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authorEliot Horowitz <eliot@10gen.com>2011-12-24 15:33:26 -0500
committerEliot Horowitz <eliot@10gen.com>2011-12-24 15:33:45 -0500
commitae1ecd9c786911f9f1f0242f0f7d702b3e5dfeba (patch)
tree92f8e1649e6f080b251ff5f1763679a72eb59b34 /src/mongo/db/pipeline/document_source_skip.cpp
parentdfa4cd7e2cf109b072440155fabc08a93c8045a0 (diff)
downloadmongo-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.cpp99
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
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+++ 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;
+ }
+}