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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* 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 _nsDiskCacheBinding_h_
#define _nsDiskCacheBinding_h_
#include "mozilla/MemoryReporting.h"
#include "nspr.h"
#include "PLDHashTable.h"
#include "nsISupports.h"
#include "nsCacheEntry.h"
#include "nsDiskCacheMap.h"
#include "nsDiskCacheStreams.h"
/******************************************************************************
* nsDiskCacheBinding
*
* Created for disk cache specific data and stored in nsCacheEntry.mData as
* an nsISupports. Also stored in nsDiskCacheHashTable, with collisions
* linked by the PRCList.
*
*****************************************************************************/
class nsDiskCacheDeviceDeactivateEntryEvent;
class nsDiskCacheBinding : public nsISupports, public PRCList {
virtual ~nsDiskCacheBinding();
public:
NS_DECL_THREADSAFE_ISUPPORTS
nsDiskCacheBinding(nsCacheEntry* entry, nsDiskCacheRecord * record);
nsresult EnsureStreamIO();
bool IsActive() { return mCacheEntry != nullptr;}
// XXX make friends
public:
nsCacheEntry* mCacheEntry; // back pointer to parent nsCacheEntry
nsDiskCacheRecord mRecord;
nsDiskCacheStreamIO* mStreamIO; // strong reference
bool mDoomed; // record is not stored in cache map
uint8_t mGeneration; // possibly just reservation
// If set, points to a pending event which will deactivate |mCacheEntry|.
// If not set then either |mCacheEntry| is not deactivated, or it has been
// deactivated but the device returned it from FindEntry() before the event
// fired. In both two latter cases this binding is to be considered valid.
nsDiskCacheDeviceDeactivateEntryEvent *mDeactivateEvent;
};
/******************************************************************************
* Utility Functions
*****************************************************************************/
nsDiskCacheBinding * GetCacheEntryBinding(nsCacheEntry * entry);
/******************************************************************************
* nsDiskCacheBindery
*
* Used to keep track of nsDiskCacheBinding associated with active/bound (and
* possibly doomed) entries. Lookups on 4 byte disk hash to find collisions
* (which need to be doomed, instead of just evicted. Collisions are linked
* using a PRCList to keep track of current generation number.
*
* Used to detect hash number collisions, and find available generation numbers.
*
* Not all nsDiskCacheBinding have a generation number.
*
* Generation numbers may be aquired late, or lost (when data fits in block file)
*
* Collisions can occur:
* BindEntry() - hashnumbers collide (possibly different keys)
*
* Generation number required:
* DeactivateEntry() - metadata written to disk, may require file
* GetFileForEntry() - force data to require file
* writing to stream - data size may require file
*
* Binding can be kept in PRCList in order of generation numbers.
* Binding with no generation number can be Appended to PRCList (last).
*
*****************************************************************************/
class nsDiskCacheBindery {
public:
nsDiskCacheBindery();
~nsDiskCacheBindery();
void Init();
void Reset();
nsDiskCacheBinding * CreateBinding(nsCacheEntry * entry,
nsDiskCacheRecord * record);
nsDiskCacheBinding * FindActiveBinding(uint32_t hashNumber);
void RemoveBinding(nsDiskCacheBinding * binding);
bool ActiveBindings();
size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf);
private:
nsresult AddBinding(nsDiskCacheBinding * binding);
// member variables
static const PLDHashTableOps ops;
PLDHashTable table;
bool initialized;
static const uint32_t kInitialTableLength = 0;
};
#endif /* _nsDiskCacheBinding_h_ */
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