170 lines
7.5 KiB
C++
170 lines
7.5 KiB
C++
/**
|
|
* @file aicurlperhost.h
|
|
* @brief Definition of class AIPerHostRequestQueue
|
|
*
|
|
* Copyright (c) 2012, 2013, Aleric Inglewood.
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*
|
|
* There are special exceptions to the terms and conditions of the GPL as
|
|
* it is applied to this Source Code. View the full text of the exception
|
|
* in the file doc/FLOSS-exception.txt in this software distribution.
|
|
*
|
|
* CHANGELOG
|
|
* and additional copyright holders.
|
|
*
|
|
* 04/11/2012
|
|
* Initial version, written by Aleric Inglewood @ SL
|
|
*
|
|
* 06/04/2013
|
|
* Renamed AIPrivate::PerHostRequestQueue[Ptr] to AIPerHostRequestQueue[Ptr]
|
|
* to allow public access.
|
|
*/
|
|
|
|
#ifndef AICURLPERHOST_H
|
|
#define AICURLPERHOST_H
|
|
|
|
#include "llerror.h" // llassert
|
|
#include <string>
|
|
#include <deque>
|
|
#include <map>
|
|
#include <boost/intrusive_ptr.hpp>
|
|
#include "aithreadsafe.h"
|
|
|
|
class AICurlEasyRequest;
|
|
class AIPerHostRequestQueue;
|
|
|
|
namespace AICurlPrivate {
|
|
namespace curlthread { class MultiHandle; }
|
|
|
|
class RefCountedThreadSafePerHostRequestQueue;
|
|
class ThreadSafeBufferedCurlEasyRequest;
|
|
|
|
// Forward declaration of BufferedCurlEasyRequestPtr (see aicurlprivate.h).
|
|
typedef boost::intrusive_ptr<ThreadSafeBufferedCurlEasyRequest> BufferedCurlEasyRequestPtr;
|
|
|
|
// AIPerHostRequestQueue objects are created by the curl thread and destructed by the main thread.
|
|
// We need locking.
|
|
typedef AIThreadSafeSimpleDC<AIPerHostRequestQueue> threadsafe_PerHostRequestQueue;
|
|
typedef AIAccessConst<AIPerHostRequestQueue> PerHostRequestQueue_crat;
|
|
typedef AIAccess<AIPerHostRequestQueue> PerHostRequestQueue_rat;
|
|
typedef AIAccess<AIPerHostRequestQueue> PerHostRequestQueue_wat;
|
|
|
|
} // namespace AICurlPrivate
|
|
|
|
// We can't put threadsafe_PerHostRequestQueue in a std::map because you can't copy a mutex.
|
|
// Therefore, use an intrusive pointer for the threadsafe type.
|
|
typedef boost::intrusive_ptr<AICurlPrivate::RefCountedThreadSafePerHostRequestQueue> AIPerHostRequestQueuePtr;
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// AIPerHostRequestQueue
|
|
|
|
// This class provides a static interface to create and maintain instances
|
|
// of AIPerHostRequestQueue objects, so that at any moment there is at most
|
|
// one instance per hostname. Those instances then are used to queue curl
|
|
// requests when the maximum number of connections for that host already
|
|
// have been reached.
|
|
class AIPerHostRequestQueue {
|
|
private:
|
|
typedef std::map<std::string, AIPerHostRequestQueuePtr> instance_map_type;
|
|
typedef AIThreadSafeSimpleDC<instance_map_type> threadsafe_instance_map_type;
|
|
typedef AIAccess<instance_map_type> instance_map_rat;
|
|
typedef AIAccess<instance_map_type> instance_map_wat;
|
|
|
|
static threadsafe_instance_map_type sInstanceMap; // Map of AIPerHostRequestQueue instances with the hostname as key.
|
|
|
|
friend class AIThreadSafeSimpleDC<AIPerHostRequestQueue>; //threadsafe_PerHostRequestQueue
|
|
AIPerHostRequestQueue(void) : mQueuedCommands(0), mAdded(0), mQueueEmpty(false), mQueueFull(false), mRequestStarvation(false) { }
|
|
|
|
public:
|
|
typedef instance_map_type::iterator iterator;
|
|
typedef instance_map_type::const_iterator const_iterator;
|
|
|
|
// Utility function; extract canonical (lowercase) hostname from url.
|
|
static std::string extract_canonical_hostname(std::string const& url);
|
|
|
|
// Return (possibly create) a unique instance for the given hostname.
|
|
static AIPerHostRequestQueuePtr instance(std::string const& hostname);
|
|
|
|
// Release instance (object will be deleted if this was the last instance).
|
|
static void release(AIPerHostRequestQueuePtr& instance);
|
|
|
|
// Remove everything. Called upon viewer exit.
|
|
static void purge(void);
|
|
|
|
private:
|
|
typedef std::deque<AICurlPrivate::BufferedCurlEasyRequestPtr> queued_request_type;
|
|
|
|
int mQueuedCommands; // Number of add commands (minus remove commands) with this host in the command queue.
|
|
int mAdded; // Number of active easy handles with this host.
|
|
queued_request_type mQueuedRequests; // Waiting (throttled) requests.
|
|
|
|
static LLAtomicS32 sTotalQueued; // The sum of mQueuedRequests.size() of all AIPerHostRequestQueue objects together.
|
|
|
|
bool mQueueEmpty; // Set to true when the queue becomes precisely empty.
|
|
bool mQueueFull; // Set to true when the queue is popped and then still isn't empty;
|
|
bool mRequestStarvation; // Set to true when the queue was about to be popped but was already empty.
|
|
|
|
static bool sQueueEmpty; // Set to true when sTotalQueued becomes precisely zero as the result of popping any queue.
|
|
static bool sQueueFull; // Set to true when sTotalQueued is still larger than zero after popping any queue.
|
|
static bool sRequestStarvation; // Set to true when any queue was about to be popped when sTotalQueued was already zero.
|
|
|
|
public:
|
|
void added_to_command_queue(void) { ++mQueuedCommands; }
|
|
void removed_from_command_queue(void) { --mQueuedCommands; llassert(mQueuedCommands >= 0); }
|
|
void added_to_multi_handle(void); // Called when an easy handle for this host has been added to the multi handle.
|
|
void removed_from_multi_handle(void); // Called when an easy handle for this host is removed again from the multi handle.
|
|
bool throttled(void) const; // Returns true if the maximum number of allowed requests for this host have been added to the multi handle.
|
|
|
|
void queue(AICurlEasyRequest const& easy_request); // Add easy_request to the queue.
|
|
bool cancel(AICurlEasyRequest const& easy_request); // Remove easy_request from the queue (if it's there).
|
|
|
|
void add_queued_to(AICurlPrivate::curlthread::MultiHandle* mh);
|
|
// Add queued easy handle (if any) to the multi handle. The request is removed from the queue,
|
|
// followed by either a call to added_to_multi_handle() or to queue() to add it back.
|
|
|
|
S32 pipelined_requests(void) const { return mQueuedCommands + mQueuedRequests.size() + mAdded; }
|
|
static S32 total_queued_size(void) { return sTotalQueued; }
|
|
|
|
// Returns true if curl can handle another request for this host.
|
|
// Should return false if the maximum allowed HTTP bandwidth is reached, or when
|
|
// the latency between request and actual delivery becomes too large.
|
|
static bool wantsMoreHTTPRequestsFor(AIPerHostRequestQueuePtr const& per_host, bool too_much_bandwidth);
|
|
|
|
private:
|
|
// Disallow copying.
|
|
AIPerHostRequestQueue(AIPerHostRequestQueue const&) { }
|
|
};
|
|
|
|
namespace AICurlPrivate {
|
|
|
|
class RefCountedThreadSafePerHostRequestQueue : public threadsafe_PerHostRequestQueue {
|
|
public:
|
|
RefCountedThreadSafePerHostRequestQueue(void) : mReferenceCount(0) { }
|
|
bool exactly_two_left(void) const { return mReferenceCount == 2; }
|
|
|
|
private:
|
|
// Used by AIPerHostRequestQueuePtr. Object is deleted when reference count reaches zero.
|
|
LLAtomicU32 mReferenceCount;
|
|
|
|
friend void intrusive_ptr_add_ref(RefCountedThreadSafePerHostRequestQueue* p);
|
|
friend void intrusive_ptr_release(RefCountedThreadSafePerHostRequestQueue* p);
|
|
};
|
|
|
|
extern U32 curl_concurrent_connections_per_host;
|
|
|
|
} // namespace AICurlPrivate
|
|
|
|
#endif // AICURLPERHOST_H
|