org.apache.hadoop.hbase.util
Interface ByteRange

All Superinterfaces:

Comparable<ByteRange>

All Known Subinterfaces:

PositionedByteRange

All Known Implementing Classes:

SimpleByteRange, SimplePositionedByteRange

@InterfaceAudience.Public
@InterfaceStability.Evolving
public interface ByteRange
extends Comparable<ByteRange>

Lightweight, reusable class for specifying ranges of byte[]'s.

ByteRange maintains an underlying byte[] and a viewport into that byte[] as a range of bytes. The ByteRange is a mutable, reusable object, so the underlying byte[] can be modified after instantiation. This is done using the set(byte[]) and unset() methods. Direct access to the byte[] is also available via getBytes(). The viewport is defined by an offset into the byte[] and a length. The range of bytes is 0-indexed, and is accessed by index via the get(int) and put(int, byte) methods.

This interface differs from ByteBuffer:

On-heap bytes only

Raw byte access only; does not encode other primitives.

Implements equals(Object), #hashCode(), and #compareTo(ByteRange) so that it can be used in standard java Collections. Comparison operations are lexicographic, which is native to HBase.

Allows the addition of simple core methods like the deep and shallow copy methods.

Can be reused in tight loops like a major compaction which can save significant amounts of garbage. (Without reuse, we throw off garbage like this thing.)

Mutable, and always evaluates #equals(Object), #hashCode(), and #compareTo(ByteRange) based on the current contents.

Can contain convenience methods for comparing, printing, cloning, spawning new arrays, copying to other arrays, etc. Please place non-core methods into ByteRangeUtils.

Method Summary

ByteRange	deepCopy() Create a new ByteRange with new backing byte[] containing a copy of the content from this range's window.
void	deepCopySubRangeTo(int innerOffset, int copyLength, byte[] destination, int destinationOffset) Wrapper for System.arraycopy.
void	deepCopyTo(byte[] destination, int destinationOffset) Wrapper for System.arraycopy.
byte[]	deepCopyToNewArray() Instantiate a new byte[] with exact length, which is at least 24 bytes + length.
byte	get(int index) Retrieve the byte at index.
ByteRange	get(int index, byte[] dst) Fill dst with bytes from the range, starting from index.
ByteRange	get(int index, byte[] dst, int offset, int length) Fill dst with bytes from the range, starting from index.
byte[]	getBytes() The underlying byte[].
int	getLength() The length of the range.
int	getOffset() The offset, the index into the underlying byte[] at which this range begins.
boolean	isEmpty()
ByteRange	put(int index, byte val) Store val at index.
ByteRange	put(int index, byte[] val) Store val at index.
ByteRange	put(int index, byte[] val, int offset, int length) Store length bytes from val into this range, starting at index.
ByteRange	set(byte[] bytes) Reuse this ByteRange over a new byte[].
ByteRange	set(byte[] bytes, int offset, int length) Reuse this ByteRange over a new byte[].
ByteRange	set(int capacity) Reuse this ByteRange over a new byte[].
ByteRange	setLength(int length) Update the length of this range.
ByteRange	setOffset(int offset) Update the beginning of this range.
ByteRange	shallowCopy() Create a new ByteRange that points at this range's byte[].
ByteRange	shallowCopySubRange(int innerOffset, int copyLength) Create a new ByteRange that points at this range's byte[].
ByteRange	unset() Nullifies this ByteRange.

Methods inherited from interface java.lang.Comparable

compareTo

Method Detail

getBytes

byte[] getBytes()

The underlying byte[].

unset

ByteRange unset()

Nullifies this ByteRange. That is, it becomes a husk, being a range over no byte[] whatsoever.

Returns:

this

set

ByteRange set(int capacity)

Reuse this ByteRange over a new byte[]. offset is set to 0 and length is set to capacity.

Parameters:

capacity - the size of a new byte[].

Returns:

this

set

ByteRange set(byte[] bytes)

Reuse this ByteRange over a new byte[]. offset is set to 0 and length is set to bytes.length. A null bytes IS supported, in which case this method will behave equivalently to unset().

Parameters:

bytes - the array to wrap.

Returns:

this

set

ByteRange set(byte[] bytes,
              int offset,
              int length)

Reuse this ByteRange over a new byte[]. A null bytes IS supported, in which case this method will behave equivalently to unset(), regardless of the values of offset and length.

Parameters:

bytes - The array to wrap.

offset - The offset into bytes considered the beginning of this range.

length - The length of this range.

Returns:

this.

getOffset

int getOffset()

The offset, the index into the underlying byte[] at which this range begins.

See Also:

getBytes()

setOffset

ByteRange setOffset(int offset)

Update the beginning of this range. offset + length may not be greater than bytes.length.

Parameters:

offset - the new start of this range.

Returns:

this.

getLength

int getLength()

The length of the range.

setLength

ByteRange setLength(int length)

Update the length of this range. offset + length should not be greater than bytes.length.

Parameters:

length - The new length of this range.

Returns:

this.

isEmpty

boolean isEmpty()

Returns:

true when this range is of zero length, false otherwise.

get

byte get(int index)

Retrieve the byte at index.

Parameters:

index - zero-based index into this range.

Returns:

single byte at index.

get

ByteRange get(int index,
              byte[] dst)

Fill dst with bytes from the range, starting from index.

Parameters:

index - zero-based index into this range.

dst - the destination of the copy.

Returns:

this.

get

ByteRange get(int index,
              byte[] dst,
              int offset,
              int length)

Fill dst with bytes from the range, starting from index. length bytes are copied into dst, starting at offset.

Parameters:

index - zero-based index into this range.

dst - the destination of the copy.

offset - the offset into dst to start the copy.

length - the number of bytes to copy into dst.

Returns:

this.

put

ByteRange put(int index,
              byte val)

Store val at index.

Parameters:

index - the index in the range where val is stored.

val - the value to store.

Returns:

this.

put

ByteRange put(int index,
              byte[] val)

Store val at index.

Parameters:

index - the index in the range where val is stored.

val - the value to store.

Returns:

this.

put

ByteRange put(int index,
              byte[] val,
              int offset,
              int length)

Store length bytes from val into this range, starting at index. Bytes from val are copied starting at offset into the range.

Parameters:

index - position in this range to start the copy.

val - the value to store.

offset - the offset in val from which to start copying.

length - the number of bytes to copy from val.

Returns:

this.

deepCopyToNewArray

byte[] deepCopyToNewArray()

Instantiate a new byte[] with exact length, which is at least 24 bytes + length. Copy the contents of this range into it.

Returns:

The newly cloned byte[].

deepCopy

ByteRange deepCopy()

Create a new ByteRange with new backing byte[] containing a copy of the content from this range's window.

Returns:

Deep copy

deepCopyTo

void deepCopyTo(byte[] destination,
                int destinationOffset)

Wrapper for System.arraycopy. Copy the contents of this range into the provided array.

Parameters:

destination - Copy to this array

destinationOffset - First index in the destination array.

deepCopySubRangeTo

void deepCopySubRangeTo(int innerOffset,
                        int copyLength,
                        byte[] destination,
                        int destinationOffset)

Wrapper for System.arraycopy. Copy the contents of this range into the provided array.

Parameters:

innerOffset - Start copying from this index in this source ByteRange. First byte copied is bytes[offset + innerOffset]

copyLength - Copy this many bytes

destination - Copy to this array

destinationOffset - First index in the destination array.

shallowCopy

ByteRange shallowCopy()

Create a new ByteRange that points at this range's byte[]. Modifying the shallowCopy will modify the bytes in this range's array. Pass over the hash code if it is already cached.

Returns:

new ByteRange object referencing this range's byte[].

shallowCopySubRange

ByteRange shallowCopySubRange(int innerOffset,
                              int copyLength)

Create a new ByteRange that points at this range's byte[]. The new range can have different values for offset and length, but modifying the shallowCopy will modify the bytes in this range's array. Pass over the hash code if it is already cached.

Parameters:

innerOffset - First byte of clone will be this.offset + copyOffset.

copyLength - Number of bytes in the clone.

Returns:

new ByteRange object referencing this range's byte[].