(hdr.sync));
-		hdr.size = htonl(bytes);
-		hdr.flags = htonl(0);
-
-		char *block = new char[bytes + sizeof(hdr)];
-		memcpy(block, &hdr, sizeof(hdr));
-		memcpy(block + sizeof(hdr), data, bytes);
-		add_data_raw(block, bytes + sizeof(hdr));
-		delete[] block;
-	} else {
-		assert(false);
+	vector<iovec> ret;
+	size_t max_iovecs = std::min<size_t>(data.size(), IOV_MAX);
+	for (size_t i = 0; i < max_iovecs && bytes_wanted > 0; ++i) {
+		if (data[i].iov_len <= bytes_wanted) {
+			// Consume the entire iovec.
+			ret.push_back(data[i]);
+			bytes_wanted -= data[i].iov_len;
+		} else {
+			// Take only parts of this iovec.
+			iovec iov;
+			iov.iov_base = data[i].iov_base;
+			iov.iov_len = bytes_wanted;	
+			ret.push_back(iov);
+			bytes_wanted = 0;
+		}
 	}
+	return ret;
 }
 
-void Stream::add_data_raw(const char *data, ssize_t bytes)
+// Return a new set of iovecs that contains all of <data> except the first <bytes_wanted> bytes.
+vector<iovec> remove_iovecs(const vector<iovec> &data, size_t bytes_wanted)
 {
-	size_t pos = bytes_received % backlog_size;
-	bytes_received += bytes;
-
-	if (pos + bytes > backlog_size) {
-		ssize_t to_copy = backlog_size - pos;
-		while (to_copy > 0) {
-			int ret = pwrite(data_fd, data, to_copy, pos);
-			if (ret == -1 && errno == EINTR) {
-				continue;
-			}
-			if (ret == -1) {
-				log_perror("pwrite");
-				// Dazed and confused, but trying to continue...
-				break;
-			}
-			pos += ret;
-			data += ret;
-			to_copy -= ret;
-			bytes -= ret;
+	vector<iovec> ret;
+	size_t i;
+	for (i = 0; i < data.size() && bytes_wanted > 0; ++i) {
+		if (data[i].iov_len <= bytes_wanted) {
+			// Consume the entire iovec.
+			bytes_wanted -= data[i].iov_len;
+		} else {
+			// Take only parts of this iovec.
+			iovec iov;
+			iov.iov_base = reinterpret_cast<char *>(data[i].iov_base) + bytes_wanted;
+			iov.iov_len = data[i].iov_len - bytes_wanted;
+			ret.push_back(iov);
+			bytes_wanted = 0;
 		}
-		pos = 0;
 	}
 
-	while (bytes > 0) {
-		int ret = pwrite(data_fd, data, bytes, pos);
-		if (ret == -1 && errno == EINTR) {
-			continue;
-		}
+	// Add the rest of the iovecs unchanged.
+	ret.insert(ret.end(), data.begin() + i, data.end());
+	return ret;
+}
+
+void Stream::add_data_raw(const vector<iovec> &orig_data)
+{
+	vector<iovec> data = orig_data;
+	while (!data.empty()) {
+		size_t pos = bytes_received % backlog_size;
+
+		// Collect as many iovecs as we can before we hit the point
+		// where the circular buffer wraps around.
+		vector<iovec> to_write = collect_iovecs(data, backlog_size - pos);
+		ssize_t ret;
+		do {
+			ret = pwritev(data_fd, to_write.data(), to_write.size(), pos);
+		} while (ret == -1 && errno == EINTR);
+
 		if (ret == -1) {
-			log_perror("pwrite");
+			log_perror("pwritev");
 			// Dazed and confused, but trying to continue...
-			break;
+			return;
 		}
-		pos += ret;
-		data += ret;
-		bytes -= ret;
+		bytes_received += ret;
+
+		// Remove the data that was actually written from the set of iovecs.
+		data = remove_iovecs(data, ret);
+	}
+}
+
+void Stream::add_data_deferred(const char *data, size_t bytes, StreamStartSuitability suitable_for_stream_start)
+{
+	assert(suitable_for_stream_start == SUITABLE_FOR_STREAM_START ||
+	       suitable_for_stream_start == NOT_SUITABLE_FOR_STREAM_START);
+	if (suitable_for_stream_start == SUITABLE_FOR_STREAM_START) {
+		queued_data_last_starting_point = queued_data.size();
+	}
+
+	if (encoding == Stream::STREAM_ENCODING_METACUBE) {
+		// Add a Metacube block header before the data.
+		metacube2_block_header hdr;
+		memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
+		hdr.size = htonl(bytes);
+		hdr.flags = htons(0);
+		if (suitable_for_stream_start == NOT_SUITABLE_FOR_STREAM_START) {
+			hdr.flags |= htons(METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START);
+		}
+		hdr.csum = htons(metacube2_compute_crc(&hdr));
+
+		iovec iov;
+		iov.iov_base = new char[bytes + sizeof(hdr)];
+		iov.iov_len = bytes + sizeof(hdr);
+
+		memcpy(iov.iov_base, &hdr, sizeof(hdr));
+		memcpy(reinterpret_cast<char *>(iov.iov_base) + sizeof(hdr), data, bytes);
+
+		queued_data.push_back(iov);
+	} else if (encoding == Stream::STREAM_ENCODING_RAW) {
+		// Just add the data itself.
+		iovec iov;
+		iov.iov_base = new char[bytes];
+		memcpy(iov.iov_base, data, bytes);
+		iov.iov_len = bytes;
+
+		queued_data.push_back(iov);
+	} else {
+		assert(false);
 	}
 }
 
-void Stream::wake_up_all_clients()
+void Stream::process_queued_data()
 {
+	if (queued_data.empty()) {
+		return;
+	}
+
+	// Update the last suitable starting point for the stream,
+	// if the queued data contains such a starting point.
+	assert(queued_data_last_starting_point < ssize_t(queued_data.size()));
+	if (queued_data_last_starting_point >= 0) {
+		last_suitable_starting_point = bytes_received;
+		for (int i = 0; i < queued_data_last_starting_point; ++i) {
+			last_suitable_starting_point += queued_data[i].iov_len;
+		}
+	}
+
+	add_data_raw(queued_data);
+	for (size_t i = 0; i < queued_data.size(); ++i) {
+		char *data = reinterpret_cast<char *>(queued_data[i].iov_base);
+		delete[] data;
+	}
+	queued_data.clear();
+	queued_data_last_starting_point = -1;
+
+	// We have more data, so wake up all clients.
 	if (to_process.empty()) {
 		swap(sleeping_clients, to_process);
 	} else {