mirror of https://gitee.com/bigwinds/arangodb
89 lines
3.3 KiB
C++
89 lines
3.3 KiB
C++
////////////////////////////////////////////////////////////////////////////////
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/// DISCLAIMER
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///
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/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
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/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
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///
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/// Licensed under the Apache License, Version 2.0 (the "License");
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/// you may not use this file except in compliance with the License.
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/// You may obtain a copy of the License at
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///
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/// http://www.apache.org/licenses/LICENSE-2.0
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///
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/// Unless required by applicable law or agreed to in writing, software
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/// distributed under the License is distributed on an "AS IS" BASIS,
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/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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/// See the License for the specific language governing permissions and
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/// limitations under the License.
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///
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/// Copyright holder is ArangoDB GmbH, Cologne, Germany
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///
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/// @author Jan Steemann
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////////////////////////////////////////////////////////////////////////////////
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#include "CollectionScanner.h"
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using namespace arangodb::aql;
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CollectionScanner::CollectionScanner(
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arangodb::AqlTransaction* trx, TRI_transaction_collection_t* trxCollection)
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: trx(trx), trxCollection(trxCollection), totalCount(0) {}
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CollectionScanner::~CollectionScanner() {}
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RandomCollectionScanner::RandomCollectionScanner(
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arangodb::AqlTransaction* trx, TRI_transaction_collection_t* trxCollection)
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: CollectionScanner(trx, trxCollection), step(0) {}
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int RandomCollectionScanner::scan(std::vector<TRI_doc_mptr_copy_t>& docs,
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size_t batchSize) {
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return trx->readRandom(trxCollection, docs, initialPosition, position,
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static_cast<uint64_t>(batchSize), step, totalCount);
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}
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int RandomCollectionScanner::forward(size_t batchSize, size_t& skipped) {
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// Basic implementation, no gain
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std::vector<TRI_doc_mptr_copy_t> unusedDocs;
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unusedDocs.reserve(batchSize);
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int res = scan(unusedDocs, batchSize);
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skipped += unusedDocs.size();
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// TRI_doc_mptr_copy_t is never freed
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unusedDocs.clear();
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return res;
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}
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void RandomCollectionScanner::reset() {
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initialPosition.reset();
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position.reset();
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step = 0;
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}
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LinearCollectionScanner::LinearCollectionScanner(
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arangodb::AqlTransaction* trx, TRI_transaction_collection_t* trxCollection)
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: CollectionScanner(trx, trxCollection) {}
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int LinearCollectionScanner::scan(std::vector<TRI_doc_mptr_copy_t>& docs,
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size_t batchSize) {
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uint64_t skip = 0;
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return trx->readIncremental(trxCollection, docs, position,
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static_cast<uint64_t>(batchSize), skip,
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UINT64_MAX, totalCount);
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}
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int LinearCollectionScanner::forward(size_t batchSize, size_t& skipped) {
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// Basic implementation, no gain
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std::vector<TRI_doc_mptr_copy_t> unusedDocs;
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uint64_t toSkip = static_cast<uint64_t>(batchSize);
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int res = trx->readIncremental(trxCollection, unusedDocs, position, 0,
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toSkip, // Will be modified. Will reach 0 if
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// batchSize many docs have been skipped
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UINT64_MAX, totalCount);
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uint64_t reallySkipped = static_cast<uint64_t>(batchSize) - toSkip;
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skipped += static_cast<size_t>(reallySkipped);
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TRI_ASSERT(unusedDocs.empty());
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return res;
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}
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void LinearCollectionScanner::reset() { position.reset(); }
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