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Diffstat (limited to 'chromium/net/disk_cache/rankings.h')
| -rw-r--r-- | chromium/net/disk_cache/rankings.h | 214 |
1 files changed, 0 insertions, 214 deletions
diff --git a/chromium/net/disk_cache/rankings.h b/chromium/net/disk_cache/rankings.h deleted file mode 100644 index cd94eaf1c59..00000000000 --- a/chromium/net/disk_cache/rankings.h +++ /dev/null @@ -1,214 +0,0 @@ -// 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_RANKINGS_H_ -#define NET_DISK_CACHE_RANKINGS_H_ - -#include <list> - -#include "base/memory/scoped_ptr.h" -#include "net/disk_cache/addr.h" -#include "net/disk_cache/mapped_file.h" -#include "net/disk_cache/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 { - explicit Iterator(Rankings* rankings); - ~Iterator(); - - 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_RANKINGS_H_ |