asiva@google.com
f120af8463
Add a RawBitmap object and a bitmap builder. Review URL: https://chromiumcodereview.appspot.com//9701010 git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@5502 260f80e4-7a28-3924-810f-c04153c831b5
68 lines
1.9 KiB
C++
68 lines
1.9 KiB
C++
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
|
|
// for details. All rights reserved. Use of this source code is governed by a
|
|
// BSD-style license that can be found in the LICENSE file.
|
|
|
|
#ifndef VM_BITMAP_H_
|
|
#define VM_BITMAP_H_
|
|
|
|
#include "vm/allocation.h"
|
|
|
|
namespace dart {
|
|
|
|
// Forward declarations.
|
|
class RawStackmap;
|
|
class Stackmap;
|
|
|
|
|
|
// BitmapBuilder is used to build a bitmap. The implementation is optimized for
|
|
// a dense set of small bit maps without an upper bound (e.g: a pointer map
|
|
// description of a stack).
|
|
class BitmapBuilder : public ZoneAllocated {
|
|
public:
|
|
BitmapBuilder() : size_in_bytes_(kInitialSizeInBytes),
|
|
bit_list_(bit_list_data_) {
|
|
memset(bit_list_data_, 0, kInitialSizeInBytes);
|
|
}
|
|
|
|
intptr_t SizeInBits() const { return (size_in_bytes_ * kBitsPerByte); }
|
|
intptr_t SizeInBytes() const { return size_in_bytes_; }
|
|
|
|
// Get/Set individual bits in the bitmap, set expands the underlying bitmap
|
|
// if needed.
|
|
bool Get(intptr_t bit_offset) const;
|
|
void Set(intptr_t bit_offset, bool value);
|
|
|
|
// Return the bit offset of the highest bit set.
|
|
intptr_t Maximum() const;
|
|
|
|
// Return the bit offset of the lowest bit set.
|
|
intptr_t Minimum() const;
|
|
|
|
// Sets min..max (inclusive) to value.
|
|
void SetRange(intptr_t min, intptr_t max, bool value);
|
|
|
|
// Replicates the bit map setting of the passed in Stackmap object.
|
|
void SetBits(const Stackmap& bitmap);
|
|
|
|
private:
|
|
static const intptr_t kInitialSizeInBytes = 16;
|
|
static const intptr_t kIncrementSizeInBytes = 16;
|
|
|
|
bool InRange(intptr_t offset) const {
|
|
return (offset >= 0) && (offset < SizeInBits());
|
|
}
|
|
|
|
bool GetBit(intptr_t bit_offset) const;
|
|
void SetBit(intptr_t bit_offset, bool value);
|
|
|
|
intptr_t size_in_bytes_;
|
|
uint8_t bit_list_data_[kInitialSizeInBytes];
|
|
uint8_t* bit_list_;
|
|
|
|
DISALLOW_COPY_AND_ASSIGN(BitmapBuilder);
|
|
};
|
|
|
|
} // namespace dart
|
|
|
|
#endif // VM_BITMAP_H_
|