dom/cache/Action.h
author Gregory Szorc <gps@mozilla.com>
Thu, 09 Nov 2017 22:26:26 -0800
changeset 391814 1cd169ff8a0dbb2ea7d50b4275472ca9298765b3
parent 331204 ff0000b808c501d75c44eadcfed14224e1fb3ca0
child 448947 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Bug 1416052 - Remove comment filtering; r=nalexander The auto-generated make file that we include (and the `mach environment` output that we included before that) should not contain comment lines. I think it is safe to remove the code that filters them out. It is possible a multi-line value in mozconfigs could contain lines looking like comments and this may cause problems. I'm inclined to believe that this scenario doesn't exist. If someone complains and we need to bring back support, we could certainly do that. MozReview-Commit-ID: 8kKw91HH4ms

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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_dom_cache_Action_h
#define mozilla_dom_cache_Action_h

#include "mozilla/Atomics.h"
#include "mozilla/dom/cache/Types.h"
#include "nsISupportsImpl.h"

class mozIStorageConnection;

namespace mozilla {
namespace dom {
namespace cache {

class Action
{
public:
  class Resolver
  {
  public:
    // Note: Action must drop Resolver ref after calling Resolve()!
    // Note: Must be called on the same thread used to execute
    //       Action::RunOnTarget().
    virtual void Resolve(nsresult aRv) = 0;

    NS_INLINE_DECL_PURE_VIRTUAL_REFCOUNTING
  };

  // Class containing data that can be opportunistically shared between
  // multiple Actions running on the same thread/Context.  In theory
  // this could be abstracted to a generic key/value map, but for now
  // just explicitly provide accessors for the data we need.
  class Data
  {
  public:
    virtual mozIStorageConnection*
    GetConnection() const = 0;

    virtual void
    SetConnection(mozIStorageConnection* aConn) = 0;
  };

  // Execute operations on the target thread.  Once complete call
  // Resolver::Resolve().  This can be done sync or async.
  // Note: Action should hold Resolver ref until its ready to call Resolve().
  // Note: The "target" thread is determined when the Action is scheduled on
  //       Context.  The Action should not assume any particular thread is used.
  virtual void RunOnTarget(Resolver* aResolver, const QuotaInfo& aQuotaInfo,
                           Data* aOptionalData) = 0;

  // Called on initiating thread when the Action is canceled.  The Action is
  // responsible for calling Resolver::Resolve() as normal; either with a
  // normal error code or NS_ERROR_ABORT.  If CancelOnInitiatingThread() is
  // called after Resolve() has already occurred, then the cancel can be
  // ignored.
  //
  // Cancellation is a best effort to stop processing as soon as possible, but
  // does not guarantee the Action will not run.
  //
  // CancelOnInitiatingThread() may be called more than once.  Subsequent
  // calls should have no effect.
  //
  // Default implementation sets an internal cancellation flag that can be
  // queried with IsCanceled().
  virtual void CancelOnInitiatingThread();

  // Executed on the initiating thread and is passed the nsresult given to
  // Resolver::Resolve().
  virtual void CompleteOnInitiatingThread(nsresult aRv) { }

  // Executed on the initiating thread.  If this Action will operate on the
  // given cache ID then override this to return true.
  virtual bool MatchesCacheId(CacheId aCacheId) const { return false; }

  NS_INLINE_DECL_REFCOUNTING(cache::Action)

protected:
  Action();

  // virtual because deleted through base class pointer
  virtual ~Action();

  // Check if this Action has been canceled.  May be called from any thread,
  // but typically used from the target thread.
  bool IsCanceled() const;

private:
  // Accessible from any thread.
  Atomic<bool> mCanceled;
};

} // namespace cache
} // namespace dom
} // namespace mozilla

#endif // mozilla_dom_cache_Action_h