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Diffstat (limited to 'netwerk/cache/nsDiskCacheBinding.h')
-rw-r--r-- | netwerk/cache/nsDiskCacheBinding.h | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/netwerk/cache/nsDiskCacheBinding.h b/netwerk/cache/nsDiskCacheBinding.h new file mode 100644 index 000000000..63c2094ce --- /dev/null +++ b/netwerk/cache/nsDiskCacheBinding.h @@ -0,0 +1,123 @@ +/* -*- 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_ */ |