xpcom/components/Module.h
author David Anderson <danderson@mozilla.com>
Wed, 18 Jul 2012 19:02:32 -0700
changeset 101447 adb60cc7b1505bc91ca1c3bb846270cfd19926cb
parent 97247 56ba58a77e8f11cff724a9ddb50839a0c5663e2c
parent 101219 9697eadafa13b4e9233b39aaeecfeac79503cb54
child 105678 6cd206b371761294125cb98fe9d0c11e2383795f
permissions -rw-r--r--
Merge from mozilla-central.

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_Module_h
#define mozilla_Module_h

#include "nscore.h"
#include "nsID.h"
#include "nsIFactory.h"
#include "nsCOMPtr.h" // for already_AddRefed

namespace mozilla {

/**
 * A module implements one or more XPCOM components. This structure is used
 * for both binary and script modules, but the registration members
 * (cids/contractids/categoryentries) are unused for modules which are loaded
 * via a module loader.
 */
struct Module
{
  static const unsigned int kVersion = 17;

  struct CIDEntry;

  typedef already_AddRefed<nsIFactory> (*GetFactoryProcPtr)
    (const Module& module, const CIDEntry& entry);

  typedef nsresult (*ConstructorProcPtr)(nsISupports* aOuter,
                                         const nsIID& aIID,
                                         void** aResult);

  typedef nsresult (*LoadFuncPtr)();
  typedef void (*UnloadFuncPtr)();

  /**
   * The constructor callback is an implementation detail of the default binary
   * loader and may be null.
   */
  struct CIDEntry
  {
    const nsCID* cid;
    bool service;
    GetFactoryProcPtr getFactoryProc;
    ConstructorProcPtr constructorProc;
  };

  struct ContractIDEntry
  {
    const char* contractid;
    nsID const * cid;
  };

  struct CategoryEntry
  {
    const char* category;
    const char* entry;
    const char* value;
  };

  /**
   * Binary compatibility check, should be kModuleVersion.
   */
  unsigned int mVersion;

  /**
   * An array of CIDs (class IDs) implemented by this module. The final entry
   * should be { NULL }.
   */
  const CIDEntry* mCIDs;

  /**
   * An array of mappings from contractid to CID. The final entry should
   * be { NULL }.
   */
  const ContractIDEntry* mContractIDs;

  /**
   * An array of category manager entries. The final entry should be
   * { NULL }.
   */
  const CategoryEntry* mCategoryEntries;

  /**
   * When the component manager tries to get the factory for a CID, it first
   * checks for this module-level getfactory callback. If this function is
   * not implemented, it checks the CIDEntry getfactory callback. If that is
   * also NULL, a generic factory is generated using the CIDEntry constructor
   * callback which must be non-NULL.
   */
  GetFactoryProcPtr getFactoryProc;

  /**
   * Optional Function which are called when this module is loaded and
   * at shutdown. These are not C++ constructor/destructors to avoid
   * calling them too early in startup or too late in shutdown.
   */
  LoadFuncPtr loadProc;
  UnloadFuncPtr unloadProc;
};

} // namespace

#if defined(XPCOM_TRANSLATE_NSGM_ENTRY_POINT)
#  define NSMODULE_NAME(_name) _name##_NSModule
#  define NSMODULE_DECL(_name) extern mozilla::Module const *const NSMODULE_NAME(_name)
#  define NSMODULE_DEFN(_name) NSMODULE_DECL(_name)
#else
#  define NSMODULE_NAME(_name) NSModule
#  define NSMODULE_DEFN(_name) extern "C" NS_EXPORT mozilla::Module const *const NSModule
#endif

#endif // mozilla_Module_h