--- gforth/blocks.fs	1999/12/03 18:24:21	1.28
+++ gforth/blocks.fs	2002/12/25 15:45:15	1.36
@@ -1,6 +1,6 @@
 \ A less simple implementation of the blocks wordset. 
 
-\ Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc.
+\ Copyright (C) 1995,1996,1997,1998,2000 Free Software Foundation, Inc.
 
 \ This file is part of Gforth.
 
@@ -16,7 +16,7 @@
 
 \ You should have received a copy of the GNU General Public License
 \ along with this program; if not, write to the Free Software
-\ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+\ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 
 
 \ A more efficient implementation would use mmap on OSs that
@@ -44,8 +44,20 @@ Variable last-block
 
 $20 Value buffers
 
+\ limit block files to 2GB; gforth <0.6.0 erases larger block files on
+\ 32-bit systems
+$200000 Value block-limit
+
 User block-fid
-User offset   0 offset !  \ store 1 here fore 0.4.0 compatibility
+User block-offset ( -- addr ) \ gforth
+\G User variable containing the number of the first block (default
+\G since 0.5.0: 0).  Block files created with Gforth versions before
+\G 0.5.0 have the offset 1.  If you use these files you can: @code{1
+\G offset !}; or add 1 to every block number used; or prepend 1024
+\G characters to the file.
+0 block-offset !  \ store 1 here fore 0.4.0 compatibility
+
+' block-offset alias offset \ !! eliminate this?
 
 : block-cold ( -- )
     block-fid off  last-block off
@@ -59,15 +71,18 @@ block-cold
 Defer flush-blocks ( -- ) \ gforth
 
 : open-blocks ( c-addr u -- ) \ gforth
-    \g Use the file, whose name is given by @i{c-addr u}, as the blocks file.
-    2dup open-fpath-file 0<>
-    if
-	r/w bin create-file throw
-    else
+\g Use the file, whose name is given by @i{c-addr u}, as the blocks file.
+    try ( c-addr u )
+	2dup open-fpath-file throw
 	rot close-file throw  2dup file-status throw bin open-file throw
 	>r 2drop r>
-    then
-    block-fid @ IF  flush-blocks block-fid @ close-file throw  THEN
+    recover ( c-addr u ior )
+	>r 2dup file-status nip 0= r> and throw \ does it really not exist?
+	r/w bin create-file throw
+    endtry
+    block-fid @ IF
+	flush-blocks block-fid @ close-file throw
+    THEN
     block-fid ! ;
 
 : use ( "file" -- ) \ gforth
@@ -87,11 +102,12 @@ Defer flush-blocks ( -- ) \ gforth
     block-fid @ ;
 
 : block-position ( u -- ) \ block
-    \G Position the block file to the start of block @i{u}.
+\G Position the block file to the start of block @i{u}.
+    dup block-limit u>= -35 and throw
     offset @ - chars/block chars um* get-block-fid reposition-file throw ;
 
 : update ( -- ) \ block
-    \G Mark the current block buffer as dirty.
+    \G Mark the state of the current block buffer as assigned-dirty.
     last-block @ ?dup IF  buffer-dirty on  THEN ;
 
 : save-buffer ( buffer -- ) \ gforth
@@ -100,7 +116,8 @@ Defer flush-blocks ( -- ) \ gforth
     if
 	r@ buffer-block @ block-position
 	r@ block-buffer chars/block  r@ buffer-fid @  write-file throw
-	r@ buffer-dirty off
+	r@ buffer-fid @ flush-file throw
+	r@ buffer-dirty off 
     endif
     rdrop ;
 
@@ -109,7 +126,7 @@ Defer flush-blocks ( -- ) \ gforth
 
 : save-buffers  ( -- ) \ block
     \G Transfer the contents of each @code{update}d block buffer to
-    \G mass storage, then mark all block buffers as unassigned.
+    \G mass storage, then mark all block buffers as assigned-clean.
     block-buffers @
     buffers 0 ?DO dup save-buffer next-buffer LOOP drop ;
 
@@ -176,7 +193,8 @@ User scr ( -- a-addr ) \ block-ext s-c-r
 
 \ nac31Mar1999 moved "scr @" to list to make the stack comment correct
 : updated?  ( n -- f ) \ gforth
-    \G Return true if block @i{n} has been marked as dirty.
+    \G Return true if @code{updated} has been used to mark block @i{n}
+    \G as assigned-dirty.
     buffer
     [ 0 buffer-dirty 0 block-buffer - ] Literal + @ ;
 
@@ -193,6 +211,23 @@ User scr ( -- a-addr ) \ block-ext s-c-r
 	i 2 .r space scr @ block i 64 * chars + 64 type cr
     loop ;
 
+[IFDEF] current-input
+:noname  2 <> -12 and throw >in ! blk ! ;
+                              \ restore-input
+:noname  blk @ >in @ 2 ;      \ save-input
+:noname  2 ;                  \ source-id "*a block*"
+:noname  1 blk +! 1 loadline +! true ;      \ refill
+:noname  blk @ block chars/block ;  \ source
+
+Create block-input   A, A, A, A, A,
+
+: load  ( i*x n -- j*x ) \ block
+    \G Save the current input source specification. Store @i{n} in
+    \G @code{BLK}, set @code{>IN} to 0 and interpret. When the parse
+    \G area is exhausted, restore the input source specification.
+    block-input 0 new-tib dup loadline ! blk !  2 loadfilename# !
+    ['] interpret catch pop-file throw ;
+[ELSE]
 : (source)  ( -- c-addr u )
   blk @ ?dup
   IF    block chars/block
@@ -207,9 +242,14 @@ User scr ( -- a-addr ) \ block-ext s-c-r
     \G Save the current input source specification. Store @i{n} in
     \G @code{BLK}, set @code{>IN} to 0 and interpret. When the parse
     \G area is exhausted, restore the input source specification.
+    loadfilename# @ >r
+    2 loadfilename# ! \ "*a block*"
     push-file
     dup loadline ! blk ! >in off ['] interpret catch
-    pop-file throw ;
+    pop-file
+    r> loadfilename# !
+    throw ;
+[THEN]
 
 : thru ( i*x n1 n2 -- j*x ) \ block-ext
     \G @code{load} the blocks @i{n1} through @i{n2} in sequence.