| | 1 | /* |
| | 2 | * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved. |
| | 3 | * |
| | 4 | * This library is free software; you can redistribute it and/or |
| | 5 | * modify it under the terms of the GNU Library General Public |
| | 6 | * License as published by the Free Software Foundation; either |
| | 7 | * version 2 of the License, or (at your option) any later version. |
| | 8 | * |
| | 9 | * This library is distributed in the hope that it will be useful, |
| | 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| | 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| | 12 | * Library General Public License for more details. |
| | 13 | * |
| | 14 | * You should have received a copy of the GNU Library General Public License |
| | 15 | * along with this library; see the file COPYING.LIB. If not, write to |
| | 16 | * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| | 17 | * Boston, MA 02110-1301, USA. |
| | 18 | * |
| | 19 | */ |
| | 20 | |
| | 21 | #ifndef PropertyMapHashTable_h |
| | 22 | #define PropertyMapHashTable_h |
| | 23 | |
| | 24 | #include "UString.h" |
| | 25 | #include <wtf/Vector.h> |
| | 26 | |
| | 27 | namespace JSC { |
| | 28 | |
| | 29 | struct PropertyMapEntry { |
| | 30 | UString::Rep* key; |
| | 31 | unsigned offset; |
| | 32 | unsigned attributes; |
| | 33 | unsigned index; |
| | 34 | |
| | 35 | PropertyMapEntry(UString::Rep* key, unsigned attributes) |
| | 36 | : key(key) |
| | 37 | , offset(0) |
| | 38 | , attributes(attributes) |
| | 39 | , index(0) |
| | 40 | { |
| | 41 | } |
| | 42 | |
| | 43 | PropertyMapEntry(UString::Rep* key, unsigned offset, unsigned attributes, unsigned index) |
| | 44 | : key(key) |
| | 45 | , offset(offset) |
| | 46 | , attributes(attributes) |
| | 47 | , index(index) |
| | 48 | { |
| | 49 | } |
| | 50 | }; |
| | 51 | |
| | 52 | // lastIndexUsed is an ever-increasing index used to identify the order items |
| | 53 | // were inserted into the property map. It's required that getEnumerablePropertyNames |
| | 54 | // return the properties in the order they were added for compatibility with other |
| | 55 | // browsers' JavaScript implementations. |
| | 56 | struct PropertyMapHashTable { |
| | 57 | unsigned sizeMask; |
| | 58 | unsigned size; |
| | 59 | unsigned keyCount; |
| | 60 | unsigned deletedSentinelCount; |
| | 61 | unsigned lastIndexUsed; |
| | 62 | Vector<unsigned>* deletedOffsets; |
| | 63 | unsigned entryIndices[1]; |
| | 64 | |
| | 65 | PropertyMapEntry* entries() |
| | 66 | { |
| | 67 | // The entries vector comes after the indices vector. |
| | 68 | // The 0th item in the entries vector is not really used; it has to |
| | 69 | // have a 0 in its key to allow the hash table lookup to handle deleted |
| | 70 | // sentinels without any special-case code, but the other fields are unused. |
| | 71 | return reinterpret_cast<PropertyMapEntry*>(&entryIndices[size]); |
| | 72 | } |
| | 73 | |
| | 74 | static size_t allocationSize(unsigned size) |
| | 75 | { |
| | 76 | // We never let a hash table get more than half full, |
| | 77 | // So the number of indices we need is the size of the hash table. |
| | 78 | // But the number of entries is half that (plus one for the deleted sentinel). |
| | 79 | return sizeof(PropertyMapHashTable) |
| | 80 | + (size - 1) * sizeof(unsigned) |
| | 81 | + (1 + size / 2) * sizeof(PropertyMapEntry); |
| | 82 | } |
| | 83 | }; |
| | 84 | |
| | 85 | } // namespace JSC |
| | 86 | |
| | 87 | #endif // PropertyMapHashTable_h |
projects / apple / javascriptcore.git / blame_incremental