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arangodb/arangod/GeneralServer/RestHandler.cpp

303 lines
9.8 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
////////////////////////////////////////////////////////////////////////////////
#include "RestHandler.h"
#include <velocypack/Exception.h>
#include "Basics/StringUtils.h"
#include "GeneralServer/GeneralCommTask.h"
#include "Logger/Logger.h"
#include "Rest/GeneralRequest.h"
#include "Statistics/RequestStatistics.h"
#include "Utils/ExecContext.h"
#include <iostream>
using namespace arangodb;
using namespace arangodb::basics;
using namespace arangodb::rest;
namespace {
std::atomic_uint_fast64_t NEXT_HANDLER_ID(
static_cast<uint64_t>(TRI_microtime() * 100000.0));
}
thread_local RestHandler const* RestHandler::CURRENT_HANDLER = nullptr;
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
RestHandler::RestHandler(GeneralRequest* request, GeneralResponse* response)
: _handlerId(NEXT_HANDLER_ID.fetch_add(1, std::memory_order_seq_cst)),
_canceled(false),
_request(request),
_response(response),
_statistics(nullptr),
_state(HandlerState::PREPARE) {
bool found;
std::string const& startThread =
_request->header(StaticStrings::StartThread, found);
if (found) {
_needsOwnThread = StringUtils::boolean(startThread);
}
}
RestHandler::~RestHandler() {
RequestStatistics* stat = _statistics.exchange(nullptr);
if (stat != nullptr) {
stat->release();
}
}
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
uint64_t RestHandler::messageId() const {
uint64_t messageId = 0UL;
auto req = _request.get();
auto res = _response.get();
if (req) {
messageId = req->messageId();
} else if (res) {
messageId = res->messageId();
} else {
LOG_TOPIC(WARN, Logger::COMMUNICATION)
<< "could not find corresponding request/response";
}
return messageId;
}
void RestHandler::setStatistics(RequestStatistics* stat) {
RequestStatistics* old = _statistics.exchange(stat);
if (old != nullptr) {
old->release();
}
}
void RestHandler::runHandlerStateMachine() {
TRI_ASSERT(_callback);
while (true) {
switch (_state) {
case HandlerState::PREPARE:
this->prepareEngine();
break;
case HandlerState::EXECUTE: {
int res = this->executeEngine();
if (res != TRI_ERROR_NO_ERROR) {
this->finalizeEngine();
}
if (_state == HandlerState::PAUSED) {
LOG_TOPIC(DEBUG, Logger::COMMUNICATION) << "Pausing rest handler execution";
return; // stop state machine
}
break;
}
case HandlerState::PAUSED:
LOG_TOPIC(DEBUG, Logger::COMMUNICATION) << "Resuming rest handler execution";
TRI_ASSERT(_response != nullptr);
_callback(this);
_state = HandlerState::FINALIZE;
break;
case HandlerState::FINALIZE:
this->finalizeEngine();
break;
case HandlerState::DONE:
case HandlerState::FAILED:
return;
}
}
}
// -----------------------------------------------------------------------------
// --SECTION-- private methods
// -----------------------------------------------------------------------------
int RestHandler::prepareEngine() {
// set end immediately so we do not get netative statistics
RequestStatistics::SET_REQUEST_START_END(_statistics);
if (_canceled) {
_state = HandlerState::DONE;
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
Exception err(TRI_ERROR_REQUEST_CANCELED,
"request has been canceled by user", __FILE__, __LINE__);
handleError(err);
_callback(this);
return TRI_ERROR_REQUEST_CANCELED;
}
try {
prepareExecute();
_state = HandlerState::EXECUTE;
return TRI_ERROR_NO_ERROR;
} catch (Exception const& ex) {
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
handleError(ex);
} catch (std::exception const& ex) {
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
Exception err(TRI_ERROR_INTERNAL, ex.what(), __FILE__, __LINE__);
handleError(err);
} catch (...) {
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
Exception err(TRI_ERROR_INTERNAL, __FILE__, __LINE__);
handleError(err);
}
_state = HandlerState::FAILED;
_callback(this);
return TRI_ERROR_INTERNAL;
}
int RestHandler::finalizeEngine() {
int res = TRI_ERROR_NO_ERROR;
try {
finalizeExecute();
} catch (Exception const& ex) {
LOG_TOPIC(ERR, arangodb::Logger::FIXME) << "caught exception in " << name() << ": "
<< DIAGNOSTIC_INFORMATION(ex);
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
handleError(ex);
res = ex.code();
} catch (std::bad_alloc const& ex) {
LOG_TOPIC(ERR, arangodb::Logger::FIXME) << "caught memory exception in " << name() << ": " << ex.what();
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
Exception err(TRI_ERROR_OUT_OF_MEMORY, ex.what(), __FILE__, __LINE__);
handleError(err);
res = TRI_ERROR_OUT_OF_MEMORY;
} catch (std::exception const& ex) {
LOG_TOPIC(ERR, arangodb::Logger::FIXME) << "caught exception in " << name() << ": " << ex.what();
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
Exception err(TRI_ERROR_INTERNAL, ex.what(), __FILE__, __LINE__);
handleError(err);
res = TRI_ERROR_INTERNAL;
} catch (...) {
LOG_TOPIC(ERR, arangodb::Logger::FIXME) << "caught unknown exception in " << name();
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
Exception err(TRI_ERROR_INTERNAL, __FILE__, __LINE__);
handleError(err);
res = TRI_ERROR_INTERNAL;
}
RequestStatistics::SET_REQUEST_END(_statistics);
if (res == TRI_ERROR_NO_ERROR) {
_state = HandlerState::DONE;
} else {
_state = HandlerState::FAILED;
_callback(this);
}
return res;
}
int RestHandler::executeEngine() {
TRI_ASSERT(ExecContext::CURRENT == nullptr);
ExecContext* exec = static_cast<ExecContext*>(_request->requestContext());
ExecContextScope scope(exec);
try {
RestStatus result = execute();
if (result == RestStatus::FAIL) {
LOG_TOPIC(WARN, Logger::REQUESTS) << "Rest handler reported fail";
} else if (result == RestStatus::WAITING) {
_state = HandlerState::PAUSED; // wait for someone to continue the state machine
return TRI_ERROR_NO_ERROR;
} else if (_response == nullptr) {
Exception err(TRI_ERROR_INTERNAL, "no response received from handler",
__FILE__, __LINE__);
handleError(err);
}
_state = HandlerState::FINALIZE;
_callback(this);
return TRI_ERROR_NO_ERROR;
} catch (Exception const& ex) {
#ifdef ARANGODB_ENABLE_MAINTAINER_MODE
LOG_TOPIC(WARN, arangodb::Logger::FIXME) << "caught exception in " << name() << ": "
<< DIAGNOSTIC_INFORMATION(ex);
#endif
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
handleError(ex);
} catch (arangodb::velocypack::Exception const& ex) {
#ifdef ARANGODB_ENABLE_MAINTAINER_MODE
LOG_TOPIC(WARN, arangodb::Logger::FIXME) << "caught velocypack exception in " << name() << ": "
<< DIAGNOSTIC_INFORMATION(ex);
#endif
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
Exception err(TRI_ERROR_INTERNAL, std::string("VPack error: ") + ex.what(),
__FILE__, __LINE__);
handleError(err);
} catch (std::bad_alloc const& ex) {
#ifdef ARANGODB_ENABLE_MAINTAINER_MODE
LOG_TOPIC(WARN, arangodb::Logger::FIXME) << "caught memory exception in " << name() << ": "
<< DIAGNOSTIC_INFORMATION(ex);
#endif
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
Exception err(TRI_ERROR_OUT_OF_MEMORY, ex.what(), __FILE__, __LINE__);
handleError(err);
} catch (std::exception const& ex) {
#ifdef ARANGODB_ENABLE_MAINTAINER_MODE
LOG_TOPIC(WARN, arangodb::Logger::FIXME) << "caught exception in " << name() << ": "
<< DIAGNOSTIC_INFORMATION(ex);
#endif
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
Exception err(TRI_ERROR_INTERNAL, ex.what(), __FILE__, __LINE__);
handleError(err);
} catch (...) {
#ifdef ARANGODB_ENABLE_MAINTAINER_MODE
LOG_TOPIC(WARN, arangodb::Logger::FIXME) << "caught unknown exception in " << name();
#endif
RequestStatistics::SET_EXECUTE_ERROR(_statistics);
Exception err(TRI_ERROR_INTERNAL, __FILE__, __LINE__);
handleError(err);
}
_state = HandlerState::FAILED;
_callback(this);
return TRI_ERROR_INTERNAL;
}
// -----------------------------------------------------------------------------
// --SECTION-- protected methods
// -----------------------------------------------------------------------------
void RestHandler::resetResponse(rest::ResponseCode code) {
TRI_ASSERT(_response != nullptr);
_response->reset(code);
}