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/* 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 CacheFileContextEvictor__h__
#define CacheFileContextEvictor__h__
#include "mozilla/UniquePtr.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#include "nsTArray.h"
class nsIFile;
class nsILoadContextInfo;
namespace mozilla {
namespace net {
class CacheIndexIterator;
struct CacheFileContextEvictorEntry {
nsCOMPtr<nsILoadContextInfo> mInfo;
bool mPinned = false;
nsString mOrigin; // it can be empty
PRTime mTimeStamp = 0; // in milliseconds
RefPtr<CacheIndexIterator> mIterator;
};
class CacheFileContextEvictor {
public:
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CacheFileContextEvictor)
CacheFileContextEvictor();
private:
virtual ~CacheFileContextEvictor();
public:
nsresult Init(nsIFile* aCacheDirectory);
void Shutdown();
// Returns number of contexts that are being evicted.
uint32_t ContextsCount();
// Start evicting given context and an origin, if not empty.
nsresult AddContext(nsILoadContextInfo* aLoadContextInfo, bool aPinned,
const nsAString& aOrigin);
// CacheFileIOManager calls this method when CacheIndex's state changes. We
// check whether the index is up to date and start or stop evicting according
// to index's state.
void CacheIndexStateChanged();
// CacheFileIOManager calls this method to check whether an entry file should
// be considered as evicted. It returns true when there is a matching context
// info to the given key and the last modified time of the entry file is
// earlier than the time stamp of the time when the context was added to the
// evictor.
void WasEvicted(const nsACString& aKey, nsIFile* aFile,
bool* aEvictedAsPinned, bool* aEvictedAsNonPinned);
private:
// Writes information about eviction of the given context to the disk. This is
// done for every context added to the evictor to be able to recover eviction
// after a shutdown or crash. When the context file is found after startup, we
// restore mTimeStamp from the last modified time of the file.
nsresult PersistEvictionInfoToDisk(nsILoadContextInfo* aLoadContextInfo,
bool aPinned, const nsAString& aOrigin);
// Once we are done with eviction for the given context, the eviction info is
// removed from the disk.
nsresult RemoveEvictInfoFromDisk(nsILoadContextInfo* aLoadContextInfo,
bool aPinned, const nsAString& aOrigin);
// Tries to load all contexts from the disk. This method is called just once
// after startup.
nsresult LoadEvictInfoFromDisk();
nsresult GetContextFile(nsILoadContextInfo* aLoadContextInfo, bool aPinned,
const nsAString& aOrigin, nsIFile** _retval);
void CreateIterators();
void CloseIterators();
void StartEvicting();
void EvictEntries();
// Whether eviction is in progress
bool mEvicting{false};
// Whether index is up to date. We wait with eviction until the index finishes
// update process when it is outdated. NOTE: We also stop eviction in progress
// when the index is found outdated, the eviction is restarted again once the
// update process finishes.
bool mIndexIsUpToDate{false};
// Whether we already tried to restore unfinished jobs from previous run after
// startup.
static bool sDiskAlreadySearched;
// Array of contexts being evicted.
nsTArray<UniquePtr<CacheFileContextEvictorEntry>> mEntries;
nsCOMPtr<nsIFile> mCacheDirectory;
nsCOMPtr<nsIFile> mEntriesDir;
};
} // namespace net
} // namespace mozilla
#endif