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      1 // Copyright (c) 2010, Google Inc.
      2 // All rights reserved.
      3 //
      4 // Redistribution and use in source and binary forms, with or without
      5 // modification, are permitted provided that the following conditions are
      6 // met:
      7 //
      8 //     * Redistributions of source code must retain the above copyright
      9 // notice, this list of conditions and the following disclaimer.
     10 //     * Redistributions in binary form must reproduce the above
     11 // copyright notice, this list of conditions and the following disclaimer
     12 // in the documentation and/or other materials provided with the
     13 // distribution.
     14 //     * Neither the name of Google Inc. nor the names of its
     15 // contributors may be used to endorse or promote products derived from
     16 // this software without specific prior written permission.
     17 //
     18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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     24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     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 (at) 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 
     47 namespace google_breakpad {
     48 
     49 template<typename AddressType, typename EntryType>
     50 class 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   uint32_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__
     97