1 files changed, 100 insertions, 0 deletions
diff --git a/netwerk/cache2/CacheFileContextEvictor.h b/netwerk/cache2/CacheFileContextEvictor.h
new file mode 100644
index 0000000000..518d3b7d5f
--- /dev/null
+++ b/netwerk/cache2/CacheFileContextEvictor.h
@@ -0,0 +1,100 @@
+/* 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