src/PeerPoolMgr.h

   1 /*
   2  * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #ifndef SQUID_PEERPOOLMGR_H
  10 #define SQUID_PEERPOOLMGR_H
  11
  12 #include "base/AsyncJob.h"
  13 #include "comm/forward.h"
  14
  15 class HttpRequest;
  16 class CachePeer;
  17 class CommConnectCbParams;
  18
  19 #if USE_OPENSSL
  20 namespace Ssl
  21 {
  22 class PeerConnectorAnswer;
  23 }
  24 #endif
  25
  26 /// Maintains an fixed-size "standby" PconnPool for a single CachePeer.
  27 class PeerPoolMgr: public AsyncJob
  28 {
  29     CBDATA_CLASS(PeerPoolMgr);
  30
  31 public:
  32     typedef CbcPointer<PeerPoolMgr> Pointer;
  33
  34     // syncs mgr state whenever connection-related peer or pool state changes
  35     static void Checkpoint(const Pointer &mgr, const char *reason);
  36
  37     explicit PeerPoolMgr(CachePeer *aPeer);
  38     virtual ~PeerPoolMgr();
  39
  40 protected:
  41     /* AsyncJob API */
  42     virtual void start();
  43     virtual void swanSong();
  44     virtual bool doneAll() const;
  45
  46     /// whether the peer is still out there and in a valid state we can safely use
  47     bool validPeer() const;
  48
  49     /// Starts new connection, or closes the excess connections
  50     /// according pool configuration
  51     void checkpoint(const char *reason);
  52     /// starts the process of opening a new standby connection (if possible)
  53     void openNewConnection();
  54     /// closes 'howMany' standby connections
  55     void closeOldConnections(const int howMany);
  56
  57     /// Comm::ConnOpener calls this when done opening a connection for us
  58     void handleOpenedConnection(const CommConnectCbParams &params);
  59 #if USE_OPENSSL
  60     /// Ssl::PeerConnector callback
  61     void handleSecuredPeer(Ssl::PeerConnectorAnswer &answer);
  62     /// called when the connection we are trying to secure is closed by a 3rd party
  63     void handleSecureClosure(const CommCloseCbParams &params);
  64 #endif
  65     /// the final step in connection opening (and, optionally, securing) sequence
  66     void pushNewConnection(const Comm::ConnectionPointer &conn);
  67
  68 private:
  69     CachePeer *peer; ///< the owner of the pool we manage
  70     RefCount<HttpRequest> request; ///< fake HTTP request for conn opening code
  71     AsyncCall::Pointer opener; ///< whether we are opening a connection
  72     AsyncCall::Pointer securer; ///< whether we are securing a connection
  73     AsyncCall::Pointer closer; ///< monitors conn while we are securing it
  74     unsigned int addrUsed; ///< counter for cycling through peer addresses
  75 };
  76
  77 #endif /* SQUID_PEERPOOLMGR_H */
  78