 ! Copyright (C) 2008 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors alien alien.c-types alien.structs byte-arrays
-classes.struct kernel libc math parser sequences sequences.private ;
+classes.struct kernel libc math parser sequences
+sequences.private words fry memoize compiler.units ;
 IN: struct-arrays
 
 : c-type-struct-class ( c-type -- class )

{ underlying c-ptr read-only }
{ length array-capacity read-only }
{ element-size array-capacity read-only }
{ class read-only } ;

M: struct-array length length>> ; inline
M: struct-array byte-length [ length>> ] [ element-size>> ] bi * ; inline

    [ element-size>> * >fixnum ] [ underlying>> ] bi <displaced-alien> ; inline

M: struct-array nth-unsafe
    [ (nth-ptr) ] [ ctor>> ] bi execute( alien -- object ) ; inline

M: struct-array set-nth-unsafe
    [ (nth-ptr) swap ] [ element-size>> ] bi memcpy ; inline

! Foldable memo word. This is an optimization; by precompiling a
! constructor for array elements, we avoid memory>struct's slow path.
MEMO: struct-element-constructor ( c-type -- word )
    [
        "struct-array-ctor" f <word>
        [
            swap dup struct-class?
            [ '[ _ memory>struct ] [ ] like ] [ drop [ ] ] if
            (( alien -- object )) define-inline
        ] keep
    ] with-compilation-unit ; foldable

: <direct-struct-array> ( alien length c-type -- struct-array )
    [ heap-size ] [ c-type-struct-class ] [ struct-element-constructor ]
    tri struct-array boa ; inline

M: struct-array new-sequence
    [ element-size>> * (byte-array) ] [ length>> ] [ class>> ] tri
    <direct-struct-array> ; inline

M: struct-array resize ( n seq -- newseq )
    [ [ element-size>> * ] [ underlying>> ] bi resize ] [ class>> ] 2bi
    <direct-struct-array> ; inline

: <struct-array> ( length c-type -- struct-array )
    [ heap-size * <byte-array> ] 2keep <direct-struct-array> ; inline

ERROR: bad-byte-array-length byte-array ;

: byte-array>struct-array ( byte-array c-type -- struct-array )
    [
        heap-size
        [ dup length ] dip /mod 0 =
        [ drop bad-byte-array-length ] unless
    ] keep <direct-struct-array> ; inline

: malloc-struct-array ( length c-type -- struct-array )
    [ heap-size calloc ] 2keep <direct-struct-array> ; inline
