src/PeerPoolMgr.h

   1 /*
   2  * Copyright (C) 1996-2021 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 #include "security/forward.h"
  15
  16 class HttpRequest;
  17 class CachePeer;
  18 class CommConnectCbParams;
  19
  20 /// Maintains an fixed-size "standby" PconnPool for a single CachePeer.
  21 class PeerPoolMgr: public AsyncJob
  22 {
  23     CBDATA_CLASS(PeerPoolMgr);
  24
  25 public:
  26     typedef CbcPointer<PeerPoolMgr> Pointer;
  27
  28     // syncs mgr state whenever connection-related peer or pool state changes
  29     static void Checkpoint(const Pointer &mgr, const char *reason);
  30
  31     explicit PeerPoolMgr(CachePeer *aPeer);
  32     virtual ~PeerPoolMgr();
  33
  34 protected:
  35     /* AsyncJob API */
  36     virtual void start();
  37     virtual void swanSong();
  38     virtual bool doneAll() const;
  39
  40     /// whether the peer is still out there and in a valid state we can safely use
  41     bool validPeer() const;
  42
  43     /// Starts new connection, or closes the excess connections
  44     /// according pool configuration
  45     void checkpoint(const char *reason);
  46     /// starts the process of opening a new standby connection (if possible)
  47     void openNewConnection();
  48     /// closes 'howMany' standby connections
  49     void closeOldConnections(const int howMany);
  50
  51     /// Comm::ConnOpener calls this when done opening a connection for us
  52     void handleOpenedConnection(const CommConnectCbParams &params);
  53
  54     /// Security::PeerConnector callback
  55     void handleSecuredPeer(Security::EncryptorAnswer &answer);
  56
  57     /// called when the connection we are trying to secure is closed by a 3rd party
  58     void handleSecureClosure(const CommCloseCbParams &params);
  59
  60     /// the final step in connection opening (and, optionally, securing) sequence
  61     void pushNewConnection(const Comm::ConnectionPointer &conn);
  62
  63 private:
  64     CachePeer *peer; ///< the owner of the pool we manage
  65     RefCount<HttpRequest> request; ///< fake HTTP request for conn opening code
  66     AsyncCall::Pointer opener; ///< whether we are opening a connection
  67     AsyncCall::Pointer securer; ///< whether we are securing a connection
  68     AsyncCall::Pointer closer; ///< monitors conn while we are securing it
  69     unsigned int addrUsed; ///< counter for cycling through peer addresses
  70 };
  71
  72 #endif /* SQUID_PEERPOOLMGR_H */
  73