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// Copyright (c) 2010 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.
// range_map-inl.h: Range map implementation.
//
// See range_map.h for documentation.
//
// Author: Mark Mentovai
#ifndef PROCESSOR_RANGE_MAP_INL_H__
#define PROCESSOR_RANGE_MAP_INL_H__
#include <assert.h>
#include "processor/range_map.h"
#include "processor/linked_ptr.h"
#include "processor/logging.h"
namespace google_breakpad {
template<typename AddressType, typename EntryType>
void RangeMap<AddressType, EntryType>::SetEnableShrinkDown(
bool enable_shrink_down) {
enable_shrink_down_ = enable_shrink_down;
}
template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::IsShrinkDownEnabled() const {
return enable_shrink_down_;
}
template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::StoreRange(const AddressType &base,
const AddressType &size,
const EntryType &entry) {
return StoreRangeInternal(base, 0 /* delta */, size, entry);
}
template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::StoreRangeInternal(
const AddressType &base, const AddressType &delta,
const AddressType &size, const EntryType &entry) {
AddressType high = base + (size - 1);
// Check for undersize or overflow.
if (size <= 0 || high < base) {
// The processor will hit this case too frequently with common symbol
// files in the size == 0 case, which is more suited to a DEBUG channel.
// Filter those out since there's no DEBUG channel at the moment.
BPLOG_IF(INFO, size != 0) << "StoreRangeInternal failed, "
<< HexString(base) << "+" << HexString(size)
<< ", " << HexString(high)
<< ", delta: " << HexString(delta);
return false;
}
// Ensure that this range does not overlap with another one already in the
// map.
MapConstIterator iterator_base = map_.lower_bound(base);
MapConstIterator iterator_high = map_.lower_bound(high);
if (iterator_base != iterator_high) {
// Some other range begins in the space used by this range. It may be
// contained within the space used by this range, or it may extend lower.
// If enable_shrink_down_ is true, shrink the current range down, otherwise
// this is an error.
if (enable_shrink_down_) {
AddressType additional_delta = iterator_base->first - base + 1;
return StoreRangeInternal(base + additional_delta,
delta + additional_delta,
size - additional_delta, entry);
} else {
// The processor hits this case too frequently with common symbol files.
// This is most appropriate for a DEBUG channel, but since none exists
// now simply comment out this logging.
// AddressType other_base = iterator_base->second.base();
// AddressType other_size = iterator_base->first - other_base + 1;
// BPLOG(INFO) << "StoreRangeInternal failed, an existing range is "
// << "overlapping with the new range: new "
// << HexString(base) << "+" << HexString(size)
// << ", existing " << HexString(other_base) << "+"
// << HexString(other_size);
return false;
}
}
if (iterator_high != map_.end()) {
if (iterator_high->second.base() <= high) {
// The range above this one overlaps with this one. It may fully
// contain this range, or it may begin within this range and extend
// higher. If enable_shrink_down_ is true, shrink the other range down,
// otherwise this is an error.
if (enable_shrink_down_ && iterator_high->first > high) {
// Shrink the other range down.
AddressType other_high = iterator_high->first;
AddressType additional_delta =
high - iterator_high->second.base() + 1;
EntryType other_entry;
AddressType other_base = AddressType();
AddressType other_size = AddressType();
AddressType other_delta = AddressType();
RetrieveRange(other_high, &other_entry, &other_base, &other_delta,
&other_size);
map_.erase(iterator_high);
map_.insert(MapValue(other_high,
Range(other_base + additional_delta,
other_delta + additional_delta,
other_entry)));
// Retry to store this range.
return StoreRangeInternal(base, delta, size, entry);
} else {
// The processor hits this case too frequently with common symbol files.
// This is most appropriate for a DEBUG channel, but since none exists
// now simply comment out this logging.
//
// AddressType other_base = iterator_high->second.base();
// AddressType other_size = iterator_high->first - other_base + 1;
// BPLOG(INFO) << "StoreRangeInternal failed, an existing range "
// << "contains or extends higher than the new range: new "
// << HexString(base) << "+" << HexString(size)
// << ", existing " << HexString(other_base) << "+"
// << HexString(other_size);
return false;
}
}
}
// Store the range in the map by its high address, so that lower_bound can
// be used to quickly locate a range by address.
map_.insert(MapValue(high, Range(base, delta, entry)));
return true;
}
template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::RetrieveRange(
const AddressType &address, EntryType *entry, AddressType *entry_base,
AddressType *entry_delta, AddressType *entry_size) const {
BPLOG_IF(ERROR, !entry) << "RangeMap::RetrieveRange requires |entry|";
assert(entry);
MapConstIterator iterator = map_.lower_bound(address);
if (iterator == map_.end())
return false;
// The map is keyed by the high address of each range, so |address| is
// guaranteed to be lower than the range's high address. If |range| is
// not directly preceded by another range, it's possible for address to
// be below the range's low address, though. When that happens, address
// references something not within any range, so return false.
if (address < iterator->second.base())
return false;
*entry = iterator->second.entry();
if (entry_base)
*entry_base = iterator->second.base();
if (entry_delta)
*entry_delta = iterator->second.delta();
if (entry_size)
*entry_size = iterator->first - iterator->second.base() + 1;
return true;
}
template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::RetrieveNearestRange(
const AddressType &address, EntryType *entry, AddressType *entry_base,
AddressType *entry_delta, AddressType *entry_size) const {
BPLOG_IF(ERROR, !entry) << "RangeMap::RetrieveNearestRange requires |entry|";
assert(entry);
// If address is within a range, RetrieveRange can handle it.
if (RetrieveRange(address, entry, entry_base, entry_delta, entry_size))
return true;
// upper_bound gives the first element whose key is greater than address,
// but we want the first element whose key is less than or equal to address.
// Decrement the iterator to get there, but not if the upper_bound already
// points to the beginning of the map - in that case, address is lower than
// the lowest stored key, so return false.
MapConstIterator iterator = map_.upper_bound(address);
if (iterator == map_.begin())
return false;
--iterator;
*entry = iterator->second.entry();
if (entry_base)
*entry_base = iterator->second.base();
if (entry_delta)
*entry_delta = iterator->second.delta();
if (entry_size)
*entry_size = iterator->first - iterator->second.base() + 1;
return true;
}
template<typename AddressType, typename EntryType>
bool RangeMap<AddressType, EntryType>::RetrieveRangeAtIndex(
int index, EntryType *entry, AddressType *entry_base,
AddressType *entry_delta, AddressType *entry_size) const {
BPLOG_IF(ERROR, !entry) << "RangeMap::RetrieveRangeAtIndex requires |entry|";
assert(entry);
if (index >= GetCount()) {
BPLOG(ERROR) << "Index out of range: " << index << "/" << GetCount();
return false;
}
// Walk through the map. Although it's ordered, it's not a vector, so it
// can't be addressed directly by index.
MapConstIterator iterator = map_.begin();
for (int this_index = 0; this_index < index; ++this_index)
++iterator;
*entry = iterator->second.entry();
if (entry_base)
*entry_base = iterator->second.base();
if (entry_delta)
*entry_delta = iterator->second.delta();
if (entry_size)
*entry_size = iterator->first - iterator->second.base() + 1;
return true;
}
template<typename AddressType, typename EntryType>
int RangeMap<AddressType, EntryType>::GetCount() const {
return static_cast<int>(map_.size());
}
template<typename AddressType, typename EntryType>
void RangeMap<AddressType, EntryType>::Clear() {
map_.clear();
}
} // namespace google_breakpad
#endif // PROCESSOR_RANGE_MAP_INL_H__