core/org.gnit.lucenekmp.store/IndexInput

IndexInput

abstract class IndexInput : DataInput, AutoCloseable

Abstract base class for input from a file in a Directory. A random-access input stream. Used for all Lucene index input operations.

IndexInput may only be used from one thread, because it is not thread safe (it keeps internal state like file position). To allow multithreaded use, every IndexInput instance must be cloned before it is used in another thread. Subclasses must therefore implement .clone, returning a new IndexInput which operates on the same underlying resource, but positioned independently.

Warning: Lucene never closes cloned IndexInputs, it will only call .close on the original object.

If you access the cloned IndexInput after closing the original object, any readXXX * methods will throw AlreadyClosedException.

Inheritors

BufferedIndexInput

ByteBuffersIndexInput

ChecksumIndexInput

FilterIndexInput

Properties

filePointer

abstract val filePointer: Long

Returns the current position in this file, where the next read will occur.

isLoaded

open val isLoaded: Optional<Boolean?>

Functions

clone

open override fun clone(): IndexInput

{@inheritDoc}

abstract override fun close()

Closes the stream to further operations.

length

abstract fun length(): Long

The number of bytes in the file.

prefetch

open fun prefetch(offset: Long, length: Long)

Optional method: Give a hint to this input that some bytes will be read in the near future. IndexInput implementations may take advantage of this hint to start fetching pages of data immediately from storage.

randomAccessSlice

fun randomAccessSlice(offset: Long, length: Long): RandomAccessInput

Creates a random-access slice of this index input, with the given offset and length.

readByte

abstract fun readByte(): Byte

Reads and returns a single byte.

readBytes

abstract fun readBytes(b: ByteArray, offset: Int, len: Int)

Reads a specified number of bytes into an array at the specified offset.

open fun readBytes(b: ByteArray, offset: Int, len: Int, useBuffer: Boolean)

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). Currently only BufferedIndexInput respects this parameter.

readFloats

open fun readFloats(floats: FloatArray, offset: Int, len: Int)

Reads a specified number of floats into an array at the specified offset.

readGroupVInt

open fun readGroupVInt(dst: IntArray, offset: Int)

Override if you have an efficient implementation. In general this is when the input supports random access.

readInt

open fun readInt(): Int

Reads four bytes and returns an int (LE byte order).

readInts

open fun readInts(dst: IntArray, offset: Int, length: Int)

Reads a specified number of ints into an array at the specified offset.

readLong

open fun readLong(): Long

Reads eight bytes and returns a long (LE byte order).

readLongs

open fun readLongs(dst: LongArray, offset: Int, length: Int)

Read a specified number of longs.

readMapOfStrings

open fun readMapOfStrings(): MutableMap<String, String>

Reads a Map previously written with .

readSetOfStrings

open fun readSetOfStrings(): MutableSet<String>

Reads a Set previously written with DataOutput.writeSetOfStrings.

readShort

open fun readShort(): Short

Reads two bytes and returns a short (LE byte order).

readString

open fun readString(): String

Reads a string.

readVInt

open fun readVInt(): Int

Reads 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.

readVLong

open fun readVLong(): Long

Reads a long stored in variable-length format. Reads between one and nine bytes. Smaller values take fewer bytes. Negative numbers are not supported.

readZInt

open fun readZInt(): Int

Read a zig-zag-encoded .readVInt integer.

readZLong

open fun readZLong(): Long

Read a zig-zag-encoded .readVLong integer. Reads between one and ten bytes.

seek

abstract fun seek(pos: Long)

Sets current position in this file, where the next read will occur. If this is beyond the end of the file then this will throw EOFException and then the stream is in an undetermined state.

skipBytes

open override fun skipBytes(numBytes: Long)

{@inheritDoc}

slice

abstract fun slice(sliceDescription: String, offset: Long, length: Long): IndexInput

Creates a slice of this index input, with the given description, offset, and length. The slice is sought to the beginning.

open fun slice(sliceDescription: String, offset: Long, length: Long, readAdvice: ReadAdvice): IndexInput

Create a slice with a specific ReadAdvice. This is typically used by [ ] implementations to honor the ReadAdvice of each file within the compound file.

toString

open override fun toString(): String

updateReadAdvice

open fun updateReadAdvice(readAdvice: ReadAdvice?)

Optional method: Give a hint to this input about the change in read access pattern. IndexInput implementations may take advantage of this hint to optimize reads from storage.

IndexInput

See also

Inheritors

Properties

Functions