Example #1
0
    /* must be same type when called, unless both sides are #s
    */
    int compareElementValues(const BSONElement& l, const BSONElement& r) {
        int f;
        double x;

        switch ( l.type() ) {
        case EOO:
        case Undefined:
        case jstNULL:
        case MaxKey:
        case MinKey:
            f = l.canonicalType() - r.canonicalType();
            if ( f<0 ) return -1;
            return f==0 ? 0 : 1;
        case Bool:
            return *l.value() - *r.value();
        case Timestamp:
        case Date:
            if ( l.date() < r.date() )
                return -1;
            return l.date() == r.date() ? 0 : 1;
        case NumberLong:
            if( r.type() == NumberLong ) {
                long long L = l._numberLong();
                long long R = r._numberLong();
                if( L < R ) return -1;
                if( L == R ) return 0;
                return 1;
            }
            // else fall through
        case NumberInt:
        case NumberDouble: {
            double left = l.number();
            double right = r.number();
            bool lNan = !( left <= numeric_limits< double >::max() &&
                         left >= -numeric_limits< double >::max() );
            bool rNan = !( right <= numeric_limits< double >::max() &&
                         right >= -numeric_limits< double >::max() );
            if ( lNan ) {
                if ( rNan ) {
                    return 0;
                } else {
                    return -1;
                }
            } else if ( rNan ) {
                return 1;
            }
            x = left - right;
            if ( x < 0 ) return -1;
            return x == 0 ? 0 : 1;
            }
        case jstOID:
            return memcmp(l.value(), r.value(), 12);
        case Code:
        case Symbol:
        case String:
            /* todo: utf version */
            return strcmp(l.valuestr(), r.valuestr());
        case Object:
        case Array:
            return l.embeddedObject().woCompare( r.embeddedObject() );
        case DBRef: {
            int lsz = l.valuesize();
            int rsz = r.valuesize();
            if ( lsz - rsz != 0 ) return lsz - rsz;
            return memcmp(l.value(), r.value(), lsz);
        }
        case BinData: {
            int lsz = l.objsize(); // our bin data size in bytes, not including the subtype byte
            int rsz = r.objsize();
            if ( lsz - rsz != 0 ) return lsz - rsz;
            return memcmp(l.value()+4, r.value()+4, lsz+1);
        }
        case RegEx:
        {
            int c = strcmp(l.regex(), r.regex());
            if ( c )
                return c;
            return strcmp(l.regexFlags(), r.regexFlags());
        }
        case CodeWScope : {
            f = l.canonicalType() - r.canonicalType();
            if ( f )
                return f;
            f = strcmp( l.codeWScopeCode() , r.codeWScopeCode() );
            if ( f )
                return f;
            f = strcmp( l.codeWScopeScopeData() , r.codeWScopeScopeData() );
            if ( f )
                return f;
            return 0;
        }
        default:
            out() << "compareElementValues: bad type " << (int) l.type() << endl;
            assert(false);
        }
        return -1;
    }
int BSONElement::compareElements(const BSONElement& l,
                                 const BSONElement& r,
                                 ComparisonRulesSet rules,
                                 const StringData::ComparatorInterface* comparator) {
    switch (l.type()) {
        case BSONType::EOO:
        case BSONType::Undefined:  // EOO and Undefined are same canonicalType
        case BSONType::jstNULL:
        case BSONType::MaxKey:
        case BSONType::MinKey: {
            auto f = l.canonicalType() - r.canonicalType();
            if (f < 0)
                return -1;
            return f == 0 ? 0 : 1;
        }
        case BSONType::Bool:
            return *l.value() - *r.value();
        case BSONType::bsonTimestamp:
            // unsigned compare for timestamps - note they are not really dates but (ordinal +
            // time_t)
            if (l.timestamp() < r.timestamp())
                return -1;
            return l.timestamp() == r.timestamp() ? 0 : 1;
        case BSONType::Date:
            // Signed comparisons for Dates.
            {
                const Date_t a = l.Date();
                const Date_t b = r.Date();
                if (a < b)
                    return -1;
                return a == b ? 0 : 1;
            }

        case BSONType::NumberInt: {
            // All types can precisely represent all NumberInts, so it is safe to simply convert to
            // whatever rhs's type is.
            switch (r.type()) {
                case NumberInt:
                    return compareInts(l._numberInt(), r._numberInt());
                case NumberLong:
                    return compareLongs(l._numberInt(), r._numberLong());
                case NumberDouble:
                    return compareDoubles(l._numberInt(), r._numberDouble());
                case NumberDecimal:
                    return compareIntToDecimal(l._numberInt(), r._numberDecimal());
                default:
                    MONGO_UNREACHABLE;
            }
        }

        case BSONType::NumberLong: {
            switch (r.type()) {
                case NumberLong:
                    return compareLongs(l._numberLong(), r._numberLong());
                case NumberInt:
                    return compareLongs(l._numberLong(), r._numberInt());
                case NumberDouble:
                    return compareLongToDouble(l._numberLong(), r._numberDouble());
                case NumberDecimal:
                    return compareLongToDecimal(l._numberLong(), r._numberDecimal());
                default:
                    MONGO_UNREACHABLE;
            }
        }

        case BSONType::NumberDouble: {
            switch (r.type()) {
                case NumberDouble:
                    return compareDoubles(l._numberDouble(), r._numberDouble());
                case NumberInt:
                    return compareDoubles(l._numberDouble(), r._numberInt());
                case NumberLong:
                    return compareDoubleToLong(l._numberDouble(), r._numberLong());
                case NumberDecimal:
                    return compareDoubleToDecimal(l._numberDouble(), r._numberDecimal());
                default:
                    MONGO_UNREACHABLE;
            }
        }

        case BSONType::NumberDecimal: {
            switch (r.type()) {
                case NumberDecimal:
                    return compareDecimals(l._numberDecimal(), r._numberDecimal());
                case NumberInt:
                    return compareDecimalToInt(l._numberDecimal(), r._numberInt());
                case NumberLong:
                    return compareDecimalToLong(l._numberDecimal(), r._numberLong());
                case NumberDouble:
                    return compareDecimalToDouble(l._numberDecimal(), r._numberDouble());
                default:
                    MONGO_UNREACHABLE;
            }
        }

        case BSONType::jstOID:
            return memcmp(l.value(), r.value(), OID::kOIDSize);
        case BSONType::Code:
            return compareElementStringValues(l, r);
        case BSONType::Symbol:
        case BSONType::String: {
            if (comparator) {
                return comparator->compare(l.valueStringData(), r.valueStringData());
            } else {
                return compareElementStringValues(l, r);
            }
        }
        case BSONType::Object:
        case BSONType::Array: {
            return l.embeddedObject().woCompare(
                r.embeddedObject(),
                BSONObj(),
                rules | BSONElement::ComparisonRules::kConsiderFieldName,
                comparator);
        }
        case BSONType::DBRef: {
            int lsz = l.valuesize();
            int rsz = r.valuesize();
            if (lsz - rsz != 0)
                return lsz - rsz;
            return memcmp(l.value(), r.value(), lsz);
        }
        case BSONType::BinData: {
            int lsz = l.objsize();  // our bin data size in bytes, not including the subtype byte
            int rsz = r.objsize();
            if (lsz - rsz != 0)
                return lsz - rsz;
            return memcmp(l.value() + 4, r.value() + 4, lsz + 1 /*+1 for subtype byte*/);
        }
        case BSONType::RegEx: {
            int c = strcmp(l.regex(), r.regex());
            if (c)
                return c;
            return strcmp(l.regexFlags(), r.regexFlags());
        }
        case BSONType::CodeWScope: {
            int cmp = StringData(l.codeWScopeCode(), l.codeWScopeCodeLen() - 1)
                          .compare(StringData(r.codeWScopeCode(), r.codeWScopeCodeLen() - 1));
            if (cmp)
                return cmp;

            // When comparing the scope object, we should consider field names. Special string
            // comparison semantics do not apply to strings nested inside the CodeWScope scope
            // object, so we do not pass through the string comparator.
            return l.codeWScopeObject().woCompare(
                r.codeWScopeObject(),
                BSONObj(),
                rules | BSONElement::ComparisonRules::kConsiderFieldName);
        }
    }

    MONGO_UNREACHABLE;
}