The Tor Browser: toolkit/crashreporter/google-breakpad/src/processor/contained_range

toolkit/crashreporter/google-breakpad/src/processor/contained_range_map-inl.h@b8a032363ba2 (annotated)

toolkit/crashreporter/google-breakpad/src/processor/contained_range_map-inl.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 // 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__

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toolkit/crashreporter/google-breakpad/src/processor/contained_range_map-inl.h@b8a032363ba2 (annotated)

toolkit/crashreporter/google-breakpad/src/processor/contained_range_map-inl.h