mirror of https://gitee.com/bigwinds/arangodb
118 lines
3.7 KiB
C++
118 lines
3.7 KiB
C++
////////////////////////////////////////////////////////////////////////////////
|
|
/// DISCLAIMER
|
|
///
|
|
/// Copyright 2014-2017 ArangoDB GmbH, Cologne, Germany
|
|
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
|
|
///
|
|
/// 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.
|
|
///
|
|
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
|
|
///
|
|
/// @author Jan Steemann
|
|
/// @author Daniel H. Larkin
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
|
|
#include "RocksDBComparator.h"
|
|
#include "Basics/VelocyPackHelper.h"
|
|
#include "RocksDBEngine/RocksDBKey.h"
|
|
#include "RocksDBEngine/RocksDBPrefixExtractor.h"
|
|
#include "RocksDBEngine/RocksDBTypes.h"
|
|
|
|
#include <velocypack/Iterator.h>
|
|
#include <velocypack/Slice.h>
|
|
#include <velocypack/velocypack-aliases.h>
|
|
|
|
using namespace arangodb;
|
|
|
|
namespace {
|
|
|
|
int compareIndexedValues(arangodb::velocypack::Slice const& lhs,
|
|
arangodb::velocypack::Slice const& rhs) {
|
|
TRI_ASSERT(lhs.isArray());
|
|
TRI_ASSERT(rhs.isArray());
|
|
|
|
arangodb::velocypack::ArrayIterator lhsIter(lhs);
|
|
arangodb::velocypack::ArrayIterator rhsIter(rhs);
|
|
size_t const lLength = lhsIter.size();
|
|
size_t const rLength = rhsIter.size();
|
|
|
|
while (lhsIter.valid() || rhsIter.valid()) {
|
|
size_t i = lhsIter.index();
|
|
int res = arangodb::basics::VelocyPackHelper::compare(
|
|
(i < lLength ? *lhsIter : VPackSlice::noneSlice()),
|
|
(i < rLength ? *rhsIter : VPackSlice::noneSlice()), true);
|
|
if (res != 0) {
|
|
return res;
|
|
}
|
|
++lhsIter;
|
|
++rhsIter;
|
|
}
|
|
|
|
return static_cast<int>(lLength - rLength);
|
|
}
|
|
|
|
} // namespace
|
|
|
|
int RocksDBVPackComparator::compareIndexValues(rocksdb::Slice const& lhs,
|
|
rocksdb::Slice const& rhs) const {
|
|
constexpr size_t objectIDLength = RocksDBKey::objectIdSize();
|
|
|
|
int r = memcmp(lhs.data(), rhs.data(), objectIDLength);
|
|
|
|
if (r != 0) {
|
|
// different object ID
|
|
return r;
|
|
}
|
|
|
|
if (ADB_UNLIKELY(lhs.size() == objectIDLength || rhs.size() == objectIDLength)) {
|
|
if (lhs.size() == rhs.size()) {
|
|
return 0;
|
|
}
|
|
return ((lhs.size() < rhs.size()) ? -1 : 1);
|
|
}
|
|
|
|
TRI_ASSERT(lhs.size() > sizeof(uint64_t));
|
|
TRI_ASSERT(rhs.size() > sizeof(uint64_t));
|
|
|
|
VPackSlice const lSlice = VPackSlice(reinterpret_cast<uint8_t const*>(lhs.data()) + sizeof(uint64_t));
|
|
VPackSlice const rSlice = VPackSlice(reinterpret_cast<uint8_t const*>(rhs.data()) + sizeof(uint64_t));
|
|
|
|
r = ::compareIndexedValues(lSlice, rSlice);
|
|
|
|
if (r != 0) {
|
|
// comparison of index values produced an unambiguous result
|
|
return r;
|
|
}
|
|
|
|
// index values were identical. now compare the leftovers (which is the
|
|
// LocalDocumentId for non-unique indexes)
|
|
|
|
constexpr size_t offset = sizeof(uint64_t);
|
|
size_t const lOffset = offset + static_cast<size_t>(lSlice.byteSize());
|
|
size_t const rOffset = offset + static_cast<size_t>(rSlice.byteSize());
|
|
size_t const lSize = lhs.size() - lOffset;
|
|
size_t const rSize = rhs.size() - rOffset;
|
|
size_t minSize = std::min(lSize, rSize);
|
|
|
|
if (minSize > 0) {
|
|
char const* lBase = lhs.data() + lOffset;
|
|
char const* rBase = rhs.data() + rOffset;
|
|
r = memcmp(lBase, rBase, minSize);
|
|
if (r != 0) {
|
|
return r;
|
|
}
|
|
}
|
|
|
|
return static_cast<int>(lSize - rSize);
|
|
}
|