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28
29// static_map-inl.h: StaticMap implementation.
30//
31// See static_map.h for documentation.
32//
33// Author: Siyang Xie (lambxsy@google.com)
34
35
36#ifndef PROCESSOR_STATIC_MAP_INL_H__
37#define PROCESSOR_STATIC_MAP_INL_H__
38
39#include "processor/static_map.h"
40#include "processor/static_map_iterator-inl.h"
41#include "processor/logging.h"
42
43namespace google_breakpad {
44
45template<typename Key, typename Value, typename Compare>
46StaticMap<Key, Value, Compare>::StaticMap(const char* raw_data)
47    : raw_data_(raw_data),
48      compare_() {
49  // First 4 Bytes store the number of nodes.
50  num_nodes_ = *(reinterpret_cast<const uint32_t*>(raw_data_));
51
52  offsets_ = reinterpret_cast<const uint32_t*>(
53      raw_data_ + sizeof(num_nodes_));
54
55  keys_ = reinterpret_cast<const Key*>(
56      raw_data_ + (1 + num_nodes_) * sizeof(uint32_t));
57}
58
59// find(), lower_bound() and upper_bound() implement binary search algorithm.
60template<typename Key, typename Value, typename Compare>
61StaticMapIterator<Key, Value, Compare>
62StaticMap<Key, Value, Compare>::find(const Key &key) const {
63  int begin = 0;
64  int end = num_nodes_;
65  int middle;
66  int compare_result;
67  while (begin < end) {
68    middle = begin + (end - begin) / 2;
69    compare_result = compare_(key, GetKeyAtIndex(middle));
70    if (compare_result == 0)
71      return IteratorAtIndex(middle);
72    if (compare_result < 0) {
73      end = middle;
74    } else {
75      begin = middle + 1;
76    }
77  }
78  return this->end();
79}
80
81template<typename Key, typename Value, typename Compare>
82StaticMapIterator<Key, Value, Compare>
83StaticMap<Key, Value, Compare>::lower_bound(const Key &key) const {
84  int begin = 0;
85  int end = num_nodes_;
86  int middle;
87  int comp_result;
88  while (begin < end) {
89    middle = begin + (end - begin) / 2;
90    comp_result = compare_(key, GetKeyAtIndex(middle));
91    if (comp_result == 0)
92      return IteratorAtIndex(middle);
93    if (comp_result < 0) {
94      end = middle;
95    } else {
96      begin = middle + 1;
97    }
98  }
99  return IteratorAtIndex(begin);
100}
101
102template<typename Key, typename Value, typename Compare>
103StaticMapIterator<Key, Value, Compare>
104StaticMap<Key, Value, Compare>::upper_bound(const Key &key) const {
105  int begin = 0;
106  int end = num_nodes_;
107  int middle;
108  int compare_result;
109  while (begin < end) {
110    middle = begin + (end - begin) / 2;
111    compare_result = compare_(key, GetKeyAtIndex(middle));
112    if (compare_result == 0)
113      return IteratorAtIndex(middle + 1);
114    if (compare_result < 0) {
115      end = middle;
116    } else {
117      begin = middle + 1;
118    }
119  }
120  return IteratorAtIndex(begin);
121}
122
123template<typename Key, typename Value, typename Compare>
124bool StaticMap<Key, Value, Compare>::ValidateInMemoryStructure() const {
125  // check the number of nodes is non-negative:
126  if (!raw_data_) return false;
127  int32_t num_nodes = *(reinterpret_cast<const int32_t*>(raw_data_));
128  if (num_nodes < 0) {
129    BPLOG(INFO) << "StaticMap check failed: negative number of nodes";
130    return false;
131  }
132
133  int node_index = 0;
134  if (num_nodes_) {
135    uint64_t first_offset = sizeof(int32_t) * (num_nodes_ + 1)
136                           + sizeof(Key) * num_nodes_;
137    // Num_nodes_ is too large.
138    if (first_offset > 0xffffffffUL) {
139      BPLOG(INFO) << "StaticMap check failed: size exceeds limit";
140      return false;
141    }
142    if (offsets_[node_index] != static_cast<uint32_t>(first_offset)) {
143      BPLOG(INFO) << "StaticMap check failed: first node offset is incorrect";
144      return false;
145    }
146  }
147
148  for (node_index = 1; node_index < num_nodes_; ++node_index) {
149    // Check offsets[i] is strictly increasing:
150    if (offsets_[node_index] <= offsets_[node_index - 1]) {
151      BPLOG(INFO) << "StaticMap check failed: node offsets non-increasing";
152      return false;
153    }
154    // Check Key[i] is strictly increasing as no duplicate keys are allowed.
155    if (compare_(GetKeyAtIndex(node_index),
156                 GetKeyAtIndex(node_index - 1)) <= 0) {
157      BPLOG(INFO) << "StaticMap check failed: node keys non-increasing";
158      return false;
159    }
160  }
161  return true;
162}
163
164template<typename Key, typename Value, typename Compare>
165const Key StaticMap<Key, Value, Compare>::GetKeyAtIndex(int index) const {
166  if (index < 0 || index >= num_nodes_) {
167    BPLOG(ERROR) << "Key index out of range error";
168    // Key type is required to be primitive type.  Return 0 if index is invalid.
169    return 0;
170  }
171  return keys_[index];
172}
173
174}  // namespace google_breakpad
175
176#endif  // PROCESSOR_STATIC_MAP_INL_H__
177