10 files changed, 73 insertions(+), 69 deletions(-)

M buildpc.fs
M fs/comp/c/lib.fs
A fs/doc/lib/file.txt
M fs/doc/sys/file.txt
M fs/emul/cos/tools/blkpack.fs
A fs/lib/file.fs
M fs/sys/file.fs
M fs/tests/comp/c/lib.fs
M fs/tests/harness.fs
M fs/tests/text/ed.fs

@@ 1,3 1,4 @@
+?f<< /lib/file.fs
 f<< /xcomp/i386/pc/build.fs
 
 S" pc.img" mountImage ( drv ) value mydrv

@@ 4,6 4,7 @@
 ?f<< /lib/str.fs
 ?f<< /lib/fmt.fs
 ?f<< /lib/ll.fs
+?f<< /lib/file.fs
 
 \ A few system word proxies
 :c void abort();

@@ 0,0 1,30 @@
+# File utilities
+
+Prerequisites: sys/file, lib/drive
+
+The lib/file unit adds extra utilities on top of sys/file.
+
+## MemFile
+
+MemFile is a structure that extends File and provides read/write/seek
+capabilities to a memory buffer. It extends File with those words:
+
+:new ( sz -- hdl )
+  Allocate a new buffer of size "sz" and return it.
+
+## DriveFile
+
+DriveFile is a structure allowing direct access to a Drive through the
+convenience of a File API. It's buffer size is the drive's sector size.
+
+Fields:
+
+drv    The Drive being interfaced.
+sec    Sector number currently in buffer, -1 if none.
+dirty? Whether the buffer has changed since it was loaded from the drive.
+
+Words:
+
+:new ( drv -- hdl )
+  Create a new DriveFile interfacing Drive "drv".
+

@@ 217,30 217,6 @@ Does it mean that Dusk couldn't read them? No, only that file/dir enumeration
 would have to go through FS-specific tools. I think that this inconvenience is
 worth it if it means an overall simpler API.
 
-## MemFile
-
-MemFile is a structure that extends File and provides read/write/seek
-capabilities to a memory buffer. It extends File with those words:
-
-:new ( sz -- hdl )
-  Allocate a new buffer of size "sz" and return it.
-
-## DriveFile
-
-DriveFile is a structure allowing direct access to a Drive through the
-convenience of a File API. It's buffer size is the drive's sector size.
-
-Fields:
-
-drv    The Drive being interfaced.
-sec    Sector number currently in buffer, -1 if none.
-dirty? Whether the buffer has changed since it was loaded from the drive.
-
-Words:
-
-:new ( drv -- hdl )
-  Create a new DriveFile interfacing Drive "drv".
-
 ## File loading shortcuts
 
 Feeding the Forth intepreter with the contents of a file is something you'll

@@ 1,3 1,4 @@
+?f<< /lib/file.fs
 ?f<< /comp/c/lib.fs
 cc<< /emul/cos/tools/blkpack.c
 

@@ 0,0 1,37 @@
+?f<< /lib/drive.fs
+
+extends File struct[ MemFile
+  : _maxn ( n hdl -- real-n ) >r V1 pos + V1 size min r> pos - ;
+  : _readbuf ( n hdl -- a? read-n )
+    >r V1 _maxn ( read-n ) dup if V1 :ptr swap dup V1 to+ pos then rdrop ;
+  : _writebuf ( a n hdl -- written-n )
+    >r V1 _maxn ( a write-n ) dup if ( a write-n )
+      tuck V1 :ptr swap ( write-n a dst n ) move ( write-n ) dup V1 to+ pos
+      else nip then rdrop ;
+  : _seek ( pos hdl -- ) to pos ;
+  : :new ( sz -- hdl ) here swap ( hdl sz )
+    0 ( putback ) , ['] _readbuf , ['] _writebuf , ['] drop , ['] drop ,
+    0 ( pos ) , dup ( size ) , over SZ + ( bufptr ) , dup ( bufsz ) ,
+    ['] _seek , ( sz ) allot ;
+]struct
+
+extends File struct[ DriveFile
+  sfield secwin
+  : :secwin [compile] secwin [compile] SectorWindow ; immediate
+  : _flush :secwin :flush ;
+  : _seek ( pos self -- ) to pos ;
+  : _readbuf ( n self -- a? read-n )
+    over if
+      swap >r bi+ pos | :secwin :seek ( self a? n ) r> min
+      dup if rot over swap to+ pos then
+      else drop then ;
+  : _writebuf ( a n self -- written-n )
+    r! _readbuf ( src dst? n ) dup if
+      r! move r> r> :secwin :dirty! else nip rdrop then ;
+  : :new ( drv -- hdl )
+    SectorWindow :new here ( secwin hdl )
+    0 ( putback ) , ['] _readbuf , ['] _writebuf , ['] _flush , ['] drop ,
+    0 ( pos ) , -1 ( size ) , over SectorWindow :buf( ( bufptr ) ,
+    over SectorWindow :drv secsz ( bufsz ) , ['] _seek , ['] drop ( truncate ) ,
+    swap ( secwin ) , dup 0 -1 rot :secwin :move ;
+]struct

@@ 124,48 124,3 @@ Path _curpath structbind Path curpath
 
 : p" [compile] S" curpath :find# ; immediate
 : f" [compile] p" Path :open >file ; immediate
-
-extends File struct[ MemFile
-  : _maxn ( n hdl -- real-n ) >r V1 pos + V1 size min r> pos - ;
-  : _readbuf ( n hdl -- a? read-n )
-    >r V1 _maxn ( read-n ) dup if V1 :ptr swap dup V1 to+ pos then rdrop ;
-  : _writebuf ( a n hdl -- written-n )
-    >r V1 _maxn ( a write-n ) dup if ( a write-n )
-      tuck V1 :ptr swap ( write-n a dst n ) move ( write-n ) dup V1 to+ pos
-      else nip then rdrop ;
-  : _seek ( pos hdl -- ) to pos ;
-  : :new ( sz -- hdl ) here swap ( hdl sz )
-    0 ( putback ) , ['] _readbuf , ['] _writebuf , ['] drop , ['] drop ,
-    0 ( pos ) , dup ( size ) , over SZ + ( bufptr ) , dup ( bufsz ) ,
-    ['] _seek , ( sz ) allot ;
-]struct
-
-extends File struct[ DriveFile
-  sfield drv
-  sfield sec \ sector in buffer, -1=none
-  sfield dirty?
-  : _flush 0 over to@! dirty? if >r
-      r@ sec r@ :buf( r> drv Drive :sec!
-      else drop then ;
-  : _seek ( pos self -- ) >r \ V1=self
-    dup r@ to pos ( pos )
-    r@ bufsz / dup r@ sec <> if ( tgtsec )
-      r@ _flush dup r@ to sec
-      r@ :buf( r> drv Drive :sec@ else drop rdrop then ;
-  : _readbuf ( n self -- a? read-n ) >r \ V1=self
-    r@ pos r@ _seek ( n )
-    r@ :ptr r@ :)buf over - ( n a nmax )
-    rot min ( a n )
-    dup r> to+ File pos ( a n ) ;
-  : _writebuf ( a n self -- written-n ) >r \ V1=self
-    r@ pos r@ _seek 1 r@ to dirty?
-    r@ :)buf r@ :ptr - ( src n nmax )
-    min ( src n ) r@ :ptr swap ( src dst n )
-    dup >r move r> ( n ) r@ pos over + r> _seek ;
-  : :new ( drv -- hdl )
-    here
-    0 ( putback ) , ['] _readbuf , ['] _writebuf , ['] _flush , ['] drop ,
-    0 ( pos ) , -1 ( size ) , dup SZ + ( bufptr ) ,
-    over Drive secsz ( bufsz ) , ['] _seek , ['] drop ( truncate ) ,
-    swap ( drv ) , -1 ( sec ) , 0 ( dirty? ) , dup bufsz allot ;
-]struct

@@ 1,6 1,7 @@
 ?f<< tests/harness.fs
 ?f<< comp/c/cc.fs
 ?f<< comp/c/lib.fs
+?f<< /lib/file.fs
 testbegin
 \ Tests for the C library
 \ "max" is a forth word defined in the system

@@ 1,3 1,4 @@
+?f<< /lib/file.fs
 \ # means "assert"
 : # ( f -- ) not if abort" assertion failed" then ;
 : #eq ( n n -- ) 2dup = if 2drop else swap .x ."  != " .x abort then ;

@@ 1,5 1,6 @@
 ?f<< /tests/harness.fs
 ?f<< /drv/ramdrive.fs
+?f<< /lib/file.fs
 ?f<< /text/ed.fs
 testbegin
 \ Ed tests