1 // Copyright 2010 Google Inc. All Rights Reserved. 2 // 3 // Redistribution and use in source and binary forms, with or without 4 // modification, are permitted provided that the following conditions are 5 // met: 6 // 7 // * Redistributions of source code must retain the above copyright 8 // notice, this list of conditions and the following disclaimer. 9 // * Redistributions in binary form must reproduce the above 10 // copyright notice, this list of conditions and the following disclaimer 11 // in the documentation and/or other materials provided with the 12 // distribution. 13 // * Neither the name of Google Inc. nor the names of its 14 // contributors may be used to endorse or promote products derived from 15 // this software without specific prior written permission. 16 // 17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 29 // static_map.h: StaticMap. 30 // 31 // StaticMap provides lookup interfaces and iterators similar as stl::map's. 32 // These lookup operations are purely Read-Only, thus memory 33 // allocation & deallocation is mostly avoided (intentionally). 34 // 35 // The chunk of memory should contain data with pre-defined pattern: 36 // **************** header *************** 37 // uint32 (4 bytes): number of nodes 38 // uint32 (4 bytes): address offset of node1's mapped_value 39 // uint32 (4 bytes): address offset of node2's mapped_value 40 // ... 41 // uint32 (4 bytes): address offset of nodeN's mapped_value 42 // 43 // ************* Key array ************ 44 // (X bytes): node1's key 45 // (X bytes): node2's key 46 // ... 47 // (X bytes): nodeN's key 48 // 49 // ************* Value array ********** 50 // (? bytes): node1's mapped_value 51 // (? bytes): node2's mapped_value 52 // ... 53 // (? bytes): nodeN's mapped_value 54 // 55 // REQUIREMENT: Key type MUST be primitive type or pointers so that: 56 // X = sizeof(typename Key); 57 // 58 // Note: since address offset is stored as uint32, user should keep in mind that 59 // StaticMap only supports up to 4GB size of memory data. 60 61 // Author: Siyang Xie (lambxsy (at) google.com) 62 63 64 #ifndef PROCESSOR_STATIC_MAP_H__ 65 #define PROCESSOR_STATIC_MAP_H__ 66 67 #include "processor/static_map_iterator-inl.h" 68 69 namespace google_breakpad { 70 71 // Default functor to compare keys. 72 template<typename Key> 73 class DefaultCompare { 74 public: 75 int operator()(const Key &k1, const Key &k2) const { 76 if (k1 < k2) return -1; 77 if (k1 == k2) return 0; 78 return 1; 79 } 80 }; 81 82 template<typename Key, typename Value, typename Compare = DefaultCompare<Key> > 83 class StaticMap { 84 public: 85 typedef StaticMapIterator<Key, Value, Compare> iterator; 86 typedef StaticMapIterator<Key, Value, Compare> const_iterator; 87 88 StaticMap() : raw_data_(0), 89 num_nodes_(0), 90 offsets_(0), 91 compare_() { } 92 93 explicit StaticMap(const char* raw_data); 94 95 inline bool empty() const { return num_nodes_ == 0; } 96 inline unsigned int size() const { return num_nodes_; } 97 98 // Return iterators. 99 inline iterator begin() const { return IteratorAtIndex(0); } 100 inline iterator last() const { return IteratorAtIndex(num_nodes_ - 1); } 101 inline iterator end() const { return IteratorAtIndex(num_nodes_); } 102 inline iterator IteratorAtIndex(int index) const { 103 return iterator(raw_data_, index); 104 } 105 106 // Lookup operations. 107 iterator find(const Key &k) const; 108 109 // lower_bound(k) searches in a sorted range for the first element that has a 110 // key not less than the argument k. 111 iterator lower_bound(const Key &k) const; 112 113 // upper_bound(k) searches in a sorted range for the first element that has a 114 // key greater than the argument k. 115 iterator upper_bound(const Key &k) const; 116 117 // Checks if the underlying memory data conforms to the predefined pattern: 118 // first check the number of nodes is non-negative, 119 // then check both offsets and keys are strictly increasing (sorted). 120 bool ValidateInMemoryStructure() const; 121 122 private: 123 const Key GetKeyAtIndex(int i) const; 124 125 // Start address of a raw memory chunk with serialized data. 126 const char* raw_data_; 127 128 // Number of nodes in the static map. 129 int32_t num_nodes_; 130 131 // Array of offset addresses for stored values. 132 // For example: 133 // address_of_i-th_node_value = raw_data_ + offsets_[i] 134 const uint32_t* offsets_; 135 136 // keys_[i] = key of i_th node 137 const Key* keys_; 138 139 Compare compare_; 140 }; 141 142 } // namespace google_breakpad 143 144 #endif // PROCESSOR_STATIC_MAP_H__ 145
