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 // Copyright (c) 2006, Google Inc.

 // All rights reserved.

 //

 // Redistribution and use in source and binary forms, with or without

 // modification, are permitted provided that the following conditions are

 // met:

 //

 //     * Redistributions of source code must retain the above copyright

 // notice, this list of conditions and the following disclaimer.

 //     * Redistributions in binary form must reproduce the above

 // copyright notice, this list of conditions and the following disclaimer

 // in the documentation and/or other materials provided with the

 // distribution.

 //     * Neither the name of Google Inc. nor the names of its

 // contributors may be used to endorse or promote products derived from

 // this software without specific prior written permission.

 //

 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 // contained_range_map-inl.h: Hierarchically-organized range map implementation.

 //

 // See contained_range_map.h for documentation.

 //

 // Author: Mark Mentovai

 #ifndef PROCESSOR_CONTAINED_RANGE_MAP_INL_H__

 #define PROCESSOR_CONTAINED_RANGE_MAP_INL_H__

 #include "processor/contained_range_map.h"

 #include <assert.h>

 #include "common/logging.h"

 namespace google_breakpad {

 template<typename AddressType, typename EntryType>

 ContainedRangeMap<AddressType, EntryType>::~ContainedRangeMap() {

   // Clear frees the children pointed to by the map, and frees the map itself.

   Clear();

 }

 template<typename AddressType, typename EntryType>

 bool ContainedRangeMap<AddressType, EntryType>::StoreRange(

     const AddressType &base, const AddressType &size, const EntryType &entry) {

   AddressType high = base + size - 1;

   // Check for undersize or overflow.

   if (size <= 0 || high < base) {

     //TODO(nealsid) We are commenting this out in order to prevent

     // excessive logging.  We plan to move to better logging as this

     // failure happens quite often and is expected(see comment in

     // basic_source_line_resolver.cc:671).

     // BPLOG(INFO) << "StoreRange failed, " << HexString(base) << "+"

     // << HexString(size) << ", " << HexString(high);

     return false;

   }

   if (!map_)

     map_ = new AddressToRangeMap();

   MapIterator iterator_base = map_->lower_bound(base);

   MapIterator iterator_high = map_->lower_bound(high);

   MapIterator iterator_end = map_->end();

   if (iterator_base == iterator_high && iterator_base != iterator_end &&

       base >= iterator_base->second->base_) {

     // The new range is entirely within an existing child range.

     // If the new range's geometry is exactly equal to an existing child

     // range's, it violates the containment rules, and an attempt to store

     // it must fail.  iterator_base->first contains the key, which was the

     // containing child's high address.

     if (iterator_base->second->base_ == base && iterator_base->first == high) {

       // TODO(nealsid): See the TODO above on why this is commented out.

 //       BPLOG(INFO) << "StoreRange failed, identical range is already "

 //                      "present: " << HexString(base) << "+" << HexString(size);

       return false;

     }

     // Pass the new range on to the child to attempt to store.

     return iterator_base->second->StoreRange(base, size, entry);

   }

   // iterator_high might refer to an irrelevant range: one whose base address

   // is higher than the new range's high address.  Set contains_high to true

   // only if iterator_high refers to a range that is at least partially

   // within the new range.

   bool contains_high = iterator_high != iterator_end &&

                        high >= iterator_high->second->base_;

   // If the new range encompasses any existing child ranges, it must do so

   // fully.  Partial containment isn't allowed.

   if ((iterator_base != iterator_end && base > iterator_base->second->base_) ||

       (contains_high && high < iterator_high->first)) {

     // TODO(mmentovai): Some symbol files will trip this check frequently

     // on STACK lines.  Too many messages will be produced.  These are more

     // suitable for a DEBUG channel than an INFO channel.

     // BPLOG(INFO) << "StoreRange failed, new range partially contains "

     //               "existing range: " << HexString(base) << "+" <<

     //               HexString(size);

     return false;

   }

   // When copying and erasing contained ranges, the "end" iterator needs to

   // point one past the last item of the range to copy.  If contains_high is

   // false, the iterator's already in the right place; the increment is safe

   // because contains_high can't be true if iterator_high == iterator_end.

   if (contains_high)

     ++iterator_high;

   // Optimization: if the iterators are equal, no child ranges would be

   // moved.  Create the new child range with a NULL map to conserve space

   // in leaf nodes, of which there will be many.

   AddressToRangeMap *child_map = NULL;

   if (iterator_base != iterator_high) {

     // The children of this range that are contained by the new range must

     // be transferred over to the new range.  Create the new child range map

     // and copy the pointers to range maps it should contain into it.

     child_map = new AddressToRangeMap(iterator_base, iterator_high);

     // Remove the copied child pointers from this range's map of children.

     map_->erase(iterator_base, iterator_high);

   }

   // Store the new range in the map by its high address.  Any children that

   // the new child range contains were formerly children of this range but

   // are now this range's grandchildren.  Ownership of these is transferred

   // to the new child range.

   map_->insert(MapValue(high,

                         new ContainedRangeMap(base, entry, child_map)));

   return true;

 }

 template<typename AddressType, typename EntryType>

 bool ContainedRangeMap<AddressType, EntryType>::RetrieveRange(

     const AddressType &address, EntryType *entry) const {

   BPLOG_IF(ERROR, !entry) << "ContainedRangeMap::RetrieveRange requires "

                              "|entry|";

   assert(entry);

   // If nothing was ever stored, then there's nothing to retrieve.

   if (!map_)

     return false;

   // Get an iterator to the child range whose high address is equal to or

   // greater than the supplied address.  If the supplied address is higher

   // than all of the high addresses in the range, then this range does not

   // contain a child at address, so return false.  If the supplied address

   // is lower than the base address of the child range, then it is not within

   // the child range, so return false.

   MapConstIterator iterator = map_->lower_bound(address);

   if (iterator == map_->end() || address < iterator->second->base_)

     return false;

   // The child in iterator->second contains the specified address.  Find out

   // if it has a more-specific descendant that also contains it.  If it does,

   // it will set |entry| appropriately.  If not, set |entry| to the child.

   if (!iterator->second->RetrieveRange(address, entry))

     *entry = iterator->second->entry_;

   return true;

 }

 template<typename AddressType, typename EntryType>

 void ContainedRangeMap<AddressType, EntryType>::Clear() {

   if (map_) {

     MapConstIterator end = map_->end();

     for (MapConstIterator child = map_->begin(); child != end; ++child)

       delete child->second;

     delete map_;

     map_ = NULL;

   }

 }

 }  // namespace google_breakpad

 #endif  // PROCESSOR_CONTAINED_RANGE_MAP_INL_H__