| InputStream {arrow} | R Documentation |
InputStream classes
Description
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:
-
pathForReadableFile, a character file name -
xForBufferReader, a Buffer or an object that can be made into a buffer viabuffer().
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 specifiednbytesor all, ifnbytesis not provided -
$ReadAt(position, nbytes): similar to$seek(position)$Read(nbytes) -
$Resize(size): for aMemoryMappedFilethat is writeable