Class ByteBuffersDataOutput
- java.lang.Object
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- org.apache.lucene.store.DataOutput
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- org.apache.lucene.store.ByteBuffersDataOutput
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- All Implemented Interfaces:
Accountable
public final class ByteBuffersDataOutput extends DataOutput implements Accountable
ADataOutputstoring data in a list ofByteBuffers.
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Nested Class Summary
Nested Classes Modifier and Type Class Description static classByteBuffersDataOutput.ByteBufferRecyclerAn implementation of aByteBufferallocation and recycling policy.
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Field Summary
Fields Modifier and Type Field Description static IntFunction<ByteBuffer>ALLOCATE_BB_ON_HEAPstatic intDEFAULT_MAX_BITS_PER_BLOCKDefaultmaxBitsPerBlockstatic intDEFAULT_MIN_BITS_PER_BLOCKDefaultminBitsPerBlockstatic intLIMIT_MAX_BITS_PER_BLOCKLargestmaxBitsPerBlockallowedstatic intLIMIT_MIN_BITS_PER_BLOCKSmallestminBitsPerBlockallowedstatic Consumer<ByteBuffer>NO_REUSEA singleton instance of "no-reuse" buffer strategy.-
Fields inherited from interface org.apache.lucene.util.Accountable
NULL_ACCOUNTABLE
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Constructor Summary
Constructors Constructor Description ByteBuffersDataOutput()Creates a new output with all defaults.ByteBuffersDataOutput(int minBitsPerBlock, int maxBitsPerBlock, IntFunction<ByteBuffer> blockAllocate, Consumer<ByteBuffer> blockReuse)Expert: Creates a new output with custom parameters.ByteBuffersDataOutput(long expectedSize)Create a new output, suitable for writing a file of aroundexpectedSizebytes.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description voidcopyBytes(DataInput input, long numBytes)Copy numBytes bytes from input to ourself.voidcopyTo(DataOutput output)Copy the current content of this object into anotherDataOutput.static ByteBuffersDataOutputnewResettableInstance()longramBytesUsed()Return the memory usage of this object in bytes.voidreset()This method resets this object to a clean (zero-size) state and publishes any currently allocated buffers for reuse to the reuse strategy provided in the constructor.longsize()byte[]toArrayCopy()Return a contiguous array with the current content written to the output.ArrayList<ByteBuffer>toBufferList()Return a list of read-only view ofByteBufferblocks over the current content written to the output.ByteBuffersDataInputtoDataInput()Return aByteBuffersDataInputfor the set of current buffers (toBufferList()).StringtoString()ArrayList<ByteBuffer>toWriteableBufferList()Returns a list of writeable blocks over the (source) content buffers.voidwriteByte(byte b)Writes a single byte.voidwriteBytes(byte[] b)voidwriteBytes(byte[] b, int length)Writes an array of bytes.voidwriteBytes(byte[] src, int offset, int length)Writes an array of bytes.voidwriteBytes(ByteBuffer buffer)voidwriteInt(int v)Writes an int as four bytes (LE byte order).voidwriteLong(long v)Writes a long as eight bytes (LE byte order).voidwriteMapOfStrings(Map<String,String> map)Writes a String map.voidwriteSetOfStrings(Set<String> set)Writes a String set.voidwriteShort(short v)Writes a short as two bytes (LE byte order).voidwriteString(String v)Writes a string.-
Methods inherited from class org.apache.lucene.store.DataOutput
writeGroupVInts, writeVInt, writeVLong, writeZInt, writeZLong
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.apache.lucene.util.Accountable
getChildResources
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Field Detail
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ALLOCATE_BB_ON_HEAP
public static final IntFunction<ByteBuffer> ALLOCATE_BB_ON_HEAP
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NO_REUSE
public static final Consumer<ByteBuffer> NO_REUSE
A singleton instance of "no-reuse" buffer strategy.
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DEFAULT_MIN_BITS_PER_BLOCK
public static final int DEFAULT_MIN_BITS_PER_BLOCK
DefaultminBitsPerBlock- See Also:
- Constant Field Values
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DEFAULT_MAX_BITS_PER_BLOCK
public static final int DEFAULT_MAX_BITS_PER_BLOCK
DefaultmaxBitsPerBlock- See Also:
- Constant Field Values
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LIMIT_MIN_BITS_PER_BLOCK
public static final int LIMIT_MIN_BITS_PER_BLOCK
SmallestminBitsPerBlockallowed- See Also:
- Constant Field Values
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LIMIT_MAX_BITS_PER_BLOCK
public static final int LIMIT_MAX_BITS_PER_BLOCK
LargestmaxBitsPerBlockallowed- See Also:
- Constant Field Values
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Constructor Detail
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ByteBuffersDataOutput
public ByteBuffersDataOutput(long expectedSize)
Create a new output, suitable for writing a file of aroundexpectedSizebytes.Memory allocation will be optimized based on the
expectedSizehint, so that there is less overhead for larger files.- Parameters:
expectedSize- estimated size of the output file
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ByteBuffersDataOutput
public ByteBuffersDataOutput()
Creates a new output with all defaults.
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ByteBuffersDataOutput
public ByteBuffersDataOutput(int minBitsPerBlock, int maxBitsPerBlock, IntFunction<ByteBuffer> blockAllocate, Consumer<ByteBuffer> blockReuse)Expert: Creates a new output with custom parameters.- Parameters:
minBitsPerBlock- minimum bits per blockmaxBitsPerBlock- maximum bits per blockblockAllocate- block allocatorblockReuse- block recycler
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Method Detail
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writeByte
public void writeByte(byte b)
Description copied from class:DataOutputWrites a single byte.The most primitive data type is an eight-bit byte. Files are accessed as sequences of bytes. All other data types are defined as sequences of bytes, so file formats are byte-order independent.
- Specified by:
writeBytein classDataOutput- See Also:
DataInput.readByte()
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writeBytes
public void writeBytes(byte[] src, int offset, int length)Description copied from class:DataOutputWrites an array of bytes.- Specified by:
writeBytesin classDataOutput- Parameters:
src- the bytes to writeoffset- the offset in the byte arraylength- the number of bytes to write- See Also:
DataInput.readBytes(byte[],int,int)
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writeBytes
public void writeBytes(byte[] b, int length)Description copied from class:DataOutputWrites an array of bytes.- Overrides:
writeBytesin classDataOutput- Parameters:
b- the bytes to writelength- the number of bytes to write- See Also:
DataInput.readBytes(byte[],int,int)
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writeBytes
public void writeBytes(byte[] b)
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writeBytes
public void writeBytes(ByteBuffer buffer)
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toBufferList
public ArrayList<ByteBuffer> toBufferList()
Return a list of read-only view ofByteBufferblocks over the current content written to the output.
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toWriteableBufferList
public ArrayList<ByteBuffer> toWriteableBufferList()
Returns a list of writeable blocks over the (source) content buffers.This method returns the raw content of source buffers that may change over the lifetime of this object (blocks can be recycled or discarded, for example). Most applications should favor calling
toBufferList()which returns a read-only view over the content of the source buffers.The difference between
toBufferList()andtoWriteableBufferList()is that read-only view of source buffers will always returnfalsefromByteBuffer.hasArray()(which sometimes may be required to avoid double copying).
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toDataInput
public ByteBuffersDataInput toDataInput()
Return aByteBuffersDataInputfor the set of current buffers (toBufferList()).
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toArrayCopy
public byte[] toArrayCopy()
Return a contiguous array with the current content written to the output. The returned array is always a copy (can be mutated).If the
size()of the underlying buffers exceeds maximum size of Java array, anRuntimeExceptionwill be thrown.
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copyBytes
public void copyBytes(DataInput input, long numBytes) throws IOException
Description copied from class:DataOutputCopy numBytes bytes from input to ourself.- Overrides:
copyBytesin classDataOutput- Throws:
IOException
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copyTo
public void copyTo(DataOutput output) throws IOException
Copy the current content of this object into anotherDataOutput.- Throws:
IOException
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size
public long size()
- Returns:
- The number of bytes written to this output so far.
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writeShort
public void writeShort(short v)
Description copied from class:DataOutputWrites a short as two bytes (LE byte order).- Overrides:
writeShortin classDataOutput- See Also:
DataInput.readShort(),BitUtil.VH_LE_SHORT
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writeInt
public void writeInt(int v)
Description copied from class:DataOutputWrites an int as four bytes (LE byte order).- Overrides:
writeIntin classDataOutput- See Also:
DataInput.readInt(),BitUtil.VH_LE_INT
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writeLong
public void writeLong(long v)
Description copied from class:DataOutputWrites a long as eight bytes (LE byte order).- Overrides:
writeLongin classDataOutput- See Also:
DataInput.readLong(),BitUtil.VH_LE_LONG
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writeString
public void writeString(String v)
Description copied from class:DataOutputWrites a string.Writes strings as UTF-8 encoded bytes. First the length, in bytes, is written as a
VInt, followed by the bytes.- Overrides:
writeStringin classDataOutput- See Also:
DataInput.readString()
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writeMapOfStrings
public void writeMapOfStrings(Map<String,String> map)
Description copied from class:DataOutputWrites a String map.First the size is written as an
vInt, followed by each key-value pair written as two consecutiveStrings.- Overrides:
writeMapOfStringsin classDataOutput- Parameters:
map- Input map.
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writeSetOfStrings
public void writeSetOfStrings(Set<String> set)
Description copied from class:DataOutputWrites a String set.First the size is written as an
vInt, followed by each value written as aString.- Overrides:
writeSetOfStringsin classDataOutput- Parameters:
set- Input set.
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ramBytesUsed
public long ramBytesUsed()
Description copied from interface:AccountableReturn the memory usage of this object in bytes. Negative values are illegal.- Specified by:
ramBytesUsedin interfaceAccountable
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reset
public void reset()
This method resets this object to a clean (zero-size) state and publishes any currently allocated buffers for reuse to the reuse strategy provided in the constructor.Sharing byte buffers for reads and writes is dangerous and will very likely lead to hard-to-debug issues, use with great care.
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newResettableInstance
public static ByteBuffersDataOutput newResettableInstance()
- Returns:
- Returns a new
ByteBuffersDataOutputwith thereset()capability.
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