src/mgr/Action.h

   1 /*
   2  * Copyright (C) 1996-2016 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 /* DEBUG: section 16    Cache Manager API */
  10
  11 #ifndef SQUID_MGR_ACTION_H
  12 #define SQUID_MGR_ACTION_H
  13
  14 #include "ipc/forward.h"
  15 #include "mgr/forward.h"
  16
  17 class StoreEntry;
  18
  19 namespace Mgr
  20 {
  21
  22 /// Base API for organizing the processing of a compiled cache manager command.
  23 /// Not a job because all methods are synchronous (but they may start jobs).
  24 class Action: public RefCountable
  25 {
  26 public:
  27     typedef RefCount<Action> Pointer;
  28
  29 public:
  30     Action(const CommandPointer &aCmd);
  31     virtual ~Action();
  32
  33     /* for local Cache Manager use */
  34
  35     /// collect + fillEntry: collect local information and fill the store entry
  36     void run(StoreEntry *entry, bool writeHttpHeader);
  37
  38     /// prepare store entry, dump info, close store entry (if possible)
  39     void fillEntry(StoreEntry *entry, bool writeHttpHeader);
  40
  41     /* for global Coordinator use */
  42
  43     /// incrementally merge in remote information (of the same action type)
  44     virtual void add(const Action &action);
  45
  46     /* global-local communication */
  47
  48     /// respond to Coordinator request; default is to collect and sendResponse
  49     virtual void respond(const Request &request);
  50
  51     /// pack collected action info into a message to be sent to Coordinator
  52     virtual void pack(Ipc::TypedMsgHdr &) const {}
  53
  54     /// unpack action info from the message received by Coordinator
  55     virtual void unpack(const Ipc::TypedMsgHdr &) {}
  56
  57     /// notify Coordinator that this action is done with local processing
  58     void sendResponse(unsigned int requestId);
  59
  60     /* Action properties */
  61
  62     /// whether at least some local kid info can be combined and, hence, the
  63     /// combined data should be written at the end of the coordinated response
  64     virtual bool aggregatable() const { return true; } // most kid classes are
  65
  66     bool atomic() const; ///< dump() call writes everything before returning
  67     const char *name() const; ///< label as seen in the cache manager menu
  68     const Command &command() const; ///< the cause of this action
  69
  70     StoreEntry *createStoreEntry() const; ///< creates store entry from params
  71
  72     ///< Content-Type: header value for this report
  73     virtual const char *contentType() const {return "text/plain;charset=utf-8";}
  74
  75 protected:
  76     /// calculate and keep local action-specific information
  77     virtual void collect() {}
  78
  79     /** start writing action-specific info to Store entry;
  80      * may collect info during dump, especially if collect() did nothing
  81      * non-atomic() actions may continue writing asynchronously after returning
  82      */
  83     virtual void dump(StoreEntry *) {}
  84
  85 private:
  86     const CommandPointer cmd; ///< the command that caused this action
  87
  88 private:
  89     Action(const Action &); // not implemented
  90     Action &operator= (const Action &); // not implemented
  91 };
  92
  93 } // namespace Mgr
  94
  95 #endif /* SQUID_MGR_ACTION_H */
  96