summaryrefslogtreecommitdiffstats
path: root/dbutil.scm
blob: 7df51ce116105056beae9f82f518588da066aaab (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
;;; "dbutil.scm" relational-database-utilities
; Copyright 1994, 1995, 1997, 2000, 2001, 2002 Aubrey Jaffer
;
;Permission to copy this software, to modify it, to redistribute it,
;to distribute modified versions, and to use it for any purpose is
;granted, subject to the following restrictions and understandings.
;
;1.  Any copy made of this software must include this copyright notice
;in full.
;
;2.  I have made no warranty or representation that the operation of
;this software will be error-free, and I am under no obligation to
;provide any services, by way of maintenance, update, or otherwise.
;
;3.  In conjunction with products arising from the use of this
;material, there shall be no use of my name in any advertising,
;promotional, or sales literature without prior written consent in
;each case.

(require 'common-list-functions)	;for nthcdr and butnthcdr
(require 'relational-database)
(require 'dynamic-wind)
(require 'transact)
(require-if 'compiling 'printf)		;used only by mdbm:report
(require-if 'compiling 'alist-table)

;;@code{(require 'databases)}
;;@ftindex databases
;;
;;@noindent
;;This enhancement wraps a utility layer on @code{relational-database}
;;which provides:
;;
;;@itemize @bullet
;;@item
;;Identification of open databases by filename.
;;@item
;;Automatic sharing of open (immutable) databases.
;;@item
;;Automatic loading of base-table package when creating a database.
;;@item
;;Detection and automatic loading of the appropriate base-table package
;;when opening a database.
;;@item
;;Table and data definition from Scheme lists.
;;@end itemize

;;;Each entry in mdbm:*databases* is a list of:

;;;  *  database (procedure)
;;;  *  number of opens (integer)
;;;  *  type (symbol)
;;;  *  lock-certificate

;;;Because of WRITE-DATABASE, database filenames can change, so we must
;;;have a global lock.
(define mdbm:*databases* (make-exchanger '()))
(define (mdbm:return-dbs dbs)
  (if (mdbm:*databases* dbs)
      (slib:error 'mdbm:*databases* 'double 'set!)))

(define (mdbm:find-db? rdb dbs)
  (and dbs
       (do ((dbs dbs (cdr dbs)))
	   ((or (null? dbs)
		(equal? ((caar dbs) 'filename)
			(if (procedure? rdb) (rdb 'filename) rdb)))
	    (and (not (null? dbs))
		 (if (and (procedure? rdb)
			  (not (eq? ((caar dbs) 'filename) (rdb 'filename))))
		     (slib:error ((caar dbs) 'filename) 'open 'twice)
		     (car dbs)))))))

(define (mdbm:remove-entry dbs entry)
  (cond ((null? dbs) (slib:error 'mdbm:remove-entry 'not 'found entry))
	((eq? entry (car dbs)) (cdr dbs))
	(else (cons (car dbs) (mdbm:remove-entry (cdr dbs) entry)))))

;;@subsubheading Database Sharing

;;@noindent
;;@dfn{Auto-sharing} refers to a call to the procedure
;;@code{open-database} returning an already open database (procedure),
;;rather than opening the database file a second time.
;;
;;@quotation
;;@emph{Note:} Databases returned by @code{open-database} do not include
;;wrappers applied by packages like @ref{Embedded Commands}.  But
;;wrapped databases do work as arguments to these functions.
;;@end quotation
;;
;;@noindent
;;When a database is created, it is mutable by the creator and not
;;auto-sharable.  A database opened mutably is also not auto-sharable.
;;But any number of readers can (open) share a non-mutable database file.

;;@noindent
;;This next set of procedures mirror the whole-database methods in
;;@ref{Database Operations}.  Except for @code{create-database}, each
;;procedure will accept either a filename or database procedure for its
;;first argument.

(define (mdbm:try-opens filename mutable?)
  (define (try base)
    (let ((rdb (base 'open-database)))
      (and rdb (rdb filename mutable?))))
  (define certificate (and mutable? (file-lock! filename)))
  (define (loop bti)
    (define rdb (try (cadar bti)))
    (cond ((procedure? rdb) (list rdb 1 (caar bti) certificate))
	  ((null? (cdr bti)) #f)
	  (else (loop (cdr bti)))))
  (if (null? *base-table-implementations*) (require 'alist-table))
  (cond ((and (not (and mutable? (not certificate)))
	      (loop *base-table-implementations*)))
	((and (not (memq 'alist-table *base-table-implementations*))
	      (let ()
		(require 'alist-table)
		(loop (list (car *base-table-implementations*))))))
	(else
	 (and certificate (file-unlock! filename certificate))
	 #f)))

(define (mdbm:open-type filename type mutable?)
  (require type)
  (let ((certificate (and mutable? (file-lock! filename))))
    (and (not (and mutable? (not certificate)))
	 (let* ((sys (cadr (assq type *base-table-implementations*)))
		(open (and sys (sys 'open-database)))
		(ndb (and open (open filename mutable?))))
	   (cond (ndb (list ndb 1 type certificate))
		 (else (and certificate (file-unlock! filename certificate))
		       #f))))))

;;@args filename base-table-type
;;@1 should be a string naming a file; or @code{#f}.  @2 must be a
;;symbol naming a feature which can be passed to @code{require}.  @0
;;returns a new, open relational database (with base-table type @2)
;;associated with @1, or a new ephemeral database if @1 is @code{#f}.
;;
;;@code{create-database} is the only run-time use of require in SLIB
;;which crosses module boundaries.  When @2 is @code{require}d by @0; it
;;adds an association of @2 with its @dfn{relational-system} procedure
;;to @var{mdbm:*databases*}.
;;
;;alist-table is the default base-table type:
;;
;;@example
;;(require 'databases)
;;(define my-rdb (create-database "my.db" 'alist-table))
;;@end example
(define (create-database filename type)
  (require type)
  (let ((dbs #f)
	(certificate (and filename (file-lock! filename))))
    (and
     (or certificate (not filename))
     (dynamic-wind
	 (lambda () (set! dbs (mdbm:*databases* #f)))
	 (lambda ()
	   (define entry (mdbm:find-db? filename dbs))
	   (cond (entry (slib:warn 'close ((car entry) 'filename)
				   'before 'create-database) #f)
		 (else
		  (let ((pair (assq type *base-table-implementations*)))
		    (define ndb (and pair (((cadr pair) 'create-database)
					   filename)))
		    (if (and ndb dbs)
			(set! dbs (cons (list ndb 1 type certificate) dbs)))
		    ndb))))
	 (lambda () (and dbs (mdbm:return-dbs dbs)))))))

;;@noindent
;;Only @code{alist-table} and base-table modules which have been
;;@code{require}d will dispatch correctly from the
;;@code{open-database} procedures.  Therefore, either pass two
;;arguments to @code{open-database}, or require the base-table of your
;;database file uses before calling @code{open-database} with one
;;argument.

;;@args rdb base-table-type
;;Returns @emph{mutable} open relational database or #f.
(define (open-database! filename . type)
  (set! type (and (not (null? type)) (car type)))
  (let ((dbs #f))
    (dynamic-wind
	(lambda () (set! dbs (mdbm:*databases* #f)))
	(lambda ()
	  (cond ((and (procedure? filename) (not (filename 'delete-table)))
		 (slib:warn (filename 'filename) 'not 'mutable) #f)
		((mdbm:find-db? filename dbs)
		 (cond ((procedure? filename) filename)
		       (else (slib:warn filename 'already 'open) #f)))
		(else (let ((entry (if type
				       (mdbm:open-type filename type #t)
				       (mdbm:try-opens filename #t))))
			(cond (entry (and dbs (set! dbs (cons entry dbs)))
				     (car entry))
			      (else #f))))))
	(lambda () (and dbs (mdbm:return-dbs dbs))))))

;;@args rdb base-table-type
;;Returns an open relational database associated with @1.  The
;;database will be opened with base-table type @2).
;;
;;@args rdb
;;Returns an open relational database associated with @1.
;;@0 will attempt to deduce the correct base-table-type.
(define (open-database rdb . type)
  (set! type (and (not (null? type)) (car type)))
  (let ((dbs #f))
    (dynamic-wind
	(lambda () (set! dbs (mdbm:*databases* #f)))
	(lambda ()
	  (define entry (mdbm:find-db? rdb dbs))
	  (and entry (set! rdb (car entry)))
	  (cond ((and entry type (not (eqv? (caddr entry) type)))
		 (slib:warn (rdb 'filename) 'type type '<> (caddr entry)) #f)
		((and (procedure? rdb) (rdb 'delete-table))
		 (slib:warn (rdb 'filename) 'mutable) #f)
		(entry (set-car! (cdr entry) (+ 1 (cadr entry))) rdb)
		(else
		 (set! entry
		       (cond ((procedure? rdb) (list rdb 1 type #f))
			     (type (mdbm:open-type rdb type #f))
			     (else (mdbm:try-opens rdb #f))))
		 (cond (entry (and dbs (set! dbs (cons entry dbs)))
			      (car entry))
		       (else #f)))))
	(lambda () (and dbs (mdbm:return-dbs dbs))))))

;;@body
;;Writes the mutable relational-database @1 to @2.
(define (write-database rdb filename)
  (let ((dbs #f))
    (dynamic-wind
	(lambda () (set! dbs (mdbm:*databases* #f)))
	(lambda ()
	  (define entry (mdbm:find-db? rdb dbs))
	  (and entry (set! rdb (car entry)))
	  (cond ((and (not entry) (procedure? rdb))
		 (set! entry (list rdb 1 #f (file-lock! filename)))
		 (and dbs (set! dbs (cons entry dbs)))))
	  (cond ((not entry) #f)
		((and (not (equal? filename (rdb 'filename)))
		      (mdbm:find-db? filename dbs))
		 (slib:warn filename 'already 'open) #f)
		(else (let ((dbwrite (rdb 'write-database)))
			(and dbwrite (dbwrite filename))))))
	(lambda () (and dbs (mdbm:return-dbs dbs))))))

;;@args rdb
;;Writes the mutable relational-database @1 to the filename it was
;;opened with.
(define (sync-database rdb)
  (let ((dbs #f))
    (dynamic-wind
	(lambda () (set! dbs (mdbm:*databases* #f)))
	(lambda ()
	  (define entry (mdbm:find-db? rdb dbs))
	  (and entry (set! rdb (car entry)))
	  (cond ((and (not entry) (procedure? rdb))
		 (set! entry (list rdb 1 #f (file-lock! (rdb 'filename))))
		 (and dbs (set! dbs (cons entry dbs)))))
	  (cond (entry (let ((db-op (rdb 'sync-database)))
			 (and db-op (db-op))))
		(else #f)))
	(lambda () (and dbs (mdbm:return-dbs dbs))))))

;;@args rdb
;;Syncs @1 and makes it immutable.
(define (solidify-database rdb)		;
  (let ((dbs #f))
    (dynamic-wind
	(lambda () (set! dbs (mdbm:*databases* #f)))
	(lambda ()
	  (define entry (mdbm:find-db? rdb dbs))
	  (define certificate #f)
	  (cond (entry (set! rdb (car entry))
		       (set! certificate (cadddr entry)))
		((procedure? rdb)
		 (set! entry (list rdb 1 #f (file-lock! (rdb 'filename))))
		 (and dbs (set! dbs (cons entry dbs)))
		 (set! certificate (cadddr entry))))
	  (cond ((or (not certificate) (not (procedure? rdb))) #f)
		(else
		 (let* ((filename (rdb 'filename))
			(dbsolid (rdb 'solidify-database))
			(ret (and dbsolid (dbsolid))))
		   (if (file-unlock! filename certificate)
		       (set-car! (cdddr entry) #f)
		       (slib:warn 'file-unlock! filename certificate 'failed))
		   ret))))
	(lambda () (and dbs (mdbm:return-dbs dbs))))))

;;@body
;;@1 will only be closed when the count of @code{open-database} - @0
;;calls for @1 (and its filename) is 0.  @0 returns #t if successful;
;;and #f otherwise.
(define (close-database rdb)
  (let ((dbs #f))
    (dynamic-wind
	(lambda () (set! dbs (mdbm:*databases* #f)))
	(lambda ()
	  (define entry (mdbm:find-db? rdb dbs))
	  (define certificate #f)
	  (and entry (set! rdb (car entry)))
	  (and (procedure? rdb)
	       (set! certificate (and entry (cadddr entry))))
	  (cond ((and entry (not (eqv? 1 (cadr entry))))
		 (set-car! (cdr entry) (+ -1 (cadr entry)))
		 #f)
		((not (procedure? rdb))
		 (slib:warn 'close-database 'not 'procedure? rdb)
		 #f)
		((not certificate)
		 (and dbs (set! dbs (mdbm:remove-entry dbs entry)))
		 #t)
		(else
		 (let* ((filename (rdb 'filename))
			(dbclose (rdb 'close-database))
			(ret (and dbclose (dbclose))))
		   (if (not (file-unlock! filename certificate))
		       (slib:warn 'file-unlock! filename certificate 'failed))
		   (cond ((not dbclose) (slib:warn 'database? rdb))
			 ((not entry))
			 (dbs (set! dbs (mdbm:remove-entry dbs entry))))
		   ret))))
	(lambda () (and dbs (mdbm:return-dbs dbs))))))

;;@body
;;Prints a table of open database files.  The columns are the
;;base-table type, number of opens, @samp{!} for mutable, the
;;filename, and the lock certificate (if locked).
(define (mdbm:report)
  (require 'printf)
  (let ((dbs #f))
    (dynamic-wind
	(lambda () (set! dbs (mdbm:*databases* #f)))
	(lambda ()
	  (cond (dbs (for-each (lambda (entry)
				 (printf "%15s %03d %1s %s %s\\n"
					 (or (caddr entry) "?")
					 (cadr entry)
					 (if ((car entry) 'delete-table) '! "")
					 (or ((car entry) 'filename) '-)
					 (or (cadddr entry) "")))
			       dbs))
		(else (printf "%s lock broken.\\n" 'mdbm:*databases*))))
	(lambda () (and dbs (mdbm:return-dbs dbs))))))
;;@example
;;(mdbm:report)
;;@print{}
;;  alist-table 003   /usr/local/lib/slib/clrnamdb.scm
;;  alist-table 001 ! sdram.db jaffer@@aubrey.jaffer.3166:1038628199
;;@end example


;;@subsubheading Opening Tables

;;@body
;;@1 must be a relational database and @2 a symbol.
;;
;;@0 returns a "methods" procedure for an existing relational table in
;;@1 if it exists and can be opened for reading, otherwise returns
;;@code{#f}.
(define (open-table rdb table-name)
  ((rdb 'open-table) table-name #f))

;;@body
;;@1 must be a relational database and @2 a symbol.
;;
;;@0 returns a "methods" procedure for an existing relational table in
;;@1 if it exists and can be opened in mutable mode, otherwise returns
;;@code{#f}.
(define (open-table! rdb table-name)
  ((rdb 'open-table) table-name #t))


;;@subsubheading Defining Tables

;;@body
;;Adds the domain rows @2 @dots{} to the @samp{*domains-data*} table
;;in @1.  The format of the row is given in @ref{Catalog Representation}.
;;
;;@example
;;(define-domains rdb '(permittivity #f complex? c64 #f))
;;@end example
(define (define-domains rdb . row5)
  (define add-domain (((rdb 'open-table) '*domains-data* #t) 'row:update))
  (for-each add-domain row5))

;;@body
;;Use @code{define-domains} instead.
(define (add-domain rdb row5)
  ((((rdb 'open-table) '*domains-data* #t) 'row:update)
   row5))

;;@args rdb spec-0 @dots{}
;;Adds tables as specified in @var{spec-0} @dots{} to the open
;;relational-database @1.  Each @var{spec} has the form:
;;
;;@lisp
;;(@r{<name>} @r{<descriptor-name>} @r{<descriptor-name>} @r{<rows>})
;;@end lisp
;;or
;;@lisp
;;(@r{<name>} @r{<primary-key-fields>} @r{<other-fields>} @r{<rows>})
;;@end lisp
;;
;;where @r{<name>} is the table name, @r{<descriptor-name>} is the symbol
;;name of a descriptor table, @r{<primary-key-fields>} and
;;@r{<other-fields>} describe the primary keys and other fields
;;respectively, and @r{<rows>} is a list of data rows to be added to the
;;table.
;;
;;@r{<primary-key-fields>} and @r{<other-fields>} are lists of field
;;descriptors of the form:
;;
;;@lisp
;;(@r{<column-name>} @r{<domain>})
;;@end lisp
;;or
;;@lisp
;;(@r{<column-name>} @r{<domain>} @r{<column-integrity-rule>})
;;@end lisp
;;
;;where @r{<column-name>} is the column name, @r{<domain>} is the domain
;;of the column, and @r{<column-integrity-rule>} is an expression whose
;;value is a procedure of one argument (which returns @code{#f} to signal
;;an error).
;;
;;If @r{<domain>} is not a defined domain name and it matches the name of
;;this table or an already defined (in one of @var{spec-0} @dots{}) single
;;key field table, a foreign-key domain will be created for it.
(define (define-tables rdb . spec-list)
  (define new-tables '())
  (define dom:typ (((rdb 'open-table) '*domains-data* #f) 'get 4))
  (define create-table (rdb 'create-table))
  (define open-table (rdb 'open-table))
  (define table-exists? (rdb 'table-exists?))
  (define (check-domain dname)
    (cond ((dom:typ dname))
	  ((member dname new-tables)
	   (let ((ftab (open-table
			(string->symbol
			 (string-append "desc:" (symbol->string dname)))
			#f)))
	     ((((rdb 'open-table) '*domains-data* #t) 'row:insert)
	      (list dname dname #f
		    (dom:typ ((ftab 'get 'domain-name) 1)) 1))))))
  (define (define-table name prikeys slots data)
    (cond
     ((table-exists? name)
      (let ((tab (open-table name #t)))
	((tab 'row:update*) data)
	((tab 'close-table))))
     ((and (symbol? prikeys) (eq? prikeys slots))
      (cond ((not (table-exists? slots))
	     (slib:error "Table doesn't exist:" slots)))
      (set! new-tables (cons name new-tables))
      (let ((tab (create-table name slots)))
	((tab 'row:insert*) data)
	((tab 'close-table))))
     (else
      (let* ((descname
	      (string->symbol (string-append "desc:" (symbol->string name))))
	     (tab (create-table descname))
	     (row:insert (tab 'row:insert))
	     (j 0))
	(set! new-tables (cons name new-tables))
	(for-each (lambda (des)
		    (set! j (+ 1 j))
		    (check-domain (cadr des))
		    (row:insert (list j #t (car des)
				      (if (null? (cddr des)) #f (caddr des))
				      (cadr des))))
		  prikeys)
	(for-each (lambda (des)
		    (set! j (+ 1 j))
		    (check-domain (cadr des))
		    (row:insert (list j #f (car des)
				      (if (null? (cddr des)) #f (caddr des))
				      (cadr des))))
		  slots)
	((tab 'close-table))
	(set! tab (create-table name descname))
	((tab 'row:insert*) data)
	((tab 'close-table))))))
  (for-each (lambda (spec) (apply define-table spec)) spec-list))


;;@subsubheading Listing Tables

;;@body
;;If symbol @2 exists in the open relational-database
;;@1, then returns a list of the table-name, its primary key names
;;and domains, its other key names and domains, and the table's records
;;(as lists).  Otherwise, returns #f.
;;
;;The list returned by @0, when passed as an
;;argument to @code{define-tables}, will recreate the table.
(define (list-table-definition rdb table-name)
  (cond (((rdb 'table-exists?) table-name)
	 (let* ((table ((rdb 'open-table) table-name #f))
		(prilimit (table 'primary-limit))
		(coldefs (map list
			      (table 'column-names)
			      (table 'column-domains))))
	   (list table-name
		 (butnthcdr prilimit coldefs)
		 (nthcdr prilimit coldefs)
		 ((table 'row:retrieve*)))))
	(else #f)))
;;(trace-all "/home/jaffer/slib/dbutil.scm") (untrace define-tables)