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 ;; This stuff is performance critical and unwind-protect is too
18 ;; slow. And without the locking the next vector can get cyclic
19 ;; causing looping in a WITHOUT-GCING form, SHRINK-VECTOR can corrupt
20 ;; memory and who knows what else.
21 (defmacro with-spinlock-and-without-gcing ((spinlock) &body body)
23 (declare (ignore spinlock))
24 (with-unique-names (old-gc-inhibit)
25 `(let ((,old-gc-inhibit *gc-inhibit*)
30 (sb!thread::get-spinlock ,spinlock)
33 (sb!thread::release-spinlock ,spinlock)
34 (let ((*gc-inhibit* ,old-gc-inhibit))
35 ;; the test is racy, but it can err only on the overeager side
36 (sb!kernel::maybe-handle-pending-gc))))))
38 (eval-when (:compile-toplevel :load-toplevel :execute)
39 (defconstant max-hash sb!xc:most-positive-fixnum))
42 `(integer 0 ,max-hash))
44 ;;; FIXME: Does this always make a nonnegative FIXNUM? If so, then
45 ;;; explain why. If not (or if the reason it always makes a
46 ;;; nonnegative FIXNUM is only the accident that pointers in supported
47 ;;; architectures happen to be in the lower half of the address
48 ;;; space), then fix it.
49 #!-sb-fluid (declaim (inline pointer-hash))
50 (defun pointer-hash (key)
51 (declare (values hash))
52 (truly-the hash (%primitive sb!c:make-fixnum key)))
54 #!-sb-fluid (declaim (inline eq-hash))
56 (declare (values hash (member t nil)))
57 (values (pointer-hash key)
58 (oddp (get-lisp-obj-address key))))
60 #!-sb-fluid (declaim (inline equal-hash))
61 (defun equal-hash (key)
62 (declare (values hash (member t nil)))
63 (values (sxhash key) nil))
65 #!-sb-fluid (declaim (inline eql-hash))
67 (declare (values hash (member t nil)))
72 (defun equalp-hash (key)
73 (declare (values hash (member t nil)))
74 (values (psxhash key) nil))
76 (defun almost-primify (num)
77 (declare (type index num))
79 "Return an almost prime number greater than or equal to NUM."
88 ;;;; user-defined hash table tests
90 (defvar *hash-table-tests* nil)
92 (defun define-hash-table-test (name test-fun hash-fun)
94 "Define a new kind of hash table test."
95 (declare (type symbol name)
96 (type function test-fun hash-fun))
97 (setf *hash-table-tests*
98 (cons (list name test-fun hash-fun)
99 (remove name *hash-table-tests* :test #'eq :key #'car)))
102 ;;;; construction and simple accessors
104 (defconstant +min-hash-table-size+ 16)
105 (defconstant +min-hash-table-rehash-threshold+ (float 1/16 1.0))
107 (defun make-hash-table (&key (test 'eql)
108 (size +min-hash-table-size+)
113 "Create and return a new hash table. The keywords are as follows:
114 :TEST -- Indicates what kind of test to use.
115 :SIZE -- A hint as to how many elements will be put in this hash
117 :REHASH-SIZE -- Indicates how to expand the table when it fills up.
118 If an integer, add space for that many elements. If a floating
119 point number (which must be greater than 1.0), multiply the size
121 :REHASH-THRESHOLD -- Indicates how dense the table can become before
122 forcing a rehash. Can be any positive number <=1, with density
123 approaching zero as the threshold approaches 0. Density 1 means an
124 average of one entry per bucket.
125 :WEAKNESS -- IF NIL (the default) it is a normal non-weak hash table.
126 If one of :KEY, :VALUE, :KEY-AND-VALUE, :KEY-OR-VALUE it is a weak
128 Depending on the type of weakness the lack of references to the
129 key and the value may allow for removal of the entry. If WEAKNESS
130 is :KEY and the key would otherwise be garbage the entry is eligible
131 for removal from the hash table. Similarly, if WEAKNESS is :VALUE
132 the life of an entry depends on its value's references. If WEAKNESS
133 is :KEY-AND-VALUE and either the key or the value would otherwise be
134 garbage the entry can be removed. If WEAKNESS is :KEY-OR-VALUE and
135 both the key and the value would otherwise be garbage the entry can
137 (declare (type (or function symbol) test))
138 (declare (type unsigned-byte size))
139 (multiple-value-bind (test test-fun hash-fun)
140 (cond ((or (eq test #'eq) (eq test 'eq))
141 (values 'eq #'eq #'eq-hash))
142 ((or (eq test #'eql) (eq test 'eql))
143 (values 'eql #'eql #'eql-hash))
144 ((or (eq test #'equal) (eq test 'equal))
145 (values 'equal #'equal #'equal-hash))
146 ((or (eq test #'equalp) (eq test 'equalp))
147 (values 'equalp #'equalp #'equalp-hash))
149 ;; FIXME: I'd like to remove *HASH-TABLE-TESTS* stuff.
150 ;; Failing that, I'd like to rename it to
151 ;; *USER-HASH-TABLE-TESTS*.
152 (dolist (info *hash-table-tests*
153 (error "unknown :TEST for MAKE-HASH-TABLE: ~S"
155 (destructuring-bind (test-name test-fun hash-fun) info
156 (when (or (eq test test-name) (eq test test-fun))
157 (return (values test-name test-fun hash-fun)))))))
158 (let* ((size (max +min-hash-table-size+
160 ;; SIZE is just a hint, so if the user asks
161 ;; for a SIZE which'd be too big for us to
162 ;; easily implement, we bump it down.
163 (floor array-dimension-limit 1024))))
164 (rehash-size (if (integerp rehash-size)
166 (float rehash-size 1.0)))
167 ;; FIXME: Original REHASH-THRESHOLD default should be 1.0,
168 ;; not 1, to make it easier for the compiler to avoid
170 (rehash-threshold (max +min-hash-table-rehash-threshold+
171 (float rehash-threshold 1.0)))
172 (size+1 (1+ size)) ; The first element is not usable.
173 ;; KLUDGE: The most natural way of expressing the below is
174 ;; (round (/ (float size+1) rehash-threshold)), and indeed
175 ;; it was expressed like that until 0.7.0. However,
176 ;; MAKE-HASH-TABLE is called very early in cold-init, and
177 ;; the SPARC has no primitive instructions for rounding,
178 ;; but only for truncating; therefore, we fudge this issue
179 ;; a little. The other uses of truncate, below, similarly
180 ;; used to be round. -- CSR, 2002-10-01
182 ;; Note that this has not yet been audited for
183 ;; correctness. It just seems to work. -- CSR, 2002-11-02
184 (scaled-size (truncate (/ (float size+1) rehash-threshold)))
185 (length (almost-primify (max scaled-size
186 (1+ +min-hash-table-size+))))
187 (index-vector (make-array length
189 '(unsigned-byte #.sb!vm:n-word-bits)
191 ;; Needs to be the half the length of the KV vector to link
192 ;; KV entries - mapped to indeces at 2i and 2i+1 -
194 (next-vector (make-array size+1
196 '(unsigned-byte #.sb!vm:n-word-bits)))
197 (kv-vector (make-array (* 2 size+1)
198 :initial-element +empty-ht-slot+))
199 (table (%make-hash-table
203 :rehash-size rehash-size
204 :rehash-threshold rehash-threshold
208 :index-vector index-vector
209 :next-vector next-vector
211 (unless (eq test 'eq)
213 :element-type '(unsigned-byte
215 :initial-element +magic-hash-vector-value+))
216 :spinlock (sb!thread::make-spinlock))))
217 (declare (type index size+1 scaled-size length))
218 ;; Set up the free list, all free. These lists are 0 terminated.
221 (setf (aref next-vector i) (1+ i)))
222 (setf (aref next-vector size) 0)
223 (setf (hash-table-next-free-kv table) 1)
224 (setf (hash-table-needing-rehash table) 0)
225 (setf (aref kv-vector 0) table)
228 (defun hash-table-count (hash-table)
230 "Return the number of entries in the given HASH-TABLE."
231 (declare (type hash-table hash-table)
233 (hash-table-number-entries hash-table))
236 (setf (fdocumentation 'hash-table-rehash-size 'function)
237 "Return the rehash-size HASH-TABLE was created with.")
240 (setf (fdocumentation 'hash-table-rehash-threshold 'function)
241 "Return the rehash-threshold HASH-TABLE was created with.")
243 (defun hash-table-size (hash-table)
245 "Return a size that can be used with MAKE-HASH-TABLE to create a hash
246 table that can hold however many entries HASH-TABLE can hold without
248 (hash-table-rehash-trigger hash-table))
251 (setf (fdocumentation 'hash-table-test 'function)
252 "Return the test HASH-TABLE was created with.")
255 (setf (fdocumentation 'hash-table-weakness 'function)
256 "Return the WEAKNESS of HASH-TABLE which is one of NIL, :KEY,
257 :VALUE, :KEY-AND-VALUE, :KEY-OR-VALUE.")
259 ;;;; accessing functions
261 ;;; Make new vectors for the table, extending the table based on the
263 (defun rehash (table)
264 (declare (type hash-table table))
265 (let* ((old-kv-vector (hash-table-table table))
266 (old-next-vector (hash-table-next-vector table))
267 (old-hash-vector (hash-table-hash-vector table))
268 (old-size (length old-next-vector))
270 (let ((rehash-size (hash-table-rehash-size table)))
271 (etypecase rehash-size
273 (+ rehash-size old-size))
275 (the index (truncate (* rehash-size old-size)))))))
276 (new-kv-vector (make-array (* 2 new-size)
277 :initial-element +empty-ht-slot+))
280 :element-type '(unsigned-byte #.sb!vm:n-word-bits)
283 (when old-hash-vector
285 :element-type '(unsigned-byte #.sb!vm:n-word-bits)
286 :initial-element +magic-hash-vector-value+)))
287 (old-index-vector (hash-table-index-vector table))
288 (new-length (almost-primify
289 (truncate (/ (float new-size)
290 (hash-table-rehash-threshold table)))))
292 (make-array new-length
293 :element-type '(unsigned-byte #.sb!vm:n-word-bits)
294 :initial-element 0)))
295 (declare (type index new-size new-length old-size))
297 ;; Disable GC tricks on the OLD-KV-VECTOR.
298 (set-header-data old-kv-vector sb!vm:vector-normal-subtype)
300 ;; Non-empty weak hash tables always need GC support.
301 (when (and (hash-table-weakness table) (plusp (hash-table-count table)))
302 (set-header-data new-kv-vector sb!vm:vector-valid-hashing-subtype))
304 ;; FIXME: here and in several other places in the hash table code,
305 ;; loops like this one are used when FILL or REPLACE would be
306 ;; appropriate. why are standard CL functions not used?
307 ;; Performance issues? General laziness? -- NJF, 2004-03-10
309 ;; Copy over the kv-vector. The element positions should not move
310 ;; in case there are active scans.
311 (dotimes (i (* old-size 2))
312 (declare (type index i))
313 (setf (aref new-kv-vector i) (aref old-kv-vector i)))
315 ;; Copy over the hash-vector.
316 (when old-hash-vector
317 (dotimes (i old-size)
318 (setf (aref new-hash-vector i) (aref old-hash-vector i))))
320 (setf (hash-table-next-free-kv table) 0)
321 (setf (hash-table-needing-rehash table) 0)
322 ;; Rehash all the entries; last to first so that after the pushes
323 ;; the chains are first to last.
324 (do ((i (1- new-size) (1- i)))
326 (declare (type index/2 i))
327 (let ((key (aref new-kv-vector (* 2 i)))
328 (value (aref new-kv-vector (1+ (* 2 i)))))
329 (cond ((and (eq key +empty-ht-slot+)
330 (eq value +empty-ht-slot+))
331 ;; Slot is empty, push it onto the free list.
332 (setf (aref new-next-vector i)
333 (hash-table-next-free-kv table))
334 (setf (hash-table-next-free-kv table) i))
335 ((and new-hash-vector
336 (not (= (aref new-hash-vector i)
337 +magic-hash-vector-value+)))
338 ;; Can use the existing hash value (not EQ based)
339 (let* ((hashing (aref new-hash-vector i))
340 (index (rem hashing new-length))
341 (next (aref new-index-vector index)))
342 (declare (type index index)
344 ;; Push this slot into the next chain.
345 (setf (aref new-next-vector i) next)
346 (setf (aref new-index-vector index) i)))
350 (set-header-data new-kv-vector
351 sb!vm:vector-valid-hashing-subtype)
352 (let* ((hashing (pointer-hash key))
353 (index (rem hashing new-length))
354 (next (aref new-index-vector index)))
355 (declare (type index index)
357 ;; Push this slot onto the next chain.
358 (setf (aref new-next-vector i) next)
359 (setf (aref new-index-vector index) i))))))
360 (setf (hash-table-table table) new-kv-vector)
361 (setf (hash-table-index-vector table) new-index-vector)
362 (setf (hash-table-next-vector table) new-next-vector)
363 (setf (hash-table-hash-vector table) new-hash-vector)
364 ;; Shrink the old vectors to 0 size to help the conservative GC.
365 (%shrink-vector old-kv-vector 0)
366 (%shrink-vector old-index-vector 0)
367 (%shrink-vector old-next-vector 0)
368 (when old-hash-vector
369 (%shrink-vector old-hash-vector 0))
370 (setf (hash-table-rehash-trigger table) new-size))
373 ;;; Use the same size as before, re-using the vectors.
374 (defun rehash-without-growing (table)
375 (declare (type hash-table table))
376 (let* ((kv-vector (hash-table-table table))
377 (next-vector (hash-table-next-vector table))
378 (hash-vector (hash-table-hash-vector table))
379 (size (length next-vector))
380 (index-vector (hash-table-index-vector table))
381 (length (length index-vector)))
382 (declare (type index size length))
384 ;; Non-empty weak hash tables always need GC support.
385 (unless (and (hash-table-weakness table) (plusp (hash-table-count table)))
386 ;; Disable GC tricks, they will be re-enabled during the re-hash
388 (set-header-data kv-vector sb!vm:vector-normal-subtype))
390 ;; Rehash all the entries.
391 (setf (hash-table-next-free-kv table) 0)
392 (setf (hash-table-needing-rehash table) 0)
394 (setf (aref next-vector i) 0))
396 (setf (aref index-vector i) 0))
397 (do ((i (1- size) (1- i)))
399 (declare (type index/2 i))
400 (let ((key (aref kv-vector (* 2 i)))
401 (value (aref kv-vector (1+ (* 2 i)))))
402 (cond ((and (eq key +empty-ht-slot+)
403 (eq value +empty-ht-slot+))
404 ;; Slot is empty, push it onto free list.
405 (setf (aref next-vector i) (hash-table-next-free-kv table))
406 (setf (hash-table-next-free-kv table) i))
407 ((and hash-vector (not (= (aref hash-vector i)
408 +magic-hash-vector-value+)))
409 ;; Can use the existing hash value (not EQ based)
410 (let* ((hashing (aref hash-vector i))
411 (index (rem hashing length))
412 (next (aref index-vector index)))
413 (declare (type index index))
414 ;; Push this slot into the next chain.
415 (setf (aref next-vector i) next)
416 (setf (aref index-vector index) i)))
420 (set-header-data kv-vector sb!vm:vector-valid-hashing-subtype)
421 (let* ((hashing (pointer-hash key))
422 (index (rem hashing length))
423 (next (aref index-vector index)))
424 (declare (type index index)
426 ;; Push this slot into the next chain.
427 (setf (aref next-vector i) next)
428 (setf (aref index-vector index) i)))))))
431 (defun flush-needing-rehash (table)
432 (let* ((kv-vector (hash-table-table table))
433 (index-vector (hash-table-index-vector table))
434 (next-vector (hash-table-next-vector table))
435 (length (length index-vector)))
436 (do ((next (hash-table-needing-rehash table)))
438 (declare (type index/2 next))
439 (let* ((key (aref kv-vector (* 2 next)))
440 (hashing (pointer-hash key))
441 (index (rem hashing length))
442 (temp (aref next-vector next)))
443 (setf (aref next-vector next) (aref index-vector index))
444 (setf (aref index-vector index) next)
446 (setf (hash-table-needing-rehash table) 0)
449 (defun gethash (key hash-table &optional default)
451 "Finds the entry in HASH-TABLE whose key is KEY and returns the associated
452 value and T as multiple values, or returns DEFAULT and NIL if there is no
453 such entry. Entries can be added using SETF."
454 (declare (type hash-table hash-table)
455 (values t (member t nil)))
456 (gethash3 key hash-table default))
458 (defun gethash2 (key hash-table)
460 "Two argument version of GETHASH"
461 (declare (type hash-table hash-table)
462 (values t (member t nil)))
463 (gethash3 key hash-table nil))
465 (defun gethash3 (key hash-table default)
467 "Three argument version of GETHASH"
468 (declare (type hash-table hash-table)
469 (values t (member t nil)))
470 (with-spinlock-and-without-gcing ((hash-table-spinlock hash-table))
471 (cond ((= (get-header-data (hash-table-table hash-table))
472 sb!vm:vector-must-rehash-subtype)
473 (rehash-without-growing hash-table))
474 ((not (zerop (hash-table-needing-rehash hash-table)))
475 (flush-needing-rehash hash-table)))
477 ;; First check the cache. Use EQ here for speed.
478 (let ((cache (hash-table-cache hash-table))
479 (table (hash-table-table hash-table)))
481 (if (and cache (< cache (length table)) (eq (aref table cache) key))
482 (values (aref table (1+ cache)) t)
484 ;; Search for key in the hash table.
485 (multiple-value-bind (hashing eq-based)
486 (funcall (hash-table-hash-fun hash-table) key)
487 (declare (type hash hashing))
488 (let* ((index-vector (hash-table-index-vector hash-table))
489 (length (length index-vector))
490 (index (rem hashing length))
491 (next (aref index-vector index))
492 (next-vector (hash-table-next-vector hash-table))
493 (hash-vector (hash-table-hash-vector hash-table))
494 (test-fun (hash-table-test-fun hash-table)))
495 (declare (type index index))
496 ;; Search next-vector chain for a matching key.
497 (if (or eq-based (not hash-vector))
498 (do ((next next (aref next-vector next)))
499 ((zerop next) (values default nil))
500 (declare (type index/2 next))
501 (when (eq key (aref table (* 2 next)))
502 (setf (hash-table-cache hash-table) (* 2 next))
503 (return (values (aref table (1+ (* 2 next))) t))))
504 (do ((next next (aref next-vector next)))
505 ((zerop next) (values default nil))
506 (declare (type index/2 next))
507 (when (and (= hashing (aref hash-vector next))
508 (funcall test-fun key (aref table (* 2 next))))
510 (setf (hash-table-cache hash-table) (* 2 next))
511 (return (values (aref table (1+ (* 2 next))) t)))))))))))
513 ;;; so people can call #'(SETF GETHASH)
514 (defun (setf gethash) (new-value key table &optional default)
515 (declare (ignore default))
516 (%puthash key table new-value))
518 (defun %puthash (key hash-table value)
519 (declare (type hash-table hash-table))
520 (aver (hash-table-index-vector hash-table))
521 (with-spinlock-and-without-gcing ((hash-table-spinlock hash-table))
522 ;; We need to rehash here so that a current key can be found if it
523 ;; exists. Check that there is room for one more entry. May not be
524 ;; needed if the key is already present.
525 (cond ((zerop (hash-table-next-free-kv hash-table))
527 ((= (get-header-data (hash-table-table hash-table))
528 sb!vm:vector-must-rehash-subtype)
529 (rehash-without-growing hash-table))
530 ((not (zerop (hash-table-needing-rehash hash-table)))
531 (flush-needing-rehash hash-table)))
533 (let ((cache (hash-table-cache hash-table))
534 (kv-vector (hash-table-table hash-table)))
537 (if (and cache (< cache (length kv-vector))
538 (eq (aref kv-vector cache) key))
539 ;; If cached, just store here
540 (setf (aref kv-vector (1+ cache)) value)
542 ;; Search for key in the hash table.
543 (multiple-value-bind (hashing eq-based)
544 (funcall (hash-table-hash-fun hash-table) key)
545 (declare (type hash hashing))
546 (let* ((index-vector (hash-table-index-vector hash-table))
547 (length (length index-vector))
548 (index (rem hashing length))
549 (next (aref index-vector index))
550 (kv-vector (hash-table-table hash-table))
551 (next-vector (hash-table-next-vector hash-table))
552 (hash-vector (hash-table-hash-vector hash-table))
553 (test-fun (hash-table-test-fun hash-table)))
554 (declare (type index index next))
555 (when (hash-table-weakness hash-table)
556 (set-header-data kv-vector sb!vm:vector-valid-hashing-subtype))
557 (cond ((or eq-based (not hash-vector))
559 (set-header-data kv-vector
560 sb!vm:vector-valid-hashing-subtype))
562 ;; Search next-vector chain for a matching key.
563 (do ((next next (aref next-vector next)))
565 (declare (type index/2 next))
566 (when (eq key (aref kv-vector (* 2 next)))
567 ;; Found, just replace the value.
568 (setf (hash-table-cache hash-table) (* 2 next))
569 (setf (aref kv-vector (1+ (* 2 next))) value)
570 (return-from %puthash value))))
572 ;; Search next-vector chain for a matching key.
573 (do ((next next (aref next-vector next)))
575 (declare (type index/2 next))
576 (when (and (= hashing (aref hash-vector next))
577 (funcall test-fun key
578 (aref kv-vector (* 2 next))))
579 ;; Found, just replace the value.
580 (setf (hash-table-cache hash-table) (* 2 next))
581 (setf (aref kv-vector (1+ (* 2 next))) value)
582 (return-from %puthash value)))))
584 ;; Pop a KV slot off the free list
585 (let ((free-kv-slot (hash-table-next-free-kv hash-table)))
586 (declare (type index/2 free-kv-slot))
587 ;; Double-check for overflow.
588 (aver (not (zerop free-kv-slot)))
589 (setf (hash-table-next-free-kv hash-table)
590 (aref next-vector free-kv-slot))
591 (incf (hash-table-number-entries hash-table))
593 (setf (hash-table-cache hash-table) (* 2 free-kv-slot))
594 (setf (aref kv-vector (* 2 free-kv-slot)) key)
595 (setf (aref kv-vector (1+ (* 2 free-kv-slot))) value)
597 ;; Setup the hash-vector if necessary.
600 (setf (aref hash-vector free-kv-slot) hashing)
601 (aver (= (aref hash-vector free-kv-slot)
602 +magic-hash-vector-value+))))
604 ;; Push this slot into the next chain.
605 (setf (aref next-vector free-kv-slot) next)
606 (setf (aref index-vector index) free-kv-slot)))))))
609 (defun remhash (key hash-table)
611 "Remove the entry in HASH-TABLE associated with KEY. Return T if there
612 was such an entry, or NIL if not."
613 (declare (type hash-table hash-table)
614 (values (member t nil)))
615 (with-spinlock-and-without-gcing ((hash-table-spinlock hash-table))
616 ;; We need to rehash here so that a current key can be found if it
618 (cond ((= (get-header-data (hash-table-table hash-table))
619 sb!vm:vector-must-rehash-subtype)
620 (rehash-without-growing hash-table))
621 ((not (zerop (hash-table-needing-rehash hash-table)))
622 (flush-needing-rehash hash-table)))
624 ;; For now, just clear the cache
625 (setf (hash-table-cache hash-table) nil)
627 ;; Search for key in the hash table.
628 (multiple-value-bind (hashing eq-based)
629 (funcall (hash-table-hash-fun hash-table) key)
630 (declare (type hash hashing))
631 (let* ((index-vector (hash-table-index-vector hash-table))
632 (length (length index-vector))
633 (index (rem hashing length))
634 (next (aref index-vector index))
635 (table (hash-table-table hash-table))
636 (next-vector (hash-table-next-vector hash-table))
637 (hash-vector (hash-table-hash-vector hash-table))
638 (test-fun (hash-table-test-fun hash-table)))
639 (declare (type index index)
641 (flet ((clear-slot (chain-vector prior-slot-location slot-location)
642 (declare (type index/2 slot-location))
643 ;; Mark slot as empty.
644 (setf (aref table (* 2 slot-location)) +empty-ht-slot+
645 (aref table (1+ (* 2 slot-location))) +empty-ht-slot+)
646 ;; Update the prior pointer in the chain to skip this.
647 (setf (aref chain-vector prior-slot-location)
648 (aref next-vector slot-location))
649 ;; Push KV slot onto free chain.
650 (setf (aref next-vector slot-location)
651 (hash-table-next-free-kv hash-table))
652 (setf (hash-table-next-free-kv hash-table) slot-location)
654 (setf (aref hash-vector slot-location)
655 +magic-hash-vector-value+))
656 (decf (hash-table-number-entries hash-table))
660 ((if (or eq-based (not hash-vector))
661 (eq key (aref table (* 2 next)))
662 (and (= hashing (aref hash-vector next))
663 (funcall test-fun key (aref table (* 2 next)))))
664 (clear-slot index-vector index next))
665 ;; Search next-vector chain for a matching key.
666 ((or eq-based (not hash-vector))
668 (do ((prior next next)
669 (next (aref next-vector next) (aref next-vector next)))
671 (declare (type index next))
672 (when (eq key (aref table (* 2 next)))
673 (return-from remhash (clear-slot next-vector prior next)))))
676 (do ((prior next next)
677 (next (aref next-vector next) (aref next-vector next)))
679 (declare (type index/2 next))
680 (when (and (= hashing (aref hash-vector next))
681 (funcall test-fun key (aref table (* 2 next))))
683 (clear-slot next-vector prior next)))))))))))
685 (defun clrhash (hash-table)
687 "This removes all the entries from HASH-TABLE and returns the hash table
689 (declare (optimize speed))
690 (with-spinlock-and-without-gcing ((hash-table-spinlock hash-table))
691 (let* ((kv-vector (hash-table-table hash-table))
692 (next-vector (hash-table-next-vector hash-table))
693 (hash-vector (hash-table-hash-vector hash-table))
694 (size (length next-vector))
695 (index-vector (hash-table-index-vector hash-table)))
696 ;; Disable GC tricks.
697 (set-header-data kv-vector sb!vm:vector-normal-subtype)
698 ;; Mark all slots as empty by setting all keys and values to magic
700 (aver (eq (aref kv-vector 0) hash-table))
701 (fill kv-vector +empty-ht-slot+ :start 2)
702 ;; Set up the free list, all free.
705 (setf (aref next-vector i) (1+ i)))
706 (setf (aref next-vector (1- size)) 0)
707 (setf (hash-table-next-free-kv hash-table) 1)
708 (setf (hash-table-needing-rehash hash-table) 0)
709 ;; Clear the index-vector.
710 (fill index-vector 0)
711 ;; Clear the hash-vector.
713 (fill hash-vector +magic-hash-vector-value+)))
714 (setf (hash-table-cache hash-table) nil)
715 (setf (hash-table-number-entries hash-table) 0))
720 ;;; FIXME: This should be made into a compiler transform for two reasons:
721 ;;; 1. It would then be available for compiling the entire system,
722 ;;; not only parts of the system which are defined after DEFUN MAPHASH.
723 ;;; 2. It could be conditional on compilation policy, so that
724 ;;; it could be compiled as a full call instead of an inline
725 ;;; expansion when SPACE>SPEED.
726 (declaim (inline maphash))
727 (defun maphash (function-designator hash-table)
729 "For each entry in HASH-TABLE, call the designated two-argument function on
730 the key and value of the entry. Return NIL."
731 ;; This essentially duplicates WITH-HASH-TABLE-ITERATOR, so
732 ;; any changes here should be reflected there as well.
733 (let ((fun (%coerce-callable-to-fun function-designator))
734 (size (length (hash-table-next-vector hash-table))))
735 (declare (type function fun))
738 (declare (type index/2 i))
739 (let* ((kv-vector (hash-table-table hash-table))
740 (key (aref kv-vector (* 2 i)))
741 (value (aref kv-vector (1+ (* 2 i)))))
742 ;; We are running without locking or WITHOUT-GCING. For a weak
743 ;; :VALUE hash table it's possible that the GC hit after KEY
744 ;; was read and now the entry is gone. So check if either the
745 ;; key or the value is empty.
746 (unless (or (eq key +empty-ht-slot+)
747 (eq value +empty-ht-slot+))
748 (funcall fun key value))))))
750 ;;;; methods on HASH-TABLE
752 ;;; Return a list of keyword args and values to use for MAKE-HASH-TABLE
753 ;;; when reconstructing HASH-TABLE.
754 (defun %hash-table-ctor-args (hash-table)
755 `(:test ',(hash-table-test hash-table)
756 :size ',(hash-table-size hash-table)
757 :rehash-size ',(hash-table-rehash-size hash-table)
758 :rehash-threshold ',(hash-table-rehash-threshold hash-table)
759 :weakness ',(hash-table-weakness hash-table)))
761 ;;; Return an association list representing the same data as HASH-TABLE.
762 (defun %hash-table-alist (hash-table)
764 (maphash (lambda (key value)
765 (push (cons key value) result))
769 ;;; Stuff an association list into HASH-TABLE. Return the hash table,
770 ;;; so that we can use this for the *PRINT-READABLY* case in
771 ;;; PRINT-OBJECT (HASH-TABLE T) without having to worry about LET
772 ;;; forms and readable gensyms and stuff.
773 (defun %stuff-hash-table (hash-table alist)
775 (setf (gethash (car x) hash-table) (cdr x)))
778 (def!method print-object ((hash-table hash-table) stream)
779 (declare (type stream stream))
780 (cond ((or (not *print-readably*) (not *read-eval*))
781 (print-unreadable-object (hash-table stream :type t :identity t)
784 (hash-table-test hash-table)
785 (hash-table-count hash-table))))
787 (with-standard-io-syntax
790 `(%stuff-hash-table (make-hash-table ,@(%hash-table-ctor-args
792 ',(%hash-table-alist hash-table)))))))
794 (def!method make-load-form ((hash-table hash-table) &optional environment)
795 (declare (ignore environment))
796 (values `(make-hash-table ,@(%hash-table-ctor-args hash-table))
797 `(%stuff-hash-table ,hash-table ',(%hash-table-alist hash-table))))