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arangodb/arangod/VocBase/Traverser.cpp

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C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 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 Michael Hackstein
////////////////////////////////////////////////////////////////////////////////
#include "Traverser.h"
#include "Basics/VelocyPackHelper.h"
#include "Indexes/EdgeIndex.h"
#include "Utils/Transaction.h"
#include "Utils/TransactionContext.h"
#include "VocBase/KeyGenerator.h"
#include <velocypack/Iterator.h>
#include <velocypack/velocypack-aliases.h>
using TraverserExpression = arangodb::traverser::TraverserExpression;
/// @brief Class Shortest Path
/// @brief Clears the path
void arangodb::traverser::ShortestPath::clear() {
_vertices.clear();
_edges.clear();
}
void arangodb::traverser::ShortestPath::edgeToVelocyPack(Transaction*, size_t position, VPackBuilder& builder) {
TRI_ASSERT(position < length());
if (position == 0) {
builder.add(basics::VelocyPackHelper::NullValue());
} else {
TRI_ASSERT(position - 1 < _edges.size());
builder.add(_edges[position - 1]);
}
}
void arangodb::traverser::ShortestPath::vertexToVelocyPack(Transaction* trx, size_t position, VPackBuilder& builder) {
TRI_ASSERT(position < length());
VPackSlice v = _vertices[position];
TRI_ASSERT(v.isString());
std::string collection = v.copyString();
size_t p = collection.find("/");
TRI_ASSERT(p != std::string::npos);
TransactionBuilderLeaser searchBuilder(trx);
searchBuilder->add(VPackValue(collection.substr(p + 1)));
collection = collection.substr(0, p);
int res = trx->documentFastPath(collection, searchBuilder->slice(), builder);
if (res != TRI_ERROR_NO_ERROR) {
builder.clear(); // Just in case...
builder.add(basics::VelocyPackHelper::NullValue());
}
}
void arangodb::traverser::TraverserOptions::setCollections(
std::vector<std::string> const& colls, TRI_edge_direction_e dir) {
// We do not allow to reset the collections.
TRI_ASSERT(_collections.empty());
TRI_ASSERT(_directions.empty());
TRI_ASSERT(!colls.empty());
_collections = colls;
_directions.emplace_back(dir);
for (auto const& it : colls) {
_indexHandles.emplace_back(_trx->edgeIndexHandle(it));
}
}
void arangodb::traverser::TraverserOptions::setCollections(
std::vector<std::string> const& colls,
std::vector<TRI_edge_direction_e> const& dirs) {
// We do not allow to reset the collections.
TRI_ASSERT(_collections.empty());
TRI_ASSERT(_directions.empty());
TRI_ASSERT(!colls.empty());
TRI_ASSERT(colls.size() == dirs.size());
_collections = colls;
_directions = dirs;
for (auto const& it : colls) {
_indexHandles.emplace_back(_trx->edgeIndexHandle(it));
}
}
size_t arangodb::traverser::TraverserOptions::collectionCount () const {
return _collections.size();
}
bool arangodb::traverser::TraverserOptions::getCollection(
size_t index, std::string& name, TRI_edge_direction_e& dir) const {
if (index >= _collections.size()) {
// No more collections stop now
return false;
}
if (_directions.size() == 1) {
dir = _directions.at(0);
} else {
dir = _directions.at(index);
}
name = _collections.at(index);
return true;
}
bool arangodb::traverser::TraverserOptions::getCollectionAndSearchValue(
size_t index, std::string const& vertexId, std::string& name,
Transaction::IndexHandle& indexHandle, VPackBuilder& builder) const {
if (index >= _collections.size()) {
// No more collections stop now
return false;
}
TRI_edge_direction_e dir;
TRI_ASSERT(!_directions.empty());
if (_directions.size() == 1) {
dir = _directions.at(0);
} else {
dir = _directions.at(index);
}
TRI_ASSERT(!_collections.empty());
name = _collections.at(index);
TRI_ASSERT(!_indexHandles.empty());
indexHandle = _indexHandles.at(index);
builder.clear();
arangodb::EdgeIndex::buildSearchValue(dir, vertexId, builder);
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief Creates an expression from a VelocyPackSlice
////////////////////////////////////////////////////////////////////////////////
TraverserExpression::TraverserExpression(VPackSlice const& slice) {
isEdgeAccess = slice.get("isEdgeAccess").getBool();
comparisonType = static_cast<aql::AstNodeType>(
slice.get("comparisonType").getNumber<uint32_t>());
auto registerNode = [&](aql::AstNode const* node)
-> void { _nodeRegister.emplace_back(node); };
auto registerString = [&](std::string const& str) -> char const* {
auto copy = std::make_unique<std::string>(str.c_str(), str.size());
_stringRegister.emplace_back(copy.get());
auto p = copy.release();
TRI_ASSERT(p != nullptr);
TRI_ASSERT(p->c_str() != nullptr);
return p->c_str(); // should never change its position, even if vector
// grows/shrinks
};
VPackSlice compareToSlice = slice.get("compareTo");
VPackBuilder* builder = new VPackBuilder;
try {
builder->add(compareToSlice);
} catch (...) {
delete builder;
throw;
}
compareTo.reset(builder);
// If this fails everything before does not leak
varAccess = new aql::AstNode(registerNode, registerString, slice.get("varAccess"));
}
////////////////////////////////////////////////////////////////////////////////
/// @brief transforms the expression into VelocyPack
////////////////////////////////////////////////////////////////////////////////
void TraverserExpression::toVelocyPack(VPackBuilder& builder) const {
builder.openObject();
builder.add("isEdgeAccess", VPackValue(isEdgeAccess));
builder.add("comparisonType",
VPackValue(static_cast<int32_t>(comparisonType)));
builder.add(VPackValue("varAccess"));
varAccess->toVelocyPack(builder, true);
if (compareTo != nullptr) {
builder.add("compareTo", compareTo->slice());
}
builder.close();
}
////////////////////////////////////////////////////////////////////////////////
/// @brief recursively iterates through the access ast
/// Returns false whenever the document does not have the required format
////////////////////////////////////////////////////////////////////////////////
bool TraverserExpression::recursiveCheck(arangodb::aql::AstNode const* node,
arangodb::velocypack::Slice& element,
arangodb::velocypack::Slice& base) const {
base = arangodb::basics::VelocyPackHelper::EmptyObjectValue();
switch (node->type) {
case arangodb::aql::NODE_TYPE_REFERENCE:
// We are on the variable access
return true;
case arangodb::aql::NODE_TYPE_ATTRIBUTE_ACCESS: {
std::string name(node->getString());
if (!recursiveCheck(node->getMember(0), element, base)) {
return false;
}
if (!element.isObject() || !element.hasKey(name)) {
return false;
}
base = element; // set base object
element = element.get(name);
break;
}
case arangodb::aql::NODE_TYPE_INDEXED_ACCESS: {
auto index = node->getMember(1);
if (!index->isIntValue()) {
return false;
}
if (!recursiveCheck(node->getMember(0), element, base)) {
return false;
}
auto idx = index->getIntValue();
if (!element.isArray()) {
return false;
}
element = element.at(idx);
break;
}
default:
return false;
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief evaluates if an element matches the given expression
////////////////////////////////////////////////////////////////////////////////
bool TraverserExpression::matchesCheck(arangodb::Transaction* trx,
VPackSlice const& element) const {
TRI_ASSERT(trx != nullptr);
VPackSlice base = arangodb::basics::VelocyPackHelper::EmptyObjectValue();
VPackSlice value = element.resolveExternal();
// initialize compare value to Null
VPackSlice result = arangodb::basics::VelocyPackHelper::NullValue();
// perform recursive check. this may modify value
if (recursiveCheck(varAccess, value, base)) {
result = value;
}
// hack for _id attribute
TransactionBuilderLeaser builder(trx);
if (result.isCustom() && base.isObject()) {
builder->add(VPackValue(trx->extractIdString(base)));
result = builder->slice();
}
TRI_ASSERT(compareTo != nullptr);
VPackOptions* options = trx->transactionContext()->getVPackOptions();
switch (comparisonType) {
case arangodb::aql::NODE_TYPE_OPERATOR_BINARY_EQ:
return arangodb::basics::VelocyPackHelper::compare(result, compareTo->slice(), false, options) == 0;
case arangodb::aql::NODE_TYPE_OPERATOR_BINARY_NE:
return arangodb::basics::VelocyPackHelper::compare(result, compareTo->slice(), false, options) != 0;
case arangodb::aql::NODE_TYPE_OPERATOR_BINARY_LT:
return arangodb::basics::VelocyPackHelper::compare(result, compareTo->slice(), true, options) < 0;
case arangodb::aql::NODE_TYPE_OPERATOR_BINARY_LE:
return arangodb::basics::VelocyPackHelper::compare(result, compareTo->slice(), true, options) <= 0;
case arangodb::aql::NODE_TYPE_OPERATOR_BINARY_GE:
return arangodb::basics::VelocyPackHelper::compare(result, compareTo->slice(), true, options) >= 0;
case arangodb::aql::NODE_TYPE_OPERATOR_BINARY_GT:
return arangodb::basics::VelocyPackHelper::compare(result, compareTo->slice(), true, options) > 0;
case arangodb::aql::NODE_TYPE_OPERATOR_BINARY_IN: {
// In means any of the elements in compareTo is identical
VPackSlice compareArray = compareTo->slice();
for (auto const& cmp : VPackArrayIterator(compareArray)) {
if (arangodb::basics::VelocyPackHelper::compare(result, cmp, false, options) == 0) {
// One is identical
return true;
}
}
// If we get here non is identical
return false;
}
case arangodb::aql::NODE_TYPE_OPERATOR_BINARY_NIN: {
// NIN means none of the elements in compareTo is identical
VPackSlice compareArray = compareTo->slice();
for (auto const& cmp : VPackArrayIterator(compareArray)) {
if (arangodb::basics::VelocyPackHelper::compare(result, cmp, false, options) == 0) {
// One is identical
return false;
}
}
// If we get here non is identical
return true;
}
default:
TRI_ASSERT(false);
}
return false;
}