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author | Eliot Horowitz <eliot@10gen.com> | 2011-12-24 15:33:26 -0500 |
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committer | Eliot Horowitz <eliot@10gen.com> | 2011-12-24 15:33:45 -0500 |
commit | ae1ecd9c786911f9f1f0242f0f7d702b3e5dfeba (patch) | |
tree | 92f8e1649e6f080b251ff5f1763679a72eb59b34 /src/mongo/db/pipeline/document_source_skip.cpp | |
parent | dfa4cd7e2cf109b072440155fabc08a93c8045a0 (diff) | |
download | mongo-ae1ecd9c786911f9f1f0242f0f7d702b3e5dfeba.tar.gz |
bulk move of code to src/ SERVER-4551
Diffstat (limited to 'src/mongo/db/pipeline/document_source_skip.cpp')
-rw-r--r-- | src/mongo/db/pipeline/document_source_skip.cpp | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/src/mongo/db/pipeline/document_source_skip.cpp b/src/mongo/db/pipeline/document_source_skip.cpp new file mode 100644 index 00000000000..74bf2360ce9 --- /dev/null +++ b/src/mongo/db/pipeline/document_source_skip.cpp @@ -0,0 +1,99 @@ +/** +* Copyright (C) 2011 10gen Inc. +* +* This program is free software: you can redistribute it and/or modify +* it under the terms of the GNU Affero General Public License, version 3, +* as published by the Free Software Foundation. +* +* This program is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU Affero General Public License for more details. +* +* You should have received a copy of the GNU Affero General Public License +* along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "pch.h" + +#include "db/pipeline/document_source.h" + +#include "db/jsobj.h" +#include "db/pipeline/document.h" +#include "db/pipeline/expression.h" +#include "db/pipeline/expression_context.h" +#include "db/pipeline/value.h" + +namespace mongo { + const char DocumentSourceSkip::skipName[] = "$skip"; + + DocumentSourceSkip::DocumentSourceSkip(const intrusive_ptr<ExpressionContext> &pTheCtx): + skip(0), + count(0), + pCtx(pTheCtx) { + } + + DocumentSourceSkip::~DocumentSourceSkip() { + } + + void DocumentSourceSkip::skipper() { + if (count == 0) { + while (!pSource->eof() && count++ < skip) { + pSource->advance(); + } + } + + if (pSource->eof()) { + pCurrent.reset(); + return; + } + + pCurrent = pSource->getCurrent(); + } + + bool DocumentSourceSkip::eof() { + skipper(); + return pSource->eof(); + } + + bool DocumentSourceSkip::advance() { + if (eof()) { + pCurrent.reset(); + return false; + } + + pCurrent = pSource->getCurrent(); + return pSource->advance(); + } + + intrusive_ptr<Document> DocumentSourceSkip::getCurrent() { + skipper(); + return pCurrent; + } + + void DocumentSourceSkip::sourceToBson(BSONObjBuilder *pBuilder) const { + pBuilder->append("$skip", skip); + } + + intrusive_ptr<DocumentSourceSkip> DocumentSourceSkip::create( + const intrusive_ptr<ExpressionContext> &pCtx) { + intrusive_ptr<DocumentSourceSkip> pSource( + new DocumentSourceSkip(pCtx)); + return pSource; + } + + intrusive_ptr<DocumentSource> DocumentSourceSkip::createFromBson( + BSONElement *pBsonElement, + const intrusive_ptr<ExpressionContext> &pCtx) { + uassert(15972, str::stream() << "the value to " << + skipName << " must be a number", pBsonElement->isNumber()); + + intrusive_ptr<DocumentSourceSkip> pSkip( + DocumentSourceSkip::create(pCtx)); + + pSkip->skip = (int)pBsonElement->numberLong(); + assert(pSkip->skip > 0); // CW TODO error code + + return pSkip; + } +} |