path: root/src/mongo/db/pipeline/value.cpp

/**
 * 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/>.
 *
 * As a special exception, the copyright holders give permission to link the
 * code of portions of this program with the OpenSSL library under certain
 * conditions as described in each individual source file and distribute
 * linked combinations including the program with the OpenSSL library. You
 * must comply with the GNU Affero General Public License in all respects for
 * all of the code used other than as permitted herein. If you modify file(s)
 * with this exception, you may extend this exception to your version of the
 * file(s), but you are not obligated to do so. If you do not wish to do so,
 * delete this exception statement from your version. If you delete this
 * exception statement from all source files in the program, then also delete
 * it in the license file.
 */

#include "mongo/pch.h"

#include "mongo/db/pipeline/value.h"

#include <boost/functional/hash.hpp>

#include "mongo/db/jsobj.h"
#include "mongo/db/pipeline/document.h"
#include "mongo/util/mongoutils/str.h"

namespace mongo {
    using namespace mongoutils;

    void ValueStorage::verifyRefCountingIfShould() const {
        switch (type) {
        case MinKey:
        case MaxKey:
        case jstOID:
        case Date:
        case Timestamp:
        case EOO:
        case jstNULL:
        case Undefined:
        case Bool:
        case NumberInt:
        case NumberLong:
        case NumberDouble:
            // the above types never reference external data
            verify(!refCounter);
            break;

        case String:
        case RegEx:
        case Code:
        case Symbol:
            // the above types reference data when not using short-string optimization
            verify(refCounter == !shortStr);
            break;

        case BinData: // TODO this should probably support short-string optimization
        case Array: // TODO this should probably support empty-is-NULL optimization
        case DBRef:
        case CodeWScope:
            // the above types always reference external data.
            verify(refCounter);
            verify(bool(genericRCPtr));
            break;

        case Object:
            // Objects either hold a NULL ptr or should be ref-counting
            verify(refCounter == bool(genericRCPtr));
            break;
        }
    }

    void ValueStorage::putString(const StringData& s) {
        // Note: this also stores data portion of BinData
        const size_t sizeNoNUL = s.size();
        if (sizeNoNUL <= sizeof(shortStrStorage)) {
            shortStr = true;
            shortStrSize = s.size();
            s.copyTo(shortStrStorage, false); // no NUL

            // All memory is zeroed before this is called.
            // Note this may be past end of shortStrStorage and into nulTerminator
            dassert(shortStrStorage[sizeNoNUL] == '\0');
        }
        else {
            putRefCountable(RCString::create(s));
        }
    }

    void ValueStorage::putDocument(const Document& d) {
        putRefCountable(d._storage);
    }

    void ValueStorage::putVector(const RCVector* vec) {
        fassert(16485, vec);
        putRefCountable(vec);
    }

    void ValueStorage::putRegEx(const BSONRegEx& re) {
        const size_t patternLen = re.pattern.size();
        const size_t flagsLen = re.flags.size();
        const size_t totalLen = patternLen + 1/*middle NUL*/ + flagsLen;

        // Need to copy since putString doesn't support scatter-gather.
        boost::scoped_array<char> buf (new char[totalLen]);
        re.pattern.copyTo(buf.get(), true);
        re.flags.copyTo(buf.get() + patternLen + 1, false); // no NUL
        putString(StringData(buf.get(), totalLen));
    }

    Document ValueStorage::getDocument() const {
        if (!genericRCPtr)
            return Document();

        dassert(typeid(*genericRCPtr) == typeid(const DocumentStorage));
        const DocumentStorage* documentPtr = static_cast<const DocumentStorage*>(genericRCPtr);
        return Document(documentPtr);
    }

    // not in header because document is fwd declared
    Value::Value(const BSONObj& obj) : _storage(Object, Document(obj)) {}

    Value::Value(const BSONElement& elem) : _storage(elem.type()) {
        switch(elem.type()) {
        // These are all type-only, no data
        case EOO:
        case MinKey:
        case MaxKey:
        case Undefined:
        case jstNULL:
            break;

        case NumberDouble:
            _storage.doubleValue = elem.Double();
            break;

        case Code:
        case Symbol:
        case String:
            _storage.putString(StringData(elem.valuestr(), elem.valuestrsize()-1));
            break;

        case Object: {
            _storage.putDocument(Document(elem.embeddedObject()));
            break;
        }

        case Array: {
            intrusive_ptr<RCVector> vec (new RCVector);
            BSONForEach(sub, elem.embeddedObject()) {
                vec->vec.push_back(Value(sub));
            }
            _storage.putVector(vec.get());
            break;
        }

        case jstOID:
            BOOST_STATIC_ASSERT(sizeof(_storage.oid) == sizeof(OID));
            memcpy(_storage.oid, elem.OID().getData(), sizeof(OID));
            break;

        case Bool:
            _storage.boolValue = elem.boolean();
            break;

        case Date:
            // this is really signed but typed as unsigned for historical reasons
            _storage.dateValue = static_cast<long long>(elem.date().millis);
            break;

        case RegEx: {
            _storage.putRegEx(BSONRegEx(elem.regex(), elem.regexFlags()));
            break;
        }

        case NumberInt:
            _storage.intValue = elem.numberInt();
            break;

        case Timestamp:
            // asDate is a poorly named function that returns a ReplTime
            _storage.timestampValue = elem._opTime().asDate();
            break;

        case NumberLong:
            _storage.longValue = elem.numberLong();
            break;

        case CodeWScope: {
            StringData code (elem.codeWScopeCode(), elem.codeWScopeCodeLen()-1);
            _storage.putCodeWScope(BSONCodeWScope(code, elem.codeWScopeObject()));
            break;
        }

        case BinData: {
            int len;
            const char* data = elem.binData(len);
            _storage.putBinData(BSONBinData(data, len, elem.binDataType()));
            break;
        }

        case DBRef:
            _storage.putDBRef(BSONDBRef(elem.dbrefNS(), elem.dbrefOID()));
            break;
        }
    }

    Value::Value(const BSONArray& arr) : _storage(Array) {
        intrusive_ptr<RCVector> vec (new RCVector);
        BSONForEach(sub, arr) {
            vec->vec.push_back(Value(sub));
        }
        _storage.putVector(vec.get());
    }

    Value Value::createIntOrLong(long long longValue) {
        int intValue = longValue;
        if (intValue != longValue) {
            // it is too large to be an int and should remain a long
            return Value(longValue);
        }

        // should be an int since all arguments were int and it fits
        return Value(intValue);
    }

    double Value::getDouble() const {
        BSONType type = getType();
        if (type == NumberInt)
            return _storage.intValue;
        if (type == NumberLong)
            return static_cast< double >( _storage.longValue );

        verify(type == NumberDouble);
        return _storage.doubleValue;
    }

    Document Value::getDocument() const {
        verify(getType() == Object);
        return _storage.getDocument();
    }

    Value Value::operator[] (size_t index) const {
        if (getType() != Array || index >= getArrayLength())
            return Value();

        return getArray()[index];
    }

    Value Value::operator[] (StringData name) const {
        if (getType() != Object)
            return Value();

        return getDocument()[name];
    }

    BSONObjBuilder& operator << (BSONObjBuilderValueStream& builder, const Value& val) {
        switch(val.getType()) {
        case EOO:          return builder.builder(); // nothing appended
        case MinKey:       return builder << MINKEY;
        case MaxKey:       return builder << MAXKEY;
        case jstNULL:      return builder << BSONNULL;
        case Undefined:    return builder << BSONUndefined;
        case jstOID:       return builder << val.getOid();
        case NumberInt:    return builder << val.getInt();
        case NumberLong:   return builder << val.getLong();
        case NumberDouble: return builder << val.getDouble();
        case String:       return builder << val.getStringData();
        case Bool:         return builder << val.getBool();
        case Date:         return builder << Date_t(val.getDate());
        case Timestamp:    return builder << val.getTimestamp();
        case Object:       return builder << val.getDocument();
        case Symbol:       return builder << BSONSymbol(val.getStringData());
        case Code:         return builder << BSONCode(val.getStringData());
        case RegEx:        return builder << BSONRegEx(val.getRegex(), val.getRegexFlags());

        case DBRef:
            return builder << BSONDBRef(val._storage.getDBRef()->ns, val._storage.getDBRef()->oid);

        case BinData:
            return builder << BSONBinData(val.getStringData().rawData(), // looking for void*
                                          val.getStringData().size(),
                                          val._storage.binDataType());

        case CodeWScope:
            return builder << BSONCodeWScope(val._storage.getCodeWScope()->code,
                                             val._storage.getCodeWScope()->scope);

        case Array: {
            const vector<Value>& array = val.getArray();
            const size_t n = array.size();
            BSONArrayBuilder arrayBuilder(builder.subarrayStart());
            for(size_t i = 0; i < n; i++) {
                array[i].addToBsonArray(&arrayBuilder);
            }
            arrayBuilder.doneFast();
            return builder.builder();
        }
        }
        verify(false);
    }

    void Value::addToBsonObj(BSONObjBuilder* pBuilder, StringData fieldName) const {
        *pBuilder << fieldName << *this;
    }

    void Value::addToBsonArray(BSONArrayBuilder* pBuilder) const {
        if (!missing()) { // don't want to increment builder's counter
            *pBuilder << *this;
        }
    }

    bool Value::coerceToBool() const {
        // TODO Unify the implementation with BSONElement::trueValue().
        switch(getType()) {
        case CodeWScope:
        case MinKey:
        case DBRef:
        case Code:
        case MaxKey:
        case String:
        case Object:
        case Array:
        case BinData:
        case jstOID:
        case Date:
        case RegEx:
        case Symbol:
        case Timestamp:
            return true;

        case EOO:
        case jstNULL:
        case Undefined:
            return false;

        case Bool: return _storage.boolValue;
        case NumberInt: return _storage.intValue;
        case NumberLong: return _storage.longValue;
        case NumberDouble: return _storage.doubleValue;
        }
        verify(false);
    }

    int Value::coerceToInt() const {
        switch(getType()) {
        case NumberInt:
            return _storage.intValue;

        case NumberLong:
            return static_cast<int>(_storage.longValue);

        case NumberDouble:
            return static_cast<int>(_storage.doubleValue);

        default:
            uassert(16003, str::stream() <<
                    "can't convert from BSON type " << typeName(getType()) <<
                    " to int",
                    false);
        } // switch(getType())
    }

    long long Value::coerceToLong() const {
        switch(getType()) {
        case NumberLong:
            return _storage.longValue;

        case NumberInt:
            return static_cast<long long>(_storage.intValue);

        case NumberDouble:
            return static_cast<long long>(_storage.doubleValue);

        default:
            uassert(16004, str::stream() <<
                    "can't convert from BSON type " << typeName(getType()) <<
                    " to long",
                    false);
        } // switch(getType())
    }

    double Value::coerceToDouble() const {
        switch(getType()) {
        case NumberDouble:
            return _storage.doubleValue;

        case NumberInt:
            return static_cast<double>(_storage.intValue);

        case NumberLong:
            return static_cast<double>(_storage.longValue);

        default:
            uassert(16005, str::stream() <<
                    "can't convert from BSON type " << typeName(getType()) <<
                    " to double",
                    false);
        } // switch(getType())
    }

    long long Value::coerceToDate() const {
        switch(getType()) {
        case Date:
            return getDate();

        case Timestamp:
            return getTimestamp().getSecs() * 1000LL;

        default:
            uassert(16006, str::stream() <<
                    "can't convert from BSON type " << typeName(getType()) << " to Date",
                    false);
        } // switch(getType())
    }

    time_t Value::coerceToTimeT() const {
        long long millis = coerceToDate();
        if (millis < 0) {
            // We want the division below to truncate toward -inf rather than 0
            // eg Dec 31, 1969 23:59:58.001 should be -2 seconds rather than -1
            // This is needed to get the correct values from coerceToTM
            if ( -1999 / 1000 != -2) { // this is implementation defined
                millis -= 1000-1;
            }
        }
        const long long seconds = millis / 1000;

        uassert(16421, "Can't handle date values outside of time_t range",
               seconds >= std::numeric_limits<time_t>::min() &&
               seconds <= std::numeric_limits<time_t>::max());

        return static_cast<time_t>(seconds);
    }
    tm Value::coerceToTm() const {
        // See implementation in Date_t.
        // Can't reuse that here because it doesn't support times before 1970
        time_t dtime = coerceToTimeT();
        tm out;

#if defined(_WIN32) // Both the argument order and the return values differ
        bool itWorked = gmtime_s(&out, &dtime) == 0;
#else
        bool itWorked = gmtime_r(&dtime, &out) != NULL;
#endif

        if (!itWorked) {
            if (dtime < 0) {
                // Windows docs say it doesn't support these, but empirically it seems to work
                uasserted(16422, "gmtime failed - your system doesn't support dates before 1970");
            }
            else {
                uasserted(16423, str::stream() << "gmtime failed to convert time_t of " << dtime);
            }
        }

        return out;
    }

    static string tmToISODateString(const tm& time) {
        char buf[128];
        size_t len = strftime(buf, 128, "%Y-%m-%dT%H:%M:%S", &time);
        verify(len > 0);
        verify(len < 128);
        return buf;
    }

    string Value::coerceToString() const {
        stringstream ss;
        switch(getType()) {
        case NumberDouble:
            ss << _storage.doubleValue;
            return ss.str();

        case NumberInt:
            ss << _storage.intValue;
            return ss.str();

        case NumberLong:
            ss << _storage.longValue;
            return ss.str();

        case Code:
        case Symbol:
        case String:
            return getStringData().toString();

        case Timestamp:
            ss << getTimestamp().toStringPretty();
            return ss.str();

        case Date:
            return tmToISODateString(coerceToTm());

        case EOO:
        case jstNULL:
        case Undefined:
            return "";

        default:
            uassert(16007, str::stream() <<
                    "can't convert from BSON type " << typeName(getType()) <<
                    " to String",
                    false);
        } // switch(getType())
    }

    OpTime Value::coerceToTimestamp() const {
        switch(getType()) {
        case Timestamp:
            return getTimestamp();

        default:
            uassert(16378, str::stream() <<
                    "can't convert from BSON type " << typeName(getType()) <<
                    " to timestamp",
                    false);
        } // switch(getType())
    }

    // Helper function for Value::compare.
    // Better than l-r for cases where difference > MAX_INT
    template <typename T>
    inline static int cmp(const T& left, const T& right) {
        if (left < right) {
            return -1;
        }
        else if (left == right) {
            return 0;
        }
        else {
            dassert(left > right);
            return 1;
        }
    }

    // Special case for double since it needs special NaN handling
    inline static int cmp(double left, double right) {
        // The following is lifted directly from compareElementValues
        // to ensure identical handling of NaN
        if (left < right) 
            return -1;
        if (left == right)
            return 0;
        if (isNaN(left))
            return isNaN(right) ? 0 : -1;
        return 1;
    }

    int Value::compare(const Value& rL, const Value& rR) {
        // Note, this function needs to behave identically to BSON's compareElementValues().
        // Additionally, any changes here must be replicated in hash_combine().
        BSONType lType = rL.getType();
        BSONType rType = rR.getType();

        int ret = lType == rType
                    ? 0 // fast-path common case
                    : cmp(canonicalizeBSONType(lType),
                          canonicalizeBSONType(rType));

        if (ret)
            return ret;

        switch(lType) {
        // Order of types is the same as in compareElementValues() to make it easier to verify

        // These are valueless types
        case EOO:
        case Undefined:
        case jstNULL:
        case MaxKey:
        case MinKey:
            return ret;

        case Bool:
            return rL.getBool() - rR.getBool();

        // WARNING: Timestamp and Date have same canonical type, but compare differently.
        // Maintaining behavior from normal BSON.
        case Timestamp: // unsigned
            return cmp(rL._storage.timestampValue, rR._storage.timestampValue);
        case Date: // signed
            return cmp(rL._storage.dateValue, rR._storage.dateValue);

        // Numbers should compare by equivalence even if different types
        case NumberLong:
        case NumberInt:
        case NumberDouble:
            switch (getWidestNumeric(lType, rType)) {
            case NumberDouble: return cmp(rL.getDouble(), rR.getDouble());
            case NumberLong:   return cmp(rL.getLong(),   rR.getLong());
            case NumberInt:    return cmp(rL.getInt(),    rR.getInt());
            default: verify(false);
            }

        case jstOID:
            return memcmp(rL._storage.oid, rR._storage.oid, sizeof(OID));

        case Code:
        case Symbol:
        case String:
            return rL.getStringData().compare(rR.getStringData());

        case Object:
            return Document::compare(rL.getDocument(), rR.getDocument());

        case Array: {
            const vector<Value>& lArr = rL.getArray();
            const vector<Value>& rArr = rR.getArray();

            const size_t elems = min(lArr.size(), rArr.size());
            for (size_t i = 0; i < elems; i++ ) {
                // compare the two corresponding elements
                ret = Value::compare(lArr[i], rArr[i]);
                if (ret)
                    return ret; // values are unequal
            }

            // if we get here we are either equal or one is prefix of the other 
            return cmp(lArr.size(), rArr.size());
        }

        case DBRef: {
            intrusive_ptr<const RCDBRef> l = rL._storage.getDBRef();
            intrusive_ptr<const RCDBRef> r = rR._storage.getDBRef();
            ret = cmp(l->ns.size(), r->ns.size());
            if (ret)
                return ret;

            return l->oid.compare(r->oid);
        }

        case BinData: {
            ret = cmp(rL.getStringData().size(), rR.getStringData().size());
            if (ret)
                return ret;

            // Need to compare as an unsigned char rather than enum since BSON uses memcmp
            ret = cmp(rL._storage.binSubType, rR._storage.binSubType);
            if (ret)
                return ret;

            return rL.getStringData().compare(rR.getStringData());
        }

        case RegEx: // same as String in this impl but keeping order same as compareElementValues
            return rL.getStringData().compare(rR.getStringData());

        case CodeWScope: {
            // This case crazy, but identical to how they are compared in BSON (SERVER-7804)

            intrusive_ptr<const RCCodeWScope> l = rL._storage.getCodeWScope();
            intrusive_ptr<const RCCodeWScope> r = rR._storage.getCodeWScope();

            // This triggers two bugs in codeWScope.
            // Since this is a very rare case I'm not handling it here.
            uassert(16557, "can't compare CodeWScope values containing a NUL byte in the code.",
                    strlen(l->code.c_str()) == l->code.size()
                 && strlen(r->code.c_str()) == r->code.size());

            ret = l->code.compare(r->code);
            if (ret)
                return ret;

            // SERVER-7804
            return strcmp(l->scope.objdata(), r->scope.objdata());
        }
        }
        verify(false);
    }

    void Value::hash_combine(size_t &seed) const {
        BSONType type = getType();

        boost::hash_combine(seed, canonicalizeBSONType(type));

        switch (type) {
        // Order of types is the same as in Value::compare() and compareElementValues().

        // These are valueless types
        case EOO:
        case Undefined:
        case jstNULL:
        case MaxKey:
        case MinKey:
            return;

        case Bool:
            boost::hash_combine(seed, getBool());
            break;

        case Timestamp:
        case Date:
            BOOST_STATIC_ASSERT(sizeof(_storage.dateValue) == sizeof(_storage.timestampValue));
            boost::hash_combine(seed, _storage.dateValue);
            break;

            /*
              Numbers whose values are equal need to hash to the same thing
              as well.  Note that Value::compare() promotes numeric values to
              their largest common form in order for comparisons to work.
              We must hash all numeric values as if they are doubles so that
              things like grouping work.  We don't know what values will come
              down the pipe later, but if we start out with int representations
              of a value, and later see double representations of it, they need
              to end up in the same buckets.
             */
        case NumberDouble:
        case NumberLong:
        case NumberInt: {
            const double dbl = getDouble();
            if (isNaN(dbl)) {
                boost::hash_combine(seed, numeric_limits<double>::quiet_NaN());
            }
            else {
                boost::hash_combine(seed, dbl);
            }
            break;
        }

        case jstOID:
            getOid().hash_combine(seed);
            break;

        case Code:
        case Symbol:
        case String: {
            StringData sd = getStringData();
            MurmurHash3_x86_32(sd.rawData(), sd.size(), seed, &seed);
            break;
        }

        case Object:
            getDocument().hash_combine(seed);
            break;

        case Array: {
            const vector<Value>& vec = getArray();
            for (size_t i=0; i < vec.size(); i++)
                vec[i].hash_combine(seed);
            break;
        }

        case DBRef:
            boost::hash_combine(seed, _storage.getDBRef()->ns);
            _storage.getDBRef()->oid.hash_combine(seed);
            break;


        case BinData: {
            StringData sd = getStringData();
            MurmurHash3_x86_32(sd.rawData(), sd.size(), seed, &seed);
            boost::hash_combine(seed, _storage.binDataType());
            break;
        }

        case RegEx: {
            StringData sd = getStringData();
            MurmurHash3_x86_32(sd.rawData(), sd.size(), seed, &seed);
            break;
        }

        case CodeWScope: {
            // SERVER-7804
            const char * code = _storage.getCodeWScope()->code.c_str();
            boost::hash_range(seed, code, (code + strlen(code)));
            // Not going to bother hashing scope. Too many edge cases. Will fall back to
            // Value::compare when code is same, so this is ok.
            break;
        }
        }
    }

    BSONType Value::getWidestNumeric(BSONType lType, BSONType rType) {
        if (lType == NumberDouble) {
            switch(rType) {
            case NumberDouble:
            case NumberLong:
            case NumberInt:
                return NumberDouble;

            default:
                break;
            }
        }
        else if (lType == NumberLong) {
            switch(rType) {
            case NumberDouble:
                return NumberDouble;

            case NumberLong:
            case NumberInt:
                return NumberLong;

            default:
                break;
            }
        }
        else if (lType == NumberInt) {
            switch(rType) {
            case NumberDouble:
                return NumberDouble;

            case NumberLong:
                return NumberLong;

            case NumberInt:
                return NumberInt;

            default:
                break;
            }
        }

        // Reachable, but callers must subsequently err out in this case.
        return Undefined;
    }

    size_t Value::getApproximateSize() const {
        switch(getType()) {
        case Code:
        case RegEx:
        case Symbol:
        case BinData:
        case String:
            return sizeof(Value) + (_storage.shortStr
                                        ? 0 // string stored inline, so no extra mem usage
                                        : sizeof(RCString) + _storage.getString().size());

        case Object:
            return sizeof(Value) + getDocument().getApproximateSize();

        case Array: {
            size_t size = sizeof(Value);
            size += sizeof(RCVector);
            const size_t n = getArray().size();
            for(size_t i = 0; i < n; ++i) {
                size += getArray()[i].getApproximateSize();
            }
            return size;
        }

        case CodeWScope:
            return sizeof(Value) + sizeof(RCCodeWScope) + _storage.getCodeWScope()->code.size()
                                                        + _storage.getCodeWScope()->scope.objsize();

        case DBRef:
            return sizeof(Value) + sizeof(RCDBRef) + _storage.getDBRef()->ns.size();

        // These types are always contained within the Value
        case EOO:
        case MinKey:
        case MaxKey:
        case NumberDouble:
        case jstOID:
        case Bool:
        case Date:
        case NumberInt:
        case Timestamp:
        case NumberLong:
        case jstNULL:
        case Undefined:
            return sizeof(Value);
        }
        verify(false);
    }

    string Value::toString() const {
        // TODO use StringBuilder when operator << is ready
        stringstream out;
        out << *this;
        return out.str();
    }

    ostream& operator << (ostream& out, const Value& val) {
        switch(val.getType()) {
        case EOO: return out << "MISSING";
        case MinKey: return out << "MinKey";
        case MaxKey: return out << "MaxKey";
        case jstOID: return out << val.getOid();
        case String: return out << '"' << val.getString() << '"';
        case RegEx: return out << '/' << val.getRegex() << '/' << val.getRegexFlags();
        case Symbol: return out << "Symbol(\"" << val.getSymbol() << "\")";
        case Code: return out << "Code(\"" << val.getCode() << "\")";
        case Bool: return out << (val.getBool() ? "true" : "false");
        case NumberDouble: return out << val.getDouble();
        case NumberLong: return out << val.getLong();
        case NumberInt: return out << val.getInt();
        case jstNULL: return out << "null";
        case Undefined: return out << "undefined";
        case Date: return out << tmToISODateString(val.coerceToTm());
        case Timestamp: return out << val.getTimestamp().toString();
        case Object: return out << val.getDocument().toString();
        case Array: {
            out << "[";
            const size_t n = val.getArray().size();
            for(size_t i = 0; i < n; i++) {
                if (i)
                    out << ", ";
                out << val.getArray()[i];
            }
            out << "]";
            return out;
        }

        case CodeWScope:
            return out << "CodeWScope(\"" << val._storage.getCodeWScope()->code << "\", "
                                          << val._storage.getCodeWScope()->scope << ')';

        case BinData: 
            return out << "BinData(" << val._storage.binDataType() << ", \""
                                     << toHex(val._storage.getString().rawData()
                                             ,val._storage.getString().size())
                                     << "\")";

        case DBRef:
            return out << "DBRef(\"" << val._storage.getDBRef()->ns << "\", "
                                     << val._storage.getDBRef()->oid << ')';
        }

        // Not in default case to trigger better warning if a case is missing
        verify(false);
    }

    void Value::serializeForSorter(BufBuilder& buf) const {
        buf.appendChar(getType());
        switch(getType()) {
        // type-only types
        case EOO:
        case MinKey:
        case MaxKey:
        case jstNULL:
        case Undefined:
            break;

        // simple types
        case jstOID:       buf.appendStruct(_storage.oid); break;
        case NumberInt:    buf.appendNum(_storage.intValue); break;
        case NumberLong:   buf.appendNum(_storage.longValue); break;
        case NumberDouble: buf.appendNum(_storage.doubleValue); break;
        case Bool:         buf.appendChar(_storage.boolValue); break;
        case Date:         buf.appendNum(_storage.dateValue); break;
        case Timestamp:    buf.appendStruct(getTimestamp()); break;

        // types that are like strings
        case String:
        case Symbol:
        case Code: {
            StringData str = getStringData();
            buf.appendNum(int(str.size()));
            buf.appendStr(str, /*NUL byte*/ false);
            break;
        }

        case BinData: {
            StringData str = getStringData();
            buf.appendChar(_storage.binDataType());
            buf.appendNum(int(str.size()));
            buf.appendStr(str, /*NUL byte*/ false);
            break;
        }

        case RegEx:
            buf.appendStr(getRegex(), /*NUL byte*/ true);
            buf.appendStr(getRegexFlags(), /*NUL byte*/ true);
            break;

        case Object:
            getDocument().serializeForSorter(buf);
            break;

        case DBRef:
            buf.appendStruct(_storage.getDBRef()->oid);
            buf.appendStr(_storage.getDBRef()->ns, /*NUL byte*/ true);
            break;

        case CodeWScope: {
            intrusive_ptr<const RCCodeWScope> cws = _storage.getCodeWScope();
            buf.appendNum(int(cws->code.size()));
            buf.appendStr(cws->code, /*NUL byte*/ false);
            cws->scope.serializeForSorter(buf);
            break;
         }

        case Array: {
            const vector<Value>& array = getArray();
            const int numElems = array.size();
            buf.appendNum(numElems);
            for (int i = 0; i < numElems; i++)
                array[i].serializeForSorter(buf);
            break;
        }
        }
    }

    Value Value::deserializeForSorter(BufReader& buf, const SorterDeserializeSettings& settings) {
        const BSONType type = BSONType(buf.read<signed char>()); // need sign extension for MinKey
        switch(type) {
        // type-only types
        case EOO:
        case MinKey:
        case MaxKey:
        case jstNULL:
        case Undefined:
            return Value(ValueStorage(type));

        // simple types
        case jstOID:       return Value(buf.read<OID>());
        case NumberInt:    return Value(buf.read<int>());
        case NumberLong:   return Value(buf.read<long long>());
        case NumberDouble: return Value(buf.read<double>());
        case Bool:         return Value(bool(buf.read<char>()));
        case Date:         return Value(Date_t(buf.read<long long>()));
        case Timestamp:    return Value(buf.read<OpTime>());

        // types that are like strings
        case String:
        case Symbol:
        case Code: {
            int size = buf.read<int>();
            const char* str = static_cast<const char*>(buf.skip(size));
            return Value(ValueStorage(type, StringData(str, size)));
        }

        case BinData: {
            BinDataType bdt = BinDataType(buf.read<char>());
            int size = buf.read<int>();
            const void* data = buf.skip(size);
            return Value(BSONBinData(data, size, bdt));
        }

        case RegEx: {
            StringData regex = buf.readCStr();
            StringData flags = buf.readCStr();
            return Value(BSONRegEx(regex, flags));
        }

        case Object:
            return Value(Document::deserializeForSorter(buf,
                                                        Document::SorterDeserializeSettings()));

        case DBRef: {
            OID oid = buf.read<OID>();
            StringData ns = buf.readCStr();
            return Value(BSONDBRef(ns, oid));
        }

        case CodeWScope: {
            int size = buf.read<int>();
            const char* str = static_cast<const char*>(buf.skip(size));
            BSONObj bson = BSONObj::deserializeForSorter(buf, BSONObj::SorterDeserializeSettings());
            return Value(BSONCodeWScope(StringData(str, size), bson));
         }

        case Array: {
            const int numElems = buf.read<int>();
            vector<Value> array;
            array.reserve(numElems);
            for (int i = 0; i < numElems; i++)
                array.push_back(deserializeForSorter(buf, settings));
            return Value::consume(array);
        }
        }
        verify(false);
    }
}