InputStream classes

RandomAccessFile inherits from InputStream and is a base class for: ReadableFile for reading from a file; MemoryMappedFile for the same but with memory mapping; and BufferReader for reading from a buffer. Use these with the various table readers.

Factory

The $create() factory methods instantiate the InputStream object and take the following arguments, depending on the subclass:

• path For ReadableFile, a character file name

• x For BufferReader, a Buffer or an object that can be made into a buffer via buffer().

To instantiate a MemoryMappedFile, call mmap_open().

Methods

• $GetSize():

• $supports_zero_copy(): Logical

• $seek(position): go to that position in the stream

• $tell(): return the position in the stream

• $close(): close the stream

• $Read(nbytes): read data from the stream, either a specified nbytes or all, if nbytes is not provided

• $ReadAt(position, nbytes): similar to $seek(position)$Read(nbytes)

• $Resize(size): for a MemoryMappedFile that is writeable

Super classes

arrow::Object -> arrow::Readable -> InputStream

Methods

Public methods

• InputStream$close()

• InputStream$clone()

Inherited methods

• arrow::Object$initialize()

• arrow::Object$pointer()

• arrow::Object$print()

• arrow::Object$set_pointer()

• arrow::Readable$Read()

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Method close()

Usage

InputStream$close()

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Method clone()

The objects of this class are cloneable with this method.

Usage

InputStream$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Super classes

arrow::Object -> arrow::Readable -> arrow::InputStream -> RandomAccessFile

Methods

Public methods

• RandomAccessFile$GetSize()

• RandomAccessFile$supports_zero_copy()

• RandomAccessFile$seek()

• RandomAccessFile$tell()

• RandomAccessFile$Read()

• RandomAccessFile$ReadAt()

• RandomAccessFile$clone()

Inherited methods

• arrow::Object$initialize()

• arrow::Object$pointer()

• arrow::Object$print()

• arrow::Object$set_pointer()

• arrow::InputStream$close()

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Method GetSize()

Usage

RandomAccessFile$GetSize()

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Method supports_zero_copy()

Usage

RandomAccessFile$supports_zero_copy()

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Method seek()

Usage

RandomAccessFile$seek(position)

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Method tell()

Usage

RandomAccessFile$tell()

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Method Read()

Usage

RandomAccessFile$Read(nbytes = NULL)

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Method ReadAt()

Usage

RandomAccessFile$ReadAt(position, nbytes = NULL)

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Method clone()

The objects of this class are cloneable with this method.

Usage

RandomAccessFile$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Super classes

arrow::Object -> arrow::Readable -> arrow::InputStream -> arrow::RandomAccessFile -> MemoryMappedFile

Methods

Public methods

• MemoryMappedFile$Resize()

• MemoryMappedFile$clone()

Inherited methods

• arrow::Object$initialize()

• arrow::Object$pointer()

• arrow::Object$print()

• arrow::Object$set_pointer()

• arrow::InputStream$close()

• arrow::RandomAccessFile$GetSize()

• arrow::RandomAccessFile$Read()

• arrow::RandomAccessFile$ReadAt()

• arrow::RandomAccessFile$seek()

• arrow::RandomAccessFile$supports_zero_copy()

• arrow::RandomAccessFile$tell()

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Method Resize()

Usage

MemoryMappedFile$Resize(size)

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Method clone()

The objects of this class are cloneable with this method.

Usage

MemoryMappedFile$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Super classes

arrow::Object -> arrow::Readable -> arrow::InputStream -> arrow::RandomAccessFile -> ReadableFile

Methods

Public methods

• ReadableFile$clone()

Inherited methods

• arrow::Object$initialize()

• arrow::Object$pointer()

• arrow::Object$print()

• arrow::Object$set_pointer()

• arrow::InputStream$close()

• arrow::RandomAccessFile$GetSize()

• arrow::RandomAccessFile$Read()

• arrow::RandomAccessFile$ReadAt()

• arrow::RandomAccessFile$seek()

• arrow::RandomAccessFile$supports_zero_copy()

• arrow::RandomAccessFile$tell()

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Method clone()

The objects of this class are cloneable with this method.

Usage

ReadableFile$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Super classes

arrow::Object -> arrow::Readable -> arrow::InputStream -> arrow::RandomAccessFile -> BufferReader

Methods

Public methods

• BufferReader$clone()

Inherited methods

• arrow::Object$initialize()

• arrow::Object$pointer()

• arrow::Object$print()

• arrow::Object$set_pointer()

• arrow::InputStream$close()

• arrow::RandomAccessFile$GetSize()

• arrow::RandomAccessFile$Read()

• arrow::RandomAccessFile$ReadAt()

• arrow::RandomAccessFile$seek()

• arrow::RandomAccessFile$supports_zero_copy()

• arrow::RandomAccessFile$tell()

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Method clone()

The objects of this class are cloneable with this method.

Usage

BufferReader$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.