"

 COPYRIGHT (c) 1989 by Claus Gittinger

              All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

PositionableStream subclass:#WriteStream

       instanceVariableNames:'writeLimit'

       classVariableNames:''

       poolDictionaries:''

       category:'Streams'

!

WriteStream comment:'

COPYRIGHT (c) 1989 by Claus Gittinger

              All Rights Reserved

'!

!WriteStream class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1989 by Claus Gittinger

              All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

!

version

"

$Header: /cvs/stx/stx/libbasic/WriteStream.st,v 1.9 1994-06-02 16:22:49 claus Exp $

"

!

documentation

"

    Streams for writing into - this implementation currently DOES change the 

    identity if the streamed-upon collection IF it cannot grow. 

    Thus it is slightly incompatible to ST-80 since 'aStream contents' does 

    not always return the original collection. This may change.

"

! !

!WriteStream class methodsFor:'instance creation'!

on:aCollection from:start to:last

    "create and return a new stream for writing onto aCollection, where

     writing is limited to the elements in the range start to last."

    |newStream|

    newStream := super on:aCollection from:start to:last.

    newStream writeLimit:last.

    ^ newStream

! !

!WriteStream methodsFor:'private'!

on:aCollection

    "create and return a new stream for writing onto aCollection"

    super on:aCollection.

    writeLimit := readLimit

! !

!WriteStream methodsFor:'accessing'!

contents

    "return the current contents (a collection) of the stream"

    collection size == (position - 1) ifFalse:[

        collection isFixedSize ifTrue:[

            collection := collection copyFrom:1 to:(position - 1)

        ] ifFalse:[

            collection grow:(position - 1)

        ]

    ].

    ^ collection

!

writeLimit:aNumber

    "set the writeLimit, thats the position after which writing is

     prohibited."

    writeLimit := aNumber

! !

!WriteStream methodsFor:'reading'!

next

    "catch read access to write stream - report an error"

    self shouldNotImplement

!

peek

    "catch read access to write stream - report an error"

    self shouldNotImplement

! !

!WriteStream methodsFor:'writing'!

nextPut:anObject

    "append the argument, anObject to the stream"

%{  /* NOCONTEXT */

#ifdef NOTDEF

    REGISTER int pos;

    unsigned ch;

    OBJ coll;

    OBJ t;

    coll = _INST(collection);

    if (_isNonNilObject(coll)

     && _isSmallInteger(t = _INST(position))) {

        pos = _intVal(t);

        if (_isSmallInteger(t = _INST(writeLimit)) 

         && (pos <= _intVal(t)) && (pos > 0)) {

            OBJ cls;

            cls = _qClass(coll);

#ifdef NOTDEF

            if (cls == String) {

                if (__isCharacter(anObject) 

                 && (pos <= _stringSize(coll))) {

                    _StringInstPtr(coll)->s_element[pos-1] = _intVal(_characterVal(anObject));

                    _INST(position) = _MKSMALLINT(pos + 1);

                    if (_isSmallInteger(_INST(readLimit))

                     && (pos >= _intVal(_INST(readLimit)))) {

                        _INST(readLimit) = _MKSMALLINT(pos + 1);

                    }

                    RETURN ( anObject );

                }

            } else 

#endif

            if (cls == ByteArray) {

                if (_isSmallInteger(anObject) 

                 && ((ch = _intVal(anObject)) >= 0)

                 && (ch <= 255)

                 && (pos <= _byteArraySize(coll))) {

                    _ByteArrayInstPtr(coll)->ba_element[pos-1] = ch;

                    _INST(position) = _MKSMALLINT(pos + 1);

                    if (_isSmallInteger(_INST(readLimit))

                     && (pos >= _intVal(_INST(readLimit)))) {

                        _INST(readLimit) = _MKSMALLINT(pos + 1);

                    }

                    RETURN ( anObject );

                }

#ifdef NOTDEF

            } else 

            if (cls == Array) {

                if (pos <= _arraySize(coll)) {

                     _ArrayInstPtr(coll)->a_element[pos-1] = anObject;

                    __STORE(coll, anObject);

                    _INST(position) = _MKSMALLINT(pos + 1);

                    if (_isSmallInteger(_INST(readLimit))

                     && (pos >= _intVal(_INST(readLimit)))) {

                        _INST(readLimit) = _MKSMALLINT(pos + 1);

                    }

                    RETURN ( anObject );

                }

#endif

            }

        }

    }

#endif

%}

.

    (position > collection size) ifTrue:[self growCollection].

    collection at:position put:anObject.

    (position > readLimit) ifTrue:[readLimit := position].

    position := position + 1.

    ^anObject

!

next:count put:anObject

    "append anObject count times to the receiver.

     Redefined to avoid count grows of the underlying collection -

     instead a single grow on the final size is performed."

    |final|

    collection isNil ifTrue:[

        count timesRepeat:[

            self nextPut:anObject

        ].

        ^ self

    ].

    final := position + count - 1.

    (final > collection size) ifTrue:[

        self growCollection:final

    ].

    collection atAll:(position to:final) put:anObject.

    position := position + count.

    (position > readLimit) ifTrue:[readLimit := position - 1].

    ^ anObject

!

nextPutAll:aCollection

    "append all elements of the argument, aCollection to the stream.

     Redefined to avoid count grows of the underlying collection -

     instead a single grow on the final size is performed."

    |nMore final|

    collection isNil ifTrue:[

        aCollection do:[:element |

            self nextPut:element

        ].

        ^ self

    ].

    nMore := aCollection size.

    final := position + nMore - 1.

    (final > collection size) ifTrue:[

        self growCollection:final

    ].

    collection replaceFrom:position

                        to:final

                      with:aCollection 

                startingAt:1.

    position := position + nMore.

    (position > readLimit) ifTrue:[readLimit := position - 1].

    ^ aCollection

! !

!WriteStream methodsFor:'ignored'!

bold

    "change font to bold - ignored here.

     - this allows WriteStreams to be compatible to PrinterStreams"

!

italic

    "change font to italic - ignored here.

     - this allows WriteStreams to be compatible to PrinterStreams"

!

boldItalic

    "change font to italic - ignored here.

     - this allows WriteStreams to be compatible to PrinterStreams"

!

normal

    "change font to normal - ignored here.

     - this allows WriteStreams to be compatible to PrinterStreams"

! !

!WriteStream methodsFor:'private'!

growCollection

    |oldSize newSize newColl|

    oldSize := collection size.

    (oldSize == 0) ifTrue:[

        newSize := 10

    ] ifFalse:[

        newSize := oldSize * 2

    ].

    collection isFixedSize ifTrue:[

        newColl := collection species new:newSize.

        newColl replaceFrom:1 to:oldSize with:collection startingAt:1.

        collection := newColl

    ] ifFalse:[

        collection grow:newSize.

    ].

    writeLimit := newSize

!

growCollection:minNewSize

    |oldSize newSize newColl|

    oldSize := collection size.

    (oldSize == 0) ifTrue:[

        newSize := minNewSize

    ] ifFalse:[

        newSize := oldSize * 2.

        [newSize < minNewSize] whileTrue:[

            newSize := newSize * 2

        ]

    ].

    collection isFixedSize ifTrue:[

        newColl := collection species new:newSize.

        newColl replaceFrom:1 to:oldSize with:collection startingAt:1.

        collection := newColl

    ] ifFalse:[

        collection grow:newSize

    ].

    writeLimit := newSize

! !