aboutsummaryrefslogtreecommitdiff
path: root/src/processor/contained_range_map-inl.h
diff options
context:
space:
mode:
Diffstat (limited to 'src/processor/contained_range_map-inl.h')
-rw-r--r--src/processor/contained_range_map-inl.h157
1 files changed, 157 insertions, 0 deletions
diff --git a/src/processor/contained_range_map-inl.h b/src/processor/contained_range_map-inl.h
new file mode 100644
index 00000000..4b22e376
--- /dev/null
+++ b/src/processor/contained_range_map-inl.h
@@ -0,0 +1,157 @@
+// Copyright (C) 2006 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// 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"
+
+
+namespace google_airbag {
+
+
+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)
+ return false;
+
+ if (!map_)
+ map_ = new AddressToRangeMap();
+
+ MapIterator iterator_base = map_->lower_bound(base);
+ MapIterator iterator_high = map_->lower_bound(high);
+ MapConstIterator 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)
+ 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)) {
+ 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 {
+ if (!entry || !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_airbag
+
+
+#endif // PROCESSOR_CONTAINED_RANGE_MAP_INL_H__