DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Untracked file

Line Code
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/*
 * JS atom table.
 */
#include "jsstddef.h"
#include <stdlib.h>
#include <string.h>
#include "jstypes.h"
#include "jsutil.h" /* Added by JSIFY */
#include "jshash.h" /* Added by JSIFY */
#include "jsprf.h"
#include "jsapi.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsconfig.h"
#include "jsgc.h"
#include "jslock.h"
#include "jsnum.h"
#include "jsscan.h"
#include "jsstr.h"

const char *
js_AtomToPrintableString(JSContext *cx, JSAtom *atom)
{
    return js_ValueToPrintableString(cx, ATOM_KEY(atom));
}

#define JS_PROTO(name,code,init) const char js_##name##_str[] = #name;
#include "jsproto.tbl"
#undef JS_PROTO

/*
 * Names for common atoms defined in JSAtomState starting from
 * JSAtomState.emptyAtom until JSAtomState.lazy.
 *
 * The elements of the array after the first empty string define strings
 * corresponding to JSType enumerators from jspubtd.h and to two boolean
 * literals, false and true. The following assert insists that JSType defines
 * exactly 8 types.
 */
JS_STATIC_ASSERT(JSTYPE_LIMIT == 8);
const char *const js_common_atom_names[] = {
    "",                         /* emptyAtom                    */
    js_undefined_str,           /* typeAtoms[JSTYPE_VOID]       */
    js_object_str,              /* typeAtoms[JSTYPE_OBJECT]     */
    js_function_str,            /* typeAtoms[JSTYPE_FUNCTION]   */
    "string",                   /* typeAtoms[JSTYPE_STRING]     */
    "number",                   /* typeAtoms[JSTYPE_NUMBER]     */
    "boolean",                  /* typeAtoms[JSTYPE_BOOLEAN]    */
    js_null_str,                /* typeAtoms[JSTYPE_NULL]       */
    "xml",                      /* typeAtoms[JSTYPE_XML]        */
    js_false_str,               /* booleanAtoms[0]              */
    js_true_str,                /* booleanAtoms[1]              */
    js_null_str,                /* nullAtom                     */

#define JS_PROTO(name,code,init) js_##name##_str,
#include "jsproto.tbl"
#undef JS_PROTO

    js_anonymous_str,           /* anonymousAtom                */
    js_arguments_str,           /* argumentsAtom                */
    js_arity_str,               /* arityAtom                    */
    js_callee_str,              /* calleeAtom                   */
    js_caller_str,              /* callerAtom                   */
    js_class_prototype_str,     /* classPrototypeAtom           */
    js_constructor_str,         /* constructorAtom              */
    js_count_str,               /* countAtom                    */
    js_each_str,                /* eachAtom                     */
    js_eval_str,                /* evalAtom                     */
    js_fileName_str,            /* fileNameAtom                 */
    js_get_str,                 /* getAtom                      */
    js_getter_str,              /* getterAtom                   */
    js_index_str,               /* indexAtom                    */
    js_input_str,               /* inputAtom                    */
    js_iterator_str,            /* iteratorAtom                 */
    js_length_str,              /* lengthAtom                   */
    js_lineNumber_str,          /* lineNumberAtom               */
    js_message_str,             /* messageAtom                  */
    js_name_str,                /* nameAtom                     */
    js_next_str,                /* nextAtom                     */
    js_noSuchMethod_str,        /* noSuchMethodAtom             */
    js_parent_str,              /* parentAtom                   */
    js_proto_str,               /* protoAtom                    */
    js_set_str,                 /* setAtom                      */
    js_setter_str,              /* setterAtom                   */
    js_stack_str,               /* stackAtom                    */
    js_toLocaleString_str,      /* toLocaleStringAtom           */
    js_toSource_str,            /* toSourceAtom                 */
    js_toString_str,            /* toStringAtom                 */
    js_valueOf_str,             /* valueOfAtom                  */
    "(void 0)",                 /* void0Atom                    */

#if JS_HAS_XML_SUPPORT
    js_etago_str,               /* etagoAtom                    */
    js_namespace_str,           /* namespaceAtom                */
    js_ptagc_str,               /* ptagcAtom                    */
    js_qualifier_str,           /* qualifierAtom                */
    js_space_str,               /* spaceAtom                    */
    js_stago_str,               /* stagoAtom                    */
    js_star_str,                /* starAtom                     */
    js_starQualifier_str,       /* starQualifierAtom            */
    js_tagc_str,                /* tagcAtom                     */
    js_xml_str,                 /* xmlAtom                      */
#endif

#ifdef NARCISSUS
    js_call_str,                /* callAtom                     */
    js_construct_str,           /* constructAtom                */
    js_hasInstance_str,         /* hasInstanceAtom              */
    js_ExecutionContext_str,    /* ExecutionContextAtom         */
    js_current_str,             /* currentAtom                  */
#endif
};
JS_STATIC_ASSERT(JS_ARRAY_LENGTH(js_common_atom_names) * sizeof(JSAtom *) ==
                 LAZY_ATOM_OFFSET_START - ATOM_OFFSET_START);

const char js_anonymous_str[]       = "anonymous";
const char js_arguments_str[]       = "arguments";
const char js_arity_str[]           = "arity";
const char js_callee_str[]          = "callee";
const char js_caller_str[]          = "caller";
const char js_class_prototype_str[] = "prototype";
const char js_constructor_str[]     = "constructor";
const char js_count_str[]           = "__count__";
const char js_each_str[]            = "each";
const char js_eval_str[]            = "eval";
const char js_fileName_str[]        = "fileName";
const char js_get_str[]             = "get";
const char js_getter_str[]          = "getter";
const char js_index_str[]           = "index";
const char js_input_str[]           = "input";
const char js_iterator_str[]        = "__iterator__";
const char js_length_str[]          = "length";
const char js_lineNumber_str[]      = "lineNumber";
const char js_message_str[]         = "message";
const char js_name_str[]            = "name";
const char js_next_str[]            = "next";
const char js_noSuchMethod_str[]    = "__noSuchMethod__";
const char js_object_str[]          = "object";
const char js_parent_str[]          = "__parent__";
const char js_proto_str[]           = "__proto__";
const char js_setter_str[]          = "setter";
const char js_set_str[]             = "set";
const char js_stack_str[]           = "stack";
const char js_toSource_str[]        = "toSource";
const char js_toString_str[]        = "toString";
const char js_toLocaleString_str[]  = "toLocaleString";
const char js_undefined_str[]       = "undefined";
const char js_valueOf_str[]         = "valueOf";

#if JS_HAS_XML_SUPPORT
const char js_etago_str[]           = "</";
const char js_namespace_str[]       = "namespace";
const char js_ptagc_str[]           = "/>";
const char js_qualifier_str[]       = "::";
const char js_space_str[]           = " ";
const char js_stago_str[]           = "<";
const char js_star_str[]            = "*";
const char js_starQualifier_str[]   = "*::";
const char js_tagc_str[]            = ">";
const char js_xml_str[]             = "xml";
#endif

#if JS_HAS_GENERATORS
const char js_close_str[]           = "close";
const char js_send_str[]            = "send";
#endif

#ifdef NARCISSUS
const char js_call_str[]             = "__call__";
const char js_construct_str[]        = "__construct__";
const char js_hasInstance_str[]      = "__hasInstance__";
const char js_ExecutionContext_str[] = "ExecutionContext";
const char js_current_str[]          = "current";
#endif

/*
 * JSAtomState.doubleAtoms and JSAtomState.stringAtoms hashtable entry. To
 * support pinned and interned string atoms, we use the lowest bits of the
 * keyAndFlags field to store ATOM_PINNED and ATOM_INTERNED flags.
 */
typedef struct JSAtomHashEntry {
    JSDHashEntryHdr hdr;
    jsuword         keyAndFlags;
} JSAtomHashEntry;

#define ATOM_ENTRY_FLAG_MASK            (ATOM_PINNED | ATOM_INTERNED)

JS_STATIC_ASSERT(ATOM_ENTRY_FLAG_MASK < JSVAL_ALIGN);

/*
 * Helper macros to access and modify JSAtomHashEntry.
 */
#define TO_ATOM_ENTRY(hdr)              ((JSAtomHashEntry *) hdr)
#define ATOM_ENTRY_KEY(entry)                                                 \
    ((void *)((entry)->keyAndFlags & ~ATOM_ENTRY_FLAG_MASK))
#define ATOM_ENTRY_FLAGS(entry)                                               \
    ((uintN)((entry)->keyAndFlags & ATOM_ENTRY_FLAG_MASK))
#define INIT_ATOM_ENTRY(entry, key)                                           \
    ((void)((entry)->keyAndFlags = (jsuword)(key)))
#define ADD_ATOM_ENTRY_FLAGS(entry, flags)                                    \
    ((void)((entry)->keyAndFlags |= (jsuword)(flags)))
#define CLEAR_ATOM_ENTRY_FLAGS(entry, flags)                                  \
    ((void)((entry)->keyAndFlags &= ~(jsuword)(flags)))

JS_STATIC_DLL_CALLBACK(JSDHashNumber)
HashDouble(JSDHashTable *table, const void *key);

JS_STATIC_DLL_CALLBACK(JSBool)
MatchDouble(JSDHashTable *table, const JSDHashEntryHdr *hdr, const void *key);

JS_STATIC_DLL_CALLBACK(JSDHashNumber)
HashString(JSDHashTable *table, const void *key);

JS_STATIC_DLL_CALLBACK(JSBool)
MatchString(JSDHashTable *table, const JSDHashEntryHdr *hdr, const void *key);

static const JSDHashTableOps DoubleHashOps = {
    JS_DHashAllocTable,
    JS_DHashFreeTable,
    HashDouble,
    MatchDouble,
    JS_DHashMoveEntryStub,
    JS_DHashClearEntryStub,
    JS_DHashFinalizeStub,
    NULL
};

static const JSDHashTableOps StringHashOps = {
    JS_DHashAllocTable,
    JS_DHashFreeTable,
    HashString,
    MatchString,
    JS_DHashMoveEntryStub,
    JS_DHashClearEntryStub,
    JS_DHashFinalizeStub,
    NULL
};

#define IS_DOUBLE_TABLE(table)      ((table)->ops == &DoubleHashOps)
#define IS_STRING_TABLE(table)      ((table)->ops == &StringHashOps)

#define IS_INITIALIZED_STATE(state) IS_DOUBLE_TABLE(&(state)->doubleAtoms)

JS_STATIC_DLL_CALLBACK(JSDHashNumber)
HashDouble(JSDHashTable *table, const void *key)
{
    jsdouble d;

    JS_ASSERT(IS_DOUBLE_TABLE(table));
    d = *(jsdouble *)key;
    return JSDOUBLE_HI32(d) ^ JSDOUBLE_LO32(d);
}

JS_STATIC_DLL_CALLBACK(JSDHashNumber)
HashString(JSDHashTable *table, const void *key)
{
    JS_ASSERT(IS_STRING_TABLE(table));
    return js_HashString((JSString *)key);
}

JS_STATIC_DLL_CALLBACK(JSBool)
MatchDouble(JSDHashTable *table, const JSDHashEntryHdr *hdr, const void *key)
{
    JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr);
    jsdouble d1, d2;

    JS_ASSERT(IS_DOUBLE_TABLE(table));
    if (entry->keyAndFlags == 0) {
        /* See comments in MatchString. */
        return JS_FALSE;
    }

    d1 = *(jsdouble *)ATOM_ENTRY_KEY(entry);
    d2 = *(jsdouble *)key;
    if (JSDOUBLE_IS_NaN(d1))
        return JSDOUBLE_IS_NaN(d2);
#if defined(XP_WIN)
    /* XXX MSVC miscompiles such that (NaN == 0) */
    if (JSDOUBLE_IS_NaN(d2))
        return JS_FALSE;
#endif
    return d1 == d2;
}

JS_STATIC_DLL_CALLBACK(JSBool)
MatchString(JSDHashTable *table, const JSDHashEntryHdr *hdr, const void *key)
{
    JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr);

    JS_ASSERT(IS_STRING_TABLE(table));
    if (entry->keyAndFlags == 0) {
        /*
         * This happens when js_AtomizeString adds a new hash entry and
         * releases the lock but before it takes the lock the second time to
         * initialize keyAndFlags for the entry.
         *
         * We always return false for such entries so JS_DHashTableOperate
         * never finds them. We clean them during GC's sweep phase.
         *
         * It means that with a contested lock or when GC is triggered outside
         * the lock we may end up adding two entries, but this is a price for
         * simpler code.
         */
        return JS_FALSE;
    }
    return js_EqualStrings((JSString *)ATOM_ENTRY_KEY(entry), (JSString *)key);
}

/*
 * For a browser build from 2007-08-09 after the browser starts up there are
 * just 55 double atoms, but over 15000 string atoms. Not to penalize more
 * economical embeddings allocating too much memory initially we initialize
 * atomized strings with just 1K entries.
 */
#define JS_STRING_HASH_COUNT   1024
#define JS_DOUBLE_HASH_COUNT   64

JSBool
js_InitAtomState(JSRuntime *rt)
{
    JSAtomState *state = &rt->atomState;

   /*
    * The caller must zero the state before calling this function.
    */
    JS_ASSERT(!state->stringAtoms.ops);
    JS_ASSERT(!state->doubleAtoms.ops);

    if (!JS_DHashTableInit(&state->stringAtoms, &StringHashOps,
                           NULL, sizeof(JSAtomHashEntry),
                           JS_DHASH_DEFAULT_CAPACITY(JS_STRING_HASH_COUNT))) {
        state->stringAtoms.ops = NULL;
        return JS_FALSE;
    }
    JS_ASSERT(IS_STRING_TABLE(&state->stringAtoms));

    if (!JS_DHashTableInit(&state->doubleAtoms, &DoubleHashOps,
                           NULL, sizeof(JSAtomHashEntry),
                           JS_DHASH_DEFAULT_CAPACITY(JS_DOUBLE_HASH_COUNT))) {
        state->doubleAtoms.ops = NULL;
        JS_DHashTableFinish(&state->stringAtoms);
        state->stringAtoms.ops = NULL;
        return JS_FALSE;
    }
    JS_ASSERT(IS_DOUBLE_TABLE(&state->doubleAtoms));

#ifdef JS_THREADSAFE
    js_InitLock(&state->lock);
#endif
    JS_ASSERT(IS_INITIALIZED_STATE(state));
    return JS_TRUE;
}

JS_STATIC_DLL_CALLBACK(JSDHashOperator)
js_string_uninterner(JSDHashTable *table, JSDHashEntryHdr *hdr,
                     uint32 number, void *arg)
{
    JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr);
    JSRuntime *rt = (JSRuntime *)arg;
    JSString *str;

    /*
     * Any string entry that remains at this point must be initialized, as the
     * last GC should clean any uninitialized ones.
     */
    JS_ASSERT(IS_STRING_TABLE(table));
    JS_ASSERT(entry->keyAndFlags != 0);
    str = (JSString *)ATOM_ENTRY_KEY(entry);

    /* Pass null as context. */
    js_FinalizeStringRT(rt, str, js_GetExternalStringGCType(str), NULL);
    return JS_DHASH_NEXT;
}

void
js_FinishAtomState(JSRuntime *rt)
{
    JSAtomState *state = &rt->atomState;

    if (!IS_INITIALIZED_STATE(state)) {
        /*
         * We are called with uninitialized state when JS_NewRuntime fails and
         * calls JS_DestroyRuntime on a partially initialized runtime.
         */
        return;
    }

    JS_DHashTableEnumerate(&state->stringAtoms, js_string_uninterner, rt);
    JS_DHashTableFinish(&state->stringAtoms);
    JS_DHashTableFinish(&state->doubleAtoms);

#ifdef JS_THREADSAFE
    js_FinishLock(&state->lock);
#endif
#ifdef DEBUG
    memset(state, JS_FREE_PATTERN, sizeof *state);
#endif
}

JSBool
js_InitCommonAtoms(JSContext *cx)
{
    JSAtomState *state = &cx->runtime->atomState;
    uintN i;
    JSAtom **atoms;

    atoms = COMMON_ATOMS_START(state);
    for (i = 0; i < JS_ARRAY_LENGTH(js_common_atom_names); i++, atoms++) {
        *atoms = js_Atomize(cx, js_common_atom_names[i],
                            strlen(js_common_atom_names[i]), ATOM_PINNED);
        if (!*atoms)
            return JS_FALSE;
    }
    JS_ASSERT((uint8 *)atoms - (uint8 *)state == LAZY_ATOM_OFFSET_START);
    memset(atoms, 0, ATOM_OFFSET_LIMIT - LAZY_ATOM_OFFSET_START);

    return JS_TRUE;
}

JS_STATIC_DLL_CALLBACK(JSDHashOperator)
js_atom_unpinner(JSDHashTable *table, JSDHashEntryHdr *hdr,
                 uint32 number, void *arg)
{
    JS_ASSERT(IS_STRING_TABLE(table));
    CLEAR_ATOM_ENTRY_FLAGS(TO_ATOM_ENTRY(hdr), ATOM_PINNED);
    return JS_DHASH_NEXT;
}

void
js_FinishCommonAtoms(JSContext *cx)
{
    JSAtomState *state = &cx->runtime->atomState;

    JS_DHashTableEnumerate(&state->stringAtoms, js_atom_unpinner, NULL);
#ifdef DEBUG
    memset(COMMON_ATOMS_START(state), JS_FREE_PATTERN,
           ATOM_OFFSET_LIMIT - ATOM_OFFSET_START);
#endif
}

JS_STATIC_DLL_CALLBACK(JSDHashOperator)
js_locked_atom_tracer(JSDHashTable *table, JSDHashEntryHdr *hdr,
                      uint32 number, void *arg)
{
    JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr);
    JSTracer *trc = (JSTracer *)arg;

    if (entry->keyAndFlags == 0) {
        /* Ignore uninitialized entries during tracing. */
        return JS_DHASH_NEXT;
    }
    JS_SET_TRACING_INDEX(trc, "locked_atom", (size_t)number);
    JS_CallTracer(trc, ATOM_ENTRY_KEY(entry),
                  IS_STRING_TABLE(table) ? JSTRACE_STRING : JSTRACE_DOUBLE);
    return JS_DHASH_NEXT;
}

JS_STATIC_DLL_CALLBACK(JSDHashOperator)
js_pinned_atom_tracer(JSDHashTable *table, JSDHashEntryHdr *hdr,
                        uint32 number, void *arg)
{
    JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr);
    JSTracer *trc = (JSTracer *)arg;
    uintN flags = ATOM_ENTRY_FLAGS(entry);

    JS_ASSERT(IS_STRING_TABLE(table));
    if (flags & (ATOM_PINNED | ATOM_INTERNED)) {
        JS_SET_TRACING_INDEX(trc,
                             flags & ATOM_PINNED
                             ? "pinned_atom"
                             : "interned_atom",
                             (size_t)number);
        JS_CallTracer(trc, ATOM_ENTRY_KEY(entry), JSTRACE_STRING);
    }
    return JS_DHASH_NEXT;
}

void
js_TraceAtomState(JSTracer *trc, JSBool allAtoms)
{
    JSAtomState *state;

    state = &trc->context->runtime->atomState;
    if (allAtoms) {
        JS_DHashTableEnumerate(&state->doubleAtoms, js_locked_atom_tracer, trc);
        JS_DHashTableEnumerate(&state->stringAtoms, js_locked_atom_tracer, trc);
    } else {
        JS_DHashTableEnumerate(&state->stringAtoms, js_pinned_atom_tracer, trc);
    }
}

JS_STATIC_DLL_CALLBACK(JSDHashOperator)
js_atom_sweeper(JSDHashTable *table, JSDHashEntryHdr *hdr,
                uint32 number, void *arg)
{
    JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr);
    JSContext *cx = (JSContext *)arg;

    /* Remove uninitialized entries.  */
    if (entry->keyAndFlags == 0)
        return JS_DHASH_REMOVE;

    if (ATOM_ENTRY_FLAGS(entry) & (ATOM_PINNED | ATOM_INTERNED)) {
        /* Pinned or interned key cannot be finalized. */
        JS_ASSERT(!js_IsAboutToBeFinalized(cx, ATOM_ENTRY_KEY(entry)));
    } else if (js_IsAboutToBeFinalized(cx, ATOM_ENTRY_KEY(entry))) {
        /* Remove entries with things about to be GC'ed. */
        return JS_DHASH_REMOVE;
    }
    return JS_DHASH_NEXT;
}

void
js_SweepAtomState(JSContext *cx)
{
    JSAtomState *state = &cx->runtime->atomState;

    JS_DHashTableEnumerate(&state->doubleAtoms, js_atom_sweeper, cx);
    JS_DHashTableEnumerate(&state->stringAtoms, js_atom_sweeper, cx);

    /*
     * Optimize for simplicity and mutate table generation numbers even if the
     * sweeper has not removed any entries.
     */
    state->doubleAtoms.generation++;
    state->stringAtoms.generation++;
}

JSAtom *
js_AtomizeDouble(JSContext *cx, jsdouble d)
{
    JSAtomState *state;
    JSDHashTable *table;
    JSAtomHashEntry *entry;
    uint32 gen;
    jsdouble *key;
    jsval v;

    state = &cx->runtime->atomState;
    table = &state->doubleAtoms;

    JS_LOCK(&state->lock, cx);
    entry = TO_ATOM_ENTRY(JS_DHashTableOperate(table, &d, JS_DHASH_ADD));
    if (!entry)
        goto failed_hash_add;
    if (entry->keyAndFlags == 0) {
        gen = ++table->generation;
        JS_UNLOCK(&state->lock, cx);

        key = js_NewWeaklyRootedDouble(cx, d);
        if (!key)
            return NULL;

        JS_LOCK(&state->lock, cx);
        if (table->generation == gen) {
            JS_ASSERT(entry->keyAndFlags == 0);
        } else {
            entry = TO_ATOM_ENTRY(JS_DHashTableOperate(table, key,
                                                       JS_DHASH_ADD));
            if (!entry)
                goto failed_hash_add;
            if (entry->keyAndFlags != 0)
                goto finish;
            ++table->generation;
        }
        INIT_ATOM_ENTRY(entry, key);
    }

  finish:
    v = DOUBLE_TO_JSVAL((jsdouble *)ATOM_ENTRY_KEY(entry));
    cx->weakRoots.lastAtom = v;
    JS_UNLOCK(&state->lock,cx);

    return (JSAtom *)v;

  failed_hash_add:
    JS_UNLOCK(&state->lock,cx);
    JS_ReportOutOfMemory(cx);
    return NULL;
}

JSAtom *
js_AtomizeString(JSContext *cx, JSString *str, uintN flags)
{
    jsval v;
    JSAtomState *state;
    JSDHashTable *table;
    JSAtomHashEntry *entry;
    JSString *key;
    uint32 gen;

    JS_ASSERT(!(flags & ~(ATOM_PINNED|ATOM_INTERNED|ATOM_TMPSTR|ATOM_NOCOPY)));
    JS_ASSERT_IF(flags & ATOM_NOCOPY, flags & ATOM_TMPSTR);

    state = &cx->runtime->atomState;
    table = &state->stringAtoms;

    JS_LOCK(&state->lock, cx);
    entry = TO_ATOM_ENTRY(JS_DHashTableOperate(table, str, JS_DHASH_ADD));
    if (!entry)
        goto failed_hash_add;
    if (entry->keyAndFlags != 0) {
        key = (JSString *)ATOM_ENTRY_KEY(entry);
    } else {
        /*
         * We created a new hashtable entry. Unless str is already allocated
         * from the GC heap and flat, we have to release state->lock as
         * string construction is a complex operation. For example, it can
         * trigger GC which may rehash the table and make the entry invalid.
         */
        ++table->generation;
        if (!(flags & ATOM_TMPSTR) && JSSTRING_IS_FLAT(str)) {
            JSFLATSTR_CLEAR_MUTABLE(str);
            key = str;
        } else {
            gen = table->generation;
            JS_UNLOCK(&state->lock, cx);

            if (flags & ATOM_TMPSTR) {
                if (flags & ATOM_NOCOPY) {
                    key = js_NewString(cx, JSFLATSTR_CHARS(str),
                                       JSFLATSTR_LENGTH(str));
                    if (!key)
                        return NULL;

                    /* Finish handing off chars to the GC'ed key string. */
                    str->u.chars = NULL;
                } else {
                    key = js_NewStringCopyN(cx, JSFLATSTR_CHARS(str),
                                            JSFLATSTR_LENGTH(str));
                    if (!key)
                        return NULL;
                }
           } else {
                JS_ASSERT(JSSTRING_IS_DEPENDENT(str));
                if (!js_UndependString(cx, str))
                    return NULL;
                key = str;
            }

            JS_LOCK(&state->lock, cx);
            if (table->generation == gen) {
                JS_ASSERT(entry->keyAndFlags == 0);
            } else {
                entry = TO_ATOM_ENTRY(JS_DHashTableOperate(table, key,
                                                           JS_DHASH_ADD));
                if (!entry)
                    goto failed_hash_add;
                if (entry->keyAndFlags != 0) {
                    key = (JSString *)ATOM_ENTRY_KEY(entry);
                    goto finish;
                }
                ++table->generation;
            }
        }
        INIT_ATOM_ENTRY(entry, key);
        JSFLATSTR_SET_ATOMIZED(key);
    }

  finish:
    ADD_ATOM_ENTRY_FLAGS(entry, flags & (ATOM_PINNED | ATOM_INTERNED));
    JS_ASSERT(JSSTRING_IS_ATOMIZED(key));
    v = STRING_TO_JSVAL(key);
    cx->weakRoots.lastAtom = v;
    JS_UNLOCK(&state->lock, cx);
    return (JSAtom *)v;

  failed_hash_add:
    JS_UNLOCK(&state->lock,cx);
    JS_ReportOutOfMemory(cx);
    return NULL;
}

JSAtom *
js_Atomize(JSContext *cx, const char *bytes, size_t length, uintN flags)
{
    jschar *chars;
    JSString str;
    JSAtom *atom;

    /*
     * Avoiding the malloc in js_InflateString on shorter strings saves us
     * over 20,000 malloc calls on mozilla browser startup. This compares to
     * only 131 calls where the string is longer than a 31 char (net) buffer.
     * The vast majority of atomized strings are already in the hashtable. So
     * js_AtomizeString rarely has to copy the temp string we make.
     */
#define ATOMIZE_BUF_MAX 32
    jschar inflated[ATOMIZE_BUF_MAX];
    size_t inflatedLength = ATOMIZE_BUF_MAX - 1;

    if (length < ATOMIZE_BUF_MAX) {
        js_InflateStringToBuffer(cx, bytes, length, inflated, &inflatedLength);
        inflated[inflatedLength] = 0;
        chars = inflated;
    } else {
        inflatedLength = length;
        chars = js_InflateString(cx, bytes, &inflatedLength);
        if (!chars)
            return NULL;
        flags |= ATOM_NOCOPY;
    }

    JSFLATSTR_INIT(&str, (jschar *)chars, inflatedLength);
    atom = js_AtomizeString(cx, &str, ATOM_TMPSTR | flags);
    if (chars != inflated && str.u.chars)
        JS_free(cx, chars);
    return atom;
}

JSAtom *
js_AtomizeChars(JSContext *cx, const jschar *chars, size_t length, uintN flags)
{
    JSString str;

    JSFLATSTR_INIT(&str, (jschar *)chars, length);
    return js_AtomizeString(cx, &str, ATOM_TMPSTR | flags);
}

JSAtom *
js_GetExistingStringAtom(JSContext *cx, const jschar *chars, size_t length)
{
    JSString str, *str2;
    JSAtomState *state;
    JSDHashEntryHdr *hdr;

    JSFLATSTR_INIT(&str, (jschar *)chars, length);
    state = &cx->runtime->atomState;

    JS_LOCK(&state->lock, cx);
    hdr = JS_DHashTableOperate(&state->stringAtoms, &str, JS_DHASH_LOOKUP);
    str2 = JS_DHASH_ENTRY_IS_BUSY(hdr)
           ? (JSString *)ATOM_ENTRY_KEY(TO_ATOM_ENTRY(hdr))
           : NULL;
    JS_UNLOCK(&state->lock, cx);

    return str2 ? (JSAtom *)STRING_TO_JSVAL(str2) : NULL;
}

JSBool
js_AtomizePrimitiveValue(JSContext *cx, jsval v, JSAtom **atomp)
{
    JSAtom *atom;

    if (JSVAL_IS_STRING(v)) {
        atom = js_AtomizeString(cx, JSVAL_TO_STRING(v), 0);
        if (!atom)
            return JS_FALSE;
    } else if (JSVAL_IS_DOUBLE(v)) {
        atom = js_AtomizeDouble(cx, *JSVAL_TO_DOUBLE(v));
        if (!atom)
            return JS_FALSE;
    } else {
        JS_ASSERT(JSVAL_IS_INT(v) || v == JSVAL_TRUE || v == JSVAL_FALSE ||
                  v == JSVAL_NULL || v == JSVAL_VOID);
        atom = (JSAtom *)v;
    }
    *atomp = atom;
    return JS_TRUE;
}

JSBool
js_ValueToStringId(JSContext *cx, jsval v, jsid *idp)
{
    JSString *str;
    JSAtom *atom;

    /*
     * Optimize for the common case where v is an already-atomized string. The
     * comment in jsstr.h before the JSSTRING_SET_ATOMIZED macro's definition
     * explains why this is thread-safe. The extra rooting via lastAtom (which
     * would otherwise be done in js_js_AtomizeString) ensures the caller that
     * the resulting id at is least weakly rooted.
     */
    if (JSVAL_IS_STRING(v)) {
        str = JSVAL_TO_STRING(v);
        if (JSSTRING_IS_ATOMIZED(str)) {
            cx->weakRoots.lastAtom = v;
            *idp = ATOM_TO_JSID((JSAtom *) v);
            return JS_TRUE;
        }
    } else {
        str = js_ValueToString(cx, v);
        if (!str)
            return JS_FALSE;
    }
    atom = js_AtomizeString(cx, str, 0);
    if (!atom)
        return JS_FALSE;
    *idp = ATOM_TO_JSID(atom);
    return JS_TRUE;
}

#ifdef DEBUG

JS_STATIC_DLL_CALLBACK(JSDHashOperator)
atom_dumper(JSDHashTable *table, JSDHashEntryHdr *hdr,
            uint32 number, void *arg)
{
    JSAtomHashEntry *entry = TO_ATOM_ENTRY(hdr);
    FILE *fp = (FILE *)arg;
    void *key;
    uintN flags;

    fprintf(fp, "%3u %08x ", number, (uintN)entry->hdr.keyHash);
    if (entry->keyAndFlags == 0) {
        fputs("<uninitialized>", fp);
    } else {
        key = ATOM_ENTRY_KEY(entry);
        if (IS_DOUBLE_TABLE(table)) {
            fprintf(fp, "%.16g", *(jsdouble *)key);
        } else {
            JS_ASSERT(IS_STRING_TABLE(table));
            js_FileEscapedString(fp, (JSString *)key, '"');
        }
        flags = ATOM_ENTRY_FLAGS(entry);
        if (flags != 0) {
            fputs((flags & (ATOM_PINNED | ATOM_INTERNED))
                  ? " pinned | interned"
                  : (flags & ATOM_PINNED) ? " pinned" : " interned",
                  fp);
        }
    }
    putc('\n', fp);
    return JS_DHASH_NEXT;
}

JS_FRIEND_API(void)
js_DumpAtoms(JSContext *cx, FILE *fp)
{
    JSAtomState *state = &cx->runtime->atomState;

    fprintf(fp, "stringAtoms table contents:\n");
    JS_DHashTableEnumerate(&state->stringAtoms, atom_dumper, fp);
#ifdef JS_DHASHMETER
    JS_DHashTableDumpMeter(&state->stringAtoms, atom_dumper, fp);
#endif
    putc('\n', fp);

    fprintf(fp, "doubleAtoms table contents:\n");
    JS_DHashTableEnumerate(&state->doubleAtoms, atom_dumper, fp);
#ifdef JS_DHASHMETER
    JS_DHashTableDumpMeter(&state->doubleAtoms, atom_dumper, fp);
#endif
    putc('\n', fp);
}

#endif

JS_STATIC_DLL_CALLBACK(JSHashNumber)
js_hash_atom_ptr(const void *key)
{
    const JSAtom *atom = (const JSAtom *) key;
    return ATOM_HASH(atom);
}

JS_STATIC_DLL_CALLBACK(void *)
js_alloc_temp_space(void *priv, size_t size)
{
    JSContext *cx = (JSContext *) priv;
    void *space;

    JS_ARENA_ALLOCATE(space, &cx->tempPool, size);
    if (!space)
        js_ReportOutOfScriptQuota(cx);
    return space;
}

JS_STATIC_DLL_CALLBACK(void)
js_free_temp_space(void *priv, void *item)
{
}

JS_STATIC_DLL_CALLBACK(JSHashEntry *)
js_alloc_temp_entry(void *priv, const void *key)
{
    JSContext *cx = (JSContext *) priv;
    JSAtomListElement *ale;

    JS_ARENA_ALLOCATE_TYPE(ale, JSAtomListElement, &cx->tempPool);
    if (!ale) {
        js_ReportOutOfScriptQuota(cx);
        return NULL;
    }
    return &ale->entry;
}

JS_STATIC_DLL_CALLBACK(void)
js_free_temp_entry(void *priv, JSHashEntry *he, uintN flag)
{
}

static JSHashAllocOps temp_alloc_ops = {
    js_alloc_temp_space,    js_free_temp_space,
    js_alloc_temp_entry,    js_free_temp_entry
};

JSAtomListElement *
js_IndexAtom(JSContext *cx, JSAtom *atom, JSAtomList *al)
{
    JSAtomListElement *ale, *ale2, *next;
    JSHashEntry **hep;

    ATOM_LIST_LOOKUP(ale, hep, al, atom);
    if (!ale) {
        if (al->count < 10) {
            /* Few enough for linear search, no hash table needed. */
            JS_ASSERT(!al->table);
            ale = (JSAtomListElement *)js_alloc_temp_entry(cx, atom);
            if (!ale)
                return NULL;
            ALE_SET_ATOM(ale, atom);
            ale->entry.next = al->list;
            al->list = &ale->entry;
        } else {
            /* We want to hash.  Have we already made a hash table? */
            if (!al->table) {
                /* No hash table yet, so hep had better be null! */
                JS_ASSERT(!hep);
                al->table = JS_NewHashTable(al->count + 1, js_hash_atom_ptr,
                                            JS_CompareValues, JS_CompareValues,
                                            &temp_alloc_ops, cx);
                if (!al->table)
                    return NULL;

                /*
                 * Set ht->nentries explicitly, because we are moving entries
                 * from al to ht, not calling JS_HashTable(Raw|)Add.
                 */
                al->table->nentries = al->count;

                /* Insert each ale on al->list into the new hash table. */
                for (ale2 = (JSAtomListElement *)al->list; ale2; ale2 = next) {
                    next = ALE_NEXT(ale2);
                    ale2->entry.keyHash = ATOM_HASH(ALE_ATOM(ale2));
                    hep = JS_HashTableRawLookup(al->table, ale2->entry.keyHash,
                                                ale2->entry.key);
                    ale2->entry.next = *hep;
                    *hep = &ale2->entry;
                }
                al->list = NULL;

                /* Set hep for insertion of atom's ale, immediately below. */
                hep = JS_HashTableRawLookup(al->table, ATOM_HASH(atom), atom);
            }

            /* Finally, add an entry for atom into the hash bucket at hep. */
            ale = (JSAtomListElement *)
                  JS_HashTableRawAdd(al->table, hep, ATOM_HASH(atom), atom,
                                     NULL);
            if (!ale)
                return NULL;
        }

        ALE_SET_INDEX(ale, al->count++);
    }
    return ale;
}

JS_STATIC_DLL_CALLBACK(intN)
js_map_atom(JSHashEntry *he, intN i, void *arg)
{
    JSAtomListElement *ale = (JSAtomListElement *)he;
    JSAtom **vector = (JSAtom **) arg;

    vector[ALE_INDEX(ale)] = ALE_ATOM(ale);
    return HT_ENUMERATE_NEXT;
}

#ifdef DEBUG
static jsrefcount js_atom_map_count;
static jsrefcount js_atom_map_hash_table_count;
#endif

void
js_InitAtomMap(JSContext *cx, JSAtomMap *map, JSAtomList *al)
{
    JSAtom **vector;
    JSAtomListElement *ale;
    uint32 count;

    /* Map length must already be initialized. */
    JS_ASSERT(al->count == map->length);
#ifdef DEBUG
    JS_ATOMIC_INCREMENT(&js_atom_map_count);
#endif
    ale = (JSAtomListElement *)al->list;
    if (!ale && !al->table) {
        JS_ASSERT(!map->vector);
        return;
    }

    count = al->count;
    vector = map->vector;
    if (al->table) {
#ifdef DEBUG
        JS_ATOMIC_INCREMENT(&js_atom_map_hash_table_count);
#endif
        JS_HashTableEnumerateEntries(al->table, js_map_atom, vector);
    } else {
        do {
            vector[ALE_INDEX(ale)] = ALE_ATOM(ale);
        } while ((ale = ALE_NEXT(ale)) != NULL);
    }
    ATOM_LIST_INIT(al);
}