Remove //net (except for Android test stuff) and sdch

net/disk_cache/blockfile/rankings.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// See net/disk_cache/disk_cache.h for the public interface.
-
-#ifndef NET_DISK_CACHE_BLOCKFILE_RANKINGS_H_
-#define NET_DISK_CACHE_BLOCKFILE_RANKINGS_H_
-
-#include <list>
-
-#include "base/memory/scoped_ptr.h"
-#include "net/disk_cache/blockfile/addr.h"
-#include "net/disk_cache/blockfile/mapped_file.h"
-#include "net/disk_cache/blockfile/storage_block.h"
-
-namespace disk_cache {
-
-class BackendImpl;
-struct LruData;
-struct RankingsNode;
-typedef StorageBlock<RankingsNode> CacheRankingsBlock;
-
-// Type of crashes generated for the unit tests.
-enum RankCrashes {
-  NO_CRASH = 0,
-  INSERT_EMPTY_1,
-  INSERT_EMPTY_2,
-  INSERT_EMPTY_3,
-  INSERT_ONE_1,
-  INSERT_ONE_2,
-  INSERT_ONE_3,
-  INSERT_LOAD_1,
-  INSERT_LOAD_2,
-  REMOVE_ONE_1,
-  REMOVE_ONE_2,
-  REMOVE_ONE_3,
-  REMOVE_ONE_4,
-  REMOVE_HEAD_1,
-  REMOVE_HEAD_2,
-  REMOVE_HEAD_3,
-  REMOVE_HEAD_4,
-  REMOVE_TAIL_1,
-  REMOVE_TAIL_2,
-  REMOVE_TAIL_3,
-  REMOVE_LOAD_1,
-  REMOVE_LOAD_2,
-  REMOVE_LOAD_3,
-  MAX_CRASH
-};
-
-// This class handles the ranking information for the cache.
-class Rankings {
- public:
-  // Possible lists of entries.
-  enum List {
-    NO_USE = 0,   // List of entries that have not been reused.
-    LOW_USE,      // List of entries with low reuse.
-    HIGH_USE,     // List of entries with high reuse.
-    RESERVED,     // Reserved for future use.
-    DELETED,      // List of recently deleted or doomed entries.
-    LAST_ELEMENT
-  };
-
-  // This class provides a specialized version of scoped_ptr, that calls
-  // Rankings whenever a CacheRankingsBlock is deleted, to keep track of cache
-  // iterators that may go stale.
-  class ScopedRankingsBlock : public scoped_ptr<CacheRankingsBlock> {
-   public:
-    ScopedRankingsBlock();
-    explicit ScopedRankingsBlock(Rankings* rankings);
-    ScopedRankingsBlock(Rankings* rankings, CacheRankingsBlock* node);
-
-    ~ScopedRankingsBlock() {
-      rankings_->FreeRankingsBlock(get());
-    }
-
-    void set_rankings(Rankings* rankings) {
-      rankings_ = rankings;
-    }
-
-    // scoped_ptr::reset will delete the object.
-    void reset(CacheRankingsBlock* p = NULL) {
-      if (p != get())
-        rankings_->FreeRankingsBlock(get());
-      scoped_ptr<CacheRankingsBlock>::reset(p);
-    }
-
-   private:
-    Rankings* rankings_;
-    DISALLOW_COPY_AND_ASSIGN(ScopedRankingsBlock);
-  };
-
-  // If we have multiple lists, we have to iterate through all at the same time.
-  // This structure keeps track of where we are on the iteration.
-  struct Iterator {
-    Iterator();
-    void Reset();
-
-    List list;                     // Which entry was returned to the user.
-    CacheRankingsBlock* nodes[3];  // Nodes on the first three lists.
-    Rankings* my_rankings;
-  };
-
-  Rankings();
-  ~Rankings();
-
-  bool Init(BackendImpl* backend, bool count_lists);
-
-  // Restores original state, leaving the object ready for initialization.
-  void Reset();
-
-  // Inserts a given entry at the head of the queue.
-  void Insert(CacheRankingsBlock* node, bool modified, List list);
-
-  // Removes a given entry from the LRU list. If |strict| is true, this method
-  // assumes that |node| is not pointed to by an active iterator. On the other
-  // hand, removing that restriction allows the current "head" of an iterator
-  // to be removed from the list (basically without control of the code that is
-  // performing the iteration), so it should be used with extra care.
-  void Remove(CacheRankingsBlock* node, List list, bool strict);
-
-  // Moves a given entry to the head.
-  void UpdateRank(CacheRankingsBlock* node, bool modified, List list);
-
-  // Iterates through the list.
-  CacheRankingsBlock* GetNext(CacheRankingsBlock* node, List list);
-  CacheRankingsBlock* GetPrev(CacheRankingsBlock* node, List list);
-  void FreeRankingsBlock(CacheRankingsBlock* node);
-
-  // Controls tracking of nodes used for enumerations.
-  void TrackRankingsBlock(CacheRankingsBlock* node, bool start_tracking);
-
-  // Peforms a simple self-check of the lists, and returns the number of items
-  // or an error code (negative value).
-  int SelfCheck();
-
-  // Returns false if the entry is clearly invalid. from_list is true if the
-  // node comes from the LRU list.
-  bool SanityCheck(CacheRankingsBlock* node, bool from_list) const;
-  bool DataSanityCheck(CacheRankingsBlock* node, bool from_list) const;
-
-  // Sets the |contents| field of |node| to |address|.
-  void SetContents(CacheRankingsBlock* node, CacheAddr address);
-
- private:
-  typedef std::pair<CacheAddr, CacheRankingsBlock*> IteratorPair;
-  typedef std::list<IteratorPair> IteratorList;
-
-  void ReadHeads();
-  void ReadTails();
-  void WriteHead(List list);
-  void WriteTail(List list);
-
-  // Gets the rankings information for a given rankings node. We may end up
-  // sharing the actual memory with a loaded entry, but we are not taking a
-  // reference to that entry, so |rankings| must be short lived.
-  bool GetRanking(CacheRankingsBlock* rankings);
-
-  // Makes |rankings| suitable to live a long life.
-  void ConvertToLongLived(CacheRankingsBlock* rankings);
-
-  // Finishes a list modification after a crash.
-  void CompleteTransaction();
-  void FinishInsert(CacheRankingsBlock* rankings);
-  void RevertRemove(CacheRankingsBlock* rankings);
-
-  // Returns false if node is not properly linked. This method may change the
-  // provided |list| to reflect the list where this node is actually stored.
-  bool CheckLinks(CacheRankingsBlock* node, CacheRankingsBlock* prev,
-                  CacheRankingsBlock* next, List* list);
-
-  // Checks the links between two consecutive nodes.
-  bool CheckSingleLink(CacheRankingsBlock* prev, CacheRankingsBlock* next);
-
-  // Peforms a simple check of the list, and returns the number of items or an
-  // error code (negative value).
-  int CheckList(List list);
-
-  // Walks a list in the desired direction until the nodes |end1| or |end2| are
-  // reached. Returns an error code (0 on success), the number of items verified
-  // and the addresses of the last nodes visited.
-  int CheckListSection(List list, Addr end1, Addr end2, bool forward,
-                       Addr* last, Addr* second_last, int* num_items);
-
-  // Returns true if addr is the head or tail of any list. When there is a
-  // match |list| will contain the list number for |addr|.
-  bool IsHead(CacheAddr addr, List* list) const;
-  bool IsTail(CacheAddr addr, List* list) const;
-
-  // Updates the iterators whenever node is being changed.
-  void UpdateIterators(CacheRankingsBlock* node);
-
-  // Invalidates the iterators pointing to this node.
-  void InvalidateIterators(CacheRankingsBlock* node);
-
-  // Keeps track of the number of entries on a list.
-  void IncrementCounter(List list);
-  void DecrementCounter(List list);
-
-  bool init_;
-  bool count_lists_;
-  Addr heads_[LAST_ELEMENT];
-  Addr tails_[LAST_ELEMENT];
-  BackendImpl* backend_;
-  LruData* control_data_;  // Data related to the LRU lists.
-  IteratorList iterators_;
-
-  DISALLOW_COPY_AND_ASSIGN(Rankings);
-};
-
-}  // namespace disk_cache
-
-#endif  // NET_DISK_CACHE_BLOCKFILE_RANKINGS_H_