Class BufferedIndexInput
- java.lang.Object
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- org.apache.lucene.store.DataInput
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- org.apache.lucene.store.IndexInput
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- org.apache.lucene.store.BufferedIndexInput
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- All Implemented Interfaces:
Closeable,AutoCloseable,Cloneable,RandomAccessInput
public abstract class BufferedIndexInput extends IndexInput implements RandomAccessInput
Base implementation class for bufferedIndexInput.
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Field Summary
Fields Modifier and Type Field Description static intBUFFER_SIZEDefault buffer size set to 1024.static intMERGE_BUFFER_SIZEA buffer size for merges set to 4096.static intMIN_BUFFER_SIZEMinimum buffer size allowed
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Constructor Summary
Constructors Constructor Description BufferedIndexInput(String resourceDesc)BufferedIndexInput(String resourceDesc, int bufferSize)Inits BufferedIndexInput with a specific bufferSizeBufferedIndexInput(String resourceDesc, IOContext context)
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Method Summary
All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description static intbufferSize(IOContext context)Returns default buffer sizes for the givenIOContextBufferedIndexInputclone()Returns a clone of this stream.intgetBufferSize()Returns buffer sizelonggetFilePointer()Returns the current position in this file, where the next read will occur.bytereadByte()Reads and returns a single byte.bytereadByte(long pos)Reads a byte at the given position in the filevoidreadBytes(byte[] b, int offset, int len)Reads a specified number of bytes into an array at the specified offset.voidreadBytes(byte[] b, int offset, int len, boolean useBuffer)Reads a specified number of bytes into an array at the specified offset with control over whether the read should be buffered (callers who have their own buffer should pass in "false" for useBuffer).voidreadFloats(float[] dst, int offset, int len)Reads a specified number of floats into an array at the specified offset.protected voidreadGroupVInt(long[] dst, int offset)Override if you have a efficient implementation.intreadInt()Reads four bytes and returns an int (LE byte order).intreadInt(long pos)Reads an integer (LE byte order) at the given position in the fileprotected abstract voidreadInternal(ByteBuffer b)Expert: implements buffer refill.voidreadInts(int[] dst, int offset, int len)Reads a specified number of ints into an array at the specified offset.longreadLong()Reads eight bytes and returns a long (LE byte order).longreadLong(long pos)Reads a long (LE byte order) at the given position in the filevoidreadLongs(long[] dst, int offset, int len)Read a specified number of longs.shortreadShort()Reads two bytes and returns a short (LE byte order).shortreadShort(long pos)Reads a short (LE byte order) at the given position in the fileintreadVInt()Reads an int stored in variable-length format.longreadVLong()Reads a long stored in variable-length format.voidseek(long pos)Sets current position in this file, where the next read will occur.protected abstract voidseekInternal(long pos)Expert: implements seek.IndexInputslice(String sliceDescription, long offset, long length)Creates a slice of this index input, with the given description, offset, and length.static BufferedIndexInputwrap(String sliceDescription, IndexInput other, long offset, long length)Wraps a portion of another IndexInput with buffering.-
Methods inherited from class org.apache.lucene.store.IndexInput
close, getFullSliceDescription, length, randomAccessSlice, skipBytes, toString
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Methods inherited from class org.apache.lucene.store.DataInput
readGroupVInts, readMapOfStrings, readSetOfStrings, readString, readZInt, readZLong
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Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.apache.lucene.store.RandomAccessInput
length
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Field Detail
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BUFFER_SIZE
public static final int BUFFER_SIZE
Default buffer size set to 1024.- See Also:
- Constant Field Values
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MIN_BUFFER_SIZE
public static final int MIN_BUFFER_SIZE
Minimum buffer size allowed- See Also:
- Constant Field Values
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MERGE_BUFFER_SIZE
public static final int MERGE_BUFFER_SIZE
A buffer size for merges set to 4096.- See Also:
- Constant Field Values
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Method Detail
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readByte
public final byte readByte() throws IOExceptionDescription copied from class:DataInputReads and returns a single byte.- Specified by:
readBytein classDataInput- Throws:
IOException- See Also:
DataOutput.writeByte(byte)
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getBufferSize
public final int getBufferSize()
Returns buffer size
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readBytes
public final void readBytes(byte[] b, int offset, int len) throws IOExceptionDescription copied from class:DataInputReads a specified number of bytes into an array at the specified offset.- Specified by:
readBytesin classDataInput- Parameters:
b- the array to read bytes intooffset- the offset in the array to start storing byteslen- the number of bytes to read- Throws:
IOException- See Also:
DataOutput.writeBytes(byte[],int)
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readBytes
public final void readBytes(byte[] b, int offset, int len, boolean useBuffer) throws IOExceptionDescription copied from class:DataInputReads a specified number of bytes into an array at the specified offset with control over whether the read should be buffered (callers who have their own buffer should pass in "false" for useBuffer). Currently onlyBufferedIndexInputrespects this parameter.- Overrides:
readBytesin classDataInput- Parameters:
b- the array to read bytes intooffset- the offset in the array to start storing byteslen- the number of bytes to readuseBuffer- set to false if the caller will handle buffering.- Throws:
IOException- See Also:
DataOutput.writeBytes(byte[],int)
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readShort
public final short readShort() throws IOExceptionDescription copied from class:DataInputReads two bytes and returns a short (LE byte order).- Overrides:
readShortin classDataInput- Throws:
IOException- See Also:
DataOutput.writeShort(short),BitUtil.VH_LE_SHORT
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readInt
public final int readInt() throws IOExceptionDescription copied from class:DataInputReads four bytes and returns an int (LE byte order).- Overrides:
readIntin classDataInput- Throws:
IOException- See Also:
DataOutput.writeInt(int),BitUtil.VH_LE_INT
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readGroupVInt
protected void readGroupVInt(long[] dst, int offset) throws IOExceptionDescription copied from class:DataInputOverride if you have a efficient implementation. In general this is when the input supports random access.- Overrides:
readGroupVIntin classDataInput- Throws:
IOException
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readLong
public final long readLong() throws IOExceptionDescription copied from class:DataInputReads eight bytes and returns a long (LE byte order).- Overrides:
readLongin classDataInput- Throws:
IOException- See Also:
DataOutput.writeLong(long),BitUtil.VH_LE_LONG
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readVInt
public final int readVInt() throws IOExceptionDescription copied from class:DataInputReads an int stored in variable-length format. Reads between one and five bytes. Smaller values take fewer bytes. Negative numbers are supported, but should be avoided.The format is described further in
DataOutput.writeVInt(int).- Overrides:
readVIntin classDataInput- Throws:
IOException- See Also:
DataOutput.writeVInt(int)
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readVLong
public final long readVLong() throws IOExceptionDescription copied from class:DataInputReads a long stored in variable-length format. Reads between one and nine bytes. Smaller values take fewer bytes. Negative numbers are not supported.The format is described further in
DataOutput.writeVInt(int).- Overrides:
readVLongin classDataInput- Throws:
IOException- See Also:
DataOutput.writeVLong(long)
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readFloats
public void readFloats(float[] dst, int offset, int len) throws IOExceptionDescription copied from class:DataInputReads a specified number of floats into an array at the specified offset.- Overrides:
readFloatsin classDataInput- Parameters:
dst- the array to read bytes intooffset- the offset in the array to start storing floatslen- the number of floats to read- Throws:
IOException
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readLongs
public void readLongs(long[] dst, int offset, int len) throws IOExceptionDescription copied from class:DataInputRead a specified number of longs.- Overrides:
readLongsin classDataInput- Throws:
IOException
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readInts
public void readInts(int[] dst, int offset, int len) throws IOExceptionDescription copied from class:DataInputReads a specified number of ints into an array at the specified offset.- Overrides:
readIntsin classDataInput- Parameters:
dst- the array to read bytes intooffset- the offset in the array to start storing intslen- the number of ints to read- Throws:
IOException
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readByte
public final byte readByte(long pos) throws IOExceptionDescription copied from interface:RandomAccessInputReads a byte at the given position in the file- Specified by:
readBytein interfaceRandomAccessInput- Throws:
IOException- See Also:
DataInput.readByte()
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readShort
public final short readShort(long pos) throws IOExceptionDescription copied from interface:RandomAccessInputReads a short (LE byte order) at the given position in the file- Specified by:
readShortin interfaceRandomAccessInput- Throws:
IOException- See Also:
DataInput.readShort(),BitUtil.VH_LE_SHORT
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readInt
public final int readInt(long pos) throws IOExceptionDescription copied from interface:RandomAccessInputReads an integer (LE byte order) at the given position in the file- Specified by:
readIntin interfaceRandomAccessInput- Throws:
IOException- See Also:
DataInput.readInt(),BitUtil.VH_LE_INT
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readLong
public final long readLong(long pos) throws IOExceptionDescription copied from interface:RandomAccessInputReads a long (LE byte order) at the given position in the file- Specified by:
readLongin interfaceRandomAccessInput- Throws:
IOException- See Also:
DataInput.readLong(),BitUtil.VH_LE_LONG
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readInternal
protected abstract void readInternal(ByteBuffer b) throws IOException
Expert: implements buffer refill. Reads bytes from the current position in the input.- Parameters:
b- the buffer to read bytes into- Throws:
IOException
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getFilePointer
public final long getFilePointer()
Description copied from class:IndexInputReturns the current position in this file, where the next read will occur.- Specified by:
getFilePointerin classIndexInput- See Also:
IndexInput.seek(long)
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seek
public final void seek(long pos) throws IOExceptionDescription copied from class:IndexInputSets current position in this file, where the next read will occur. If this is beyond the end of the file then this will throwEOFExceptionand then the stream is in an undetermined state.- Specified by:
seekin classIndexInput- Throws:
IOException- See Also:
IndexInput.getFilePointer()
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seekInternal
protected abstract void seekInternal(long pos) throws IOExceptionExpert: implements seek. Sets current position in this file, where the nextreadInternal(ByteBuffer)will occur.- Throws:
IOException- See Also:
readInternal(ByteBuffer)
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clone
public BufferedIndexInput clone()
Description copied from class:IndexInputReturns a clone of this stream.Clones of a stream access the same data, and are positioned at the same point as the stream they were cloned from.
Expert: Subclasses must ensure that clones may be positioned at different points in the input from each other and from the stream they were cloned from.
Warning: Lucene never closes cloned
IndexInputs, it will only callIndexInput.close()on the original object.If you access the cloned IndexInput after closing the original object, any
readXXXmethods will throwAlreadyClosedException.This method is NOT thread safe, so if the current
IndexInputis being used by one thread whilecloneis called by another, disaster could strike.- Overrides:
clonein classIndexInput
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slice
public IndexInput slice(String sliceDescription, long offset, long length) throws IOException
Description copied from class:IndexInputCreates a slice of this index input, with the given description, offset, and length. The slice is sought to the beginning.- Specified by:
slicein classIndexInput- Throws:
IOException
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bufferSize
public static int bufferSize(IOContext context)
Returns default buffer sizes for the givenIOContext
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wrap
public static BufferedIndexInput wrap(String sliceDescription, IndexInput other, long offset, long length)
Wraps a portion of another IndexInput with buffering.Please note: This is in most cases ineffective, because it may double buffer!
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