+++ /dev/null
-(* $Id$
- * ----------------------------------------------------------------------
- *
- *)
-
-
-(* A netstream is an input channel that is read block by block. The
- * fragment of the channel currently loaded into memory is called the
- * current window of the netstream.
- *
- * PICTURE:
- *
- * 0 window_position current_length EOS
- * +------------------+-------------------+--------------------------+
- * ====================
- * The current window
- *
- * window_length = current_length - window_position
- *
- * There is an automatism that the window has a certain length. If possible,
- * the window is at least twice the block size long, where a "block" is
- * the amount of data that is read from the input channel in one step.
- *
- * (The idea is that you choose as block size the number of bytes you want
- * to analyze at once, and which must be loaded into memory. You can start
- * your analysis at window_position and proceed until window_position +
- * blocksize without having to check whether your window is large enough.
- * Only when the first blocksize bytes of the window are already processed,
- * the window must be enlarged by loading the next block.)
- *
- * If you want that the window becomes larger, you can call 'want' (to
- * enlarge the window to a certain size) or 'want_another_block' (to load
- * just another block from the input channel). Note that this affects only
- * the current window and not future windows.
- *
- * If you do not need the first n bytes of the window anymore, you can
- * call 'move' to move the beginning of the window by n bytes. If the
- * window becomes too small after this operation, it is enlarged until
- * it has twice the block size or until it reaches EOS.
- *)
-
-type t
-
-val create_from_channel : in_channel -> int option -> int -> t
- (* create_from_channel ch maxlength blocksize:
- * The new netstream reads from the channel 'ch'. If maxlength = None,
- * the channel is read until EOF. If maxlength = Some n, at most n bytes
- * are read; i.e. the netstream reads until n bytes have been read or
- * until EOF has been reached, whatever comes first. The blocksize
- * specifies the number of bytes to read at once.
- *)
-
-val create_from_string : string -> t
- (* Creates a new netstream from a string. The initial window of this
- * netstream is a copy of the passed string.
- *)
-
-val block_size : t -> int
- (* Returns the (immutable) block size. *)
-
-val current_length : t -> int
- (* Returns the number of bytes read so far. *)
-
-val at_eos : t -> bool
- (* True iff EOS (end of stream) is reached, i.e. the last byte of the
- * window is the last byte of the stream.
- *)
-
-val window_position : t -> int
- (* Returns the absolute position of the current window. *)
-
-val window_length : t -> int
- (* Returns the length of the current window. *)
-
-val window : t -> Netbuffer.t
- (* Returns the current window. *)
-
-val move : t -> int -> unit
- (* move s n:
- * Moves the window: The first n bytes of the current window are
- * discarded. If the window would become smaller than twice the
- * blocksize and if the end of the stream is not yet reached, another
- * block is read from the input channel and appended to the window.
- *
- * PRECONDITION:
- * - n <= window_length
- *)
-
-val want : t -> int -> unit
- (* want s n:
- * If the window is smaller than n bytes, it is tried to enlarge
- * the window such that it is at least n bytes long. The enlargement
- * is not possible if the stream is not long enough; in this case
- * the window becomes as large as possible.
- *)
-
-val want_another_block : t -> unit
- (* Enlarges the window by another block (if possible i.e. if the stream
- * is long enough).
- *)
-
-val print_stream : t -> unit
-
-(* ======================================================================
- * History:
- *
- * $Log$
- * Revision 1.1 2000/11/17 09:57:27 lpadovan
- * Initial revision
- *
- * Revision 1.2 2000/06/24 20:20:33 gerd
- * Added the toploop printer.
- *
- * Revision 1.1 2000/04/15 13:07:48 gerd
- * Initial revision.
- *
- *
- *)