1 ;;;; that part of the implementation of HASH-TABLE which lives solely
2 ;;;; on the target system, not on the cross-compilation host
4 ;;;; This software is part of the SBCL system. See the README file for
7 ;;;; This software is derived from the CMU CL system, which was
8 ;;;; written at Carnegie Mellon University and released into the
9 ;;;; public domain. The software is in the public domain and is
10 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
11 ;;;; files for more information.
13 (in-package "SB!IMPL")
17 ;;; Without the locking the next vector can get cyclic causing
18 ;;; looping in a WITHOUT-GCING form, SHRINK-VECTOR can corrupt memory
19 ;;; and who knows what else.
21 ;;; WITHOUT-GCING implies WITHOUT-INTERRUPTS.
22 (defmacro with-spinlock-and-without-gcing
((spinlock) &body body
)
24 (declare (ignore spinlock
))
29 (sb!thread
::get-spinlock
,spinlock
)
32 (sb!thread
::release-spinlock
,spinlock
))))
34 (eval-when (:compile-toplevel
:load-toplevel
:execute
)
35 (defconstant max-hash sb
!xc
:most-positive-fixnum
))
38 `(integer 0 ,max-hash
))
40 ;;; FIXME: Does this always make a nonnegative FIXNUM? If so, then
41 ;;; explain why. If not (or if the reason it always makes a
42 ;;; nonnegative FIXNUM is only the accident that pointers in supported
43 ;;; architectures happen to be in the lower half of the address
44 ;;; space), then fix it.
45 #!-sb-fluid
(declaim (inline pointer-hash
))
46 (defun pointer-hash (key)
47 (declare (values hash
))
48 (truly-the hash
(%primitive sb
!c
:make-fixnum key
)))
50 #!-sb-fluid
(declaim (inline eq-hash
))
52 (declare (values hash
(member t nil
)))
53 (values (pointer-hash key
)
54 (oddp (get-lisp-obj-address key
))))
56 #!-sb-fluid
(declaim (inline equal-hash
))
57 (defun equal-hash (key)
58 (declare (values hash
(member t nil
)))
60 ;; For some types the definition of EQUAL implies a special hash
61 ((or string cons number bit-vector pathname
)
62 (values (sxhash key
) nil
))
63 ;; Otherwise use an EQ hash, rather than SXHASH, since the values
64 ;; of SXHASH will be extremely badly distributed due to the
65 ;; requirements of the spec fitting badly with our implementation
70 #!-sb-fluid
(declaim (inline eql-hash
))
72 (declare (values hash
(member t nil
)))
77 (defun equalp-hash (key)
78 (declare (values hash
(member t nil
)))
80 ;; Types requiring special treatment. Note that PATHNAME and
81 ;; HASH-TABLE are caught by the STRUCTURE-OBJECT test.
82 ((or array cons number character structure-object
)
83 (values (psxhash key
) nil
))
87 (defun almost-primify (num)
88 (declare (type index num
))
90 "Return an almost prime number greater than or equal to NUM."
99 ;;;; user-defined hash table tests
101 (defvar *hash-table-tests
* nil
)
103 (defun define-hash-table-test (name test-fun hash-fun
)
105 "Define a new kind of hash table test."
106 (declare (type symbol name
)
107 (type function test-fun hash-fun
))
108 (setf *hash-table-tests
*
109 (cons (list name test-fun hash-fun
)
110 (remove name
*hash-table-tests
* :test
#'eq
:key
#'car
)))
113 ;;;; construction and simple accessors
115 (defconstant +min-hash-table-size
+ 16)
116 (defconstant +min-hash-table-rehash-threshold
+ (float 1/16 1.0))
118 (defun make-hash-table (&key
(test 'eql
)
119 (size +min-hash-table-size
+)
124 "Create and return a new hash table. The keywords are as follows:
125 :TEST -- Indicates what kind of test to use.
126 :SIZE -- A hint as to how many elements will be put in this hash
128 :REHASH-SIZE -- Indicates how to expand the table when it fills up.
129 If an integer, add space for that many elements. If a floating
130 point number (which must be greater than 1.0), multiply the size
132 :REHASH-THRESHOLD -- Indicates how dense the table can become before
133 forcing a rehash. Can be any positive number <=1, with density
134 approaching zero as the threshold approaches 0. Density 1 means an
135 average of one entry per bucket.
136 :WEAKNESS -- IF NIL (the default) it is a normal non-weak hash table.
137 If one of :KEY, :VALUE, :KEY-AND-VALUE, :KEY-OR-VALUE it is a weak
139 Depending on the type of weakness the lack of references to the
140 key and the value may allow for removal of the entry. If WEAKNESS
141 is :KEY and the key would otherwise be garbage the entry is eligible
142 for removal from the hash table. Similarly, if WEAKNESS is :VALUE
143 the life of an entry depends on its value's references. If WEAKNESS
144 is :KEY-AND-VALUE and either the key or the value would otherwise be
145 garbage the entry can be removed. If WEAKNESS is :KEY-OR-VALUE and
146 both the key and the value would otherwise be garbage the entry can
148 (declare (type (or function symbol
) test
))
149 (declare (type unsigned-byte size
))
150 (multiple-value-bind (test test-fun hash-fun
)
151 (cond ((or (eq test
#'eq
) (eq test
'eq
))
152 (values 'eq
#'eq
#'eq-hash
))
153 ((or (eq test
#'eql
) (eq test
'eql
))
154 (values 'eql
#'eql
#'eql-hash
))
155 ((or (eq test
#'equal
) (eq test
'equal
))
156 (values 'equal
#'equal
#'equal-hash
))
157 ((or (eq test
#'equalp
) (eq test
'equalp
))
158 (values 'equalp
#'equalp
#'equalp-hash
))
160 ;; FIXME: I'd like to remove *HASH-TABLE-TESTS* stuff.
161 ;; Failing that, I'd like to rename it to
162 ;; *USER-HASH-TABLE-TESTS*.
163 (dolist (info *hash-table-tests
*
164 (error "unknown :TEST for MAKE-HASH-TABLE: ~S"
166 (destructuring-bind (test-name test-fun hash-fun
) info
167 (when (or (eq test test-name
) (eq test test-fun
))
168 (return (values test-name test-fun hash-fun
)))))))
169 (let* ((size (max +min-hash-table-size
+
171 ;; SIZE is just a hint, so if the user asks
172 ;; for a SIZE which'd be too big for us to
173 ;; easily implement, we bump it down.
174 (floor array-dimension-limit
1024))))
175 (rehash-size (if (integerp rehash-size
)
177 (float rehash-size
1.0)))
178 ;; FIXME: Original REHASH-THRESHOLD default should be 1.0,
179 ;; not 1, to make it easier for the compiler to avoid
181 (rehash-threshold (max +min-hash-table-rehash-threshold
+
182 (float rehash-threshold
1.0)))
183 (size+1 (1+ size
)) ; The first element is not usable.
184 ;; KLUDGE: The most natural way of expressing the below is
185 ;; (round (/ (float size+1) rehash-threshold)), and indeed
186 ;; it was expressed like that until 0.7.0. However,
187 ;; MAKE-HASH-TABLE is called very early in cold-init, and
188 ;; the SPARC has no primitive instructions for rounding,
189 ;; but only for truncating; therefore, we fudge this issue
190 ;; a little. The other uses of truncate, below, similarly
191 ;; used to be round. -- CSR, 2002-10-01
193 ;; Note that this has not yet been audited for
194 ;; correctness. It just seems to work. -- CSR, 2002-11-02
195 (scaled-size (truncate (/ (float size
+1) rehash-threshold
)))
196 (length (almost-primify (max scaled-size
197 (1+ +min-hash-table-size
+))))
198 (index-vector (make-array length
200 '(unsigned-byte #.sb
!vm
:n-word-bits
)
202 ;; Needs to be the half the length of the KV vector to link
203 ;; KV entries - mapped to indeces at 2i and 2i+1 -
205 (next-vector (make-array size
+1
207 '(unsigned-byte #.sb
!vm
:n-word-bits
)))
208 (kv-vector (make-array (* 2 size
+1)
209 :initial-element
+empty-ht-slot
+))
210 (table (%make-hash-table
214 :rehash-size rehash-size
215 :rehash-threshold rehash-threshold
219 :index-vector index-vector
220 :next-vector next-vector
222 (unless (eq test
'eq
)
224 :element-type
'(unsigned-byte
226 :initial-element
+magic-hash-vector-value
+))
227 :spinlock
(sb!thread
::make-spinlock
))))
228 (declare (type index size
+1 scaled-size length
))
229 ;; Set up the free list, all free. These lists are 0 terminated.
232 (setf (aref next-vector i
) (1+ i
)))
233 (setf (aref next-vector size
) 0)
234 (setf (hash-table-next-free-kv table
) 1)
235 (setf (hash-table-needing-rehash table
) 0)
236 (setf (aref kv-vector
0) table
)
239 (defun hash-table-count (hash-table)
241 "Return the number of entries in the given HASH-TABLE."
242 (declare (type hash-table hash-table
)
244 (hash-table-number-entries hash-table
))
247 (setf (fdocumentation 'hash-table-rehash-size
'function
)
248 "Return the rehash-size HASH-TABLE was created with.")
251 (setf (fdocumentation 'hash-table-rehash-threshold
'function
)
252 "Return the rehash-threshold HASH-TABLE was created with.")
254 (defun hash-table-size (hash-table)
256 "Return a size that can be used with MAKE-HASH-TABLE to create a hash
257 table that can hold however many entries HASH-TABLE can hold without
259 (hash-table-rehash-trigger hash-table
))
262 (setf (fdocumentation 'hash-table-test
'function
)
263 "Return the test HASH-TABLE was created with.")
266 (setf (fdocumentation 'hash-table-weakness
'function
)
267 "Return the WEAKNESS of HASH-TABLE which is one of NIL, :KEY,
268 :VALUE, :KEY-AND-VALUE, :KEY-OR-VALUE.")
270 ;;;; accessing functions
272 ;;; Make new vectors for the table, extending the table based on the
274 (defun rehash (table)
275 (declare (type hash-table table
))
276 (let* ((old-kv-vector (hash-table-table table
))
277 (old-next-vector (hash-table-next-vector table
))
278 (old-hash-vector (hash-table-hash-vector table
))
279 (old-size (length old-next-vector
))
281 (let ((rehash-size (hash-table-rehash-size table
)))
282 (etypecase rehash-size
284 (+ rehash-size old-size
))
286 (the index
(truncate (* rehash-size old-size
)))))))
287 (new-kv-vector (make-array (* 2 new-size
)
288 :initial-element
+empty-ht-slot
+))
291 :element-type
'(unsigned-byte #.sb
!vm
:n-word-bits
)
294 (when old-hash-vector
296 :element-type
'(unsigned-byte #.sb
!vm
:n-word-bits
)
297 :initial-element
+magic-hash-vector-value
+)))
298 (old-index-vector (hash-table-index-vector table
))
299 (new-length (almost-primify
300 (truncate (/ (float new-size
)
301 (hash-table-rehash-threshold table
)))))
303 (make-array new-length
304 :element-type
'(unsigned-byte #.sb
!vm
:n-word-bits
)
305 :initial-element
0)))
306 (declare (type index new-size new-length old-size
))
308 ;; Disable GC tricks on the OLD-KV-VECTOR.
309 (set-header-data old-kv-vector sb
!vm
:vector-normal-subtype
)
311 ;; Non-empty weak hash tables always need GC support.
312 (when (and (hash-table-weakness table
) (plusp (hash-table-count table
)))
313 (set-header-data new-kv-vector sb
!vm
:vector-valid-hashing-subtype
))
315 ;; FIXME: here and in several other places in the hash table code,
316 ;; loops like this one are used when FILL or REPLACE would be
317 ;; appropriate. why are standard CL functions not used?
318 ;; Performance issues? General laziness? -- NJF, 2004-03-10
320 ;; Copy over the kv-vector. The element positions should not move
321 ;; in case there are active scans.
322 (dotimes (i (* old-size
2))
323 (declare (type index i
))
324 (setf (aref new-kv-vector i
) (aref old-kv-vector i
)))
326 ;; Copy over the hash-vector.
327 (when old-hash-vector
328 (dotimes (i old-size
)
329 (setf (aref new-hash-vector i
) (aref old-hash-vector i
))))
331 (setf (hash-table-next-free-kv table
) 0)
332 (setf (hash-table-needing-rehash table
) 0)
333 ;; Rehash all the entries; last to first so that after the pushes
334 ;; the chains are first to last.
335 (do ((i (1- new-size
) (1- i
)))
337 (declare (type index
/2 i
))
338 (let ((key (aref new-kv-vector
(* 2 i
)))
339 (value (aref new-kv-vector
(1+ (* 2 i
)))))
340 (cond ((and (eq key
+empty-ht-slot
+)
341 (eq value
+empty-ht-slot
+))
342 ;; Slot is empty, push it onto the free list.
343 (setf (aref new-next-vector i
)
344 (hash-table-next-free-kv table
))
345 (setf (hash-table-next-free-kv table
) i
))
346 ((and new-hash-vector
347 (not (= (aref new-hash-vector i
)
348 +magic-hash-vector-value
+)))
349 ;; Can use the existing hash value (not EQ based)
350 (let* ((hashing (aref new-hash-vector i
))
351 (index (rem hashing new-length
))
352 (next (aref new-index-vector index
)))
353 (declare (type index index
)
355 ;; Push this slot into the next chain.
356 (setf (aref new-next-vector i
) next
)
357 (setf (aref new-index-vector index
) i
)))
361 (set-header-data new-kv-vector
362 sb
!vm
:vector-valid-hashing-subtype
)
363 (let* ((hashing (pointer-hash key
))
364 (index (rem hashing new-length
))
365 (next (aref new-index-vector index
)))
366 (declare (type index index
)
368 ;; Push this slot onto the next chain.
369 (setf (aref new-next-vector i
) next
)
370 (setf (aref new-index-vector index
) i
))))))
371 (setf (hash-table-table table
) new-kv-vector
)
372 (setf (hash-table-index-vector table
) new-index-vector
)
373 (setf (hash-table-next-vector table
) new-next-vector
)
374 (setf (hash-table-hash-vector table
) new-hash-vector
)
375 ;; Shrink the old vectors to 0 size to help the conservative GC.
376 (%shrink-vector old-kv-vector
0)
377 (%shrink-vector old-index-vector
0)
378 (%shrink-vector old-next-vector
0)
379 (when old-hash-vector
380 (%shrink-vector old-hash-vector
0))
381 (setf (hash-table-rehash-trigger table
) new-size
))
384 ;;; Use the same size as before, re-using the vectors.
385 (defun rehash-without-growing (table)
386 (declare (type hash-table table
))
387 (let* ((kv-vector (hash-table-table table
))
388 (next-vector (hash-table-next-vector table
))
389 (hash-vector (hash-table-hash-vector table
))
390 (size (length next-vector
))
391 (index-vector (hash-table-index-vector table
))
392 (length (length index-vector
)))
393 (declare (type index size length
))
395 ;; Non-empty weak hash tables always need GC support.
396 (unless (and (hash-table-weakness table
) (plusp (hash-table-count table
)))
397 ;; Disable GC tricks, they will be re-enabled during the re-hash
399 (set-header-data kv-vector sb
!vm
:vector-normal-subtype
))
401 ;; Rehash all the entries.
402 (setf (hash-table-next-free-kv table
) 0)
403 (setf (hash-table-needing-rehash table
) 0)
405 (setf (aref next-vector i
) 0))
407 (setf (aref index-vector i
) 0))
408 (do ((i (1- size
) (1- i
)))
410 (declare (type index
/2 i
))
411 (let ((key (aref kv-vector
(* 2 i
)))
412 (value (aref kv-vector
(1+ (* 2 i
)))))
413 (cond ((and (eq key
+empty-ht-slot
+)
414 (eq value
+empty-ht-slot
+))
415 ;; Slot is empty, push it onto free list.
416 (setf (aref next-vector i
) (hash-table-next-free-kv table
))
417 (setf (hash-table-next-free-kv table
) i
))
418 ((and hash-vector
(not (= (aref hash-vector i
)
419 +magic-hash-vector-value
+)))
420 ;; Can use the existing hash value (not EQ based)
421 (let* ((hashing (aref hash-vector i
))
422 (index (rem hashing length
))
423 (next (aref index-vector index
)))
424 (declare (type index index
))
425 ;; Push this slot into the next chain.
426 (setf (aref next-vector i
) next
)
427 (setf (aref index-vector index
) i
)))
431 (set-header-data kv-vector sb
!vm
:vector-valid-hashing-subtype
)
432 (let* ((hashing (pointer-hash key
))
433 (index (rem hashing length
))
434 (next (aref index-vector index
)))
435 (declare (type index index
)
437 ;; Push this slot into the next chain.
438 (setf (aref next-vector i
) next
)
439 (setf (aref index-vector index
) i
)))))))
442 (defun flush-needing-rehash (table)
443 (let* ((kv-vector (hash-table-table table
))
444 (index-vector (hash-table-index-vector table
))
445 (next-vector (hash-table-next-vector table
))
446 (length (length index-vector
)))
447 (do ((next (hash-table-needing-rehash table
)))
449 (declare (type index
/2 next
))
450 (let* ((key (aref kv-vector
(* 2 next
)))
451 (hashing (pointer-hash key
))
452 (index (rem hashing length
))
453 (temp (aref next-vector next
)))
454 (setf (aref next-vector next
) (aref index-vector index
))
455 (setf (aref index-vector index
) next
)
457 (setf (hash-table-needing-rehash table
) 0)
460 (defun gethash (key hash-table
&optional default
)
462 "Finds the entry in HASH-TABLE whose key is KEY and returns the associated
463 value and T as multiple values, or returns DEFAULT and NIL if there is no
464 such entry. Entries can be added using SETF."
465 (declare (type hash-table hash-table
)
466 (values t
(member t nil
)))
467 (gethash3 key hash-table default
))
469 (defun gethash2 (key hash-table
)
471 "Two argument version of GETHASH"
472 (declare (type hash-table hash-table
)
473 (values t
(member t nil
)))
474 (gethash3 key hash-table nil
))
476 (defun gethash3 (key hash-table default
)
478 "Three argument version of GETHASH"
479 (declare (type hash-table hash-table
)
480 (values t
(member t nil
)))
481 (with-spinlock-and-without-gcing ((hash-table-spinlock hash-table
))
482 (cond ((= (get-header-data (hash-table-table hash-table
))
483 sb
!vm
:vector-must-rehash-subtype
)
484 (rehash-without-growing hash-table
))
485 ((not (zerop (hash-table-needing-rehash hash-table
)))
486 (flush-needing-rehash hash-table
)))
488 ;; First check the cache. Use EQ here for speed.
489 (let ((cache (hash-table-cache hash-table
))
490 (table (hash-table-table hash-table
)))
492 (if (and cache
(< cache
(length table
)) (eq (aref table cache
) key
))
493 (values (aref table
(1+ cache
)) t
)
495 ;; Search for key in the hash table.
496 (multiple-value-bind (hashing eq-based
)
497 (funcall (hash-table-hash-fun hash-table
) key
)
498 (declare (type hash hashing
))
499 (let* ((index-vector (hash-table-index-vector hash-table
))
500 (length (length index-vector
))
501 (index (rem hashing length
))
502 (next (aref index-vector index
))
503 (next-vector (hash-table-next-vector hash-table
))
504 (hash-vector (hash-table-hash-vector hash-table
))
505 (test-fun (hash-table-test-fun hash-table
)))
506 (declare (type index index
))
507 ;; Search next-vector chain for a matching key.
508 (if (or eq-based
(not hash-vector
))
509 (do ((next next
(aref next-vector next
)))
510 ((zerop next
) (values default nil
))
511 (declare (type index
/2 next
))
512 (when (eq key
(aref table
(* 2 next
)))
513 (setf (hash-table-cache hash-table
) (* 2 next
))
514 (return (values (aref table
(1+ (* 2 next
))) t
))))
515 (do ((next next
(aref next-vector next
)))
516 ((zerop next
) (values default nil
))
517 (declare (type index
/2 next
))
518 (when (and (= hashing
(aref hash-vector next
))
519 (funcall test-fun key
(aref table
(* 2 next
))))
521 (setf (hash-table-cache hash-table
) (* 2 next
))
522 (return (values (aref table
(1+ (* 2 next
))) t
)))))))))))
524 ;;; so people can call #'(SETF GETHASH)
525 (defun (setf gethash
) (new-value key table
&optional default
)
526 (declare (ignore default
))
527 (%puthash key table new-value
))
529 (defun %puthash
(key hash-table value
)
530 (declare (type hash-table hash-table
))
531 (aver (hash-table-index-vector hash-table
))
532 (with-spinlock-and-without-gcing ((hash-table-spinlock hash-table
))
533 ;; We need to rehash here so that a current key can be found if it
534 ;; exists. Check that there is room for one more entry. May not be
535 ;; needed if the key is already present.
536 (cond ((zerop (hash-table-next-free-kv hash-table
))
538 ((= (get-header-data (hash-table-table hash-table
))
539 sb
!vm
:vector-must-rehash-subtype
)
540 (rehash-without-growing hash-table
))
541 ((not (zerop (hash-table-needing-rehash hash-table
)))
542 (flush-needing-rehash hash-table
)))
544 (let ((cache (hash-table-cache hash-table
))
545 (kv-vector (hash-table-table hash-table
)))
548 (if (and cache
(< cache
(length kv-vector
))
549 (eq (aref kv-vector cache
) key
))
550 ;; If cached, just store here
551 (setf (aref kv-vector
(1+ cache
)) value
)
553 ;; Search for key in the hash table.
554 (multiple-value-bind (hashing eq-based
)
555 (funcall (hash-table-hash-fun hash-table
) key
)
556 (declare (type hash hashing
))
557 (let* ((index-vector (hash-table-index-vector hash-table
))
558 (length (length index-vector
))
559 (index (rem hashing length
))
560 (next (aref index-vector index
))
561 (kv-vector (hash-table-table hash-table
))
562 (next-vector (hash-table-next-vector hash-table
))
563 (hash-vector (hash-table-hash-vector hash-table
))
564 (test-fun (hash-table-test-fun hash-table
)))
565 (declare (type index index next
))
566 (when (hash-table-weakness hash-table
)
567 (set-header-data kv-vector sb
!vm
:vector-valid-hashing-subtype
))
568 (cond ((or eq-based
(not hash-vector
))
570 (set-header-data kv-vector
571 sb
!vm
:vector-valid-hashing-subtype
))
573 ;; Search next-vector chain for a matching key.
574 (do ((next next
(aref next-vector next
)))
576 (declare (type index
/2 next
))
577 (when (eq key
(aref kv-vector
(* 2 next
)))
578 ;; Found, just replace the value.
579 (setf (hash-table-cache hash-table
) (* 2 next
))
580 (setf (aref kv-vector
(1+ (* 2 next
))) value
)
581 (return-from %puthash value
))))
583 ;; Search next-vector chain for a matching key.
584 (do ((next next
(aref next-vector next
)))
586 (declare (type index
/2 next
))
587 (when (and (= hashing
(aref hash-vector next
))
588 (funcall test-fun key
589 (aref kv-vector
(* 2 next
))))
590 ;; Found, just replace the value.
591 (setf (hash-table-cache hash-table
) (* 2 next
))
592 (setf (aref kv-vector
(1+ (* 2 next
))) value
)
593 (return-from %puthash value
)))))
595 ;; Pop a KV slot off the free list
596 (let ((free-kv-slot (hash-table-next-free-kv hash-table
)))
597 (declare (type index
/2 free-kv-slot
))
598 ;; Double-check for overflow.
599 (aver (not (zerop free-kv-slot
)))
600 (setf (hash-table-next-free-kv hash-table
)
601 (aref next-vector free-kv-slot
))
602 (incf (hash-table-number-entries hash-table
))
604 (setf (hash-table-cache hash-table
) (* 2 free-kv-slot
))
605 (setf (aref kv-vector
(* 2 free-kv-slot
)) key
)
606 (setf (aref kv-vector
(1+ (* 2 free-kv-slot
))) value
)
608 ;; Setup the hash-vector if necessary.
611 (setf (aref hash-vector free-kv-slot
) hashing
)
612 (aver (= (aref hash-vector free-kv-slot
)
613 +magic-hash-vector-value
+))))
615 ;; Push this slot into the next chain.
616 (setf (aref next-vector free-kv-slot
) next
)
617 (setf (aref index-vector index
) free-kv-slot
)))))))
620 (defun remhash (key hash-table
)
622 "Remove the entry in HASH-TABLE associated with KEY. Return T if there
623 was such an entry, or NIL if not."
624 (declare (type hash-table hash-table
)
625 (values (member t nil
)))
626 (with-spinlock-and-without-gcing ((hash-table-spinlock hash-table
))
627 ;; We need to rehash here so that a current key can be found if it
629 (cond ((= (get-header-data (hash-table-table hash-table
))
630 sb
!vm
:vector-must-rehash-subtype
)
631 (rehash-without-growing hash-table
))
632 ((not (zerop (hash-table-needing-rehash hash-table
)))
633 (flush-needing-rehash hash-table
)))
635 ;; For now, just clear the cache
636 (setf (hash-table-cache hash-table
) nil
)
638 ;; Search for key in the hash table.
639 (multiple-value-bind (hashing eq-based
)
640 (funcall (hash-table-hash-fun hash-table
) key
)
641 (declare (type hash hashing
))
642 (let* ((index-vector (hash-table-index-vector hash-table
))
643 (length (length index-vector
))
644 (index (rem hashing length
))
645 (next (aref index-vector index
))
646 (table (hash-table-table hash-table
))
647 (next-vector (hash-table-next-vector hash-table
))
648 (hash-vector (hash-table-hash-vector hash-table
))
649 (test-fun (hash-table-test-fun hash-table
)))
650 (declare (type index index
)
652 (flet ((clear-slot (chain-vector prior-slot-location slot-location
)
653 (declare (type index
/2 slot-location
))
654 ;; Mark slot as empty.
655 (setf (aref table
(* 2 slot-location
)) +empty-ht-slot
+
656 (aref table
(1+ (* 2 slot-location
))) +empty-ht-slot
+)
657 ;; Update the prior pointer in the chain to skip this.
658 (setf (aref chain-vector prior-slot-location
)
659 (aref next-vector slot-location
))
660 ;; Push KV slot onto free chain.
661 (setf (aref next-vector slot-location
)
662 (hash-table-next-free-kv hash-table
))
663 (setf (hash-table-next-free-kv hash-table
) slot-location
)
665 (setf (aref hash-vector slot-location
)
666 +magic-hash-vector-value
+))
667 (decf (hash-table-number-entries hash-table
))
671 ((if (or eq-based
(not hash-vector
))
672 (eq key
(aref table
(* 2 next
)))
673 (and (= hashing
(aref hash-vector next
))
674 (funcall test-fun key
(aref table
(* 2 next
)))))
675 (clear-slot index-vector index next
))
676 ;; Search next-vector chain for a matching key.
677 ((or eq-based
(not hash-vector
))
679 (do ((prior next next
)
680 (next (aref next-vector next
) (aref next-vector next
)))
682 (declare (type index next
))
683 (when (eq key
(aref table
(* 2 next
)))
684 (return-from remhash
(clear-slot next-vector prior next
)))))
687 (do ((prior next next
)
688 (next (aref next-vector next
) (aref next-vector next
)))
690 (declare (type index
/2 next
))
691 (when (and (= hashing
(aref hash-vector next
))
692 (funcall test-fun key
(aref table
(* 2 next
))))
694 (clear-slot next-vector prior next
)))))))))))
696 (defun clrhash (hash-table)
698 "This removes all the entries from HASH-TABLE and returns the hash table
700 (declare (optimize speed
))
701 (with-spinlock-and-without-gcing ((hash-table-spinlock hash-table
))
702 (let* ((kv-vector (hash-table-table hash-table
))
703 (next-vector (hash-table-next-vector hash-table
))
704 (hash-vector (hash-table-hash-vector hash-table
))
705 (size (length next-vector
))
706 (index-vector (hash-table-index-vector hash-table
)))
707 ;; Disable GC tricks.
708 (set-header-data kv-vector sb
!vm
:vector-normal-subtype
)
709 ;; Mark all slots as empty by setting all keys and values to magic
711 (aver (eq (aref kv-vector
0) hash-table
))
712 (fill kv-vector
+empty-ht-slot
+ :start
2)
713 ;; Set up the free list, all free.
716 (setf (aref next-vector i
) (1+ i
)))
717 (setf (aref next-vector
(1- size
)) 0)
718 (setf (hash-table-next-free-kv hash-table
) 1)
719 (setf (hash-table-needing-rehash hash-table
) 0)
720 ;; Clear the index-vector.
721 (fill index-vector
0)
722 ;; Clear the hash-vector.
724 (fill hash-vector
+magic-hash-vector-value
+)))
725 (setf (hash-table-cache hash-table
) nil
)
726 (setf (hash-table-number-entries hash-table
) 0))
731 ;;; FIXME: This should be made into a compiler transform for two reasons:
732 ;;; 1. It would then be available for compiling the entire system,
733 ;;; not only parts of the system which are defined after DEFUN MAPHASH.
734 ;;; 2. It could be conditional on compilation policy, so that
735 ;;; it could be compiled as a full call instead of an inline
736 ;;; expansion when SPACE>SPEED.
737 (declaim (inline maphash
))
738 (defun maphash (function-designator hash-table
)
740 "For each entry in HASH-TABLE, call the designated two-argument function on
741 the key and value of the entry. Return NIL."
742 ;; This essentially duplicates WITH-HASH-TABLE-ITERATOR, so
743 ;; any changes here should be reflected there as well.
744 (let ((fun (%coerce-callable-to-fun function-designator
))
745 (size (length (hash-table-next-vector hash-table
))))
746 (declare (type function fun
))
749 (declare (type index
/2 i
))
750 (let* ((kv-vector (hash-table-table hash-table
))
751 (key (aref kv-vector
(* 2 i
)))
752 (value (aref kv-vector
(1+ (* 2 i
)))))
753 ;; We are running without locking or WITHOUT-GCING. For a weak
754 ;; :VALUE hash table it's possible that the GC hit after KEY
755 ;; was read and now the entry is gone. So check if either the
756 ;; key or the value is empty.
757 (unless (or (eq key
+empty-ht-slot
+)
758 (eq value
+empty-ht-slot
+))
759 (funcall fun key value
))))))
761 ;;;; methods on HASH-TABLE
763 ;;; Return a list of keyword args and values to use for MAKE-HASH-TABLE
764 ;;; when reconstructing HASH-TABLE.
765 (defun %hash-table-ctor-args
(hash-table)
766 `(:test
',(hash-table-test hash-table
)
767 :size
',(hash-table-size hash-table
)
768 :rehash-size
',(hash-table-rehash-size hash-table
)
769 :rehash-threshold
',(hash-table-rehash-threshold hash-table
)
770 :weakness
',(hash-table-weakness hash-table
)))
772 ;;; Return an association list representing the same data as HASH-TABLE.
773 (defun %hash-table-alist
(hash-table)
775 (maphash (lambda (key value
)
776 (push (cons key value
) result
))
780 ;;; Stuff an association list into HASH-TABLE. Return the hash table,
781 ;;; so that we can use this for the *PRINT-READABLY* case in
782 ;;; PRINT-OBJECT (HASH-TABLE T) without having to worry about LET
783 ;;; forms and readable gensyms and stuff.
784 (defun %stuff-hash-table
(hash-table alist
)
786 (setf (gethash (car x
) hash-table
) (cdr x
)))
789 (def!method print-object
((hash-table hash-table
) stream
)
790 (declare (type stream stream
))
791 (cond ((or (not *print-readably
*) (not *read-eval
*))
792 (print-unreadable-object (hash-table stream
:type t
:identity t
)
795 (hash-table-test hash-table
)
796 (hash-table-count hash-table
))))
798 (with-standard-io-syntax
801 `(%stuff-hash-table
(make-hash-table ,@(%hash-table-ctor-args
803 ',(%hash-table-alist hash-table
)))))))
805 (def!method make-load-form
((hash-table hash-table
) &optional environment
)
806 (declare (ignore environment
))
807 (values `(make-hash-table ,@(%hash-table-ctor-args hash-table
))
808 `(%stuff-hash-table
,hash-table
',(%hash-table-alist hash-table
))))