#include <assert.h>
#include <errno.h>
+#include <limits.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <string.h>
-#include <unistd.h>
+#include <sys/types.h>
#include <string>
#include <vector>
#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);
}
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);
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()
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;
}
// Now cheat a bit by rewinding, and adding all the old data back.
bytes_received -= existing_data.size();
- add_data_raw(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)
sleeping_clients.push_back(client);
}
-void Stream::add_data_raw(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)
{
- 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 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;
}
- pos = 0;
}
+ return ret;
+}
- while (bytes > 0) {
- int ret = pwrite(data_fd, data, bytes, pos);
- if (ret == -1 && errno == EINTR) {
- continue;
+// 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)
+{
+ 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;
}
+ }
+
+ // 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)
+void Stream::add_data_deferred(const char *data, size_t bytes, StreamStartSuitability suitable_for_stream_start)
{
- if (encoding == Stream::STREAM_ENCODING_RAW) {
- queued_data.append(string(data, data + bytes));
- } else if (encoding == STREAM_ENCODING_METACUBE) {
- metacube_block_header hdr;
- memcpy(hdr.sync, METACUBE_SYNC, sizeof(hdr.sync));
+ 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 = htonl(0);
+ 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);
- char *block = new char[bytes + sizeof(hdr)];
- memcpy(block, &hdr, sizeof(hdr));
- memcpy(block + sizeof(hdr), data, bytes);
- queued_data.append(string(block, block + bytes + sizeof(hdr)));
- delete[] block;
+ 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);
}
return;
}
- add_data_raw(queued_data.data(), queued_data.size());
+ // 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()) {
projects / cubemap / blobdiff