gecko/js/src/jsarray.cpp
Tom Schuster 537c5775ed Bug 601689 - Optimize GetArrayElement for arguments objects (r=lw)
--HG--
extra : rebase_source : 6360a47b95660da477a1f312ab8654a23e4019c1
2010-10-06 12:04:31 -07:00

3292 lines
97 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set sw=4 ts=8 et tw=78:
*
* ***** 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 array class.
*
* Array objects begin as "dense" arrays, optimized for index-only property
* access over a vector of slots with high load factor. Array methods
* optimize for denseness by testing that the object's class is
* &js_ArrayClass, and can then directly manipulate the slots for efficiency.
*
* We track these pieces of metadata for arrays in dense mode:
* - The array's length property as a uint32, accessible with
* getArrayLength(), setArrayLength().
* - The number of element slots (capacity), gettable with
* getDenseArrayCapacity().
*
* In dense mode, holes in the array are represented by (JS_ARRAY_HOLE) invalid
* values. The final slot in fslots is unused.
*
* NB: the capacity and length of a dense array are entirely unrelated! The
* length may be greater than, less than, or equal to the capacity. See
* array_length_setter for an explanation of how the first, most surprising
* case may occur.
*
* Arrays are converted to use js_SlowArrayClass when any of these conditions
* are met:
* - the load factor (COUNT / capacity) is less than 0.25, and there are
* more than MIN_SPARSE_INDEX slots total
* - a property is set that is not indexed (and not "length"); or
* - a property is defined that has non-default property attributes.
*
* Dense arrays do not track property creation order, so unlike other native
* objects and slow arrays, enumerating an array does not necessarily visit the
* properties in the order they were created. We could instead maintain the
* scope to track property enumeration order, but still use the fast slot
* access. That would have the same memory cost as just using a
* js_SlowArrayClass, but have the same performance characteristics as a dense
* array for slot accesses, at some cost in code complexity.
*/
#include <stdlib.h>
#include <string.h>
#include "jstypes.h"
#include "jsstdint.h"
#include "jsutil.h"
#include "jsapi.h"
#include "jsarray.h"
#include "jsatom.h"
#include "jsbit.h"
#include "jsbool.h"
#include "jstracer.h"
#include "jsbuiltins.h"
#include "jscntxt.h"
#include "jsversion.h"
#include "jsdbgapi.h" /* for js_TraceWatchPoints */
#include "jsfun.h"
#include "jsgc.h"
#include "jsinterp.h"
#include "jsiter.h"
#include "jslock.h"
#include "jsnum.h"
#include "jsobj.h"
#include "jsscope.h"
#include "jsstr.h"
#include "jsstaticcheck.h"
#include "jsvector.h"
#include "jsatominlines.h"
#include "jscntxtinlines.h"
#include "jsinterpinlines.h"
#include "jsobjinlines.h"
using namespace js;
using namespace js::gc;
/* 2^32 - 1 as a number and a string */
#define MAXINDEX 4294967295u
#define MAXSTR "4294967295"
/* Small arrays are dense, no matter what. */
#define MIN_SPARSE_INDEX 256
/*
* Use the limit on number of object slots for sanity and consistency (see the
* assertion in JSObject::makeDenseArraySlow).
*/
static inline bool
INDEX_TOO_BIG(jsuint index)
{
return index >= JSObject::NSLOTS_LIMIT;
}
static inline bool
INDEX_TOO_SPARSE(JSObject *array, jsuint index)
{
/* Small arrays with less than 256 elements are dense, no matter what. */
if (index < 256)
return false;
/*
* Otherwise if the index becomes too large or is more than 256 past
* the current capacity, we have to slowify.
*/
return INDEX_TOO_BIG(index) || (index > array->getDenseArrayCapacity() + 256);
}
static inline bool
ENSURE_SLOW_ARRAY(JSContext *cx, JSObject *obj)
{
return obj->getClass() == &js_SlowArrayClass ||
obj->makeDenseArraySlow(cx);
}
/*
* Determine if the id represents an array index or an XML property index.
*
* An id is an array index according to ECMA by (15.4):
*
* "Array objects give special treatment to a certain class of property names.
* A property name P (in the form of a string value) is an array index if and
* only if ToString(ToUint32(P)) is equal to P and ToUint32(P) is not equal
* to 2^32-1."
*
* In our implementation, it would be sufficient to check for JSVAL_IS_INT(id)
* except that by using signed 31-bit integers we miss the top half of the
* valid range. This function checks the string representation itself; note
* that calling a standard conversion routine might allow strings such as
* "08" or "4.0" as array indices, which they are not.
*
* 'id' is passed as a jsboxedword since the given id need not necessarily hold
* an atomized string.
*/
JSBool
js_StringIsIndex(JSString *str, jsuint *indexp)
{
jschar *cp = str->chars();
if (JS7_ISDEC(*cp) && str->length() < sizeof(MAXSTR)) {
jsuint index = JS7_UNDEC(*cp++);
jsuint oldIndex = 0;
jsuint c = 0;
if (index != 0) {
while (JS7_ISDEC(*cp)) {
oldIndex = index;
c = JS7_UNDEC(*cp);
index = 10*index + c;
cp++;
}
}
/* Ensure that all characters were consumed and we didn't overflow. */
if (*cp == 0 &&
(oldIndex < (MAXINDEX / 10) ||
(oldIndex == (MAXINDEX / 10) && c < (MAXINDEX % 10))))
{
*indexp = index;
return JS_TRUE;
}
}
return JS_FALSE;
}
static jsuint
ValueIsLength(JSContext *cx, Value* vp)
{
if (vp->isInt32()) {
int32_t i = vp->toInt32();
if (i < 0)
goto error;
return (jsuint) i;
}
jsdouble d;
if (!ValueToNumber(cx, *vp, &d))
goto error;
if (JSDOUBLE_IS_NaN(d))
goto error;
jsuint length;
length = (jsuint) d;
if (d != (jsdouble) length)
goto error;
vp->setNumber(length);
return length;
error:
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
JSMSG_BAD_ARRAY_LENGTH);
vp->setNull();
return 0;
}
JSBool
js_GetLengthProperty(JSContext *cx, JSObject *obj, jsuint *lengthp)
{
if (obj->isArray()) {
*lengthp = obj->getArrayLength();
return true;
}
if (obj->isArguments() && !obj->isArgsLengthOverridden()) {
*lengthp = obj->getArgsInitialLength();
return true;
}
AutoValueRooter tvr(cx);
if (!obj->getProperty(cx, ATOM_TO_JSID(cx->runtime->atomState.lengthAtom), tvr.addr()))
return false;
if (tvr.value().isInt32()) {
*lengthp = jsuint(jsint(tvr.value().toInt32())); /* jsuint cast does ToUint32 */
return true;
}
JS_STATIC_ASSERT(sizeof(jsuint) == sizeof(uint32_t));
return ValueToECMAUint32(cx, tvr.value(), (uint32_t *)lengthp);
}
JSBool JS_FASTCALL
js_IndexToId(JSContext *cx, jsuint index, jsid *idp)
{
JSString *str;
if (index <= JSID_INT_MAX) {
*idp = INT_TO_JSID(index);
return JS_TRUE;
}
str = js_NumberToString(cx, index);
if (!str)
return JS_FALSE;
return js_ValueToStringId(cx, StringValue(str), idp);
}
static JSBool
BigIndexToId(JSContext *cx, JSObject *obj, jsuint index, JSBool createAtom,
jsid *idp)
{
jschar buf[10], *start;
Class *clasp;
JSAtom *atom;
JS_STATIC_ASSERT((jsuint)-1 == 4294967295U);
JS_ASSERT(index > JSID_INT_MAX);
start = JS_ARRAY_END(buf);
do {
--start;
*start = (jschar)('0' + index % 10);
index /= 10;
} while (index != 0);
/*
* Skip the atomization if the class is known to store atoms corresponding
* to big indexes together with elements. In such case we know that the
* array does not have an element at the given index if its atom does not
* exist. Fast arrays (clasp == &js_ArrayClass) don't use atoms for
* any indexes, though it would be rare to see them have a big index
* in any case.
*/
if (!createAtom &&
((clasp = obj->getClass()) == &js_SlowArrayClass ||
clasp == &js_ArgumentsClass ||
clasp == &js_ObjectClass)) {
atom = js_GetExistingStringAtom(cx, start, JS_ARRAY_END(buf) - start);
if (!atom) {
*idp = JSID_VOID;
return JS_TRUE;
}
} else {
atom = js_AtomizeChars(cx, start, JS_ARRAY_END(buf) - start, 0);
if (!atom)
return JS_FALSE;
}
*idp = ATOM_TO_JSID(atom);
return JS_TRUE;
}
bool
JSObject::growDenseArrayElements(JSContext *cx, uint32 oldcap, uint32 newcap)
{
JS_ASSERT(isDenseArray());
JS_ASSERT(newcap >= ARRAY_CAPACITY_MIN);
JS_ASSERT(newcap >= oldcap);
if (newcap > MAX_DSLOTS_LENGTH32) {
if (!JS_ON_TRACE(cx))
js_ReportAllocationOverflow(cx);
return JS_FALSE;
}
/* dslots can be NULL during array creation. */
Value *slots = dslots ? dslots - 1 : NULL;
Value *newslots = (Value *) cx->realloc(slots, (size_t(newcap) + 1) * sizeof(Value));
if (!newslots)
return false;
dslots = newslots + 1;
setDenseArrayCapacity(newcap);
Value *base = addressOfDenseArrayElement(0);
for (Value *vp = base + oldcap, *end = base + newcap; vp < end; ++vp)
vp->setMagic(JS_ARRAY_HOLE);
return true;
}
bool
JSObject::ensureDenseArrayElements(JSContext *cx, uint32 newcap)
{
/*
* When a dense array with CAPACITY_DOUBLING_MAX or fewer slots needs to
* grow, double its capacity, to push() N elements in amortized O(N) time.
*
* Above this limit, grow by 12.5% each time. Speed is still amortized
* O(N), with a higher constant factor, and we waste less space.
*/
static const size_t CAPACITY_DOUBLING_MAX = 1024 * 1024;
/*
* Round up all large allocations to a multiple of this (1MB), so as not
* to waste space if malloc gives us 1MB-sized chunks (as jemalloc does).
*/
static const size_t CAPACITY_CHUNK = 1024 * 1024 / sizeof(Value);
uint32 oldcap = getDenseArrayCapacity();
if (newcap > oldcap) {
/*
* If this overflows uint32, newcap is very large. nextsize will end
* up being less than newcap, the code below will thus disregard it,
* and resizeDenseArrayElements() will fail.
*
* The way we use dslots[-1] forces a few +1s and -1s here. For
* example, (oldcap * 2 + 1) produces the sequence 7, 15, 31, 63, ...
* which makes the total allocation size (with dslots[-1]) a power
* of two.
*/
uint32 nextsize = (oldcap <= CAPACITY_DOUBLING_MAX)
? oldcap * 2 + 1
: oldcap + (oldcap >> 3);
uint32 actualCapacity = JS_MAX(newcap, nextsize);
if (actualCapacity >= CAPACITY_CHUNK)
actualCapacity = JS_ROUNDUP(actualCapacity + 1, CAPACITY_CHUNK) - 1; /* -1 for dslots[-1] */
else if (actualCapacity < ARRAY_CAPACITY_MIN)
actualCapacity = ARRAY_CAPACITY_MIN;
if (!growDenseArrayElements(cx, oldcap, actualCapacity))
return false;
}
return true;
}
bool
JSObject::shrinkDenseArrayElements(JSContext *cx, uint32 newcap)
{
JS_ASSERT(isDenseArray());
JS_ASSERT(newcap < getDenseArrayCapacity());
JS_ASSERT(dslots);
uint32 fill = newcap;
if (newcap < ARRAY_CAPACITY_MIN)
newcap = ARRAY_CAPACITY_MIN;
Value *newslots = (Value *) cx->realloc(dslots - 1, (size_t(newcap) + 1) * sizeof(Value));
if (!newslots)
return false;
dslots = newslots + 1;
setDenseArrayCapacity(newcap);
/* we refuse to shrink below a minimum value, so we have to clear the excess space */
Value *base = addressOfDenseArrayElement(0);
while (fill < newcap)
base[fill++].setMagic(JS_ARRAY_HOLE);
return true;
}
static bool
ReallyBigIndexToId(JSContext* cx, jsdouble index, jsid* idp)
{
return js_ValueToStringId(cx, DoubleValue(index), idp);
}
static bool
IndexToId(JSContext* cx, JSObject* obj, jsdouble index, JSBool* hole, jsid* idp,
JSBool createAtom = JS_FALSE)
{
if (index <= JSID_INT_MAX) {
*idp = INT_TO_JSID(int(index));
return JS_TRUE;
}
if (index <= jsuint(-1)) {
if (!BigIndexToId(cx, obj, jsuint(index), createAtom, idp))
return JS_FALSE;
if (hole && JSID_IS_VOID(*idp))
*hole = JS_TRUE;
return JS_TRUE;
}
return ReallyBigIndexToId(cx, index, idp);
}
/*
* If the property at the given index exists, get its value into location
* pointed by vp and set *hole to false. Otherwise set *hole to true and *vp
* to JSVAL_VOID. This function assumes that the location pointed by vp is
* properly rooted and can be used as GC-protected storage for temporaries.
*/
static JSBool
GetArrayElement(JSContext *cx, JSObject *obj, jsdouble index, JSBool *hole,
Value *vp)
{
JS_ASSERT(index >= 0);
if (obj->isDenseArray() && index < obj->getDenseArrayCapacity() &&
!(*vp = obj->getDenseArrayElement(uint32(index))).isMagic(JS_ARRAY_HOLE)) {
*hole = JS_FALSE;
return JS_TRUE;
}
if (obj->isArguments() &&
index < obj->getArgsInitialLength() &&
!(*vp = obj->getArgsElement(uint32(index))).isMagic(JS_ARRAY_HOLE)) {
*hole = JS_FALSE;
JSStackFrame *fp = (JSStackFrame *)obj->getPrivate();
if (fp != JS_ARGUMENTS_OBJECT_ON_TRACE) {
if (fp)
*vp = fp->canonicalActualArg(index);
return JS_TRUE;
}
}
AutoIdRooter idr(cx);
*hole = JS_FALSE;
if (!IndexToId(cx, obj, index, hole, idr.addr()))
return JS_FALSE;
if (*hole) {
vp->setUndefined();
return JS_TRUE;
}
JSObject *obj2;
JSProperty *prop;
if (!obj->lookupProperty(cx, idr.id(), &obj2, &prop))
return JS_FALSE;
if (!prop) {
*hole = JS_TRUE;
vp->setUndefined();
} else {
obj2->dropProperty(cx, prop);
if (!obj->getProperty(cx, idr.id(), vp))
return JS_FALSE;
*hole = JS_FALSE;
}
return JS_TRUE;
}
/*
* Set the value of the property at the given index to v assuming v is rooted.
*/
static JSBool
SetArrayElement(JSContext *cx, JSObject *obj, jsdouble index, const Value &v)
{
JS_ASSERT(index >= 0);
if (obj->isDenseArray()) {
/* Predicted/prefetched code should favor the remains-dense case. */
if (index <= jsuint(-1)) {
jsuint idx = jsuint(index);
if (!INDEX_TOO_SPARSE(obj, idx)) {
JS_ASSERT(idx + 1 > idx);
if (!obj->ensureDenseArrayElements(cx, idx + 1))
return JS_FALSE;
if (idx >= obj->getArrayLength())
obj->setArrayLength(idx + 1);
obj->setDenseArrayElement(idx, v);
return JS_TRUE;
}
}
if (!obj->makeDenseArraySlow(cx))
return JS_FALSE;
}
AutoIdRooter idr(cx);
if (!IndexToId(cx, obj, index, NULL, idr.addr(), JS_TRUE))
return JS_FALSE;
JS_ASSERT(!JSID_IS_VOID(idr.id()));
Value tmp = v;
return obj->setProperty(cx, idr.id(), &tmp, true);
}
#ifdef JS_TRACER
JSBool JS_FASTCALL
js_EnsureDenseArrayCapacity(JSContext *cx, JSObject *obj, jsint i)
{
jsuint u = jsuint(i);
jsuint capacity = obj->getDenseArrayCapacity();
if (u < capacity)
return true;
if (INDEX_TOO_SPARSE(obj, u))
return false;
return obj->ensureDenseArrayElements(cx, u + 1);
}
JS_DEFINE_CALLINFO_3(extern, BOOL, js_EnsureDenseArrayCapacity, CONTEXT, OBJECT, INT32, 0,
nanojit::ACCSET_STORE_ANY)
#endif
static JSBool
DeleteArrayElement(JSContext *cx, JSObject *obj, jsdouble index, JSBool strict)
{
JS_ASSERT(index >= 0);
if (obj->isDenseArray()) {
if (index <= jsuint(-1)) {
jsuint idx = jsuint(index);
if (idx < obj->getDenseArrayCapacity()) {
obj->setDenseArrayElement(idx, MagicValue(JS_ARRAY_HOLE));
return JS_TRUE;
}
}
return JS_TRUE;
}
AutoIdRooter idr(cx);
if (!IndexToId(cx, obj, index, NULL, idr.addr()))
return JS_FALSE;
if (JSID_IS_VOID(idr.id()))
return JS_TRUE;
Value junk;
return obj->deleteProperty(cx, idr.id(), &junk, strict);
}
/*
* When hole is true, delete the property at the given index. Otherwise set
* its value to v assuming v is rooted.
*/
static JSBool
SetOrDeleteArrayElement(JSContext *cx, JSObject *obj, jsdouble index,
JSBool hole, const Value &v)
{
if (hole) {
JS_ASSERT(v.isUndefined());
return DeleteArrayElement(cx, obj, index, true);
}
return SetArrayElement(cx, obj, index, v);
}
JSBool
js_SetLengthProperty(JSContext *cx, JSObject *obj, jsdouble length)
{
Value v;
jsid id;
v.setNumber(length);
id = ATOM_TO_JSID(cx->runtime->atomState.lengthAtom);
/* We don't support read-only array length yet. */
return obj->setProperty(cx, id, &v, false);
}
JSBool
js_HasLengthProperty(JSContext *cx, JSObject *obj, jsuint *lengthp)
{
JSErrorReporter older = JS_SetErrorReporter(cx, NULL);
AutoValueRooter tvr(cx);
jsid id = ATOM_TO_JSID(cx->runtime->atomState.lengthAtom);
JSBool ok = obj->getProperty(cx, id, tvr.addr());
JS_SetErrorReporter(cx, older);
if (!ok)
return false;
*lengthp = ValueIsLength(cx, tvr.addr());
return !tvr.value().isNull();
}
/*
* Since SpiderMonkey supports cross-class prototype-based delegation, we have
* to be careful about the length getter and setter being called on an object
* not of Array class. For the getter, we search obj's prototype chain for the
* array that caused this getter to be invoked. In the setter case to overcome
* the JSPROP_SHARED attribute, we must define a shadowing length property.
*/
static JSBool
array_length_getter(JSContext *cx, JSObject *obj, jsid id, Value *vp)
{
do {
if (obj->isArray()) {
vp->setNumber(obj->getArrayLength());
return JS_TRUE;
}
} while ((obj = obj->getProto()) != NULL);
return JS_TRUE;
}
static JSBool
array_length_setter(JSContext *cx, JSObject *obj, jsid id, Value *vp, JSBool strict)
{
jsuint newlen, oldlen, gap, index;
Value junk;
/* Check for a sealed object first. */
if (!obj->isExtensible()) {
return js_ReportValueErrorFlags(cx, JSREPORT_ERROR, JSMSG_READ_ONLY,
JSDVG_IGNORE_STACK, IdToValue(id), NULL,
NULL, NULL);
}
if (!obj->isArray()) {
jsid lengthId = ATOM_TO_JSID(cx->runtime->atomState.lengthAtom);
return obj->defineProperty(cx, lengthId, *vp, NULL, NULL, JSPROP_ENUMERATE);
}
newlen = ValueIsLength(cx, vp);
if (vp->isNull())
return false;
oldlen = obj->getArrayLength();
if (oldlen == newlen)
return true;
vp->setNumber(newlen);
if (oldlen < newlen) {
obj->setArrayLength(newlen);
return true;
}
if (obj->isDenseArray()) {
/*
* Don't reallocate if we're not actually shrinking our slots. If we do
* shrink slots here, resizeDenseArrayElements will fill all slots to the
* right of newlen with JS_ARRAY_HOLE. This permits us to disregard
* length when reading from arrays as long we are within the capacity.
*/
jsuint oldcap = obj->getDenseArrayCapacity();
if (oldcap > newlen && !obj->shrinkDenseArrayElements(cx, newlen))
return false;
obj->setArrayLength(newlen);
} else if (oldlen - newlen < (1 << 24)) {
do {
--oldlen;
if (!JS_CHECK_OPERATION_LIMIT(cx)) {
obj->setArrayLength(oldlen + 1);
return false;
}
if (!DeleteArrayElement(cx, obj, oldlen, true)) {
obj->setArrayLength(oldlen + 1);
if (strict)
return false;
JS_ClearPendingException(cx);
return true;
}
} while (oldlen != newlen);
obj->setArrayLength(newlen);
} else {
/*
* We are going to remove a lot of indexes in a presumably sparse
* array. So instead of looping through indexes between newlen and
* oldlen, we iterate through all properties and remove those that
* correspond to indexes in the half-open range [newlen, oldlen). See
* bug 322135.
*/
JSObject *iter = JS_NewPropertyIterator(cx, obj);
if (!iter)
return false;
/* Protect iter against GC under JSObject::deleteProperty. */
AutoObjectRooter tvr(cx, iter);
gap = oldlen - newlen;
for (;;) {
if (!JS_CHECK_OPERATION_LIMIT(cx) || !JS_NextProperty(cx, iter, &id))
return false;
if (JSID_IS_VOID(id))
break;
if (js_IdIsIndex(id, &index) && index - newlen < gap &&
!obj->deleteProperty(cx, id, &junk, false)) {
return false;
}
}
obj->setArrayLength(newlen);
}
return true;
}
/*
* We have only indexed properties up to capacity (excepting holes), plus the
* length property. For all else, we delegate to the prototype.
*/
static inline bool
IsDenseArrayId(JSContext *cx, JSObject *obj, jsid id)
{
JS_ASSERT(obj->isDenseArray());
uint32 i;
return JSID_IS_ATOM(id, cx->runtime->atomState.lengthAtom) ||
(js_IdIsIndex(id, &i) &&
obj->getArrayLength() != 0 &&
i < obj->getDenseArrayCapacity() &&
!obj->getDenseArrayElement(i).isMagic(JS_ARRAY_HOLE));
}
static JSBool
array_lookupProperty(JSContext *cx, JSObject *obj, jsid id, JSObject **objp,
JSProperty **propp)
{
if (!obj->isDenseArray())
return js_LookupProperty(cx, obj, id, objp, propp);
if (IsDenseArrayId(cx, obj, id)) {
*propp = (JSProperty *) 1; /* non-null to indicate found */
*objp = obj;
return JS_TRUE;
}
JSObject *proto = obj->getProto();
if (!proto) {
*objp = NULL;
*propp = NULL;
return JS_TRUE;
}
return proto->lookupProperty(cx, id, objp, propp);
}
JSBool
js_GetDenseArrayElementValue(JSContext *cx, JSObject *obj, jsid id, Value *vp)
{
JS_ASSERT(obj->isDenseArray());
uint32 i;
if (!js_IdIsIndex(id, &i)) {
JS_ASSERT(JSID_IS_ATOM(id, cx->runtime->atomState.lengthAtom));
vp->setNumber(obj->getArrayLength());
return JS_TRUE;
}
*vp = obj->getDenseArrayElement(i);
return JS_TRUE;
}
static JSBool
array_getProperty(JSContext *cx, JSObject *obj, jsid id, Value *vp)
{
uint32 i;
if (JSID_IS_ATOM(id, cx->runtime->atomState.lengthAtom)) {
vp->setNumber(obj->getArrayLength());
return JS_TRUE;
}
if (JSID_IS_ATOM(id, cx->runtime->atomState.protoAtom)) {
vp->setObjectOrNull(obj->getProto());
return JS_TRUE;
}
if (!obj->isDenseArray())
return js_GetProperty(cx, obj, id, vp);
if (!js_IdIsIndex(id, &i) || i >= obj->getDenseArrayCapacity() ||
obj->getDenseArrayElement(i).isMagic(JS_ARRAY_HOLE)) {
JSObject *obj2;
JSProperty *prop;
const Shape *shape;
JSObject *proto = obj->getProto();
if (!proto) {
vp->setUndefined();
return JS_TRUE;
}
vp->setUndefined();
if (js_LookupPropertyWithFlags(cx, proto, id, cx->resolveFlags,
&obj2, &prop) < 0)
return JS_FALSE;
if (prop && obj2->isNative()) {
shape = (const Shape *) prop;
if (!js_NativeGet(cx, obj, obj2, shape, JSGET_METHOD_BARRIER, vp))
return JS_FALSE;
JS_UNLOCK_OBJ(cx, obj2);
}
return JS_TRUE;
}
*vp = obj->getDenseArrayElement(i);
return JS_TRUE;
}
static JSBool
slowarray_addProperty(JSContext *cx, JSObject *obj, jsid id, Value *vp)
{
jsuint index, length;
if (!js_IdIsIndex(id, &index))
return JS_TRUE;
length = obj->getArrayLength();
if (index >= length)
obj->setArrayLength(index + 1);
return JS_TRUE;
}
static JSType
array_typeOf(JSContext *cx, JSObject *obj)
{
return JSTYPE_OBJECT;
}
static JSBool
array_setProperty(JSContext *cx, JSObject *obj, jsid id, Value *vp, JSBool strict)
{
uint32 i;
if (JSID_IS_ATOM(id, cx->runtime->atomState.lengthAtom))
return array_length_setter(cx, obj, id, vp, strict);
if (!obj->isDenseArray())
return js_SetProperty(cx, obj, id, vp, strict);
if (!js_IdIsIndex(id, &i) || js_PrototypeHasIndexedProperties(cx, obj) ||
INDEX_TOO_SPARSE(obj, i)) {
if (!obj->makeDenseArraySlow(cx))
return false;
return js_SetProperty(cx, obj, id, vp, strict);
}
if (!obj->ensureDenseArrayElements(cx, i + 1))
return false;
if (i >= obj->getArrayLength())
obj->setArrayLength(i + 1);
obj->setDenseArrayElement(i, *vp);
return true;
}
static JSBool
slowarray_setProperty(JSContext *cx, JSObject *obj, jsid id, Value *vp, JSBool strict)
{
JS_ASSERT(obj->isSlowArray());
if (JSID_IS_ATOM(id, cx->runtime->atomState.lengthAtom))
return array_length_setter(cx, obj, id, vp, strict);
return js_SetProperty(cx, obj, id, vp, strict);
}
JSBool
js_PrototypeHasIndexedProperties(JSContext *cx, JSObject *obj)
{
/*
* Walk up the prototype chain and see if this indexed element already
* exists. If we hit the end of the prototype chain, it's safe to set the
* element on the original object.
*/
while ((obj = obj->getProto()) != NULL) {
/*
* If the prototype is a non-native object (possibly a dense array), or
* a native object (possibly a slow array) that has indexed properties,
* return true.
*/
if (!obj->isNative())
return JS_TRUE;
if (obj->isIndexed())
return JS_TRUE;
}
return JS_FALSE;
}
#ifdef JS_TRACER
JSBool FASTCALL
js_Array_dense_setelem_hole(JSContext* cx, JSObject* obj, jsint i)
{
if (js_PrototypeHasIndexedProperties(cx, obj))
return false;
jsuint u = jsuint(i);
if (u >= obj->getArrayLength())
obj->setArrayLength(u + 1);
return true;
}
JS_DEFINE_CALLINFO_3(extern, BOOL, js_Array_dense_setelem_hole, CONTEXT, OBJECT, INT32,
0, nanojit::ACCSET_STORE_ANY)
#endif
static JSBool
array_defineProperty(JSContext *cx, JSObject *obj, jsid id, const Value *value,
PropertyOp getter, PropertyOp setter, uintN attrs)
{
uint32 i = 0; // init to shut GCC up
JSBool isIndex;
if (JSID_IS_ATOM(id, cx->runtime->atomState.lengthAtom))
return JS_TRUE;
isIndex = js_IdIsIndex(id, &i);
if (!isIndex || attrs != JSPROP_ENUMERATE || !obj->isDenseArray() || INDEX_TOO_SPARSE(obj, i)) {
if (!ENSURE_SLOW_ARRAY(cx, obj))
return JS_FALSE;
return js_DefineProperty(cx, obj, id, value, getter, setter, attrs);
}
Value tmp = *value;
return array_setProperty(cx, obj, id, &tmp, false);
}
static JSBool
array_getAttributes(JSContext *cx, JSObject *obj, jsid id, uintN *attrsp)
{
*attrsp = JSID_IS_ATOM(id, cx->runtime->atomState.lengthAtom)
? JSPROP_PERMANENT : JSPROP_ENUMERATE;
return JS_TRUE;
}
static JSBool
array_setAttributes(JSContext *cx, JSObject *obj, jsid id, uintN *attrsp)
{
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
JSMSG_CANT_SET_ARRAY_ATTRS);
return JS_FALSE;
}
static JSBool
array_deleteProperty(JSContext *cx, JSObject *obj, jsid id, Value *rval, JSBool strict)
{
uint32 i;
if (!obj->isDenseArray())
return js_DeleteProperty(cx, obj, id, rval, strict);
if (JSID_IS_ATOM(id, cx->runtime->atomState.lengthAtom)) {
rval->setBoolean(false);
return JS_TRUE;
}
if (js_IdIsIndex(id, &i) && i < obj->getDenseArrayCapacity())
obj->setDenseArrayElement(i, MagicValue(JS_ARRAY_HOLE));
if (!js_SuppressDeletedProperty(cx, obj, id))
return false;
rval->setBoolean(true);
return JS_TRUE;
}
static void
array_finalize(JSContext *cx, JSObject *obj)
{
obj->freeDenseArrayElements(cx);
}
static void
array_trace(JSTracer *trc, JSObject *obj)
{
JS_ASSERT(obj->isDenseArray());
if (!obj->dslots)
return;
size_t holes = 0;
uint32 capacity = obj->getDenseArrayCapacity();
for (uint32 i = 0; i < capacity; i++) {
Value v = obj->getDenseArrayElement(i);
if (v.isMagic(JS_ARRAY_HOLE))
++holes;
else
MarkValue(trc, obj->getDenseArrayElement(i), "dense_array_elems");
}
if (IS_GC_MARKING_TRACER(trc) && holes > MIN_SPARSE_INDEX && holes > capacity / 4 * 3) {
/* This might fail, in which case we don't slowify it. */
static_cast<GCMarker *>(trc)->arraysToSlowify.append(obj);
}
}
namespace {
JSBool
array_fix(JSContext *cx, JSObject *obj, bool *success, AutoIdVector *props)
{
JS_ASSERT(obj->isDenseArray());
/*
* We must slowify dense arrays; otherwise, we'd need to detect assignments to holes,
* since that is effectively adding a new property to the array.
*/
if (!obj->makeDenseArraySlow(cx) ||
!GetPropertyNames(cx, obj, JSITER_HIDDEN | JSITER_OWNONLY, props))
return false;
*success = true;
return true;
}
} // namespace
Class js_ArrayClass = {
"Array",
Class::NON_NATIVE |
JSCLASS_HAS_RESERVED_SLOTS(JSObject::DENSE_ARRAY_CLASS_RESERVED_SLOTS) |
JSCLASS_HAS_CACHED_PROTO(JSProto_Array),
PropertyStub, /* addProperty */
PropertyStub, /* delProperty */
PropertyStub, /* getProperty */
PropertyStub, /* setProperty */
EnumerateStub,
ResolveStub,
js_TryValueOf,
array_finalize,
NULL, /* reserved0 */
NULL, /* checkAccess */
NULL, /* call */
NULL, /* construct */
NULL, /* xdrObject */
NULL, /* hasInstance */
NULL, /* mark */
JS_NULL_CLASS_EXT,
{
array_lookupProperty,
array_defineProperty,
array_getProperty,
array_setProperty,
array_getAttributes,
array_setAttributes,
array_deleteProperty,
NULL, /* enumerate */
array_typeOf,
array_trace,
array_fix,
NULL, /* thisObject */
NULL, /* clear */
}
};
Class js_SlowArrayClass = {
"Array",
JSCLASS_HAS_PRIVATE |
JSCLASS_HAS_CACHED_PROTO(JSProto_Array),
slowarray_addProperty,
PropertyStub, /* delProperty */
PropertyStub, /* getProperty */
PropertyStub, /* setProperty */
EnumerateStub,
ResolveStub,
js_TryValueOf,
NULL, /* finalize */
NULL, /* reserved0 */
NULL, /* checkAccess */
NULL, /* call */
NULL, /* construct */
NULL, /* xdrObject */
NULL, /* hasInstance */
NULL, /* mark */
JS_NULL_CLASS_EXT,
{
NULL, /* lookupProperty */
NULL, /* defineProperty */
NULL, /* getProperty */
/*
* For assignments to 'length', we need to know the setter's strictness. A property's
* setter isn't passed that, but the ObjectOps member is, so use that.
*/
slowarray_setProperty,
NULL, /* getAttributes */
NULL, /* setAttributes */
NULL, /* deleteProperty */
NULL, /* enumerate */
NULL, /* typeOf */
NULL, /* trace */
NULL, /* thisObject */
NULL, /* clear */
}
};
/*
* Convert an array object from fast-and-dense to slow-and-flexible.
*/
JSBool
JSObject::makeDenseArraySlow(JSContext *cx)
{
JS_ASSERT(isDenseArray());
/*
* Save old map now, before calling InitScopeForObject. We'll have to undo
* on error. This is gross, but a better way is not obvious.
*/
JSObjectMap *oldMap = map;
/*
* Create a native scope. All slow arrays other than Array.prototype get
* the same initial shape.
*/
JSObject *arrayProto = getProto();
if (!InitScopeForObject(cx, this, &js_SlowArrayClass, arrayProto))
return false;
uint32 capacity;
if (dslots) {
capacity = getDenseArrayCapacity();
dslots[-1].setPrivateUint32(JS_INITIAL_NSLOTS + capacity);
} else {
/*
* Array.prototype is constructed as a dense array, but is immediately slowified before
* we have time to set capacity.
*/
capacity = 0;
}
/* Begin with the length property to share more of the property tree. */
if (!addProperty(cx, ATOM_TO_JSID(cx->runtime->atomState.lengthAtom),
array_length_getter, NULL,
JSSLOT_ARRAY_LENGTH, JSPROP_PERMANENT | JSPROP_SHARED, 0, 0)) {
setMap(oldMap);
return false;
}
/* Create new properties pointing to existing elements. */
for (uint32 i = 0; i < capacity; i++) {
jsid id;
if (!ValueToId(cx, Int32Value(i), &id)) {
setMap(oldMap);
return false;
}
if (getDenseArrayElement(i).isMagic(JS_ARRAY_HOLE)) {
setDenseArrayElement(i, UndefinedValue());
continue;
}
/* Assert that the length covering i fits in the alloted bits. */
JS_ASSERT(JS_INITIAL_NSLOTS + i + 1 < NSLOTS_LIMIT);
if (!addDataProperty(cx, id, JS_INITIAL_NSLOTS + i, JSPROP_ENUMERATE)) {
setMap(oldMap);
return false;
}
}
/*
* Render our formerly-reserved non-private properties GC-safe. We do not
* need to make the length slot GC-safe because it is the private slot
* (this is statically asserted within JSObject) where the implementation
* can store an arbitrary value.
*/
JS_ASSERT(js_SlowArrayClass.flags & JSCLASS_HAS_PRIVATE);
voidDenseOnlyArraySlots();
/*
* Finally, update class. If |this| is Array.prototype, then js_InitClass
* will create an emptyShape whose class is &js_SlowArrayClass, to ensure
* that delegating instances can share shapes in the tree rooted at the
* proto's empty shape.
*/
clasp = &js_SlowArrayClass;
return true;
}
/* Transfer ownership of buffer to returned string. */
static inline JSBool
BufferToString(JSContext *cx, JSCharBuffer &cb, Value *rval)
{
JSString *str = js_NewStringFromCharBuffer(cx, cb);
if (!str)
return false;
rval->setString(str);
return true;
}
#if JS_HAS_TOSOURCE
static JSBool
array_toSource(JSContext *cx, uintN argc, Value *vp)
{
JS_CHECK_RECURSION(cx, return false);
JSObject *obj = ComputeThisFromVp(cx, vp);
if (!obj ||
(obj->getClass() != &js_SlowArrayClass &&
!InstanceOf(cx, obj, &js_ArrayClass, vp + 2))) {
return false;
}
/* Find joins or cycles in the reachable object graph. */
jschar *sharpchars;
JSHashEntry *he = js_EnterSharpObject(cx, obj, NULL, &sharpchars);
if (!he)
return false;
bool initiallySharp = IS_SHARP(he);
/* After this point, all paths exit through the 'out' label. */
MUST_FLOW_THROUGH("out");
bool ok = false;
/*
* This object will take responsibility for the jschar buffer until the
* buffer is transferred to the returned JSString.
*/
JSCharBuffer cb(cx);
/* Cycles/joins are indicated by sharp objects. */
#if JS_HAS_SHARP_VARS
if (IS_SHARP(he)) {
JS_ASSERT(sharpchars != 0);
cb.replaceRawBuffer(sharpchars, js_strlen(sharpchars));
goto make_string;
} else if (sharpchars) {
MAKE_SHARP(he);
cb.replaceRawBuffer(sharpchars, js_strlen(sharpchars));
}
#else
if (IS_SHARP(he)) {
if (!js_AppendLiteral(cb, "[]"))
goto out;
cx->free(sharpchars);
goto make_string;
}
#endif
if (!cb.append('['))
goto out;
jsuint length;
if (!js_GetLengthProperty(cx, obj, &length))
goto out;
for (jsuint index = 0; index < length; index++) {
/* Use vp to locally root each element value. */
JSBool hole;
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!GetArrayElement(cx, obj, index, &hole, vp)) {
goto out;
}
/* Get element's character string. */
JSString *str;
if (hole) {
str = cx->runtime->emptyString;
} else {
str = js_ValueToSource(cx, *vp);
if (!str)
goto out;
}
vp->setString(str);
const jschar *chars;
size_t charlen;
str->getCharsAndLength(chars, charlen);
/* Append element to buffer. */
if (!cb.append(chars, charlen))
goto out;
if (index + 1 != length) {
if (!js_AppendLiteral(cb, ", "))
goto out;
} else if (hole) {
if (!cb.append(','))
goto out;
}
}
/* Finalize the buffer. */
if (!cb.append(']'))
goto out;
make_string:
if (!BufferToString(cx, cb, vp))
goto out;
ok = true;
out:
if (!initiallySharp)
js_LeaveSharpObject(cx, NULL);
return ok;
}
#endif
static JSBool
array_toString_sub(JSContext *cx, JSObject *obj, JSBool locale,
JSString *sepstr, Value *rval)
{
JS_CHECK_RECURSION(cx, return false);
/*
* Use HashTable entry as the cycle indicator. On first visit, create the
* entry, and, when leaving, remove the entry.
*/
typedef js::HashSet<JSObject *> ObjSet;
ObjSet::AddPtr hashp = cx->busyArrays.lookupForAdd(obj);
uint32 genBefore;
if (!hashp) {
/* Not in hash table, so not a cycle. */
if (!cx->busyArrays.add(hashp, obj)) {
JS_ReportOutOfMemory(cx);
return false;
}
genBefore = cx->busyArrays.generation();
} else {
/* Cycle, so return empty string. */
rval->setString(ATOM_TO_STRING(cx->runtime->atomState.emptyAtom));
return true;
}
AutoObjectRooter tvr(cx, obj);
/* After this point, all paths exit through the 'out' label. */
MUST_FLOW_THROUGH("out");
bool ok = false;
/* Get characters to use for the separator. */
static const jschar comma = ',';
const jschar *sep;
size_t seplen;
if (sepstr) {
sepstr->getCharsAndLength(sep, seplen);
} else {
sep = &comma;
seplen = 1;
}
/*
* This object will take responsibility for the jschar buffer until the
* buffer is transferred to the returned JSString.
*/
JSCharBuffer cb(cx);
jsuint length;
if (!js_GetLengthProperty(cx, obj, &length))
goto out;
for (jsuint index = 0; index < length; index++) {
/* Use rval to locally root each element value. */
JSBool hole;
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!GetArrayElement(cx, obj, index, &hole, rval)) {
goto out;
}
/* Get element's character string. */
if (!(hole || rval->isNullOrUndefined())) {
if (locale) {
/* Work on obj.toLocalString() instead. */
JSObject *robj;
if (!js_ValueToObjectOrNull(cx, *rval, &robj))
goto out;
rval->setObjectOrNull(robj);
JSAtom *atom = cx->runtime->atomState.toLocaleStringAtom;
if (!js_TryMethod(cx, robj, atom, 0, NULL, rval))
goto out;
}
if (!js_ValueToCharBuffer(cx, *rval, cb))
goto out;
}
/* Append the separator. */
if (index + 1 != length) {
if (!cb.append(sep, seplen))
goto out;
}
}
/* Finalize the buffer. */
if (!BufferToString(cx, cb, rval))
goto out;
ok = true;
out:
if (genBefore == cx->busyArrays.generation())
cx->busyArrays.remove(hashp);
else
cx->busyArrays.remove(obj);
return ok;
}
/* ES5 15.4.4.2. NB: The algorithm here differs from the one in ES3. */
static JSBool
array_toString(JSContext *cx, uintN argc, Value *vp)
{
JSObject *obj = ComputeThisFromVp(cx, vp);
if (!obj)
return false;
Value &join = vp[0];
if (!obj->getProperty(cx, ATOM_TO_JSID(cx->runtime->atomState.joinAtom), &join))
return false;
if (!js_IsCallable(join)) {
JSString *str = obj_toStringHelper(cx, obj);
if (!str)
return false;
vp->setString(str);
return true;
}
LeaveTrace(cx);
InvokeArgsGuard args;
if (!cx->stack().pushInvokeArgs(cx, 0, &args))
return false;
args.callee() = join;
args.thisv().setObject(*obj);
/* Do the call. */
if (!Invoke(cx, args, 0))
return false;
*vp = args.rval();
return true;
}
static JSBool
array_toLocaleString(JSContext *cx, uintN argc, Value *vp)
{
JSObject *obj = ComputeThisFromVp(cx, vp);
if (!obj)
return false;
/*
* Passing comma here as the separator. Need a way to get a
* locale-specific version.
*/
return array_toString_sub(cx, obj, JS_TRUE, NULL, vp);
}
static JSBool
InitArrayElements(JSContext *cx, JSObject *obj, jsuint start, jsuint count, Value *vector)
{
JS_ASSERT(count < MAXINDEX);
/*
* Optimize for dense arrays so long as adding the given set of elements
* wouldn't otherwise make the array slow.
*/
if (obj->isDenseArray() && !js_PrototypeHasIndexedProperties(cx, obj) &&
start <= MAXINDEX - count && !INDEX_TOO_BIG(start + count)) {
jsuint newlen = start + count;
JS_ASSERT(jsdouble(start) + count == jsdouble(newlen));
if (!obj->ensureDenseArrayElements(cx, newlen))
return JS_FALSE;
if (newlen > obj->getArrayLength())
obj->setArrayLength(newlen);
JS_ASSERT(count < uint32(-1) / sizeof(Value));
memcpy(obj->getDenseArrayElements() + start, vector, sizeof(jsval) * count);
JS_ASSERT_IF(count != 0, !obj->getDenseArrayElement(newlen - 1).isMagic(JS_ARRAY_HOLE));
return JS_TRUE;
}
Value* end = vector + count;
while (vector != end && start < MAXINDEX) {
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!SetArrayElement(cx, obj, start++, *vector++)) {
return JS_FALSE;
}
}
if (vector == end)
return JS_TRUE;
/* Finish out any remaining elements past the max array index. */
if (obj->isDenseArray() && !ENSURE_SLOW_ARRAY(cx, obj))
return JS_FALSE;
JS_ASSERT(start == MAXINDEX);
AutoValueRooter tvr(cx);
AutoIdRooter idr(cx);
Value idval = DoubleValue(MAXINDEX);
do {
*tvr.addr() = *vector++;
if (!js_ValueToStringId(cx, idval, idr.addr()) ||
!obj->setProperty(cx, idr.id(), tvr.addr(), true)) {
return JS_FALSE;
}
idval.getDoubleRef() += 1;
} while (vector != end);
return JS_TRUE;
}
static JSBool
InitArrayObject(JSContext *cx, JSObject *obj, jsuint length, const Value *vector)
{
JS_ASSERT(obj->isArray());
JS_ASSERT(obj->isDenseArray());
obj->setArrayLength(length);
obj->setDenseArrayCapacity(0);
if (!vector || !length)
return true;
if (!obj->ensureDenseArrayElements(cx, length))
return false;
memcpy(obj->getDenseArrayElements(), vector, length * sizeof(Value));
return true;
}
/*
* Perl-inspired join, reverse, and sort.
*/
static JSBool
array_join(JSContext *cx, uintN argc, Value *vp)
{
JSString *str;
if (argc == 0 || vp[2].isUndefined()) {
str = NULL;
} else {
str = js_ValueToString(cx, vp[2]);
if (!str)
return JS_FALSE;
vp[2].setString(str);
}
JSObject *obj = ComputeThisFromVp(cx, vp);
return obj && array_toString_sub(cx, obj, JS_FALSE, str, vp);
}
static JSBool
array_reverse(JSContext *cx, uintN argc, Value *vp)
{
jsuint len;
JSObject *obj = ComputeThisFromVp(cx, vp);
if (!obj || !js_GetLengthProperty(cx, obj, &len))
return JS_FALSE;
vp->setObject(*obj);
if (obj->isDenseArray() && !js_PrototypeHasIndexedProperties(cx, obj)) {
/* An empty array or an array with no elements is already reversed. */
if (len == 0 || obj->getDenseArrayCapacity() == 0)
return JS_TRUE;
/*
* It's actually surprisingly complicated to reverse an array due to the
* orthogonality of array length and array capacity while handling
* leading and trailing holes correctly. Reversing seems less likely to
* be a common operation than other array mass-mutation methods, so for
* now just take a probably-small memory hit (in the absence of too many
* holes in the array at its start) and ensure that the capacity is
* sufficient to hold all the elements in the array if it were full.
*/
if (!obj->ensureDenseArrayElements(cx, len))
return JS_FALSE;
uint32 lo = 0, hi = len - 1;
for (; lo < hi; lo++, hi--) {
Value tmp = obj->getDenseArrayElement(lo);
obj->setDenseArrayElement(lo, obj->getDenseArrayElement(hi));
obj->setDenseArrayElement(hi, tmp);
}
/*
* Per ECMA-262, don't update the length of the array, even if the new
* array has trailing holes (and thus the original array began with
* holes).
*/
return JS_TRUE;
}
AutoValueRooter tvr(cx);
for (jsuint i = 0, half = len / 2; i < half; i++) {
JSBool hole, hole2;
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!GetArrayElement(cx, obj, i, &hole, tvr.addr()) ||
!GetArrayElement(cx, obj, len - i - 1, &hole2, vp) ||
!SetOrDeleteArrayElement(cx, obj, len - i - 1, hole, tvr.value()) ||
!SetOrDeleteArrayElement(cx, obj, i, hole2, *vp)) {
return false;
}
}
vp->setObject(*obj);
return true;
}
typedef struct MSortArgs {
size_t elsize;
JSComparator cmp;
void *arg;
JSBool isValue;
} MSortArgs;
/* Helper function for js_MergeSort. */
static JSBool
MergeArrays(MSortArgs *msa, void *src, void *dest, size_t run1, size_t run2)
{
void *arg, *a, *b, *c;
size_t elsize, runtotal;
int cmp_result;
JSComparator cmp;
JSBool isValue;
runtotal = run1 + run2;
elsize = msa->elsize;
cmp = msa->cmp;
arg = msa->arg;
isValue = msa->isValue;
#define CALL_CMP(a, b) \
if (!cmp(arg, (a), (b), &cmp_result)) return JS_FALSE;
/* Copy runs already in sorted order. */
b = (char *)src + run1 * elsize;
a = (char *)b - elsize;
CALL_CMP(a, b);
if (cmp_result <= 0) {
memcpy(dest, src, runtotal * elsize);
return JS_TRUE;
}
#define COPY_ONE(p,q,n) \
(isValue ? (void)(*(Value*)p = *(Value*)q) : (void)memcpy(p, q, n))
a = src;
c = dest;
for (; runtotal != 0; runtotal--) {
JSBool from_a = run2 == 0;
if (!from_a && run1 != 0) {
CALL_CMP(a,b);
from_a = cmp_result <= 0;
}
if (from_a) {
COPY_ONE(c, a, elsize);
run1--;
a = (char *)a + elsize;
} else {
COPY_ONE(c, b, elsize);
run2--;
b = (char *)b + elsize;
}
c = (char *)c + elsize;
}
#undef COPY_ONE
#undef CALL_CMP
return JS_TRUE;
}
/*
* This sort is stable, i.e. sequence of equal elements is preserved.
* See also bug #224128.
*/
bool
js_MergeSort(void *src, size_t nel, size_t elsize,
JSComparator cmp, void *arg, void *tmp,
JSMergeSortElemType elemType)
{
void *swap, *vec1, *vec2;
MSortArgs msa;
size_t i, j, lo, hi, run;
int cmp_result;
JS_ASSERT_IF(JS_SORTING_VALUES, elsize == sizeof(Value));
bool isValue = elemType == JS_SORTING_VALUES;
/* Avoid memcpy overhead for word-sized and word-aligned elements. */
#define COPY_ONE(p,q,n) \
(isValue ? (void)(*(Value*)p = *(Value*)q) : (void)memcpy(p, q, n))
#define CALL_CMP(a, b) \
if (!cmp(arg, (a), (b), &cmp_result)) return JS_FALSE;
#define INS_SORT_INT 4
/*
* Apply insertion sort to small chunks to reduce the number of merge
* passes needed.
*/
for (lo = 0; lo < nel; lo += INS_SORT_INT) {
hi = lo + INS_SORT_INT;
if (hi >= nel)
hi = nel;
for (i = lo + 1; i < hi; i++) {
vec1 = (char *)src + i * elsize;
vec2 = (char *)vec1 - elsize;
for (j = i; j > lo; j--) {
CALL_CMP(vec2, vec1);
/* "<=" instead of "<" insures the sort is stable */
if (cmp_result <= 0) {
break;
}
/* Swap elements, using "tmp" as tmp storage */
COPY_ONE(tmp, vec2, elsize);
COPY_ONE(vec2, vec1, elsize);
COPY_ONE(vec1, tmp, elsize);
vec1 = vec2;
vec2 = (char *)vec1 - elsize;
}
}
}
#undef CALL_CMP
#undef COPY_ONE
msa.elsize = elsize;
msa.cmp = cmp;
msa.arg = arg;
msa.isValue = isValue;
vec1 = src;
vec2 = tmp;
for (run = INS_SORT_INT; run < nel; run *= 2) {
for (lo = 0; lo < nel; lo += 2 * run) {
hi = lo + run;
if (hi >= nel) {
memcpy((char *)vec2 + lo * elsize, (char *)vec1 + lo * elsize,
(nel - lo) * elsize);
break;
}
if (!MergeArrays(&msa, (char *)vec1 + lo * elsize,
(char *)vec2 + lo * elsize, run,
hi + run > nel ? nel - hi : run)) {
return JS_FALSE;
}
}
swap = vec1;
vec1 = vec2;
vec2 = swap;
}
if (src != vec1)
memcpy(src, tmp, nel * elsize);
return JS_TRUE;
}
struct CompareArgs
{
JSContext *context;
InvokeSessionGuard session;
CompareArgs(JSContext *cx)
: context(cx)
{}
};
static JS_REQUIRES_STACK JSBool
sort_compare(void *arg, const void *a, const void *b, int *result)
{
const Value *av = (const Value *)a, *bv = (const Value *)b;
CompareArgs *ca = (CompareArgs *) arg;
JSContext *cx = ca->context;
/*
* array_sort deals with holes and undefs on its own and they should not
* come here.
*/
JS_ASSERT(!av->isMagic() && !av->isUndefined());
JS_ASSERT(!av->isMagic() && !bv->isUndefined());
if (!JS_CHECK_OPERATION_LIMIT(cx))
return JS_FALSE;
InvokeSessionGuard &session = ca->session;
session[0] = *av;
session[1] = *bv;
if (!session.invoke(cx))
return JS_FALSE;
jsdouble cmp;
if (!ValueToNumber(cx, session.rval(), &cmp))
return JS_FALSE;
/* Clamp cmp to -1, 0, 1. */
*result = 0;
if (!JSDOUBLE_IS_NaN(cmp) && cmp != 0)
*result = cmp > 0 ? 1 : -1;
/*
* XXX else report some kind of error here? ECMA talks about 'consistent
* compare functions' that don't return NaN, but is silent about what the
* result should be. So we currently ignore it.
*/
return JS_TRUE;
}
typedef JSBool (JS_REQUIRES_STACK *JSRedComparator)(void*, const void*,
const void*, int *);
static inline JS_IGNORE_STACK JSComparator
comparator_stack_cast(JSRedComparator func)
{
return func;
}
static int
sort_compare_strings(void *arg, const void *a, const void *b, int *result)
{
const Value *av = (const Value *)a, *bv = (const Value *)b;
JS_ASSERT(av->isString());
JS_ASSERT(bv->isString());
if (!JS_CHECK_OPERATION_LIMIT((JSContext *)arg))
return JS_FALSE;
*result = (int) js_CompareStrings(av->toString(), bv->toString());
return JS_TRUE;
}
JSBool
js::array_sort(JSContext *cx, uintN argc, Value *vp)
{
jsuint len, newlen, i, undefs;
size_t elemsize;
JSString *str;
Value *argv = JS_ARGV(cx, vp);
Value fval;
if (argc > 0) {
if (argv[0].isPrimitive()) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_BAD_SORT_ARG);
return false;
}
fval = argv[0]; /* non-default compare function */
} else {
fval.setNull();
}
JSObject *obj = ComputeThisFromVp(cx, vp);
if (!obj || !js_GetLengthProperty(cx, obj, &len))
return false;
if (len == 0) {
vp->setObject(*obj);
return true;
}
/*
* We need a temporary array of 2 * len Value to hold the array elements
* and the scratch space for merge sort. Check that its size does not
* overflow size_t, which would allow for indexing beyond the end of the
* malloc'd vector.
*/
#if JS_BITS_PER_WORD == 32
if (size_t(len) > size_t(-1) / (2 * sizeof(Value))) {
js_ReportAllocationOverflow(cx);
return false;
}
#endif
/*
* Initialize vec as a root. We will clear elements of vec one by
* one while increasing the rooted amount of vec when we know that the
* property at the corresponding index exists and its value must be rooted.
*
* In this way when sorting a huge mostly sparse array we will not
* access the tail of vec corresponding to properties that do not
* exist, allowing OS to avoiding committing RAM. See bug 330812.
*/
{
Value *vec = (Value *) cx->malloc(2 * size_t(len) * sizeof(Value));
if (!vec)
return false;
DEFINE_LOCAL_CLASS_OF_STATIC_FUNCTION(AutoFreeVector) {
JSContext *const cx;
Value *&vec;
public:
AutoFreeVector(JSContext *cx, Value *&vec) : cx(cx), vec(vec) { }
~AutoFreeVector() {
cx->free(vec);
}
} free(cx, vec);
AutoArrayRooter tvr(cx, 0, vec);
/*
* By ECMA 262, 15.4.4.11, a property that does not exist (which we
* call a "hole") is always greater than an existing property with
* value undefined and that is always greater than any other property.
* Thus to sort holes and undefs we simply count them, sort the rest
* of elements, append undefs after them and then make holes after
* undefs.
*/
undefs = 0;
newlen = 0;
bool allStrings = true;
for (i = 0; i < len; i++) {
if (!JS_CHECK_OPERATION_LIMIT(cx))
return false;
/* Clear vec[newlen] before including it in the rooted set. */
JSBool hole;
vec[newlen].setNull();
tvr.changeLength(newlen + 1);
if (!GetArrayElement(cx, obj, i, &hole, &vec[newlen]))
return false;
if (hole)
continue;
if (vec[newlen].isUndefined()) {
++undefs;
continue;
}
allStrings = allStrings && vec[newlen].isString();
++newlen;
}
if (newlen == 0)
return true; /* The array has only holes and undefs. */
/*
* The first newlen elements of vec are copied from the array object
* (above). The remaining newlen positions are used as GC-rooted scratch
* space for mergesort. We must clear the space before including it to
* the root set covered by tvr.count.
*/
Value *mergesort_tmp = vec + newlen;
MakeValueRangeGCSafe(mergesort_tmp, newlen);
tvr.changeLength(newlen * 2);
/* Here len == 2 * (newlen + undefs + number_of_holes). */
if (fval.isNull()) {
/*
* Sort using the default comparator converting all elements to
* strings.
*/
if (allStrings) {
elemsize = sizeof(Value);
} else {
/*
* To avoid string conversion on each compare we do it only once
* prior to sorting. But we also need the space for the original
* values to recover the sorting result. To reuse
* sort_compare_strings we move the original values to the odd
* indexes in vec, put the string conversion results in the even
* indexes and pass 2 * sizeof(Value) as an element size to the
* sorting function. In this way sort_compare_strings will only
* see the string values when it casts the compare arguments as
* pointers to Value.
*
* This requires doubling the temporary storage including the
* scratch space for the merge sort. Since vec already contains
* the rooted scratch space for newlen elements at the tail, we
* can use it to rearrange and convert to strings first and try
* realloc only when we know that we successfully converted all
* the elements.
*/
#if JS_BITS_PER_WORD == 32
if (size_t(newlen) > size_t(-1) / (4 * sizeof(Value))) {
js_ReportAllocationOverflow(cx);
return false;
}
#endif
/*
* Rearrange and string-convert the elements of the vector from
* the tail here and, after sorting, move the results back
* starting from the start to prevent overwrite the existing
* elements.
*/
i = newlen;
do {
--i;
if (!JS_CHECK_OPERATION_LIMIT(cx))
return false;
const Value &v = vec[i];
str = js_ValueToString(cx, v);
if (!str)
return false;
// Copying v must come first, because the following line overwrites v
// when i == 0.
vec[2 * i + 1] = v;
vec[2 * i].setString(str);
} while (i != 0);
JS_ASSERT(tvr.array == vec);
vec = (Value *) cx->realloc(vec, 4 * size_t(newlen) * sizeof(Value));
if (!vec) {
vec = tvr.array; /* N.B. AutoFreeVector */
return false;
}
mergesort_tmp = vec + 2 * newlen;
MakeValueRangeGCSafe(mergesort_tmp, 2 * newlen);
tvr.changeArray(vec, newlen * 4);
elemsize = 2 * sizeof(Value);
}
if (!js_MergeSort(vec, size_t(newlen), elemsize,
sort_compare_strings, cx, mergesort_tmp,
JS_SORTING_GENERIC)) {
return false;
}
if (!allStrings) {
/*
* We want to make the following loop fast and to unroot the
* cached results of toString invocations before the operation
* callback has a chance to run the GC. For this reason we do
* not call JS_CHECK_OPERATION_LIMIT in the loop.
*/
i = 0;
do {
vec[i] = vec[2 * i + 1];
} while (++i != newlen);
}
} else {
CompareArgs ca(cx);
if (!ca.session.start(cx, fval, NullValue(), 2))
return false;
if (!js_MergeSort(vec, size_t(newlen), sizeof(Value),
comparator_stack_cast(sort_compare),
&ca, mergesort_tmp,
JS_SORTING_VALUES)) {
return false;
}
}
/*
* We no longer need to root the scratch space for the merge sort, so
* unroot it now to make the job of a potential GC under
* InitArrayElements easier.
*/
tvr.changeLength(newlen);
if (!InitArrayElements(cx, obj, 0, newlen, vec))
return false;
}
/* Set undefs that sorted after the rest of elements. */
while (undefs != 0) {
--undefs;
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!SetArrayElement(cx, obj, newlen++, UndefinedValue())) {
return false;
}
}
/* Re-create any holes that sorted to the end of the array. */
while (len > newlen) {
if (!JS_CHECK_OPERATION_LIMIT(cx) || !DeleteArrayElement(cx, obj, --len, true))
return false;
}
vp->setObject(*obj);
return true;
}
/*
* Perl-inspired push, pop, shift, unshift, and splice methods.
*/
static JSBool
array_push_slowly(JSContext *cx, JSObject *obj, uintN argc, Value *argv, Value *rval)
{
jsuint length;
if (!js_GetLengthProperty(cx, obj, &length))
return JS_FALSE;
if (!InitArrayElements(cx, obj, length, argc, argv))
return JS_FALSE;
/* Per ECMA-262, return the new array length. */
jsdouble newlength = length + jsdouble(argc);
rval->setNumber(newlength);
return js_SetLengthProperty(cx, obj, newlength);
}
static JSBool
array_push1_dense(JSContext* cx, JSObject* obj, const Value &v, Value *rval)
{
uint32 length = obj->getArrayLength();
if (INDEX_TOO_SPARSE(obj, length)) {
if (!obj->makeDenseArraySlow(cx))
return JS_FALSE;
Value tmp = v;
return array_push_slowly(cx, obj, 1, &tmp, rval);
}
if (!obj->ensureDenseArrayElements(cx, length + 1))
return JS_FALSE;
obj->setArrayLength(length + 1);
JS_ASSERT(obj->getDenseArrayElement(length).isMagic(JS_ARRAY_HOLE));
obj->setDenseArrayElement(length, v);
rval->setNumber(obj->getArrayLength());
return JS_TRUE;
}
JS_ALWAYS_INLINE JSBool
ArrayCompPushImpl(JSContext *cx, JSObject *obj, const Value &v)
{
JS_ASSERT(obj->isDenseArray());
uint32_t length = obj->getArrayLength();
JS_ASSERT(length <= obj->getDenseArrayCapacity());
if (length == obj->getDenseArrayCapacity()) {
if (length > JS_ARGS_LENGTH_MAX) {
JS_ReportErrorNumberUC(cx, js_GetErrorMessage, NULL,
JSMSG_ARRAY_INIT_TOO_BIG);
return JS_FALSE;
}
if (!obj->ensureDenseArrayElements(cx, length + 1))
return JS_FALSE;
}
obj->setArrayLength(length + 1);
obj->setDenseArrayElement(length, v);
return JS_TRUE;
}
JSBool
js_ArrayCompPush(JSContext *cx, JSObject *obj, const Value &vp)
{
return ArrayCompPushImpl(cx, obj, vp);
}
JSBool JS_FASTCALL
js_ArrayCompPush_tn(JSContext *cx, JSObject *obj, ValueArgType v)
{
return ArrayCompPushImpl(cx, obj, ValueArgToConstRef(v));
}
JS_DEFINE_CALLINFO_3(extern, BOOL, js_ArrayCompPush_tn, CONTEXT, OBJECT, VALUE,
0, nanojit::ACCSET_STORE_ANY)
static JSBool
array_push(JSContext *cx, uintN argc, Value *vp)
{
/* Insist on one argument and obj of the expected class. */
JSObject *obj = ComputeThisFromVp(cx, vp);
if (!obj)
return JS_FALSE;
if (argc != 1 || !obj->isDenseArray())
return array_push_slowly(cx, obj, argc, vp + 2, vp);
return array_push1_dense(cx, obj, vp[2], vp);
}
static JSBool
array_pop_slowly(JSContext *cx, JSObject* obj, Value *vp)
{
jsuint index;
JSBool hole;
if (!js_GetLengthProperty(cx, obj, &index))
return JS_FALSE;
if (index == 0) {
vp->setUndefined();
} else {
index--;
/* Get the to-be-deleted property's value into vp. */
if (!GetArrayElement(cx, obj, index, &hole, vp))
return JS_FALSE;
if (!hole && !DeleteArrayElement(cx, obj, index, true))
return JS_FALSE;
}
return js_SetLengthProperty(cx, obj, index);
}
static JSBool
array_pop_dense(JSContext *cx, JSObject* obj, Value *vp)
{
jsuint index;
JSBool hole;
index = obj->getArrayLength();
if (index == 0) {
vp->setUndefined();
return JS_TRUE;
}
index--;
if (!GetArrayElement(cx, obj, index, &hole, vp))
return JS_FALSE;
if (!hole && !DeleteArrayElement(cx, obj, index, true))
return JS_FALSE;
obj->setArrayLength(index);
return JS_TRUE;
}
static JSBool
array_pop(JSContext *cx, uintN argc, Value *vp)
{
JSObject *obj = ComputeThisFromVp(cx, vp);
if (!obj)
return JS_FALSE;
if (obj->isDenseArray())
return array_pop_dense(cx, obj, vp);
return array_pop_slowly(cx, obj, vp);
}
static JSBool
array_shift(JSContext *cx, uintN argc, Value *vp)
{
jsuint length, i;
JSBool hole;
JSObject *obj = ComputeThisFromVp(cx, vp);
if (!obj || !js_GetLengthProperty(cx, obj, &length))
return JS_FALSE;
if (length == 0) {
vp->setUndefined();
} else {
length--;
if (obj->isDenseArray() && !js_PrototypeHasIndexedProperties(cx, obj) &&
length < obj->getDenseArrayCapacity()) {
*vp = obj->getDenseArrayElement(0);
if (vp->isMagic(JS_ARRAY_HOLE))
vp->setUndefined();
Value *elems = obj->getDenseArrayElements();
memmove(elems, elems + 1, length * sizeof(jsval));
obj->setDenseArrayElement(length, MagicValue(JS_ARRAY_HOLE));
obj->setArrayLength(length);
return JS_TRUE;
}
/* Get the to-be-deleted property's value into vp ASAP. */
if (!GetArrayElement(cx, obj, 0, &hole, vp))
return JS_FALSE;
/* Slide down the array above the first element. */
AutoValueRooter tvr(cx);
for (i = 0; i != length; i++) {
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!GetArrayElement(cx, obj, i + 1, &hole, tvr.addr()) ||
!SetOrDeleteArrayElement(cx, obj, i, hole, tvr.value())) {
return JS_FALSE;
}
}
/* Delete the only or last element when it exists. */
if (!hole && !DeleteArrayElement(cx, obj, length, true))
return JS_FALSE;
}
return js_SetLengthProperty(cx, obj, length);
}
static JSBool
array_unshift(JSContext *cx, uintN argc, Value *vp)
{
Value *argv;
jsuint length;
JSBool hole;
jsdouble last, newlen;
JSObject *obj = ComputeThisFromVp(cx, vp);
if (!obj || !js_GetLengthProperty(cx, obj, &length))
return JS_FALSE;
newlen = length;
if (argc > 0) {
/* Slide up the array to make room for argc at the bottom. */
argv = JS_ARGV(cx, vp);
if (length > 0) {
if (obj->isDenseArray() && !js_PrototypeHasIndexedProperties(cx, obj) &&
!INDEX_TOO_SPARSE(obj, unsigned(newlen + argc))) {
JS_ASSERT(newlen + argc == length + argc);
if (!obj->ensureDenseArrayElements(cx, length + argc))
return JS_FALSE;
Value *elems = obj->getDenseArrayElements();
memmove(elems + argc, elems, length * sizeof(jsval));
for (uint32 i = 0; i < argc; i++)
obj->setDenseArrayElement(i, MagicValue(JS_ARRAY_HOLE));
} else {
last = length;
jsdouble upperIndex = last + argc;
AutoValueRooter tvr(cx);
do {
--last, --upperIndex;
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!GetArrayElement(cx, obj, last, &hole, tvr.addr()) ||
!SetOrDeleteArrayElement(cx, obj, upperIndex, hole, tvr.value())) {
return JS_FALSE;
}
} while (last != 0);
}
}
/* Copy from argv to the bottom of the array. */
if (!InitArrayElements(cx, obj, 0, argc, argv))
return JS_FALSE;
newlen += argc;
if (!js_SetLengthProperty(cx, obj, newlen))
return JS_FALSE;
}
/* Follow Perl by returning the new array length. */
vp->setNumber(newlen);
return JS_TRUE;
}
static JSBool
array_splice(JSContext *cx, uintN argc, Value *vp)
{
jsuint length, begin, end, count, delta, last;
JSBool hole;
/*
* Create a new array value to return. Our ECMA v2 proposal specs
* that splice always returns an array value, even when given no
* arguments. We think this is best because it eliminates the need
* for callers to do an extra test to handle the empty splice case.
*/
JSObject *obj2 = js_NewArrayObject(cx, 0, NULL);
if (!obj2)
return JS_FALSE;
vp->setObject(*obj2);
/* Nothing to do if no args. Otherwise get length. */
if (argc == 0)
return JS_TRUE;
Value *argv = JS_ARGV(cx, vp);
JSObject *obj = ComputeThisFromVp(cx, vp);
if (!obj || !js_GetLengthProperty(cx, obj, &length))
return JS_FALSE;
jsuint origlength = length;
/* Convert the first argument into a starting index. */
jsdouble d;
if (!ValueToNumber(cx, *argv, &d))
return JS_FALSE;
d = js_DoubleToInteger(d);
if (d < 0) {
d += length;
if (d < 0)
d = 0;
} else if (d > length) {
d = length;
}
begin = (jsuint)d; /* d has been clamped to uint32 */
argc--;
argv++;
/* Convert the second argument from a count into a fencepost index. */
delta = length - begin;
if (argc == 0) {
count = delta;
end = length;
} else {
if (!ValueToNumber(cx, *argv, &d))
return JS_FALSE;
d = js_DoubleToInteger(d);
if (d < 0)
d = 0;
else if (d > delta)
d = delta;
count = (jsuint)d;
end = begin + count;
argc--;
argv++;
}
AutoValueRooter tvr(cx);
/* If there are elements to remove, put them into the return value. */
if (count > 0) {
if (obj->isDenseArray() && !js_PrototypeHasIndexedProperties(cx, obj) &&
!js_PrototypeHasIndexedProperties(cx, obj2) &&
end <= obj->getDenseArrayCapacity()) {
if (!InitArrayObject(cx, obj2, count, obj->getDenseArrayElements() + begin))
return JS_FALSE;
} else {
for (last = begin; last < end; last++) {
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!GetArrayElement(cx, obj, last, &hole, tvr.addr())) {
return JS_FALSE;
}
/* Copy tvr.value() to the new array unless it's a hole. */
if (!hole && !SetArrayElement(cx, obj2, last - begin, tvr.value()))
return JS_FALSE;
}
if (!js_SetLengthProperty(cx, obj2, count))
return JS_FALSE;
}
}
/* Find the direction (up or down) to copy and make way for argv. */
if (argc > count) {
delta = (jsuint)argc - count;
last = length;
if (obj->isDenseArray() && !js_PrototypeHasIndexedProperties(cx, obj) &&
length <= obj->getDenseArrayCapacity() &&
(length == 0 || !obj->getDenseArrayElement(length - 1).isMagic(JS_ARRAY_HOLE))) {
if (!obj->ensureDenseArrayElements(cx, length + delta))
return JS_FALSE;
Value *arraybeg = obj->getDenseArrayElements();
Value *srcbeg = arraybeg + last - 1;
Value *srcend = arraybeg + end - 1;
Value *dstbeg = srcbeg + delta;
for (Value *src = srcbeg, *dst = dstbeg; src > srcend; --src, --dst)
*dst = *src;
obj->setArrayLength(obj->getArrayLength() + delta);
} else {
/* (uint) end could be 0, so we can't use a vanilla >= test. */
while (last-- > end) {
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!GetArrayElement(cx, obj, last, &hole, tvr.addr()) ||
!SetOrDeleteArrayElement(cx, obj, last + delta, hole, tvr.value())) {
return JS_FALSE;
}
}
}
length += delta;
} else if (argc < count) {
delta = count - (jsuint)argc;
if (obj->isDenseArray() && !js_PrototypeHasIndexedProperties(cx, obj) &&
length <= obj->getDenseArrayCapacity()) {
Value *arraybeg = obj->getDenseArrayElements();
Value *srcbeg = arraybeg + end;
Value *srcend = arraybeg + length;
Value *dstbeg = srcbeg - delta;
for (Value *src = srcbeg, *dst = dstbeg; src < srcend; ++src, ++dst)
*dst = *src;
} else {
for (last = end; last < length; last++) {
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!GetArrayElement(cx, obj, last, &hole, tvr.addr()) ||
!SetOrDeleteArrayElement(cx, obj, last - delta, hole, tvr.value())) {
return JS_FALSE;
}
}
}
length -= delta;
}
if (length < origlength && !js_SuppressDeletedIndexProperties(cx, obj, length, origlength))
return JS_FALSE;
/*
* Copy from argv into the hole to complete the splice, and update length in
* case we deleted elements from the end.
*/
return InitArrayElements(cx, obj, begin, argc, argv) &&
js_SetLengthProperty(cx, obj, length);
}
/*
* Python-esque sequence operations.
*/
static JSBool
array_concat(JSContext *cx, uintN argc, Value *vp)
{
/* Treat our |this| object as the first argument; see ECMA 15.4.4.4. */
Value *p = JS_ARGV(cx, vp) - 1;
/* Create a new Array object and root it using *vp. */
JSObject *aobj = ComputeThisFromVp(cx, vp);
JSObject *nobj;
jsuint length;
if (aobj->isDenseArray()) {
/*
* Clone aobj but pass the minimum of its length and capacity, to
* handle a = [1,2,3]; a.length = 10000 "dense" cases efficiently. In
* such a case we'll pass 8 (not 3) due to ARRAY_CAPACITY_MIN, which
* will cause nobj to be over-allocated to 16. But in the normal case
* where length is <= capacity, nobj and aobj will have the same
* capacity.
*/
length = aobj->getArrayLength();
jsuint capacity = aobj->getDenseArrayCapacity();
nobj = js_NewArrayObject(cx, JS_MIN(length, capacity), aobj->getDenseArrayElements());
if (!nobj)
return JS_FALSE;
nobj->setArrayLength(length);
vp->setObject(*nobj);
if (argc == 0)
return JS_TRUE;
argc--;
p++;
} else {
nobj = js_NewArrayObject(cx, 0, NULL);
if (!nobj)
return JS_FALSE;
vp->setObject(*nobj);
length = 0;
}
AutoValueRooter tvr(cx);
/* Loop over [0, argc] to concat args into nobj, expanding all Arrays. */
for (uintN i = 0; i <= argc; i++) {
if (!JS_CHECK_OPERATION_LIMIT(cx))
return false;
const Value &v = p[i];
if (v.isObject()) {
JSObject *wobj;
aobj = &v.toObject();
wobj = aobj->wrappedObject(cx);
if (wobj->isArray()) {
jsid id = ATOM_TO_JSID(cx->runtime->atomState.lengthAtom);
if (!aobj->getProperty(cx, id, tvr.addr()))
return false;
jsuint alength = ValueIsLength(cx, tvr.addr());
if (tvr.value().isNull())
return false;
for (jsuint slot = 0; slot < alength; slot++) {
JSBool hole;
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!GetArrayElement(cx, aobj, slot, &hole, tvr.addr())) {
return false;
}
/*
* Per ECMA 262, 15.4.4.4, step 9, ignore nonexistent
* properties.
*/
if (!hole &&
!SetArrayElement(cx, nobj, length+slot, tvr.value())) {
return false;
}
}
length += alength;
continue;
}
}
if (!SetArrayElement(cx, nobj, length, v))
return false;
length++;
}
return js_SetLengthProperty(cx, nobj, length);
}
static JSBool
array_slice(JSContext *cx, uintN argc, Value *vp)
{
Value *argv;
JSObject *nobj;
jsuint length, begin, end, slot;
JSBool hole;
argv = JS_ARGV(cx, vp);
JSObject *obj = ComputeThisFromVp(cx, vp);
if (!obj || !js_GetLengthProperty(cx, obj, &length))
return JS_FALSE;
begin = 0;
end = length;
if (argc > 0) {
jsdouble d;
if (!ValueToNumber(cx, argv[0], &d))
return JS_FALSE;
d = js_DoubleToInteger(d);
if (d < 0) {
d += length;
if (d < 0)
d = 0;
} else if (d > length) {
d = length;
}
begin = (jsuint)d;
if (argc > 1) {
if (!ValueToNumber(cx, argv[1], &d))
return JS_FALSE;
d = js_DoubleToInteger(d);
if (d < 0) {
d += length;
if (d < 0)
d = 0;
} else if (d > length) {
d = length;
}
end = (jsuint)d;
}
}
if (begin > end)
begin = end;
if (obj->isDenseArray() && end <= obj->getDenseArrayCapacity() &&
!js_PrototypeHasIndexedProperties(cx, obj)) {
nobj = js_NewArrayObject(cx, end - begin, obj->getDenseArrayElements() + begin);
if (!nobj)
return JS_FALSE;
vp->setObject(*nobj);
return JS_TRUE;
}
/* Create a new Array object and root it using *vp. */
nobj = js_NewArrayObject(cx, 0, NULL);
if (!nobj)
return JS_FALSE;
vp->setObject(*nobj);
AutoValueRooter tvr(cx);
for (slot = begin; slot < end; slot++) {
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!GetArrayElement(cx, obj, slot, &hole, tvr.addr())) {
return JS_FALSE;
}
if (!hole && !SetArrayElement(cx, nobj, slot - begin, tvr.value()))
return JS_FALSE;
}
return js_SetLengthProperty(cx, nobj, end - begin);
}
#if JS_HAS_ARRAY_EXTRAS
static JSBool
array_indexOfHelper(JSContext *cx, JSBool isLast, uintN argc, Value *vp)
{
jsuint length, i, stop;
Value tosearch;
jsint direction;
JSBool hole;
JSObject *obj = ComputeThisFromVp(cx, vp);
if (!obj || !js_GetLengthProperty(cx, obj, &length))
return JS_FALSE;
if (length == 0)
goto not_found;
if (argc <= 1) {
i = isLast ? length - 1 : 0;
tosearch = (argc != 0) ? vp[2] : UndefinedValue();
} else {
jsdouble start;
tosearch = vp[2];
if (!ValueToNumber(cx, vp[3], &start))
return JS_FALSE;
start = js_DoubleToInteger(start);
if (start < 0) {
start += length;
if (start < 0) {
if (isLast)
goto not_found;
i = 0;
} else {
i = (jsuint)start;
}
} else if (start >= length) {
if (!isLast)
goto not_found;
i = length - 1;
} else {
i = (jsuint)start;
}
}
if (isLast) {
stop = 0;
direction = -1;
} else {
stop = length - 1;
direction = 1;
}
for (;;) {
if (!JS_CHECK_OPERATION_LIMIT(cx) ||
!GetArrayElement(cx, obj, (jsuint)i, &hole, vp)) {
return JS_FALSE;
}
if (!hole && StrictlyEqual(cx, *vp, tosearch)) {
vp->setNumber(i);
return JS_TRUE;
}
if (i == stop)
goto not_found;
i += direction;
}
not_found:
vp->setInt32(-1);
return JS_TRUE;
}
static JSBool
array_indexOf(JSContext *cx, uintN argc, Value *vp)
{
return array_indexOfHelper(cx, JS_FALSE, argc, vp);
}
static JSBool
array_lastIndexOf(JSContext *cx, uintN argc, Value *vp)
{
return array_indexOfHelper(cx, JS_TRUE, argc, vp);
}
/* Order is important; extras that take a predicate funarg must follow MAP. */
typedef enum ArrayExtraMode {
FOREACH,
REDUCE,
REDUCE_RIGHT,
MAP,
FILTER,
SOME,
EVERY
} ArrayExtraMode;
#define REDUCE_MODE(mode) ((mode) == REDUCE || (mode) == REDUCE_RIGHT)
static JSBool
array_extra(JSContext *cx, ArrayExtraMode mode, uintN argc, Value *vp)
{
JSObject *obj = ComputeThisFromVp(cx, vp);
jsuint length;
if (!obj || !js_GetLengthProperty(cx, obj, &length))
return JS_FALSE;
/*
* First, get or compute our callee, so that we error out consistently
* when passed a non-callable object.
*/
if (argc == 0) {
js_ReportMissingArg(cx, *vp, 0);
return JS_FALSE;
}
Value *argv = vp + 2;
JSObject *callable = js_ValueToCallableObject(cx, &argv[0], JSV2F_SEARCH_STACK);
if (!callable)
return JS_FALSE;
/*
* Set our initial return condition, used for zero-length array cases
* (and pre-size our map return to match our known length, for all cases).
*/
jsuint newlen;
JSObject *newarr;
#ifdef __GNUC__ /* quell GCC overwarning */
newlen = 0;
newarr = NULL;
#endif
jsint start = 0, end = length, step = 1;
switch (mode) {
case REDUCE_RIGHT:
start = length - 1, end = -1, step = -1;
/* FALL THROUGH */
case REDUCE:
if (length == 0 && argc == 1) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
JSMSG_EMPTY_ARRAY_REDUCE);
return JS_FALSE;
}
if (argc >= 2) {
*vp = argv[1];
} else {
JSBool hole;
do {
if (!GetArrayElement(cx, obj, start, &hole, vp))
return JS_FALSE;
start += step;
} while (hole && start != end);
if (hole && start == end) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
JSMSG_EMPTY_ARRAY_REDUCE);
return JS_FALSE;
}
}
break;
case MAP:
case FILTER:
newlen = (mode == MAP) ? length : 0;
newarr = js_NewArrayObject(cx, newlen, NULL);
if (!newarr)
return JS_FALSE;
vp->setObject(*newarr);
break;
case SOME:
vp->setBoolean(false);
break;
case EVERY:
vp->setBoolean(true);
break;
case FOREACH:
vp->setUndefined();
break;
}
if (length == 0)
return JS_TRUE;
Value thisv;
if (argc > 1 && !REDUCE_MODE(mode)) {
JSObject *thisp;
if (!js_ValueToObjectOrNull(cx, argv[1], &thisp))
return JS_FALSE;
thisv.setObjectOrNull(thisp);
} else {
thisv.setNull();
}
/*
* For all but REDUCE, we call with 3 args (value, index, array). REDUCE
* requires 4 args (accum, value, index, array).
*/
argc = 3 + REDUCE_MODE(mode);
InvokeSessionGuard session;
if (!session.start(cx, ObjectValue(*callable), thisv, argc))
return JS_FALSE;
MUST_FLOW_THROUGH("out");
JSBool ok = JS_TRUE;
JSBool cond;
Value objv = ObjectValue(*obj);
AutoValueRooter tvr(cx);
for (jsint i = start; i != end; i += step) {
JSBool hole;
ok = JS_CHECK_OPERATION_LIMIT(cx) &&
GetArrayElement(cx, obj, i, &hole, tvr.addr());
if (!ok)
goto out;
if (hole)
continue;
/*
* Push callable and 'this', then args. We must do this for every
* iteration around the loop since Invoke clobbers its arguments.
*/
uintN argi = 0;
if (REDUCE_MODE(mode))
session[argi++] = *vp;
session[argi++] = tvr.value();
session[argi++] = Int32Value(i);
session[argi] = objv;
/* Do the call. */
ok = session.invoke(cx);
if (!ok)
break;
const Value &rval = session.rval();
if (mode > MAP)
cond = js_ValueToBoolean(rval);
#ifdef __GNUC__ /* quell GCC overwarning */
else
cond = JS_FALSE;
#endif
switch (mode) {
case FOREACH:
break;
case REDUCE:
case REDUCE_RIGHT:
*vp = rval;
break;
case MAP:
ok = SetArrayElement(cx, newarr, i, rval);
if (!ok)
goto out;
break;
case FILTER:
if (!cond)
break;
/* The element passed the filter, so push it onto our result. */
ok = SetArrayElement(cx, newarr, newlen++, tvr.value());
if (!ok)
goto out;
break;
case SOME:
if (cond) {
vp->setBoolean(true);
goto out;
}
break;
case EVERY:
if (!cond) {
vp->setBoolean(false);
goto out;
}
break;
}
}
out:
if (ok && mode == FILTER)
ok = js_SetLengthProperty(cx, newarr, newlen);
return ok;
}
static JSBool
array_forEach(JSContext *cx, uintN argc, Value *vp)
{
return array_extra(cx, FOREACH, argc, vp);
}
static JSBool
array_map(JSContext *cx, uintN argc, Value *vp)
{
return array_extra(cx, MAP, argc, vp);
}
static JSBool
array_reduce(JSContext *cx, uintN argc, Value *vp)
{
return array_extra(cx, REDUCE, argc, vp);
}
static JSBool
array_reduceRight(JSContext *cx, uintN argc, Value *vp)
{
return array_extra(cx, REDUCE_RIGHT, argc, vp);
}
static JSBool
array_filter(JSContext *cx, uintN argc, Value *vp)
{
return array_extra(cx, FILTER, argc, vp);
}
static JSBool
array_some(JSContext *cx, uintN argc, Value *vp)
{
return array_extra(cx, SOME, argc, vp);
}
static JSBool
array_every(JSContext *cx, uintN argc, Value *vp)
{
return array_extra(cx, EVERY, argc, vp);
}
#endif
static JSBool
array_isArray(JSContext *cx, uintN argc, Value *vp)
{
vp->setBoolean(argc > 0 &&
vp[2].isObject() &&
vp[2].toObject().wrappedObject(cx)->isArray());
return JS_TRUE;
}
static JSFunctionSpec array_methods[] = {
#if JS_HAS_TOSOURCE
JS_FN(js_toSource_str, array_toSource, 0,0),
#endif
JS_FN(js_toString_str, array_toString, 0,0),
JS_FN(js_toLocaleString_str,array_toLocaleString,0,0),
/* Perl-ish methods. */
JS_FN("join", array_join, 1,JSFUN_GENERIC_NATIVE),
JS_FN("reverse", array_reverse, 0,JSFUN_GENERIC_NATIVE),
JS_FN("sort", array_sort, 1,JSFUN_GENERIC_NATIVE),
JS_FN("push", array_push, 1,JSFUN_GENERIC_NATIVE),
JS_FN("pop", array_pop, 0,JSFUN_GENERIC_NATIVE),
JS_FN("shift", array_shift, 0,JSFUN_GENERIC_NATIVE),
JS_FN("unshift", array_unshift, 1,JSFUN_GENERIC_NATIVE),
JS_FN("splice", array_splice, 2,JSFUN_GENERIC_NATIVE),
/* Pythonic sequence methods. */
JS_FN("concat", array_concat, 1,JSFUN_GENERIC_NATIVE),
JS_FN("slice", array_slice, 2,JSFUN_GENERIC_NATIVE),
#if JS_HAS_ARRAY_EXTRAS
JS_FN("indexOf", array_indexOf, 1,JSFUN_GENERIC_NATIVE),
JS_FN("lastIndexOf", array_lastIndexOf, 1,JSFUN_GENERIC_NATIVE),
JS_FN("forEach", array_forEach, 1,JSFUN_GENERIC_NATIVE),
JS_FN("map", array_map, 1,JSFUN_GENERIC_NATIVE),
JS_FN("reduce", array_reduce, 1,JSFUN_GENERIC_NATIVE),
JS_FN("reduceRight", array_reduceRight, 1,JSFUN_GENERIC_NATIVE),
JS_FN("filter", array_filter, 1,JSFUN_GENERIC_NATIVE),
JS_FN("some", array_some, 1,JSFUN_GENERIC_NATIVE),
JS_FN("every", array_every, 1,JSFUN_GENERIC_NATIVE),
#endif
JS_FS_END
};
static JSFunctionSpec array_static_methods[] = {
JS_FN("isArray", array_isArray, 1,0),
JS_FS_END
};
static inline JSObject *
NewDenseArrayObject(JSContext *cx)
{
return NewNonFunction<WithProto::Class>(cx, &js_ArrayClass, NULL, NULL);
}
JSBool
js_Array(JSContext *cx, uintN argc, Value *vp)
{
jsuint length;
const Value *vector;
/* Whether called with 'new' or not, use a new Array object. */
JSObject *obj = NewDenseArrayObject(cx);
if (!obj)
return JS_FALSE;
vp->setObject(*obj);
if (argc == 0) {
length = 0;
vector = NULL;
} else if (argc > 1) {
length = (jsuint) argc;
vector = vp + 2;
} else if (!vp[2].isNumber()) {
length = 1;
vector = vp + 2;
} else {
length = ValueIsLength(cx, vp + 2);
if (vp[2].isNull())
return JS_FALSE;
vector = NULL;
}
return InitArrayObject(cx, obj, length, vector);
}
JSObject* JS_FASTCALL
js_NewEmptyArray(JSContext* cx, JSObject* proto, int32 len)
{
if (len < 0)
return NULL;
JS_ASSERT(proto->isArray());
JSObject* obj = js_NewGCObject(cx);
if (!obj)
return NULL;
/* Initialize all fields, calling init before setting obj->map. */
obj->init(&js_ArrayClass, proto, proto->getParent(), NullValue(), cx);
obj->setSharedNonNativeMap();
obj->setArrayLength(len);
obj->setDenseArrayCapacity(0);
return obj;
}
#ifdef JS_TRACER
JS_DEFINE_CALLINFO_3(extern, OBJECT, js_NewEmptyArray, CONTEXT, OBJECT, INT32, 0,
nanojit::ACCSET_STORE_ANY)
#endif
JSObject* JS_FASTCALL
js_NewPreallocatedArray(JSContext* cx, JSObject* proto, int32 len)
{
JSObject *obj = js_NewEmptyArray(cx, proto, len);
if (!obj)
return NULL;
if (!obj->growDenseArrayElements(cx, 0, JS_MAX(len, ARRAY_CAPACITY_MIN)))
return NULL;
return obj;
}
#ifdef JS_TRACER
JS_DEFINE_CALLINFO_3(extern, OBJECT, js_NewPreallocatedArray, CONTEXT, OBJECT, INT32,
0, nanojit::ACCSET_STORE_ANY)
#endif
JSObject *
js_InitArrayClass(JSContext *cx, JSObject *obj)
{
JSObject *proto = js_InitClass(cx, obj, NULL, &js_ArrayClass, js_Array, 1,
NULL, array_methods, NULL, array_static_methods);
if (!proto)
return NULL;
/*
* Assert that js_InitClass used the correct (slow array, not dense array)
* class for proto's emptyShape class.
*/
JS_ASSERT(proto->emptyShape->getClass() == proto->getClass());
proto->setArrayLength(0);
return proto;
}
JSObject *
js_NewArrayObject(JSContext *cx, jsuint length, const Value *vector)
{
JSObject *obj = NewDenseArrayObject(cx);
if (!obj)
return NULL;
/*
* If this fails, the global object was not initialized and its class does
* not have JSCLASS_IS_GLOBAL.
*/
JS_ASSERT(obj->getProto());
return InitArrayObject(cx, obj, length, vector) ? obj : NULL;
}
JSObject *
js_NewSlowArrayObject(JSContext *cx)
{
JSObject *obj = NewNonFunction<WithProto::Class>(cx, &js_SlowArrayClass, NULL, NULL);
if (obj)
obj->setArrayLength(0);
return obj;
}
#ifdef DEBUG
JSBool
js_ArrayInfo(JSContext *cx, uintN argc, jsval *vp)
{
uintN i;
JSObject *array;
for (i = 0; i < argc; i++) {
Value arg = Valueify(JS_ARGV(cx, vp)[i]);
char *bytes = DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, arg, NULL);
if (!bytes)
return JS_FALSE;
if (arg.isPrimitive() ||
!(array = arg.toObjectOrNull())->isArray()) {
fprintf(stderr, "%s: not array\n", bytes);
cx->free(bytes);
continue;
}
fprintf(stderr, "%s: %s (len %u", bytes,
array->isDenseArray() ? "dense" : "sparse",
array->getArrayLength());
if (array->isDenseArray()) {
fprintf(stderr, ", capacity %u",
array->getDenseArrayCapacity());
}
fputs(")\n", stderr);
cx->free(bytes);
}
JS_SET_RVAL(cx, vp, JSVAL_VOID);
return true;
}
#endif
JS_FRIEND_API(JSBool)
js_CoerceArrayToCanvasImageData(JSObject *obj, jsuint offset, jsuint count,
JSUint8 *dest)
{
uint32 length;
if (!obj || !obj->isDenseArray())
return JS_FALSE;
length = obj->getArrayLength();
if (length < offset + count)
return JS_FALSE;
JSUint8 *dp = dest;
for (uintN i = offset; i < offset+count; i++) {
const Value &v = obj->getDenseArrayElement(i);
if (v.isInt32()) {
jsint vi = v.toInt32();
if (jsuint(vi) > 255)
vi = (vi < 0) ? 0 : 255;
*dp++ = JSUint8(vi);
} else if (v.isDouble()) {
jsdouble vd = v.toDouble();
if (!(vd >= 0)) /* Not < so that NaN coerces to 0 */
*dp++ = 0;
else if (vd > 255)
*dp++ = 255;
else {
jsdouble toTruncate = vd + 0.5;
JSUint8 val = JSUint8(toTruncate);
/*
* now val is rounded to nearest, ties rounded up. We want
* rounded to nearest ties to even, so check whether we had a
* tie.
*/
if (val == toTruncate) {
/*
* It was a tie (since adding 0.5 gave us the exact integer
* we want). Since we rounded up, we either already have an
* even number or we have an odd number but the number we
* want is one less. So just unconditionally masking out the
* ones bit should do the trick to get us the value we
* want.
*/
*dp++ = (val & ~1);
} else {
*dp++ = val;
}
}
} else {
return JS_FALSE;
}
}
return JS_TRUE;
}
JS_FRIEND_API(JSBool)
js_IsDensePrimitiveArray(JSObject *obj)
{
if (!obj || !obj->isDenseArray())
return JS_FALSE;
jsuint capacity = obj->getDenseArrayCapacity();
for (jsuint i = 0; i < capacity; i++) {
if (obj->dslots[i].isObject())
return JS_FALSE;
}
return JS_TRUE;
}
JS_FRIEND_API(JSBool)
js_CloneDensePrimitiveArray(JSContext *cx, JSObject *obj, JSObject **clone)
{
JS_ASSERT(obj);
if (!obj->isDenseArray()) {
/*
* This wasn't a dense array. Return JS_TRUE but a NULL clone to signal
* that no exception was encountered.
*/
*clone = NULL;
return JS_TRUE;
}
jsuint length = obj->getArrayLength();
/*
* Must use the minimum of original array's length and capacity, to handle
* |a = [1,2,3]; a.length = 10000| "dense" cases efficiently. In such a case
* we would use ARRAY_CAPACITY_MIN (not 3), which will cause the clone to be
* over-allocated. In the normal case where length is <= capacity the
* clone and original array will have the same capacity.
*/
jsuint jsvalCount = JS_MIN(obj->getDenseArrayCapacity(), length);
js::AutoValueVector vector(cx);
if (!vector.reserve(jsvalCount))
return JS_FALSE;
for (jsuint i = 0; i < jsvalCount; i++) {
const Value &val = obj->dslots[i];
if (val.isString()) {
// Strings must be made immutable before being copied to a clone.
if (!js_MakeStringImmutable(cx, val.toString()))
return JS_FALSE;
} else if (val.isObject()) {
/*
* This wasn't an array of primitives. Return JS_TRUE but a null
* clone to signal that no exception was encountered.
*/
*clone = NULL;
return JS_TRUE;
}
vector.append(val);
}
*clone = js_NewArrayObject(cx, jsvalCount, vector.begin());
if (!*clone)
return JS_FALSE;
(*clone)->setArrayLength(length);
return JS_TRUE;
}