[gforth] / gforth / blocks.fs  

gforth: gforth/blocks.fs


1 : pazsan 1.5 \ A less simple implementation of the blocks wordset.
2 : anton 1.1
3 : anton 1.52 \ Copyright (C) 1995,1996,1997,1998,2000,2003,2006,2007 Free Software Foundation, Inc.
4 : anton 1.7
5 :     \ This file is part of Gforth.
6 :    
7 :     \ Gforth is free software; you can redistribute it and/or
8 :     \ modify it under the terms of the GNU General Public License
9 : anton 1.53 \ as published by the Free Software Foundation, either version 3
10 : anton 1.7 \ of the License, or (at your option) any later version.
11 :    
12 :     \ This program is distributed in the hope that it will be useful,
13 :     \ but WITHOUT ANY WARRANTY; without even the implied warranty of
14 :     \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 :     \ GNU General Public License for more details.
16 :    
17 :     \ You should have received a copy of the GNU General Public License
18 : anton 1.53 \ along with this program. If not, see http://www.gnu.org/licenses/.
19 : anton 1.7
20 :    
21 :     \ A more efficient implementation would use mmap on OSs that
22 : anton 1.1 \ provide it and many buffers on OSs that do not provide mmap.
23 :    
24 : pazsan 1.5 \ Now, the replacement algorithm is "direct mapped"; change to LRU
25 :     \ if too slow. Using more buffers helps, too.
26 :    
27 : anton 1.1 \ I think I avoid the assumption 1 char = 1 here, but I have not tested this
28 :    
29 : pazsan 1.2 \ 1024 constant chars/block \ mandated by the standard
30 : anton 1.1
31 : pazsan 1.5 require struct.fs
32 :    
33 :     struct
34 : anton 1.17 cell% field buffer-block \ the block number
35 :     cell% field buffer-fid \ the block's fid
36 :     cell% field buffer-dirty \ the block dirty flag
37 :     char% chars/block * field block-buffer \ the data
38 :     cell% 0 * field next-buffer
39 : pazsan 1.5 end-struct buffer-struct
40 :    
41 :     Variable block-buffers
42 :     Variable last-block
43 :    
44 :     $20 Value buffers
45 :    
46 : anton 1.36 \ limit block files to 2GB; gforth <0.6.0 erases larger block files on
47 :     \ 32-bit systems
48 :     $200000 Value block-limit
49 :    
50 : pazsan 1.5 User block-fid
51 : anton 1.30 User block-offset ( -- addr ) \ gforth
52 :     \G User variable containing the number of the first block (default
53 :     \G since 0.5.0: 0). Block files created with Gforth versions before
54 :     \G 0.5.0 have the offset 1. If you use these files you can: @code{1
55 :     \G offset !}; or add 1 to every block number used; or prepend 1024
56 :     \G characters to the file.
57 :     0 block-offset ! \ store 1 here fore 0.4.0 compatibility
58 :    
59 :     ' block-offset alias offset \ !! eliminate this?
60 : anton 1.1
61 : anton 1.17 : block-cold ( -- )
62 : jwilke 1.16 block-fid off last-block off
63 : anton 1.17 buffer-struct buffers * %alloc dup block-buffers ! ( addr )
64 :     buffer-struct %size buffers * erase ;
65 : anton 1.1
66 : anton 1.43 :noname ( -- )
67 :     defers 'cold
68 :     block-cold
69 :     ; is 'cold
70 : pazsan 1.5
71 :     block-cold
72 :    
73 : crook 1.24 Defer flush-blocks ( -- ) \ gforth
74 : pazsan 1.5
75 : crook 1.24 : open-blocks ( c-addr u -- ) \ gforth
76 : anton 1.36 \g Use the file, whose name is given by @i{c-addr u}, as the blocks file.
77 :     try ( c-addr u )
78 :     2dup open-fpath-file throw
79 : pazsan 1.8 rot close-file throw 2dup file-status throw bin open-file throw
80 : anton 1.50 >r 2drop r>
81 :     endtry-iferror ( c-addr u ior )
82 : anton 1.36 >r 2dup file-status nip 0= r> and throw \ does it really not exist?
83 :     r/w bin create-file throw
84 : anton 1.48 then
85 : anton 1.36 block-fid @ IF
86 :     flush-blocks block-fid @ close-file throw
87 :     THEN
88 : pazsan 1.5 block-fid ! ;
89 : pazsan 1.8
90 : anton 1.10 : use ( "file" -- ) \ gforth
91 : crook 1.24 \g Use @i{file} as the blocks file.
92 : anton 1.11 name open-blocks ;
93 : anton 1.1
94 : anton 1.3 \ the file is opened as binary file, since it either will contain text
95 :     \ without newlines or binary data
96 : crook 1.24 : get-block-fid ( -- wfileid ) \ gforth
97 :     \G Return the file-id of the current blocks file. If no blocks
98 :     \G file has been opened, use @file{blocks.fb} as the default
99 :     \G blocks file.
100 : anton 1.1 block-fid @ 0=
101 :     if
102 : anton 1.11 s" blocks.fb" open-blocks
103 : anton 1.1 then
104 :     block-fid @ ;
105 :    
106 : pazsan 1.20 : block-position ( u -- ) \ block
107 : anton 1.36 \G Position the block file to the start of block @i{u}.
108 :     dup block-limit u>= -35 and throw
109 : pazsan 1.26 offset @ - chars/block chars um* get-block-fid reposition-file throw ;
110 : anton 1.1
111 : pazsan 1.20 : update ( -- ) \ block
112 : crook 1.29 \G Mark the state of the current block buffer as assigned-dirty.
113 : pazsan 1.5 last-block @ ?dup IF buffer-dirty on THEN ;
114 : anton 1.1
115 : pazsan 1.20 : save-buffer ( buffer -- ) \ gforth
116 :     >r
117 : pazsan 1.42 r@ buffer-dirty @
118 : anton 1.1 if
119 : pazsan 1.5 r@ buffer-block @ block-position
120 :     r@ block-buffer chars/block r@ buffer-fid @ write-file throw
121 : anton 1.36 r@ buffer-fid @ flush-file throw
122 :     r@ buffer-dirty off
123 : pazsan 1.5 endif
124 :     rdrop ;
125 :    
126 : pazsan 1.20 : empty-buffer ( buffer -- ) \ gforth
127 : pazsan 1.54 dup buffer-block on buffer-dirty off ;
128 : pazsan 1.5
129 : pazsan 1.20 : save-buffers ( -- ) \ block
130 : crook 1.24 \G Transfer the contents of each @code{update}d block buffer to
131 : anton 1.30 \G mass storage, then mark all block buffers as assigned-clean.
132 : pazsan 1.20 block-buffers @
133 : crook 1.24 buffers 0 ?DO dup save-buffer next-buffer LOOP drop ;
134 : anton 1.1
135 : crook 1.24 : empty-buffers ( -- ) \ block-ext
136 :     \G Mark all block buffers as unassigned; if any had been marked as
137 :     \G assigned-dirty (by @code{update}), the changes to those blocks
138 :     \G will be lost.
139 : pazsan 1.20 block-buffers @
140 : crook 1.24 buffers 0 ?DO dup empty-buffer next-buffer LOOP drop ;
141 : anton 1.1
142 : pazsan 1.20 : flush ( -- ) \ block
143 : crook 1.24 \G Perform the functions of @code{save-buffers} then
144 :     \G @code{empty-buffers}.
145 : anton 1.1 save-buffers
146 :     empty-buffers ;
147 :    
148 : anton 1.12 ' flush IS flush-blocks
149 : pazsan 1.5
150 : pazsan 1.26 : get-buffer ( u -- a-addr ) \ gforth
151 :     0 buffers um/mod drop buffer-struct %size * block-buffers @ + ;
152 : pazsan 1.5
153 : anton 1.51 : block ( u -- a-addr ) \ block
154 : crook 1.24 \G If a block buffer is assigned for block @i{u}, return its
155 :     \G start address, @i{a-addr}. Otherwise, assign a block buffer
156 :     \G for block @i{u} (if the assigned block buffer has been
157 :     \G @code{update}d, transfer the contents to mass storage), read
158 :     \G the block into the block buffer and return its start address,
159 :     \G @i{a-addr}.
160 : pazsan 1.26 dup offset @ u< -35 and throw
161 : pazsan 1.5 dup get-buffer >r
162 :     dup r@ buffer-block @ <>
163 : pazsan 1.9 r@ buffer-fid @ block-fid @ <> or
164 : anton 1.1 if
165 : pazsan 1.5 r@ save-buffer
166 : anton 1.1 dup block-position
167 : pazsan 1.5 r@ block-buffer chars/block get-block-fid read-file throw
168 : anton 1.1 \ clear the rest of the buffer if the file is too short
169 : pazsan 1.5 r@ block-buffer over chars + chars/block rot chars - blank
170 :     r@ buffer-block !
171 :     get-block-fid r@ buffer-fid !
172 : anton 1.1 else
173 :     drop
174 :     then
175 : pazsan 1.5 r> dup last-block ! block-buffer ;
176 : anton 1.1
177 : pazsan 1.20 : buffer ( u -- a-addr ) \ block
178 : crook 1.24 \G If a block buffer is assigned for block @i{u}, return its
179 :     \G start address, @i{a-addr}. Otherwise, assign a block buffer
180 :     \G for block @i{u} (if the assigned block buffer has been
181 :     \G @code{update}d, transfer the contents to mass storage) and
182 :     \G return its start address, @i{a-addr}. The subtle difference
183 :     \G between @code{buffer} and @code{block} mean that you should
184 :     \G only use @code{buffer} if you don't care about the previous
185 :     \G contents of block @i{u}. In Gforth, this simply calls
186 :     \G @code{block}.
187 : anton 1.1 \ reading in the block is unnecessary, but simpler
188 :     block ;
189 :    
190 : crook 1.28 User scr ( -- a-addr ) \ block-ext s-c-r
191 : crook 1.27 \G @code{User} variable -- @i{a-addr} is the address of a cell containing
192 : crook 1.21 \G the block number of the block most recently processed by
193 : crook 1.24 \G @code{list}.
194 :     0 scr !
195 : anton 1.1
196 : crook 1.24 \ nac31Mar1999 moved "scr @" to list to make the stack comment correct
197 : pazsan 1.20 : updated? ( n -- f ) \ gforth
198 : crook 1.29 \G Return true if @code{updated} has been used to mark block @i{n}
199 :     \G as assigned-dirty.
200 : crook 1.24 buffer
201 : pazsan 1.5 [ 0 buffer-dirty 0 block-buffer - ] Literal + @ ;
202 :    
203 : crook 1.24 : list ( u -- ) \ block-ext
204 :     \G Display block @i{u}. In Gforth, the block is displayed as 16
205 :     \G numbered lines, each of 64 characters.
206 : anton 1.1 \ calling block again and again looks inefficient but is necessary
207 :     \ in a multitasking environment
208 :     dup scr !
209 : pazsan 1.5 ." Screen " u.
210 : crook 1.24 scr @ updated? 0= IF ." not " THEN ." modified " cr
211 : anton 1.1 16 0
212 :     ?do
213 : anton 1.4 i 2 .r space scr @ block i 64 * chars + 64 type cr
214 : anton 1.1 loop ;
215 :    
216 : pazsan 1.34 [IFDEF] current-input
217 :     :noname 2 <> -12 and throw >in ! blk ! ;
218 :     \ restore-input
219 :     :noname blk @ >in @ 2 ; \ save-input
220 :     :noname 2 ; \ source-id "*a block*"
221 : pazsan 1.42 :noname 1 blk +! 1 loadline +! >in off true ; \ refill
222 : pazsan 1.34 :noname blk @ block chars/block ; \ source
223 :    
224 :     Create block-input A, A, A, A, A,
225 :    
226 :     : load ( i*x n -- j*x ) \ block
227 :     \G Save the current input source specification. Store @i{n} in
228 :     \G @code{BLK}, set @code{>IN} to 0 and interpret. When the parse
229 :     \G area is exhausted, restore the input source specification.
230 : anton 1.39 block-input 0 new-tib dup loadline ! blk ! s" * a block*" loadfilename 2!
231 : pazsan 1.45 ['] interpret catch pop-file throw ;
232 : pazsan 1.34 [ELSE]
233 : crook 1.23 : (source) ( -- c-addr u )
234 : pazsan 1.2 blk @ ?dup
235 :     IF block chars/block
236 :     ELSE tib #tib @
237 :     THEN ;
238 :    
239 : crook 1.23 ' (source) IS source ( -- c-addr u ) \ core
240 : crook 1.24 \G @i{c-addr} is the address of the input buffer and @i{u} is the
241 : crook 1.23 \G number of characters in it.
242 : pazsan 1.2
243 : pazsan 1.20 : load ( i*x n -- j*x ) \ block
244 : crook 1.24 \G Save the current input source specification. Store @i{n} in
245 :     \G @code{BLK}, set @code{>IN} to 0 and interpret. When the parse
246 :     \G area is exhausted, restore the input source specification.
247 : anton 1.40 s" * a block*" loadfilename>r
248 : crook 1.24 push-file
249 :     dup loadline ! blk ! >in off ['] interpret catch
250 : anton 1.31 pop-file
251 : anton 1.40 r>loadfilename
252 : pazsan 1.45 throw ;
253 : pazsan 1.34 [THEN]
254 : crook 1.24
255 :     : thru ( i*x n1 n2 -- j*x ) \ block-ext
256 :     \G @code{load} the blocks @i{n1} through @i{n2} in sequence.
257 :     1+ swap ?DO I load LOOP ;
258 :    
259 :     : +load ( i*x n -- j*x ) \ gforth
260 :     \G Used within a block to load the block specified as the
261 :     \G current block + @i{n}.
262 : pazsan 1.20 blk @ + load ;
263 : pazsan 1.2
264 : crook 1.24 : +thru ( i*x n1 n2 -- j*x ) \ gforth
265 :     \G Used within a block to load the range of blocks specified as the
266 :     \G current block + @i{n1} thru the current block + @i{n2}.
267 :     1+ swap ?DO I +load LOOP ;
268 :    
269 : crook 1.28 : --> ( -- ) \ gforthman- gforth chain
270 : crook 1.24 \G If this symbol is encountered whilst loading block @i{n},
271 :     \G discard the remainder of the block and load block @i{n+1}. Used
272 : anton 1.25 \G for chaining multiple blocks together as a single loadable
273 :     \G unit. Not recommended, because it destroys the independence of
274 :     \G loading. Use @code{thru} (which is standard) or @code{+thru}
275 :     \G instead.
276 : pazsan 1.20 refill drop ; immediate
277 : pazsan 1.5
278 : crook 1.24 : block-included ( a-addr u -- ) \ gforth
279 :     \G Use within a block that is to be processed by @code{load}. Save
280 :     \G the current blocks file specification, open the blocks file
281 :     \G specified by @i{a-addr u} and @code{load} block 1 from that
282 :     \G file (which may in turn chain or load other blocks). Finally,
283 :     \G close the blocks file and restore the original blocks file.
284 : anton 1.11 block-fid @ >r block-fid off open-blocks
285 : pazsan 1.5 1 load block-fid @ close-file throw flush
286 :     r> block-fid ! ;
287 :    
288 : anton 1.13 \ thrown out because it may provide unpleasant surprises - anton
289 :     \ : include ( "name" -- )
290 :     \ name 2dup dup 3 - /string s" .fb" compare
291 :     \ 0= IF block-included ELSE included THEN ;
292 : pazsan 1.5
293 : anton 1.4 get-current environment-wordlist set-current
294 : anton 1.51 true constant block \ environment- environment
295 : anton 1.4 true constant block-ext
296 :     set-current
297 : pazsan 1.5
298 : crook 1.21 : bye ( -- ) \ tools-ext
299 :     \G Return control to the host operating system (if any).
300 :     ['] flush catch drop bye ;

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