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arangodb/lib/HttpServer/AsyncJobManager.h

526 lines
18 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// @brief job manager
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2004-2013 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 triAGENS GmbH, Cologne, Germany
///
/// @author Jan Steemann
/// @author Copyright 2004-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#ifndef TRIAGENS_HTTP_SERVER_JOB_MANAGER_H
#define TRIAGENS_HTTP_SERVER_JOB_MANAGER_H 1
#include "Basics/Common.h"
#include "Basics/ReadLocker.h"
#include "Basics/WriteLocker.h"
#include "GeneralServer/GeneralServerJob.h"
using namespace std;
using namespace triagens::rest;
namespace triagens {
namespace rest {
// -----------------------------------------------------------------------------
// --SECTION-- class AsyncCallbackContext
// -----------------------------------------------------------------------------
class AsyncCallbackContext {
// -----------------------------------------------------------------------------
// --SECTION-- constructors / destructors
// -----------------------------------------------------------------------------
public:
AsyncCallbackContext (std::string const& coordHeader)
: _coordHeader(coordHeader),
_response(0) {
}
~AsyncCallbackContext () {
if (_response != 0) {
delete _response;
}
}
// -----------------------------------------------------------------------------
// --SECTION-- public functions
// -----------------------------------------------------------------------------
public:
string& getCoordinatorHeader() {
return _coordHeader;
}
// -----------------------------------------------------------------------------
// --SECTION-- private variables
// -----------------------------------------------------------------------------
private:
std::string _coordHeader;
HttpResponse* _response;
};
// -----------------------------------------------------------------------------
// --SECTION-- class AsyncJobResult
// -----------------------------------------------------------------------------
struct AsyncJobResult {
// -----------------------------------------------------------------------------
// --SECTION-- public types
// -----------------------------------------------------------------------------
public:
////////////////////////////////////////////////////////////////////////////////
/// @brief job statuses
////////////////////////////////////////////////////////////////////////////////
typedef enum {
JOB_UNDEFINED,
JOB_PENDING,
JOB_DONE
}
Status;
////////////////////////////////////////////////////////////////////////////////
/// @brief id typedef
////////////////////////////////////////////////////////////////////////////////
typedef uint64_t IdType;
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief constructor for an unspecified job result
////////////////////////////////////////////////////////////////////////////////
AsyncJobResult () :
_jobId(0),
_response(0),
_stamp(0.0),
_status(JOB_UNDEFINED),
_ctx(0) {
}
////////////////////////////////////////////////////////////////////////////////
/// @brief constructor for a specific job result
////////////////////////////////////////////////////////////////////////////////
AsyncJobResult (IdType jobId,
HttpResponse* response,
double stamp,
Status status,
AsyncCallbackContext* ctx) :
_jobId(jobId),
_response(response),
_stamp(stamp),
_status(status),
_ctx(ctx) {
}
////////////////////////////////////////////////////////////////////////////////
/// @brief destructor
////////////////////////////////////////////////////////////////////////////////
~AsyncJobResult () {
}
// -----------------------------------------------------------------------------
// --SECTION-- public variables
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief job id
////////////////////////////////////////////////////////////////////////////////
IdType _jobId;
////////////////////////////////////////////////////////////////////////////////
/// @brief the full HTTP response object of the job, can be 0
////////////////////////////////////////////////////////////////////////////////
HttpResponse* _response;
////////////////////////////////////////////////////////////////////////////////
/// @brief job creation stamp
////////////////////////////////////////////////////////////////////////////////
double _stamp;
////////////////////////////////////////////////////////////////////////////////
/// @brief job status
////////////////////////////////////////////////////////////////////////////////
Status _status;
////////////////////////////////////////////////////////////////////////////////
/// @brief callback context object (normally 0, used in cluster operations)
////////////////////////////////////////////////////////////////////////////////
AsyncCallbackContext* _ctx;
};
// -----------------------------------------------------------------------------
// --SECTION-- class AsyncJobManager
// -----------------------------------------------------------------------------
class AsyncJobManager {
private:
AsyncJobManager (AsyncJobManager const&);
AsyncJobManager& operator= (AsyncJobManager const&);
// -----------------------------------------------------------------------------
// --SECTION-- constructors / destructors
// -----------------------------------------------------------------------------
public:
////////////////////////////////////////////////////////////////////////////////
/// @brief constructor
////////////////////////////////////////////////////////////////////////////////
AsyncJobManager (uint64_t (*idFunc)(),
void (*callbackFunc)(string&, HttpResponse*))
: _lock(),
_jobs(),
generate(idFunc),
callback(callbackFunc) {
}
////////////////////////////////////////////////////////////////////////////////
/// @brief destructor
////////////////////////////////////////////////////////////////////////////////
~AsyncJobManager () {
}
// -----------------------------------------------------------------------------
// --SECTION-- public types
// -----------------------------------------------------------------------------
public:
////////////////////////////////////////////////////////////////////////////////
/// @brief joblist typedef
////////////////////////////////////////////////////////////////////////////////
typedef std::map<AsyncJobResult::IdType, AsyncJobResult> JobList;
// -----------------------------------------------------------------------------
// --SECTION-- public methods
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief get the result of an async job, and remove it from the list
////////////////////////////////////////////////////////////////////////////////
HttpResponse* getJobResult (AsyncJobResult::IdType jobId,
AsyncJobResult::Status& status) {
WRITE_LOCKER(_lock);
JobList::iterator it = _jobs.find(jobId);
if (it == _jobs.end()) {
status = AsyncJobResult::JOB_UNDEFINED;
return 0;
}
HttpResponse* response = (*it).second._response;
status = (*it).second._status;
// remove the job from the list
_jobs.erase(it);
return response;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief delete the result of an async job, without returning it
////////////////////////////////////////////////////////////////////////////////
bool deleteJobResult (AsyncJobResult::IdType jobId) {
WRITE_LOCKER(_lock);
JobList::iterator it = _jobs.find(jobId);
if (it == _jobs.end()) {
return false;
}
HttpResponse* response = (*it).second._response;
if (response != 0) {
delete response;
}
// remove the job from the list
_jobs.erase(it);
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief delete all results
////////////////////////////////////////////////////////////////////////////////
void deleteJobResults () {
WRITE_LOCKER(_lock);
JobList::iterator it = _jobs.begin();
while (it != _jobs.end()) {
HttpResponse* response = (*it).second._response;
if (response != 0) {
delete response;
}
++it;
}
_jobs.clear();
}
////////////////////////////////////////////////////////////////////////////////
/// @brief delete expired results
////////////////////////////////////////////////////////////////////////////////
void deleteExpiredJobResults (double stamp) {
WRITE_LOCKER(_lock);
JobList::iterator it = _jobs.begin();
while (it != _jobs.end()) {
AsyncJobResult ajr = (*it).second;
if (ajr._stamp < stamp) {
HttpResponse* response = ajr._response;
if (response != 0) {
delete response;
}
_jobs.erase(it++);
}
else {
++it;
}
}
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return the list of pending jobs
////////////////////////////////////////////////////////////////////////////////
const std::vector<AsyncJobResult::IdType> pending (size_t maxCount) {
return byStatus(AsyncJobResult::JOB_PENDING, maxCount);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return the list of done jobs
////////////////////////////////////////////////////////////////////////////////
const std::vector<AsyncJobResult::IdType> done (size_t maxCount) {
return byStatus(AsyncJobResult::JOB_DONE, maxCount);
}
////////////////////////////////////////////////////////////////////////////////
/// @brief return the list of jobs by status
////////////////////////////////////////////////////////////////////////////////
const std::vector<AsyncJobResult::IdType> byStatus (AsyncJobResult::Status status,
size_t maxCount) {
vector<AsyncJobResult::IdType> jobs;
size_t n = 0;
{
READ_LOCKER(_lock);
JobList::iterator it = _jobs.begin();
// iterate the list. the list is sorted by id
while (it != _jobs.end()) {
AsyncJobResult::IdType jobId = (*it).first;
if ((*it).second._status == status) {
jobs.push_back(jobId);
if (++n >= maxCount) {
break;
}
}
++it;
}
}
return jobs;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief initialise an async job
////////////////////////////////////////////////////////////////////////////////
template<typename S, typename HF>
void initAsyncJob (GeneralServerJob<S, typename HF::GeneralHandler>* job,
uint64_t* jobId) {
if (jobId == 0) {
return;
}
assert(job != 0);
*jobId = (AsyncJobResult::IdType) generate();
job->assignId((uint64_t) *jobId);
AsyncCallbackContext* ctx = 0;
bool found;
char const* hdr = job->getHandler()->getRequest()->header("x-arango-coordinator", found);
if (found) {
LOG_DEBUG("Found header X-Arango-Coordinator in async request");
ctx = new AsyncCallbackContext(std::string(hdr));
}
AsyncJobResult ajr(*jobId, 0, TRI_microtime(),
AsyncJobResult::JOB_PENDING, ctx);
WRITE_LOCKER(_lock);
_jobs[*jobId] = ajr;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief finish the execution of an async job
////////////////////////////////////////////////////////////////////////////////
template<typename S, typename HF>
void finishAsyncJob (GeneralServerJob<S, typename HF::GeneralHandler>* job) {
assert(job != 0);
typename HF::GeneralHandler* handler = job->getHandler();
assert(handler != 0);
AsyncJobResult::IdType jobId = job->id();
if (jobId == 0) {
return;
}
const double now = TRI_microtime();
AsyncCallbackContext* ctx = 0;
HttpResponse* response = 0;
{
WRITE_LOCKER(_lock);
JobList::iterator it = _jobs.find(jobId);
if (it == _jobs.end()) {
// job is already deleted.
// do nothing here. the dispatcher will throw away the handler,
// which will also dispose the response
return;
}
else {
response = handler->stealResponse();
(*it).second._response = response;
(*it).second._status = AsyncJobResult::JOB_DONE;
(*it).second._stamp = now;
ctx = (*it).second._ctx;
if (ctx != 0) {
// we have found a context object, so we can immediately remove the job
// from the list of "done" jobs
_jobs.erase(it);
}
}
}
// If we got here, then we have stolen the pointer to the response
// If there is a callback context, the job is no longer in the
// list of "done" jobs, so we have to free the response and the
// callback context:
if (0 != ctx && 0 != callback) {
callback(ctx->getCoordinatorHeader(), response);
delete ctx;
if (response != 0) {
delete response;
}
}
}
// -----------------------------------------------------------------------------
// --SECTION-- private variables
// -----------------------------------------------------------------------------
private:
////////////////////////////////////////////////////////////////////////////////
/// @brief lock to protect the _jobs map
////////////////////////////////////////////////////////////////////////////////
basics::ReadWriteLock _lock;
////////////////////////////////////////////////////////////////////////////////
/// @brief list of pending/done async jobs
////////////////////////////////////////////////////////////////////////////////
JobList _jobs;
////////////////////////////////////////////////////////////////////////////////
/// @brief function pointer for id generation
////////////////////////////////////////////////////////////////////////////////
uint64_t (*generate)();
////////////////////////////////////////////////////////////////////////////////
/// @brief function pointer for callback registered at initialisation
////////////////////////////////////////////////////////////////////////////////
void (*callback)(string& coordinator, HttpResponse* response);
};
}
}
#endif
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
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