Reorganize net/disk_cache into backend specific directories.

net/disk_cache/bitmap.h

-// Copyright (c) 2011 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.
-
-#ifndef NET_DISK_CACHE_BITMAP_H_
-#define NET_DISK_CACHE_BITMAP_H_
-
-#include "base/basictypes.h"
-#include "net/base/net_export.h"
-
-namespace disk_cache {
-
-// This class provides support for simple maps of bits.
-class NET_EXPORT_PRIVATE Bitmap {
- public:
-  Bitmap() : map_(NULL), num_bits_(0), array_size_(0), alloc_(false) {}
-
-  // This constructor will allocate on a uint32 boundary. If |clear_bits| is
-  // false, the bitmap bits will not be initialized.
-  Bitmap(int num_bits, bool clear_bits);
-
-  // Constructs a Bitmap with the actual storage provided by the caller. |map|
-  // has to be valid until this object destruction. |num_bits| is the number of
-  // bits in the bitmap, and |num_words| is the size of |map| in 32-bit words.
-  Bitmap(uint32* map, int num_bits, int num_words);
-
-  ~Bitmap();
-
-  // Resizes the bitmap.
-  // If |num_bits| < Size(), the extra bits will be discarded.
-  // If |num_bits| > Size(), the extra bits will be filled with zeros if
-  // |clear_bits| is true.
-  // This object cannot be using memory provided during construction.
-  void Resize(int num_bits, bool clear_bits);
-
-  // Returns the number of bits in the bitmap.
-  int Size() const { return num_bits_; }
-
-  // Returns the number of 32-bit words in the bitmap.
-  int ArraySize() const { return array_size_; }
-
-  // Sets all the bits to true or false.
-  void SetAll(bool value) {
-    memset(map_, (value ? 0xFF : 0x00), array_size_ * sizeof(*map_));
-  }
-
-  // Clears all bits in the bitmap
-  void Clear() { SetAll(false); }
-
-  // Sets the value, gets the value or toggles the value of a given bit.
-  void Set(int index, bool value);
-  bool Get(int index) const;
-  void Toggle(int index);
-
-  // Directly sets an element of the internal map. Requires |array_index| <
-  // ArraySize();
-  void SetMapElement(int array_index, uint32 value);
-
-  // Gets an entry of the internal map. Requires array_index <
-  // ArraySize()
-  uint32 GetMapElement(int array_index) const;
-
-  // Directly sets the whole internal map. |size| is the number of 32-bit words
-  // to set from |map|. If  |size| > array_size(), it ignores the end of |map|.
-  void SetMap(const uint32* map, int size);
-
-  // Gets a pointer to the internal map.
-  const uint32* GetMap() const { return map_; }
-
-  // Sets a range of bits to |value|.
-  void SetRange(int begin, int end, bool value);
-
-  // Returns true if any bit between begin inclusive and end exclusive is set.
-  // 0 <= |begin| <= |end| <= Size() is required.
-  bool TestRange(int begin, int end, bool value) const;
-
-  // Scans bits starting at bit *|index|, looking for a bit set to |value|. If
-  // it finds that bit before reaching bit index |limit|, sets *|index| to the
-  // bit index and returns true. Otherwise returns false.
-  // Requires |limit| <= Size().
-  //
-  // Note that to use these methods in a loop you must increment the index
-  // after each use, as in:
-  //
-  //  for (int index = 0 ; map.FindNextBit(&index, limit, value) ; ++index) {
-  //    DoSomethingWith(index);
-  //  }
-  bool FindNextBit(int* index, int limit, bool value) const;
-
-  // Finds the first offset >= *|index| and < |limit| that has its bit set.
-  // See FindNextBit() for more info.
-  bool FindNextSetBitBeforeLimit(int* index, int limit) const {
-    return FindNextBit(index, limit, true);
-  }
-
-  // Finds the first offset >= *|index| that has its bit set.
-  // See FindNextBit() for more info.
-  bool FindNextSetBit(int *index) const {
-    return FindNextSetBitBeforeLimit(index, num_bits_);
-  }
-
-  // Scans bits starting at bit *|index|, looking for a bit set to |value|. If
-  // it finds that bit before reaching bit index |limit|, sets *|index| to the
-  // bit index and then counts the number of consecutive bits set to |value|
-  // (before reaching |limit|), and returns that count. If no bit is found
-  // returns 0. Requires |limit| <= Size().
-  int FindBits(int* index, int limit, bool value) const;
-
-  // Returns number of allocated words required for a bitmap of size |num_bits|.
-  static int RequiredArraySize(int num_bits) {
-    // Force at least one allocated word.
-    if (num_bits <= kIntBits)
-      return 1;
-
-    return (num_bits + kIntBits - 1) >> kLogIntBits;
-  }
-
- private:
-  static const int kIntBits = sizeof(uint32) * 8;
-  static const int kLogIntBits = 5;  // 2^5 == 32 bits per word.
-
-  // Sets |len| bits from |start| to |value|. All the bits to be set should be
-  // stored in the same word, and len < kIntBits.
-  void SetWordBits(int start, int len, bool value);
-
-  uint32* map_;           // The bitmap.
-  int num_bits_;          // The upper bound of the bitmap.
-  int array_size_;        // The physical size (in uint32s) of the bitmap.
-  bool alloc_;            // Whether or not we allocated the memory.
-
-  DISALLOW_COPY_AND_ASSIGN(Bitmap);
-};
-
-}  // namespace disk_cache
-
-#endif  // NET_DISK_CACHE_BITMAP_H_