intrusive_ptr<DocumentSource> DocumentSourceProject::createFromBson(
BSONElement *pBsonElement,
const intrusive_ptr<ExpressionContext> &pExpCtx) {
/* validate */
uassert(15969, str::stream() << projectName <<
" specification must be an object",
pBsonElement->type() == Object);
/* chain the projection onto the original source */
intrusive_ptr<DocumentSourceProject> pProject(
DocumentSourceProject::create(pExpCtx));
/*
Pull out the $project object. This should just be a list of
field inclusion or exclusion specifications. Note you can't do
both, except for the case of _id.
*/
BSONObj projectObj(pBsonElement->Obj());
BSONObjIterator fieldIterator(projectObj);
Expression::ObjectCtx objectCtx(
Expression::ObjectCtx::DOCUMENT_OK);
while(fieldIterator.more()) {
BSONElement outFieldElement(fieldIterator.next());
string outFieldPath(outFieldElement.fieldName());
string inFieldName(outFieldPath);
BSONType specType = outFieldElement.type();
int fieldInclusion = -1;
switch(specType) {
case NumberDouble: {
double inclusion = outFieldElement.numberDouble();
fieldInclusion = static_cast<int>(inclusion);
goto IncludeExclude;
}
case NumberLong: {
long long inclusion = outFieldElement.numberLong();
fieldInclusion = static_cast<int>(inclusion);
goto IncludeExclude;
}
case NumberInt:
/* just a plain integer include/exclude specification */
fieldInclusion = outFieldElement.numberInt();
IncludeExclude:
uassert(15970, str::stream() <<
"field inclusion or exclusion specification for \"" <<
outFieldPath <<
"\" must be true, 1, false, or zero",
((fieldInclusion == 0) || (fieldInclusion == 1)));
if (fieldInclusion == 0)
pProject->excludePath(outFieldPath);
else
pProject->includePath(outFieldPath);
break;
case Bool:
/* just a plain boolean include/exclude specification */
fieldInclusion = (outFieldElement.Bool() ? 1 : 0);
goto IncludeExclude;
case String:
/* include a field, with rename */
fieldInclusion = 1;
inFieldName = outFieldElement.String();
pProject->addField(
outFieldPath,
ExpressionFieldPath::create(
Expression::removeFieldPrefix(inFieldName)));
break;
case Object: {
intrusive_ptr<Expression> pDocument(
Expression::parseObject(&outFieldElement, &objectCtx));
/* add The document expression to the projection */
pProject->addField(outFieldPath, pDocument);
break;
}
default:
uassert(15971, str::stream() <<
"invalid BSON type (" << specType <<
") for " << projectName <<
" field " << outFieldPath, false);
}
}
return pProject;
}
intrusive_ptr<DocumentSource> DocumentSourceProject::createFromBson(
BSONElement *pBsonElement,
const intrusive_ptr<ExpressionContext> &pCtx) {
/* validate */
assert(pBsonElement->type() == Object); // CW TODO user error
/* chain the projection onto the original source */
intrusive_ptr<DocumentSourceProject> pProject(
DocumentSourceProject::create());
/*
Pull out the $project object. This should just be a list of
field inclusion or exclusion specifications. Note you can't do
both, except for the case of _id.
*/
BSONObj projectObj(pBsonElement->Obj());
BSONObjIterator fieldIterator(projectObj);
Expression::ObjectCtx objectCtx(
Expression::ObjectCtx::DOCUMENT_OK);
while(fieldIterator.more()) {
BSONElement outFieldElement(fieldIterator.next());
string outFieldPath(outFieldElement.fieldName());
string inFieldName(outFieldPath);
BSONType specType = outFieldElement.type();
int fieldInclusion = -1;
switch(specType) {
case NumberDouble: {
double inclusion = outFieldElement.numberDouble();
if ((inclusion == 0) || (inclusion == 1))
fieldInclusion = (int)inclusion;
else {
assert(false); // CW TODO unimplemented constant expression
}
goto IncludeExclude;
}
case NumberInt:
/* just a plain integer include/exclude specification */
fieldInclusion = outFieldElement.numberInt();
assert((fieldInclusion >= 0) && (fieldInclusion <= 1));
// CW TODO invalid field projection specification
IncludeExclude:
if (fieldInclusion == 0)
pProject->excludePath(outFieldPath);
else
pProject->includePath(outFieldPath);
break;
case Bool:
/* just a plain boolean include/exclude specification */
fieldInclusion = outFieldElement.Bool() ? 1 : 0;
goto IncludeExclude;
case String:
/* include a field, with rename */
fieldInclusion = 1;
inFieldName = outFieldElement.String();
pProject->addField(
outFieldPath,
ExpressionFieldPath::create(
Expression::removeFieldPrefix(inFieldName)));
break;
case Object: {
intrusive_ptr<Expression> pDocument(
Expression::parseObject(&outFieldElement, &objectCtx));
/* add The document expression to the projection */
pProject->addField(outFieldPath, pDocument);
break;
}
default:
assert(false); // CW TODO invalid field projection specification
}
}
return pProject;
}