/thirdparty/breakpad/processor/static_contained_range_map.h

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29
30// static_contained_range_map.h: StaticContainedRangeMap.
31//
32// StaticContainedRangeMap is similar to ContainedRangeMap.  However,
33// StaticContainedRangeMap wraps a StaticMap instead of std::map, and does not
34// support dynamic operations like StoreRange(...).
35// StaticContainedRangeMap provides same RetrieveRange(...) interfaces as
36// ContainedRangeMap.
37//
38// Please see contained_range_map.h for more documentation.
39//
40// Author: Siyang Xie (lambxsy@google.com)
41
42#ifndef PROCESSOR_STATIC_CONTAINED_RANGE_MAP_H__
43#define PROCESSOR_STATIC_CONTAINED_RANGE_MAP_H__
44
45#include "processor/static_map-inl.h"
46
47namespace google_breakpad {
48
49template<typename AddressType, typename EntryType>
50class StaticContainedRangeMap {
51 public:
52  StaticContainedRangeMap(): base_(), entry_size_(), entry_ptr_(), map_() { }
53  explicit StaticContainedRangeMap(const char *base);
54
55  // Retrieves the most specific (smallest) descendant range encompassing
56  // the specified address.  This method will only return entries held by
57  // child ranges, and not the entry contained by |this|.  This is necessary
58  // to support a sparsely-populated root range.  If no descendant range
59  // encompasses the address, returns false.
60  bool RetrieveRange(const AddressType &address, const EntryType *&entry) const;
61
62 private:
63  friend class ModuleComparer;
64  // AddressToRangeMap stores pointers.  This makes reparenting simpler in
65  // StoreRange, because it doesn't need to copy entire objects.
66  typedef StaticContainedRangeMap* SelfPtr;
67  typedef
68  StaticMap<AddressType, StaticContainedRangeMap> AddressToRangeMap;
69  typedef typename AddressToRangeMap::const_iterator MapConstIterator;
70
71  // The base address of this range.  The high address does not need to
72  // be stored, because it is used as the key to an object in its parent's
73  // map, and all ContainedRangeMaps except for the root range are contained
74  // within maps.  The root range does not actually contain an entry, so its
75  // base_ field is meaningless, and the fact that it has no parent and thus
76  // no key is unimportant.  For this reason, the base_ field should only be
77  // is accessed on child ContainedRangeMap objects, and never on |this|.
78  AddressType base_;
79
80  // The entry corresponding to this range.  The root range does not
81  // actually contain an entry, so its entry_ field is meaningless.  For
82  // this reason, the entry_ field should only be accessed on child
83  // ContainedRangeMap objects, and never on |this|.
84  u_int32_t entry_size_;
85  const EntryType *entry_ptr_;
86
87  // The map containing child ranges, keyed by each child range's high
88  // address.  This is a pointer to avoid allocating map structures for
89  // leaf nodes, where they are not needed.
90  AddressToRangeMap map_;
91};
92
93}  // namespace google_breakpad
94
95
96#endif  // PROCESSOR_STATIC_CONTAINED_RANGE_MAP_H__