jsatom.c

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/* -*- 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 "jsgc.h"
#include "jslock.h"
#include "jsnum.h"
#include "jsopcode.h"
#include "jsstr.h"

JS_FRIEND_API(const char *)
js_AtomToPrintableString(JSContext *cx, JSAtom *atom)
{
    JSString *str;
    const char *bytes;

    str = js_QuoteString(cx, ATOM_TO_STRING(atom), 0);
    if (!str)
        return NULL;
    bytes = js_GetStringBytes(str);
    if (!bytes)
        JS_ReportOutOfMemory(cx);
    return bytes;
}

extern const char js_Error_str[];       /* trivial, from jsexn.h */

/*
 * Keep this in sync with jspubtd.h -- an assertion below will insist that
 * its length match the JSType enum's JSTYPE_LIMIT limit value.
 */
const char *js_type_str[] = {
    "undefined",
    "object",
    "function",
    "string",
    "number",
    "boolean",
};

const char *js_boolean_str[] = {
    js_false_str,
    js_true_str
};

const char js_Arguments_str[]       = "Arguments";
const char js_Array_str[]           = "Array";
const char js_Boolean_str[]         = "Boolean";
const char js_Call_str[]            = "Call";
const char js_Date_str[]            = "Date";
const char js_Function_str[]        = "Function";
const char js_Math_str[]            = "Math";
const char js_Number_str[]          = "Number";
const char js_Object_str[]          = "Object";
const char js_RegExp_str[]          = "RegExp";
const char js_Script_str[]          = "Script";
const char js_String_str[]          = "String";
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_eval_str[]            = "eval";
const char js_getter_str[]          = "getter";
const char js_get_str[]             = "get";
const char js_index_str[]           = "index";
const char js_input_str[]           = "input";
const char js_length_str[]          = "length";
const char js_name_str[]            = "name";
const char js_noSuchMethod_str[]    = "__noSuchMethod__";
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_toSource_str[]        = "toSource";
const char js_toString_str[]        = "toString";
const char js_toLocaleString_str[]  = "toLocaleString";
const char js_valueOf_str[]         = "valueOf";

#define HASH_OBJECT(o)  ((JSHashNumber)(o) >> JSVAL_TAGBITS)
#define HASH_INT(i)     ((JSHashNumber)(i))
#define HASH_DOUBLE(dp) ((JSHashNumber)(((uint32*)(dp))[0] ^ ((uint32*)(dp))[1]))
#define HASH_BOOLEAN(b) ((JSHashNumber)(b))

JS_STATIC_DLL_CALLBACK(JSHashNumber)
js_hash_atom_key(const void *key)
{
    jsval v;
    jsdouble *dp;

    /* Order JSVAL_IS_* tests by likelihood of success. */
    v = (jsval)key;
    if (JSVAL_IS_STRING(v))
        return js_HashString(JSVAL_TO_STRING(v));
    if (JSVAL_IS_INT(v))
        return HASH_INT(JSVAL_TO_INT(v));
    if (JSVAL_IS_DOUBLE(v)) {
        dp = JSVAL_TO_DOUBLE(v);
        return HASH_DOUBLE(dp);
    }
    if (JSVAL_IS_OBJECT(v))
        return HASH_OBJECT(JSVAL_TO_OBJECT(v));
    if (JSVAL_IS_BOOLEAN(v))
        return HASH_BOOLEAN(JSVAL_TO_BOOLEAN(v));
    return (JSHashNumber)v;
}

JS_STATIC_DLL_CALLBACK(intN)
js_compare_atom_keys(const void *k1, const void *k2)
{
    jsval v1, v2;

    v1 = (jsval)k1, v2 = (jsval)k2;
    if (JSVAL_IS_STRING(v1) && JSVAL_IS_STRING(v2))
        return !js_CompareStrings(JSVAL_TO_STRING(v1), JSVAL_TO_STRING(v2));
    if (JSVAL_IS_DOUBLE(v1) && JSVAL_IS_DOUBLE(v2)) {
        double d1 = *JSVAL_TO_DOUBLE(v1);
        double d2 = *JSVAL_TO_DOUBLE(v2);
        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;
    }
    return v1 == v2;
}

JS_STATIC_DLL_CALLBACK(int)
js_compare_stub(const void *v1, const void *v2)
{
    return 1;
}

/* These next two are exported to jsscript.c and used similarly there. */
void * JS_DLL_CALLBACK
js_alloc_table_space(void *priv, size_t size)
{
    return malloc(size);
}

void JS_DLL_CALLBACK
js_free_table_space(void *priv, void *item)
{
    free(item);
}

JS_STATIC_DLL_CALLBACK(JSHashEntry *)
js_alloc_atom(void *priv, const void *key)
{
    JSAtomState *state = (JSAtomState *) priv;
    JSAtom *atom;

    atom = (JSAtom *) malloc(sizeof(JSAtom));
    if (!atom)
        return NULL;
#ifdef JS_THREADSAFE
    state->tablegen++;
#endif
    atom->entry.key = key;
    atom->entry.value = NULL;
    atom->flags = 0;
    atom->number = state->number++;
    return &atom->entry;
}

JS_STATIC_DLL_CALLBACK(void)
js_free_atom(void *priv, JSHashEntry *he, uintN flag)
{
    if (flag != HT_FREE_ENTRY)
        return;
#ifdef JS_THREADSAFE
    ((JSAtomState *)priv)->tablegen++;
#endif
    free(he);
}

static JSHashAllocOps atom_alloc_ops = {
    js_alloc_table_space,   js_free_table_space,
    js_alloc_atom,          js_free_atom
};

#define JS_ATOM_HASH_SIZE   1024

JSBool
js_InitAtomState(JSContext *cx, JSAtomState *state)
{
    state->table = JS_NewHashTable(JS_ATOM_HASH_SIZE, js_hash_atom_key,
                                   js_compare_atom_keys, js_compare_stub,
                                   &atom_alloc_ops, state);
    if (!state->table) {
        JS_ReportOutOfMemory(cx);
        return JS_FALSE;
    }

    state->runtime = cx->runtime;
#ifdef JS_THREADSAFE
    js_InitLock(&state->lock);
    state->tablegen = 0;
#endif

    if (!js_InitPinnedAtoms(cx, state)) {
        js_FreeAtomState(cx, state);
        return JS_FALSE;
    }
    return JS_TRUE;
}

JSBool
js_InitPinnedAtoms(JSContext *cx, JSAtomState *state)
{
    uintN i;

#define FROB(lval,str)                                                        \
    JS_BEGIN_MACRO                                                            \
        if (!(state->lval = js_Atomize(cx, str, strlen(str), ATOM_PINNED)))   \
            return JS_FALSE;                                                  \
    JS_END_MACRO

    JS_ASSERT(sizeof js_type_str / sizeof js_type_str[0] == JSTYPE_LIMIT);
    for (i = 0; i < JSTYPE_LIMIT; i++)
        FROB(typeAtoms[i],        js_type_str[i]);

    FROB(booleanAtoms[0],         js_false_str);
    FROB(booleanAtoms[1],         js_true_str);
    FROB(nullAtom,                js_null_str);

    FROB(ArgumentsAtom,           js_Arguments_str);
    FROB(ArrayAtom,               js_Array_str);
    FROB(BooleanAtom,             js_Boolean_str);
    FROB(CallAtom,                js_Call_str);
    FROB(DateAtom,                js_Date_str);
    FROB(ErrorAtom,               js_Error_str);
    FROB(FunctionAtom,            js_Function_str);
    FROB(MathAtom,                js_Math_str);
    FROB(NumberAtom,              js_Number_str);
    FROB(ObjectAtom,              js_Object_str);
    FROB(RegExpAtom,              js_RegExp_str);
    FROB(ScriptAtom,              js_Script_str);
    FROB(StringAtom,              js_String_str);
    FROB(anonymousAtom,           js_anonymous_str);
    FROB(argumentsAtom,           js_arguments_str);
    FROB(arityAtom,               js_arity_str);
    FROB(calleeAtom,              js_callee_str);
    FROB(callerAtom,              js_caller_str);
    FROB(classPrototypeAtom,      js_class_prototype_str);
    FROB(constructorAtom,         js_constructor_str);
    FROB(countAtom,               js_count_str);
    FROB(evalAtom,                js_eval_str);
    FROB(getAtom,                 js_get_str);
    FROB(getterAtom,              js_getter_str);
    FROB(indexAtom,               js_index_str);
    FROB(inputAtom,               js_input_str);
    FROB(lengthAtom,              js_length_str);
    FROB(nameAtom,                js_name_str);
    FROB(noSuchMethodAtom,        js_noSuchMethod_str);
    FROB(parentAtom,              js_parent_str);
    FROB(protoAtom,               js_proto_str);
    FROB(setAtom,                 js_set_str);
    FROB(setterAtom,              js_setter_str);
    FROB(toSourceAtom,            js_toSource_str);
    FROB(toStringAtom,            js_toString_str);
    FROB(toLocaleStringAtom,      js_toLocaleString_str);
    FROB(valueOfAtom,             js_valueOf_str);

#undef FROB

    memset(&state->lazy, 0, sizeof state->lazy);
    return JS_TRUE;
}

/* NB: cx unused; js_FinishAtomState calls us with null cx. */
void
js_FreeAtomState(JSContext *cx, JSAtomState *state)
{
    if (state->table)
        JS_HashTableDestroy(state->table);
#ifdef JS_THREADSAFE
    js_FinishLock(&state->lock);
#endif
    memset(state, 0, sizeof *state);
}

typedef struct UninternArgs {
    JSRuntime   *rt;
    jsatomid    leaks;
} UninternArgs;

JS_STATIC_DLL_CALLBACK(intN)
js_atom_uninterner(JSHashEntry *he, intN i, void *arg)
{
    JSAtom *atom;
    UninternArgs *args;

    atom = (JSAtom *)he;
    args = (UninternArgs *)arg;
    if (ATOM_IS_STRING(atom))
        js_FinalizeStringRT(args->rt, ATOM_TO_STRING(atom));
    else if (ATOM_IS_OBJECT(atom))
        args->leaks++;
    return HT_ENUMERATE_NEXT;
}

void
js_FinishAtomState(JSAtomState *state)
{
    UninternArgs args;

    if (!state->table)
        return;
    args.rt = state->runtime;
    args.leaks = 0;
    JS_HashTableEnumerateEntries(state->table, js_atom_uninterner, &args);
#ifdef DEBUG
    if (args.leaks != 0) {
        fprintf(stderr,
"JS engine warning: %lu atoms remain after destroying the JSRuntime.\n"
"                   These atoms may point to freed memory. Things reachable\n"
"                   through them have not been finalized.\n",
                (unsigned long) args.leaks);
    }
#endif
    js_FreeAtomState(NULL, state);
}

typedef struct MarkArgs {
    uintN           gcflags;
    JSGCThingMarker mark;
    void            *data;
} MarkArgs;

JS_STATIC_DLL_CALLBACK(intN)
js_atom_marker(JSHashEntry *he, intN i, void *arg)
{
    JSAtom *atom;
    MarkArgs *args;
    jsval key;

    atom = (JSAtom *)he;
    args = (MarkArgs *)arg;
    if ((atom->flags & (ATOM_PINNED | ATOM_INTERNED)) ||
        (args->gcflags & GC_KEEP_ATOMS)) {
        atom->flags |= ATOM_MARK;
        key = ATOM_KEY(atom);
        if (JSVAL_IS_GCTHING(key))
            args->mark(JSVAL_TO_GCTHING(key), args->data);
    }
    return HT_ENUMERATE_NEXT;
}

void
js_MarkAtomState(JSAtomState *state, uintN gcflags, JSGCThingMarker mark,
                 void *data)
{
    MarkArgs args;

    if (!state->table)
        return;
    args.gcflags = gcflags;
    args.mark = mark;
    args.data = data;
    JS_HashTableEnumerateEntries(state->table, js_atom_marker, &args);
}

JS_STATIC_DLL_CALLBACK(intN)
js_atom_sweeper(JSHashEntry *he, intN i, void *arg)
{
    JSAtom *atom;
    JSAtomState *state;

    atom = (JSAtom *)he;
    if (atom->flags & ATOM_MARK) {
        atom->flags &= ~ATOM_MARK;
        state = (JSAtomState *)arg;
        state->liveAtoms++;
        return HT_ENUMERATE_NEXT;
    }
    JS_ASSERT((atom->flags & (ATOM_PINNED | ATOM_INTERNED)) == 0);
    atom->entry.key = NULL;
    atom->flags = 0;
    return HT_ENUMERATE_REMOVE;
}

void
js_SweepAtomState(JSAtomState *state)
{
    state->liveAtoms = 0;
    if (state->table)
        JS_HashTableEnumerateEntries(state->table, js_atom_sweeper, state);
}

JS_STATIC_DLL_CALLBACK(intN)
js_atom_unpinner(JSHashEntry *he, intN i, void *arg)
{
    JSAtom *atom;

    atom = (JSAtom *)he;
    atom->flags &= ~ATOM_PINNED;
    return HT_ENUMERATE_NEXT;
}

void
js_UnpinPinnedAtoms(JSAtomState *state)