SkBlockAllocator::Block Class Reference

#include <SkBlockAllocator.h>

Public Member Functions
	~Block ()
void	operator delete (void *p)
template<size_t Align = 1, size_t Padding = 0>
int	avail () const
template<size_t Align = 1, size_t Padding = 0>
int	firstAlignedOffset () const
void *	ptr (int offset)
const void *	ptr (int offset) const
int	metadata () const
void	setMetadata (int value)
bool	release (int start, int end)
bool	resize (int start, int end, int deltaBytes)

Friends
class	SkBlockAllocator

Detailed Description

Definition at line 71 of file SkBlockAllocator.h.

Constructor & Destructor Documentation

~Block()

SkBlockAllocator::Block::~Block

(

)

Definition at line 48 of file SkBlockAllocator.cpp.

                              {
    this->unpoisonRange(kDataStart, fSize);
 
    SkASSERT(fSentinel == kAssignedMarker);
    SkDEBUGCODE(fSentinel = kFreedMarker;) // FWIW
}

Member Function Documentation

avail()

template<size_t Align = 1, size_t Padding = 0>

int SkBlockAllocator::Block::avail ( ) const

inline

Definition at line 78 of file SkBlockAllocator.h.

{ return std::max(0, fSize - this->cursor<Align, Padding>()); }

firstAlignedOffset()

template<size_t Align = 1, size_t Padding = 0>

int SkBlockAllocator::Block::firstAlignedOffset ( ) const

inline

Definition at line 85 of file SkBlockAllocator.h.

{ return this->alignedOffset<Align, Padding>(kDataStart); }

metadata()

int SkBlockAllocator::Block::metadata ( ) const

inline

Definition at line 96 of file SkBlockAllocator.h.

{ return fMetadata; }

operator delete()

void SkBlockAllocator::Block::operator delete ( void *  p )

inline

Definition at line 74 of file SkBlockAllocator.h.

{ ::operator delete(p); }

ptr() [1/2]

void * SkBlockAllocator::Block::ptr ( int  offset )

inline

Definition at line 88 of file SkBlockAllocator.h.

                              {
            SkASSERT(offset >= kDataStart && offset < fSize);
            return reinterpret_cast<char*>(this) + offset;
        }

ptr() [2/2]

const void * SkBlockAllocator::Block::ptr ( int  offset ) const

inline

Definition at line 92 of file SkBlockAllocator.h.

{ return const_cast<Block*>(this)->ptr(offset); }

release()

bool SkBlockAllocator::Block::release ( int  start, int  end  )

inline

Release the byte range between offset 'start' (inclusive) and 'end' (exclusive). This will return true if those bytes were successfully reclaimed, i.e. a subsequent allocation request could occupy the space. Regardless of return value, the provided byte range that [start, end) represents should not be used until it's re-allocated with allocate<...>().

Definition at line 677 of file SkBlockAllocator.h.

                                                      {
    SkASSERT(fSentinel == kAssignedMarker);
    SkASSERT(start >= kDataStart && end <= fSize && start < end);
 
    this->poisonRange(start, end);
 
    if (fCursor == end) {
        fCursor = start;
        return true;
    } else {
        return false;
    }
}

resize()

bool SkBlockAllocator::Block::resize ( int  start, int  end, int  deltaBytes  )

inline

Resize a previously reserved byte range of offset 'start' (inclusive) to 'end' (exclusive). 'deltaBytes' is the SIGNED change to length of the reservation.

When negative this means the reservation is shrunk and the new length is (end - start - |deltaBytes|). If this new length would be 0, the byte range can no longer be used (as if it were released instead). Asserts that it would not shrink the reservation below 0.

If 'deltaBytes' is positive, the allocator attempts to increase the length of the reservation. If 'deltaBytes' is less than or equal to avail() and it was the last allocation in the block, it can be resized. If there is not enough available bytes to accommodate the increase in size, or another allocation is blocking the increase in size, then false will be returned and the reserved byte range is unmodified.

Definition at line 646 of file SkBlockAllocator.h.

                                                                     {
    SkASSERT(fSentinel == kAssignedMarker);
    SkASSERT(start >= kDataStart && end <= fSize && start < end);
 
    if (deltaBytes > kMaxAllocationSize || deltaBytes < -kMaxAllocationSize) {
        // Cannot possibly satisfy the resize and could overflow subsequent math
        return false;
    }
    if (fCursor == end) {
        int nextCursor = end + deltaBytes;
        SkASSERT(nextCursor >= start);
        // We still check nextCursor >= start for release builds that wouldn't assert.
        if (nextCursor <= fSize && nextCursor >= start) {
            if (nextCursor < fCursor) {
                // The allocation got smaller; poison the space that can no longer be used.
                this->poisonRange(nextCursor + 1, end);
            } else {
                // The allocation got larger; unpoison the space that can now be used.
                this->unpoisonRange(end, nextCursor);
            }
 
            fCursor = nextCursor;
            return true;
        }
    }
    return false;
}

setMetadata()

void SkBlockAllocator::Block::setMetadata ( int  value )

inline

Definition at line 97 of file SkBlockAllocator.h.

{ fMetadata = value; }

Friends And Related Function Documentation

SkBlockAllocator

friend class SkBlockAllocator

friend

Definition at line 124 of file SkBlockAllocator.h.

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The documentation for this class was generated from the following files:

• third_party/skia/src/base/SkBlockAllocator.h
• third_party/skia/src/base/SkBlockAllocator.cpp