stream-read-partial-unsafe ( n buf stream -- count )
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Vocabulary
io

Inputs

n	a non-negative integer
buf	a c-ptr or a string
stream	an input stream

Outputs

count

an integer

Generic word contract
Reads up to n elements from the stream without blocking. If no data is available immediately on the stream, blocks until data is available. The data is stored directly into the buffer provided by buf, which must be a string (in the case of a character stream), or a byte array, specialized array, or other pointer to memory (in the case of a byte stream). There must be space in the buffer for at least n elements. Returns the number of elements read from the stream, or zero if the end of the stream was reached.

Warning
This word does not perform bounds checking on buf. Most code should use stream-read-partial or stream-read-partial-into instead.

Errors
Throws an error if the I/O operation fails.

Definition

IN: io

GENERIC: stream-read-partial-unsafe ( n buf stream -- count )

Methods

USING: accessors io io.streams.counting kernel math ;

M:: counting-stream stream-read-partial-unsafe
    ( n buf stream -- count )
    n buf stream stream>> stream-read-partial-unsafe
    :> count stream [ count + ] change-in-count drop count ;


USING: accessors io io.streams.duplex kernel ;

M: duplex-stream stream-read-partial-unsafe
    [ in>> ] call \ stream-read-partial-unsafe execute ;


USING: io kernel ;

M: f stream-read-partial-unsafe 3drop 0 ; inline


USING: alien classes io io.ports io.ports.private kernel libc ;

M: input-port stream-read-partial-unsafe
    [ c-ptr check-instance swap ] dip prepare-read read-step
    [ swap [ memcpy ] keep ] [ 2drop 0 ] if* ;


USING: io ;

M: input-stream stream-read-partial-unsafe
    stream-read-unsafe ; inline


USING: io io.streams.limited io.streams.limited.private ;

M: limited-stream stream-read-partial-unsafe
    [ stream-read-partial-unsafe ] maybe-read-unsafe ;


USING: io io.streams.null kernel ;

M: null-reader stream-read-partial-unsafe 3drop 0 ;


USING: io io.streams.random ;

M: random-stream stream-read-partial-unsafe stream-read-unsafe ;


USING: io io.streams.tee io.streams.tee.private kernel math
sequences ;

M:: tee-stream stream-read-partial-unsafe
    ( n buf stream -- count )
    n buf stream
    [ stream-read-partial-unsafe ] [
        [ [ buf swap head ] ] dip [ stream-write ] curry compose
        unless-zero
    ] tee1 ;


USING: accessors io io.streams.throwing math ;

M:: throws-on-eof-stream stream-read-partial-unsafe
    ( n buf stream -- count )
    n buf stream stream>> stream-read-partial-unsafe
    [ n stream \ stream-read-partial-unsafe stream-exhausted ]
    when-zero ;


USING: io io.streams.zeros ;

M: zero-stream stream-read-partial-unsafe stream-read-unsafe ;