This class has a single octet buffer and allows read-modify-write operations. File streams are single-channel streams.
A single-channel stream has one buffer and a directional state to specify whether the buffer and stream is in read, write, or read-modify mode. Flushes (device-writes) are performed when switching from write or read-modify to read mode if the buffer is dirty, and may involve a call to device-file-position. single-channel-simple-streams tend to support file-position and file-length, though this is not required.
A subclass of single-channel-simple-stream, namely direct-simple-stream, allows
input from or output to a buffer directly. Subclasses of direct-simple-stream allow
buffers to be read form or written to, in a similar manner as
string-input or string-output streams.
A subclass of file-simple-stream and of
direct-simple-stream
allows the opening of mapped files. Instead
of a buffer, a mapped file provides a direct mapping to the file
within memory. Mapping overflows are handled by
device-extend instead of
device-read and
device-write.
This kind of stream is useful for files and other devices which must allow random write/read access.
See streams.htm for a description of the new simple-stream stream implementation.
The documentation is described in introduction.htm and the index is in index.htm.
Copyright (c) 1998-2000, Franz Inc. Berkeley, CA., USA. All rights reserved.
Created 2000.10.5.