netwerk/cache2/CacheFileContextEvictor.h
author Tom Schuster <evilpies@gmail.com>
Sun, 14 Jun 2020 18:59:08 +0000
changeset 535622 c68fe15a81fc2dc9fc5765f3be2573519c09b6c1
parent 513365 6107ec699b838b776aa6c5385c5d4f9e5a27b25c
permissions -rw-r--r--
Bug 1644878 - Don't define Map/Set identical iterator methods in self-hosted JS. r=arai I think we were defining those methods in self-hosted JS, because that automatically gives us the property that they all have the same identity. This causes bad error messages. Instead redefine them in the finishInit ClassSpec hook. We still have the "wrong" methods in the 'methods' array so that JSXray tests continue to pass. Differential Revision: https://phabricator.services.mozilla.com/D79615

/* 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 "nsTArray.h"
#include "nsCOMPtr.h"

class nsIFile;
class nsILoadContextInfo;

namespace mozilla {
namespace net {

class CacheIndexIterator;

struct CacheFileContextEvictorEntry {
  nsCOMPtr<nsILoadContextInfo> mInfo;
  bool mPinned;
  nsString mOrigin;   // it can be empty
  PRTime mTimeStamp;  // 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;
  // 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;
  // 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