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arangodb/arangod/VocBase/edge-collection.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 Dr. Frank Celler
/// @author Jan Steemann
////////////////////////////////////////////////////////////////////////////////
#include "edge-collection.h"
#include "Logger/Logger.h"
#include "Indexes/EdgeIndex.h"
#include "Utils/CollectionNameResolver.h"
#include "Utils/Transaction.h"
#include "VocBase/document-collection.h"
#include <velocypack/Slice.h>
#include <velocypack/velocypack-aliases.h>
////////////////////////////////////////////////////////////////////////////////
/// @brief find edges matching search criteria and add them to the result
/// this function is called two times for each edge query:
/// the first call (with matchType 1) will query the index with the originally
/// requested direction, whereas the second call will query the index with the
/// opposite direction (with matchType 2 or 3) to find all counterparts
////////////////////////////////////////////////////////////////////////////////
static bool FindEdges(arangodb::Transaction* trx,
TRI_edge_direction_e direction,
arangodb::EdgeIndex* edgeIndex,
std::vector<TRI_doc_mptr_t>& result,
VPackSlice const entry, int matchType) {
std::unique_ptr<std::vector<TRI_doc_mptr_t*>> found;
if (direction == TRI_EDGE_OUT) {
found.reset(edgeIndex->from()->lookupByKey(trx, &entry));
} else if (direction == TRI_EDGE_IN) {
found.reset(edgeIndex->to()->lookupByKey(trx, &entry));
} else {
TRI_ASSERT(false); // TRI_EDGE_ANY not supported here
}
size_t const n = found->size();
if (n > 0) {
if (result.capacity() == 0) {
// if result vector is still empty and we have results, re-init the
// result vector to a "good" size. this will save later reallocations
result.reserve(n);
}
// add all results found
for (size_t i = 0; i < n; ++i) {
TRI_doc_mptr_t* mptr = found->at(i);
// the following queries will use the following sequences of matchTypes:
// inEdges(): 1, outEdges(): 1, edges(): 1, 3
// if matchType is 1, we'll return all found edges without filtering
// We'll exclude all loop edges now (we already got them in iteration 1),
// and also exclude all unidirectional edges
//
// if matchType is 3, the direction is also reversed. We'll exclude all
// loop edges now (we already got them in iteration 1)
if (matchType > 1) {
// if the edge is a loop, we have already found it in iteration 1
// we must skip it here, otherwise we would produce duplicates
VPackSlice const slice(mptr->vpack());
if (slice.get(TRI_VOC_ATTRIBUTE_FROM).equals(slice.get(TRI_VOC_ATTRIBUTE_TO))) {
continue;
}
}
result.emplace_back(*mptr);
}
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
/// @brief looks up edges
/// DEPRECATED
////////////////////////////////////////////////////////////////////////////////
std::vector<TRI_doc_mptr_t> TRI_LookupEdgesDocumentCollection(
arangodb::Transaction* trx, TRI_document_collection_t* document,
TRI_edge_direction_e direction, TRI_voc_cid_t cid,
std::string const& key) {
auto resolver = trx->resolver();
std::string cname = resolver->getCollectionName(cid);
VPackBuilder b;
b.add(VPackValue(cname + "/" + key));
// initialize the result vector
std::vector<TRI_doc_mptr_t> result;
auto edgeIndex = document->edgeIndex();
if (edgeIndex == nullptr) {
LOG(ERR) << "collection does not have an edges index";
return result;
}
if (direction == TRI_EDGE_IN) {
// get all edges with a matching IN vertex
FindEdges(trx, TRI_EDGE_IN, edgeIndex, result, b.slice(), 1);
} else if (direction == TRI_EDGE_OUT) {
// get all edges with a matching OUT vertex
FindEdges(trx, TRI_EDGE_OUT, edgeIndex, result, b.slice(), 1);
} else if (direction == TRI_EDGE_ANY) {
// get all edges with a matching IN vertex
FindEdges(trx, TRI_EDGE_IN, edgeIndex, result, b.slice(), 1);
// add all non-reflexive edges with a matching OUT vertex
FindEdges(trx, TRI_EDGE_OUT, edgeIndex, result, b.slice(), 3);
}
return result;
}