michael@0: // Copyright (c) 2006, Google Inc.
michael@0: // All rights reserved.
michael@0: //
michael@0: // Redistribution and use in source and binary forms, with or without
michael@0: // modification, are permitted provided that the following conditions are
michael@0: // met:
michael@0: //
michael@0: //     * Redistributions of source code must retain the above copyright
michael@0: // notice, this list of conditions and the following disclaimer.
michael@0: //     * Redistributions in binary form must reproduce the above
michael@0: // copyright notice, this list of conditions and the following disclaimer
michael@0: // in the documentation and/or other materials provided with the
michael@0: // distribution.
michael@0: //     * Neither the name of Google Inc. nor the names of its
michael@0: // contributors may be used to endorse or promote products derived from
michael@0: // this software without specific prior written permission.
michael@0: //
michael@0: // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0: // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0: // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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michael@0: // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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michael@0: // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
michael@0: // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
michael@0: // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0: // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
michael@0: // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0: 
michael@0: // contained_range_map-inl.h: Hierarchically-organized range map implementation.
michael@0: //
michael@0: // See contained_range_map.h for documentation.
michael@0: //
michael@0: // Author: Mark Mentovai
michael@0: 
michael@0: #ifndef PROCESSOR_CONTAINED_RANGE_MAP_INL_H__
michael@0: #define PROCESSOR_CONTAINED_RANGE_MAP_INL_H__
michael@0: 
michael@0: #include "processor/contained_range_map.h"
michael@0: 
michael@0: #include <assert.h>
michael@0: 
michael@0: #include "common/logging.h"
michael@0: 
michael@0: 
michael@0: namespace google_breakpad {
michael@0: 
michael@0: 
michael@0: template<typename AddressType, typename EntryType>
michael@0: ContainedRangeMap<AddressType, EntryType>::~ContainedRangeMap() {
michael@0:   // Clear frees the children pointed to by the map, and frees the map itself.
michael@0:   Clear();
michael@0: }
michael@0: 
michael@0: 
michael@0: template<typename AddressType, typename EntryType>
michael@0: bool ContainedRangeMap<AddressType, EntryType>::StoreRange(
michael@0:     const AddressType &base, const AddressType &size, const EntryType &entry) {
michael@0:   AddressType high = base + size - 1;
michael@0: 
michael@0:   // Check for undersize or overflow.
michael@0:   if (size <= 0 || high < base) {
michael@0:     //TODO(nealsid) We are commenting this out in order to prevent
michael@0:     // excessive logging.  We plan to move to better logging as this
michael@0:     // failure happens quite often and is expected(see comment in
michael@0:     // basic_source_line_resolver.cc:671).
michael@0:     // BPLOG(INFO) << "StoreRange failed, " << HexString(base) << "+"
michael@0:     // << HexString(size) << ", " << HexString(high);
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   if (!map_)
michael@0:     map_ = new AddressToRangeMap();
michael@0: 
michael@0:   MapIterator iterator_base = map_->lower_bound(base);
michael@0:   MapIterator iterator_high = map_->lower_bound(high);
michael@0:   MapIterator iterator_end = map_->end();
michael@0: 
michael@0:   if (iterator_base == iterator_high && iterator_base != iterator_end &&
michael@0:       base >= iterator_base->second->base_) {
michael@0:     // The new range is entirely within an existing child range.
michael@0: 
michael@0:     // If the new range's geometry is exactly equal to an existing child
michael@0:     // range's, it violates the containment rules, and an attempt to store
michael@0:     // it must fail.  iterator_base->first contains the key, which was the
michael@0:     // containing child's high address.
michael@0:     if (iterator_base->second->base_ == base && iterator_base->first == high) {
michael@0:       // TODO(nealsid): See the TODO above on why this is commented out.
michael@0: //       BPLOG(INFO) << "StoreRange failed, identical range is already "
michael@0: //                      "present: " << HexString(base) << "+" << HexString(size);
michael@0:       return false;
michael@0:     }
michael@0: 
michael@0:     // Pass the new range on to the child to attempt to store.
michael@0:     return iterator_base->second->StoreRange(base, size, entry);
michael@0:   }
michael@0: 
michael@0:   // iterator_high might refer to an irrelevant range: one whose base address
michael@0:   // is higher than the new range's high address.  Set contains_high to true
michael@0:   // only if iterator_high refers to a range that is at least partially
michael@0:   // within the new range.
michael@0:   bool contains_high = iterator_high != iterator_end &&
michael@0:                        high >= iterator_high->second->base_;
michael@0: 
michael@0:   // If the new range encompasses any existing child ranges, it must do so
michael@0:   // fully.  Partial containment isn't allowed.
michael@0:   if ((iterator_base != iterator_end && base > iterator_base->second->base_) ||
michael@0:       (contains_high && high < iterator_high->first)) {
michael@0:     // TODO(mmentovai): Some symbol files will trip this check frequently
michael@0:     // on STACK lines.  Too many messages will be produced.  These are more
michael@0:     // suitable for a DEBUG channel than an INFO channel.
michael@0:     // BPLOG(INFO) << "StoreRange failed, new range partially contains "
michael@0:     //               "existing range: " << HexString(base) << "+" <<
michael@0:     //               HexString(size);
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   // When copying and erasing contained ranges, the "end" iterator needs to
michael@0:   // point one past the last item of the range to copy.  If contains_high is
michael@0:   // false, the iterator's already in the right place; the increment is safe
michael@0:   // because contains_high can't be true if iterator_high == iterator_end.
michael@0:   if (contains_high)
michael@0:     ++iterator_high;
michael@0: 
michael@0:   // Optimization: if the iterators are equal, no child ranges would be
michael@0:   // moved.  Create the new child range with a NULL map to conserve space
michael@0:   // in leaf nodes, of which there will be many.
michael@0:   AddressToRangeMap *child_map = NULL;
michael@0: 
michael@0:   if (iterator_base != iterator_high) {
michael@0:     // The children of this range that are contained by the new range must
michael@0:     // be transferred over to the new range.  Create the new child range map
michael@0:     // and copy the pointers to range maps it should contain into it.
michael@0:     child_map = new AddressToRangeMap(iterator_base, iterator_high);
michael@0: 
michael@0:     // Remove the copied child pointers from this range's map of children.
michael@0:     map_->erase(iterator_base, iterator_high);
michael@0:   }
michael@0: 
michael@0:   // Store the new range in the map by its high address.  Any children that
michael@0:   // the new child range contains were formerly children of this range but
michael@0:   // are now this range's grandchildren.  Ownership of these is transferred
michael@0:   // to the new child range.
michael@0:   map_->insert(MapValue(high,
michael@0:                         new ContainedRangeMap(base, entry, child_map)));
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: 
michael@0: template<typename AddressType, typename EntryType>
michael@0: bool ContainedRangeMap<AddressType, EntryType>::RetrieveRange(
michael@0:     const AddressType &address, EntryType *entry) const {
michael@0:   BPLOG_IF(ERROR, !entry) << "ContainedRangeMap::RetrieveRange requires "
michael@0:                              "|entry|";
michael@0:   assert(entry);
michael@0: 
michael@0:   // If nothing was ever stored, then there's nothing to retrieve.
michael@0:   if (!map_)
michael@0:     return false;
michael@0: 
michael@0:   // Get an iterator to the child range whose high address is equal to or
michael@0:   // greater than the supplied address.  If the supplied address is higher
michael@0:   // than all of the high addresses in the range, then this range does not
michael@0:   // contain a child at address, so return false.  If the supplied address
michael@0:   // is lower than the base address of the child range, then it is not within
michael@0:   // the child range, so return false.
michael@0:   MapConstIterator iterator = map_->lower_bound(address);
michael@0:   if (iterator == map_->end() || address < iterator->second->base_)
michael@0:     return false;
michael@0: 
michael@0:   // The child in iterator->second contains the specified address.  Find out
michael@0:   // if it has a more-specific descendant that also contains it.  If it does,
michael@0:   // it will set |entry| appropriately.  If not, set |entry| to the child.
michael@0:   if (!iterator->second->RetrieveRange(address, entry))
michael@0:     *entry = iterator->second->entry_;
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: 
michael@0: template<typename AddressType, typename EntryType>
michael@0: void ContainedRangeMap<AddressType, EntryType>::Clear() {
michael@0:   if (map_) {
michael@0:     MapConstIterator end = map_->end();
michael@0:     for (MapConstIterator child = map_->begin(); child != end; ++child)
michael@0:       delete child->second;
michael@0: 
michael@0:     delete map_;
michael@0:     map_ = NULL;
michael@0:   }
michael@0: }
michael@0: 
michael@0: 
michael@0: }  // namespace google_breakpad
michael@0: 
michael@0: 
michael@0: #endif  // PROCESSOR_CONTAINED_RANGE_MAP_INL_H__