sapling/eden/fs/fuse/RequestData.h
Adam Simpkins aa5e6c7295 update license headers in C++ files
Summary:
Update the copyright & license headers in C++ files to reflect the
relicensing to GPLv2

Reviewed By: wez

Differential Revision: D15487078

fbshipit-source-id: 19f24c933a64ecad0d3a692d0f8d2a38b4194b1d
2019-06-19 17:02:45 -07:00

111 lines
3.2 KiB
C++

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This software may be used and distributed according to the terms of the
* GNU General Public License version 2.
*/
#pragma once
#include <folly/futures/Future.h>
#include <folly/io/async/Request.h>
#include <atomic>
#include <utility>
#include "eden/fs/fuse/FuseChannel.h"
#include "eden/fs/fuse/FuseTypes.h"
#include "eden/fs/tracing/EdenStats.h"
namespace facebook {
namespace eden {
class Dispatcher;
class RequestData : public folly::RequestData {
FuseChannel* channel_;
fuse_in_header fuseHeader_;
// Needed to track stats
std::chrono::time_point<std::chrono::steady_clock> startTime_;
FuseThreadStats::HistogramPtr latencyHistogram_{nullptr};
EdenStats* stats_{nullptr};
Dispatcher* dispatcher_{nullptr};
fuse_in_header stealReq();
public:
static const std::string kKey;
RequestData(const RequestData&) = delete;
RequestData& operator=(const RequestData&) = delete;
RequestData(RequestData&&) = delete;
RequestData& operator=(RequestData&&) = delete;
explicit RequestData(
FuseChannel* channel,
const fuse_in_header& fuseHeader,
Dispatcher* dispatcher);
static RequestData& get();
static RequestData& create(
FuseChannel* channel,
const fuse_in_header& fuseHeader,
Dispatcher* dispatcher);
bool hasCallback() override {
return false;
}
// Returns true if the current context is being called from inside
// a FUSE request, false otherwise.
static bool isFuseRequest();
void startRequest(EdenStats* stats, FuseThreadStats::HistogramPtr histogram);
void finishRequest();
// Returns the associated dispatcher instance
Dispatcher* getDispatcher() const;
// Returns the underlying fuse request, throwing an error if it has
// already been released
const fuse_in_header& getReq() const;
// Returns the underlying fuse request. Unlike getReq this function doesn't
// throw. The caller is responsible to verify that the fuse_in_header is valid
// by checking if (fuseHeader.opcode != 0)
const fuse_in_header& examineReq() const;
/** Append error handling clauses to a future chain
* These clauses result in reporting a fuse request error back to the
* kernel. */
template <typename T>
folly::Future<folly::Unit> catchErrors(folly::Future<T>&& fut) {
return std::move(fut)
.thenError(folly::tag_t<std::system_error>{}, systemErrorHandler)
.thenError(folly::tag_t<std::exception>{}, genericErrorHandler)
.ensure([] { RequestData::get().finishRequest(); });
}
static void systemErrorHandler(const std::system_error& err);
static void genericErrorHandler(const std::exception& err);
template <typename T>
void sendReply(const T& payload) {
channel_->sendReply(stealReq(), payload);
}
void sendReply(folly::ByteRange bytes) {
channel_->sendReply(stealReq(), bytes);
}
void sendReply(folly::fbvector<iovec>&& vec) {
channel_->sendReply(stealReq(), std::move(vec));
}
void sendReply(folly::StringPiece piece) {
channel_->sendReply(stealReq(), folly::ByteRange(piece));
}
// Reply with a negative errno value or 0 for success
void replyError(int err);
// Don't send a reply, just release req_
void replyNone();
};
} // namespace eden
} // namespace facebook