// 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;
+ for (size_t i = 0; i < data.size() && 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");
// 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)
{
- if (encoding == Stream::STREAM_ENCODING_RAW) {
- queued_data.append(string(data, data + bytes));
- } else if (encoding == STREAM_ENCODING_METACUBE) {
+ if (encoding == Stream::STREAM_ENCODING_METACUBE) {
+ // Add a Metacube block header before the data.
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);
- queued_data.append(string(block, block + bytes + sizeof(hdr)));
- delete[] block;
+ iovec iov;
+ iov.iov_base = new char[sizeof(hdr)];
+ memcpy(iov.iov_base, &hdr, sizeof(hdr));
+ iov.iov_len = sizeof(hdr);
+ queued_data.push_back(iov);
} else {
- assert(false);
+ assert(encoding == Stream::STREAM_ENCODING_RAW);
}
+
+ // 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);
}
void Stream::process_queued_data()
return;
}
- add_data_raw(queued_data.data(), queued_data.size());
+ 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();
// We have more data, so wake up all clients.
projects / cubemap / blobdiff