js/src/jsarray.h

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  *
   3  * ***** BEGIN LICENSE BLOCK *****
   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
  10  *
  11  * Software distributed under the License is distributed on an "AS IS" basis,
  12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13  * for the specific language governing rights and limitations under the
  14  * License.
  15  *
  16  * The Original Code is Mozilla Communicator client code, released
  17  * March 31, 1998.
  18  *
  19  * The Initial Developer of the Original Code is
  20  * Netscape Communications Corporation.
  21  * Portions created by the Initial Developer are Copyright (C) 1998
  22  * the Initial Developer. All Rights Reserved.
  23  *
  24  * Contributor(s):
  25  *
  26  * Alternatively, the contents of this file may be used under the terms of
  27  * either of the GNU General Public License Version 2 or later (the "GPL"),
  28  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  29  * in which case the provisions of the GPL or the LGPL are applicable instead
  30  * of those above. If you wish to allow use of your version of this file only
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  35  * the provisions above, a recipient may use your version of this file under
  36  * the terms of any one of the MPL, the GPL or the LGPL.
  37  *
  38  * ***** END LICENSE BLOCK ***** */
  39
  40 #ifndef jsarray_h___
  41 #define jsarray_h___
  42 /*
  43  * JS Array interface.
  44  */
  45 #include "jsprvtd.h"
  46 #include "jspubtd.h"
  47 #include "jsobj.h"
  48
  49 JS_BEGIN_EXTERN_C
  50
  51 #define ARRAY_CAPACITY_MIN      7
  52
  53 /* Generous sanity-bound on length (in elements) of array initialiser. */
  54 #define ARRAY_INIT_LIMIT        JS_BIT(24)
  55
  56 extern JSBool
  57 js_IdIsIndex(jsval id, jsuint *indexp);
  58
  59 extern JSClass js_ArrayClass, js_SlowArrayClass;
  60
  61 #define OBJ_IS_DENSE_ARRAY(cx,obj)  (OBJ_GET_CLASS(cx, obj) == &js_ArrayClass)
  62
  63 #define OBJ_IS_ARRAY(cx,obj)    (OBJ_IS_DENSE_ARRAY(cx, obj) ||               \
  64                                  OBJ_GET_CLASS(cx, obj) == &js_SlowArrayClass)
  65
  66 /*
  67  * Dense arrays are not native (OBJ_IS_NATIVE(cx, aobj) for a dense array aobj
  68  * results in false, meaning aobj->map does not point to a JSScope).
  69  *
  70  * But Array methods are called via aobj.sort(), e.g., and the interpreter and
  71  * the trace recorder must consult the property cache in order to perform well.
  72  * The cache works only for native objects.
  73  *
  74  * Therefore the interpreter (js_Interpret in JSOP_GETPROP and JSOP_CALLPROP)
  75  * and js_GetPropertyHelper use this inline function to skip up one link in the
  76  * prototype chain when obj is a dense array, in order to find a likely-native
  77  * object (to wit, Array.prototype) in which to probe for cached methods.
  78  *
  79  * Callers of js_GetProtoIfDenseArray must take care to use the original object
  80  * (obj) for the |this| value of a getter, setter, or method call (bug 476447).
  81  */
  82 static JS_INLINE JSObject *
  83 js_GetProtoIfDenseArray(JSContext *cx, JSObject *obj)
  84 {
  85     return OBJ_IS_DENSE_ARRAY(cx, obj) ? OBJ_GET_PROTO(cx, obj) : obj;
  86 }
  87
  88 extern JSObject *
  89 js_InitArrayClass(JSContext *cx, JSObject *obj);
  90
  91 extern JSObject *
  92 js_NewArrayObject(JSContext *cx, jsuint length, jsval *vector,
  93                   JSBool holey = JS_FALSE);
  94
  95 /* Create an array object that starts out already made slow/sparse. */
  96 extern JSObject *
  97 js_NewSlowArrayObject(JSContext *cx);
  98
  99 extern JSBool
 100 js_MakeArraySlow(JSContext *cx, JSObject *obj);
 101
 102 #define JSSLOT_ARRAY_LENGTH            JSSLOT_PRIVATE
 103 #define JSSLOT_ARRAY_COUNT             (JSSLOT_ARRAY_LENGTH + 1)
 104 #define JSSLOT_ARRAY_LOOKUP_HOLDER     (JSSLOT_ARRAY_COUNT + 1)
 105
 106 static JS_INLINE uint32
 107 js_DenseArrayCapacity(JSObject *obj)
 108 {
 109     JS_ASSERT(OBJ_IS_DENSE_ARRAY(BOGUS_CX, obj));
 110     return obj->dslots ? (uint32) obj->dslots[-1] : 0;
 111 }
 112
 113 static JS_INLINE void
 114 js_SetDenseArrayCapacity(JSObject *obj, uint32 capacity)
 115 {
 116     JS_ASSERT(OBJ_IS_DENSE_ARRAY(BOGUS_CX, obj));
 117     JS_ASSERT(obj->dslots);
 118     obj->dslots[-1] = (jsval) capacity;
 119 }
 120
 121 extern JSBool
 122 js_GetLengthProperty(JSContext *cx, JSObject *obj, jsuint *lengthp);
 123
 124 extern JSBool
 125 js_SetLengthProperty(JSContext *cx, JSObject *obj, jsdouble length);
 126
 127 extern JSBool
 128 js_HasLengthProperty(JSContext *cx, JSObject *obj, jsuint *lengthp);
 129
 130 extern JSBool JS_FASTCALL
 131 js_IndexToId(JSContext *cx, jsuint index, jsid *idp);
 132
 133 /*
 134  * Test whether an object is "array-like".  Currently this means whether obj
 135  * is an Array or an arguments object.  We would like an API, and probably a
 136  * way in the language, to bless other objects as array-like: having indexed
 137  * properties, and a 'length' property of uint32 value equal to one more than
 138  * the greatest index.
 139  */
 140 extern JSBool
 141 js_IsArrayLike(JSContext *cx, JSObject *obj, JSBool *answerp, jsuint *lengthp);
 142
 143 /*
 144  * JS-specific merge sort function.
 145  */
 146 typedef JSBool (*JSComparator)(void *arg, const void *a, const void *b,
 147                                int *result);
 148 /*
 149  * NB: vec is the array to be sorted, tmp is temporary space at least as big
 150  * as vec. Both should be GC-rooted if appropriate.
 151  *
 152  * The sorted result is in vec. vec may be in an inconsistent state if the
 153  * comparator function cmp returns an error inside a comparison, so remember
 154  * to check the return value of this function.
 155  */
 156 extern JS_REQUIRES_STACK JSBool
 157 js_MergeSort(void *vec, size_t nel, size_t elsize, JSComparator cmp,
 158              void *arg, void *tmp);
 159
 160 #ifdef DEBUG_ARRAYS
 161 extern JSBool
 162 js_ArrayInfo(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
 163 #endif
 164
 165 extern JSBool JS_FASTCALL
 166 js_ArrayCompPush(JSContext *cx, JSObject *obj, jsval v);
 167
 168 /*
 169  * Fast dense-array-to-buffer conversions.
 170  *
 171  * If the array is a dense array, fill [offset..offset+count] values
 172  * into destination, assuming that types are consistent.  Return
 173  * JS_TRUE if successful, otherwise JS_FALSE -- note that the
 174  * destination buffer may be modified even if JS_FALSE is returned
 175  * (e.g. due to finding an inappropriate type later on in the array).
 176  * If JS_FALSE is returned, no error conditions or exceptions are set
 177  * on the context.
 178  *
 179  * For ArrayToJSUint8, ArrayToJSUint16, and ArrayToJSUint32, each element
 180  * in the array a) must be an integer; b) must be >= 0.  Integers
 181  * are clamped to fit in the destination size.  Only JSVAL_IS_INT values
 182  * are considered to be valid, so for JSUint32, the maximum value that
 183  * can be fast-converted is less than the full unsigned 32-bit range.
 184  *
 185  * For ArrayToJSInt8, ArrayToJSInt16, ArrayToJSInt32, each element in
 186  * the array must be an integer.  Integers are clamped to fit in the
 187  * destination size.  Only JSVAL_IS_INT values are considered to be
 188  * valid, so for JSInt32, the maximum value that can be
 189  * fast-converted is less than the full signed 32-bit range.
 190  *
 191  * For ArrayToJSDouble, each element in the array must be an
 192  * integer -or- a double (JSVAL_IS_NUMBER).
 193  */
 194
 195 JS_FRIEND_API(JSBool)
 196 js_ArrayToJSUint8Buffer(JSContext *cx, JSObject *obj, jsuint offset, jsuint count,
 197                         JSUint8 *dest);
 198
 199 JS_FRIEND_API(JSBool)
 200 js_ArrayToJSUint16Buffer(JSContext *cx, JSObject *obj, jsuint offset, jsuint count,
 201                          JSUint16 *dest);
 202
 203 JS_FRIEND_API(JSBool)
 204 js_ArrayToJSUint32Buffer(JSContext *cx, JSObject *obj, jsuint offset, jsuint count,
 205                          JSUint32 *dest);
 206
 207 JS_FRIEND_API(JSBool)
 208 js_ArrayToJSInt8Buffer(JSContext *cx, JSObject *obj, jsuint offset, jsuint count,
 209                        JSInt8 *dest);
 210
 211 JS_FRIEND_API(JSBool)
 212 js_ArrayToJSInt16Buffer(JSContext *cx, JSObject *obj, jsuint offset, jsuint count,
 213                         JSInt16 *dest);
 214
 215 JS_FRIEND_API(JSBool)
 216 js_ArrayToJSInt32Buffer(JSContext *cx, JSObject *obj, jsuint offset, jsuint count,
 217                         JSInt32 *dest);
 218
 219 JS_FRIEND_API(JSBool)
 220 js_ArrayToJSDoubleBuffer(JSContext *cx, JSObject *obj, jsuint offset, jsuint count,
 221                          jsdouble *dest);
 222
 223 JSBool
 224 js_PrototypeHasIndexedProperties(JSContext *cx, JSObject *obj);
 225
 226 /*
 227  * Utility to access the value from the id returned by array_lookupProperty.
 228  */
 229 jsval
 230 js_GetDenseArrayElementValue(JSObject *obj, JSProperty *prop);
 231
 232 JS_END_EXTERN_C
 233
 234 #endif /* jsarray_h___ */