#include <assert.h>
#include <errno.h>
+#include <limits.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
using namespace std;
-Stream::Stream(const string &url, size_t backlog_size, Encoding encoding)
+Stream::Stream(const string &url, size_t backlog_size, size_t prebuffering_bytes, Encoding encoding)
: url(url),
encoding(encoding),
data_fd(make_tempfile("")),
backlog_size(backlog_size),
+ prebuffering_bytes(prebuffering_bytes),
bytes_received(0),
last_suitable_starting_point(-1),
- mark_pool(NULL),
- pacing_rate(~0U),
- queued_data_last_starting_point(-1)
+ pacing_rate(~0U)
{
if (data_fd == -1) {
exit(1);
encoding(Stream::STREAM_ENCODING_RAW), // Will be changed later.
data_fd(data_fd),
backlog_size(serialized.backlog_size()),
+ prebuffering_bytes(serialized.prebuffering_bytes()),
bytes_received(serialized.bytes_received()),
- mark_pool(NULL),
- pacing_rate(~0U),
- queued_data_last_starting_point(-1)
+ pacing_rate(~0U)
{
if (data_fd == -1) {
exit(1);
serialized.set_stream_header(stream_header);
serialized.add_data_fds(data_fd);
serialized.set_backlog_size(backlog_size);
+ serialized.set_prebuffering_bytes(prebuffering_bytes);
serialized.set_bytes_received(bytes_received);
serialized.set_last_suitable_starting_point(last_suitable_starting_point);
serialized.set_url(url);
// Now cheat a bit by rewinding, and adding all the old data back.
bytes_received -= 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);
+ DataElement data_element;
+ data_element.data.iov_base = const_cast<char *>(existing_data.data());
+ data_element.data.iov_len = existing_data.size();
+ data_element.suitable_for_stream_start = NOT_SUITABLE_FOR_STREAM_START; // Ignored by add_data_raw().
+
+ vector<DataElement> data_elements;
+ data_elements.push_back(data_element);
+ add_data_raw(data_elements);
}
void Stream::put_client_to_sleep(Client *client)
}
// 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)
+vector<iovec> collect_iovecs(const vector<Stream::DataElement> &data, size_t bytes_wanted)
{
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) {
+ if (data[i].data.iov_len <= bytes_wanted) {
// Consume the entire iovec.
- ret.push_back(data[i]);
- bytes_wanted -= data[i].iov_len;
+ ret.push_back(data[i].data);
+ bytes_wanted -= data[i].data.iov_len;
} else {
// Take only parts of this iovec.
iovec iov;
- iov.iov_base = data[i].iov_base;
- iov.iov_len = bytes_wanted;
+ iov.iov_base = data[i].data.iov_base;
+ iov.iov_len = bytes_wanted;
ret.push_back(iov);
bytes_wanted = 0;
}
}
// 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<Stream::DataElement> remove_iovecs(const vector<Stream::DataElement> &data, size_t bytes_wanted)
{
- vector<iovec> ret;
+ vector<Stream::DataElement> ret;
size_t i;
for (i = 0; i < data.size() && bytes_wanted > 0; ++i) {
- if (data[i].iov_len <= bytes_wanted) {
+ if (data[i].data.iov_len <= bytes_wanted) {
// Consume the entire iovec.
- bytes_wanted -= data[i].iov_len;
+ bytes_wanted -= data[i].data.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);
+ Stream::DataElement data_element;
+ data_element.data.iov_base = reinterpret_cast<char *>(data[i].data.iov_base) + bytes_wanted;
+ data_element.data.iov_len = data[i].data.iov_len - bytes_wanted;
+ data_element.suitable_for_stream_start = NOT_SUITABLE_FOR_STREAM_START;
+ ret.push_back(data_element);
bytes_wanted = 0;
}
}
return ret;
}
-void Stream::add_data_raw(const vector<iovec> &orig_data)
+void Stream::add_data_raw(const vector<DataElement> &orig_data)
{
- vector<iovec> data = orig_data;
+ vector<DataElement> data = orig_data;
while (!data.empty()) {
size_t pos = bytes_received % backlog_size;
MutexLock lock(&queued_data_mutex);
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();
- }
+
+ DataElement data_element;
+ data_element.suitable_for_stream_start = suitable_for_stream_start;
if (encoding == Stream::STREAM_ENCODING_METACUBE) {
// Add a Metacube block header before the data.
}
hdr.csum = htons(metacube2_compute_crc(&hdr));
- iovec iov;
- iov.iov_base = new char[bytes + sizeof(hdr)];
- iov.iov_len = bytes + sizeof(hdr);
+ data_element.data.iov_base = new char[bytes + sizeof(hdr)];
+ data_element.data.iov_len = bytes + sizeof(hdr);
- memcpy(iov.iov_base, &hdr, sizeof(hdr));
- memcpy(reinterpret_cast<char *>(iov.iov_base) + sizeof(hdr), data, bytes);
+ memcpy(data_element.data.iov_base, &hdr, sizeof(hdr));
+ memcpy(reinterpret_cast<char *>(data_element.data.iov_base) + sizeof(hdr), data, bytes);
- queued_data.push_back(iov);
+ queued_data.push_back(data_element);
} 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;
+ data_element.data.iov_base = new char[bytes];
+ memcpy(data_element.data.iov_base, data, bytes);
+ data_element.data.iov_len = bytes;
- queued_data.push_back(iov);
+ queued_data.push_back(data_element);
} else {
assert(false);
}
void Stream::process_queued_data()
{
- std::vector<iovec> queued_data_copy;
- int queued_data_last_starting_point_copy = -1;
+ std::vector<DataElement> queued_data_copy;
// Hold the lock for as short as possible, since add_data_raw() can possibly
// write to disk, which might disturb the input thread.
}
swap(queued_data, queued_data_copy);
- swap(queued_data_last_starting_point, queued_data_last_starting_point_copy);
}
// Update the last suitable starting point for the stream,
// if the queued data contains such a starting point.
- assert(queued_data_last_starting_point_copy < ssize_t(queued_data_copy.size()));
- if (queued_data_last_starting_point_copy >= 0) {
- last_suitable_starting_point = bytes_received;
- for (int i = 0; i < queued_data_last_starting_point_copy; ++i) {
- last_suitable_starting_point += queued_data_copy[i].iov_len;
+ size_t byte_position = bytes_received;
+ for (size_t i = 0; i < queued_data_copy.size(); ++i) {
+ if (queued_data_copy[i].suitable_for_stream_start == SUITABLE_FOR_STREAM_START) {
+ last_suitable_starting_point = byte_position;
}
+ byte_position += queued_data_copy[i].data.iov_len;
}
add_data_raw(queued_data_copy);
for (size_t i = 0; i < queued_data_copy.size(); ++i) {
- char *data = reinterpret_cast<char *>(queued_data_copy[i].iov_base);
+ char *data = reinterpret_cast<char *>(queued_data_copy[i].data.iov_base);
delete[] data;
}