mongodb/scripting/v8_wrapper.cpp

// v8_wrapper.cpp

/*    Copyright 2009 10gen Inc.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

#include "v8_wrapper.h"
#include "v8_utils.h"
#include "v8_db.h"

#include <iostream>

using namespace std;
using namespace v8;

namespace mongo {

#define CONN_STRING (v8::String::New( "_conn" ))

#define DDD(x)

    Handle<Value> NamedReadOnlySet( Local<v8::String> property, Local<Value> value, const AccessorInfo& info ) {
        cout << "cannot write to read-only object" << endl;
        return value;
    }

    Handle<Boolean> NamedReadOnlyDelete( Local<v8::String> property, const AccessorInfo& info ) {
        cout << "cannot delete from read-only object" << endl;
        return Boolean::New( false );
    }

    Handle<Value> IndexedReadOnlySet( uint32_t index, Local<Value> value, const AccessorInfo& info ) {
        cout << "cannot write to read-only array" << endl;
        return value;
    }

    Handle<Boolean> IndexedReadOnlyDelete( uint32_t index, const AccessorInfo& info ) {
        cout << "cannot delete from read-only array" << endl;
        return Boolean::New( false );
    }

    Local< v8::Value > newFunction( const char *code ) {
        stringstream codeSS;
        codeSS << "____MontoToV8_newFunction_temp = " << code;
        string codeStr = codeSS.str();
        Local< Script > compiled = Script::New( v8::String::New( codeStr.c_str() ) );
        Local< Value > ret = compiled->Run();
        return ret;
    }

    Local< v8::Value > newId( const OID &id ) {
        v8::Function * idCons = getObjectIdCons();
        v8::Handle<v8::Value> argv[1];
        argv[0] = v8::String::New( id.str().c_str() );
        return idCons->NewInstance( 1 , argv );
    }

    Local<v8::Object> mongoToV8( const BSONObj& m , bool array, bool readOnly ) {

        Local<v8::Object> o;

        // handle DBRef. needs to come first. isn't it? (metagoto)
        static string ref = "$ref";
        if ( ref == m.firstElement().fieldName() ) {
            const BSONElement& id = m["$id"];
            if (!id.eoo()) { // there's no check on $id exitence in sm implementation. risky ?
                v8::Function* dbRef = getNamedCons( "DBRef" );
                o = dbRef->NewInstance();
            }
        }

        Local< v8::ObjectTemplate > readOnlyObjects;
        // Hoping template construction is fast...
        Local< v8::ObjectTemplate > internalFieldObjects = v8::ObjectTemplate::New();
        internalFieldObjects->SetInternalFieldCount( 1 );

        if ( !o.IsEmpty() ) {
            readOnly = false;
        }
        else if ( array ) {
            // NOTE Looks like it's impossible to add interceptors to v8 arrays.
            readOnly = false;
            o = v8::Array::New();
        }
        else if ( !readOnly ) {
            o = v8::Object::New();
        }
        else {
            // NOTE Our readOnly implemention relies on undocumented ObjectTemplate
            // functionality that may be fragile, but it still seems like the best option
            // for now -- fwiw, the v8 docs are pretty sparse.  I've determined experimentally
            // that when property handlers are set for an object template, they will attach
            // to objects previously created by that template.  To get this to work, though,
            // it is necessary to initialize the template's property handlers before
            // creating objects from the template (as I have in the following few lines
            // of code).
            // NOTE In my first attempt, I configured the permanent property handlers before
            // constructiong the object and replaced the Set() calls below with ForceSet().
            // However, it turns out that ForceSet() only bypasses handlers for named
            // properties and not for indexed properties.
            readOnlyObjects = v8::ObjectTemplate::New();
            // NOTE This internal field will store type info for special db types.  For
            // regular objects the field is unnecessary - for simplicity I'm creating just
            // one readOnlyObjects template for objects where the field is & isn't necessary,
            // assuming that the overhead of an internal field is slight.
            readOnlyObjects->SetInternalFieldCount( 1 );
            readOnlyObjects->SetNamedPropertyHandler( 0 );
            readOnlyObjects->SetIndexedPropertyHandler( 0 );
            o = readOnlyObjects->NewInstance();
        }

        mongo::BSONObj sub;

        for ( BSONObjIterator i(m); i.more(); ) {
            const BSONElement& f = i.next();

            Local<Value> v;

            switch ( f.type() ) {

            case mongo::Code:
                o->Set( v8::String::New( f.fieldName() ), newFunction( f.valuestr() ) );
                break;

            case CodeWScope:
                if ( f.codeWScopeObject().isEmpty() )
                    log() << "warning: CodeWScope doesn't transfer to db.eval" << endl;
                o->Set( v8::String::New( f.fieldName() ), newFunction( f.codeWScopeCode() ) );
                break;

            case mongo::String:
                o->Set( v8::String::New( f.fieldName() ) , v8::String::New( f.valuestr() ) );
                break;

            case mongo::jstOID: {
                v8::Function * idCons = getObjectIdCons();
                v8::Handle<v8::Value> argv[1];
                argv[0] = v8::String::New( f.__oid().str().c_str() );
                o->Set( v8::String::New( f.fieldName() ) ,
                        idCons->NewInstance( 1 , argv ) );
                break;
            }

            case mongo::NumberDouble:
            case mongo::NumberInt:
                o->Set( v8::String::New( f.fieldName() ) , v8::Number::New( f.number() ) );
                break;

            case mongo::Array:
            case mongo::Object:
                sub = f.embeddedObject();
                o->Set( v8::String::New( f.fieldName() ) , mongoToV8( sub , f.type() == mongo::Array, readOnly ) );
                break;

            case mongo::Date:
                o->Set( v8::String::New( f.fieldName() ) , v8::Date::New( f.date() ) );
                break;

            case mongo::Bool:
                o->Set( v8::String::New( f.fieldName() ) , v8::Boolean::New( f.boolean() ) );
                break;

            case mongo::jstNULL:
            case mongo::Undefined: // duplicate sm behavior
                o->Set( v8::String::New( f.fieldName() ) , v8::Null() );
                break;

            case mongo::RegEx: {
                v8::Function * regex = getNamedCons( "RegExp" );

                v8::Handle<v8::Value> argv[2];
                argv[0] = v8::String::New( f.regex() );
                argv[1] = v8::String::New( f.regexFlags() );

                o->Set( v8::String::New( f.fieldName() ) , regex->NewInstance( 2 , argv ) );
                break;
            }

            case mongo::BinData: {
                Local<v8::Object> b = readOnly ? readOnlyObjects->NewInstance() : internalFieldObjects->NewInstance();

                int len;
                const char *data = f.binData( len );

                v8::Function* binData = getNamedCons( "BinData" );
                v8::Handle<v8::Value> argv[3];
                argv[0] = v8::Number::New( len );
                argv[1] = v8::Number::New( f.binDataType() );
                argv[2] = v8::String::New( data, len );
                o->Set( v8::String::New( f.fieldName() ), binData->NewInstance(3, argv) );
                break;
            }

            case mongo::Timestamp: {
                Local<v8::Object> sub = readOnly ? readOnlyObjects->NewInstance() : internalFieldObjects->NewInstance();

                sub->Set( v8::String::New( "t" ) , v8::Number::New( f.timestampTime() ) );
                sub->Set( v8::String::New( "i" ) , v8::Number::New( f.timestampInc() ) );
                sub->SetInternalField( 0, v8::Uint32::New( f.type() ) );

                o->Set( v8::String::New( f.fieldName() ) , sub );
                break;
            }

            case mongo::NumberLong: {
                Local<v8::Object> sub = readOnly ? readOnlyObjects->NewInstance() : internalFieldObjects->NewInstance();
                unsigned long long val = f.numberLong();
                v8::Function* numberLong = getNamedCons( "NumberLong" );
                if ( (long long)val == (long long)(double)(long long)(val) ) {
                    v8::Handle<v8::Value> argv[1];
                    argv[0] = v8::Number::New( (double)(long long)( val ) );
                    o->Set( v8::String::New( f.fieldName() ), numberLong->NewInstance( 1, argv ) );
                }
                else {
                    v8::Handle<v8::Value> argv[3];
                    argv[0] = v8::Number::New( (double)(long long)(val) );
                    argv[1] = v8::Integer::New( val >> 32 );
                    argv[2] = v8::Integer::New( (unsigned long)(val & 0x00000000ffffffff) );
                    o->Set( v8::String::New( f.fieldName() ), numberLong->NewInstance(3, argv) );
                }
                break;
            }

            case mongo::MinKey: {
                Local<v8::Object> sub = readOnly ? readOnlyObjects->NewInstance() : internalFieldObjects->NewInstance();
                sub->Set( v8::String::New( "$MinKey" ), v8::Boolean::New( true ) );
                sub->SetInternalField( 0, v8::Uint32::New( f.type() ) );
                o->Set( v8::String::New( f.fieldName() ) , sub );
                break;
            }

            case mongo::MaxKey: {
                Local<v8::Object> sub = readOnly ? readOnlyObjects->NewInstance() : internalFieldObjects->NewInstance();
                sub->Set( v8::String::New( "$MaxKey" ), v8::Boolean::New( true ) );
                sub->SetInternalField( 0, v8::Uint32::New( f.type() ) );
                o->Set( v8::String::New( f.fieldName() ) , sub );
                break;
            }

            case mongo::DBRef: {
                v8::Function* dbPointer = getNamedCons( "DBPointer" );
                v8::Handle<v8::Value> argv[2];
                argv[0] = v8::String::New( f.dbrefNS() );
                argv[1] = newId( f.dbrefOID() );
                o->Set( v8::String::New( f.fieldName() ), dbPointer->NewInstance(2, argv) );
                break;
            }

            default:
                cout << "can't handle type: ";
                cout  << f.type() << " ";
                cout  << f.toString();
                cout  << endl;
                break;
            }

        }

        if ( readOnly ) {
            readOnlyObjects->SetNamedPropertyHandler( 0, NamedReadOnlySet, 0, NamedReadOnlyDelete );
            readOnlyObjects->SetIndexedPropertyHandler( 0, IndexedReadOnlySet, 0, IndexedReadOnlyDelete );
        }

        return o;
    }

    Handle<v8::Value> mongoToV8Element( const BSONElement &f ) {
        Local< v8::ObjectTemplate > internalFieldObjects = v8::ObjectTemplate::New();
        internalFieldObjects->SetInternalFieldCount( 1 );

        switch ( f.type() ) {

        case mongo::Code:
            return newFunction( f.valuestr() );

        case CodeWScope:
            if ( f.codeWScopeObject().isEmpty() )
                log() << "warning: CodeWScope doesn't transfer to db.eval" << endl;
            return newFunction( f.codeWScopeCode() );

        case mongo::String:
            return v8::String::New( f.valuestr() );

        case mongo::jstOID:
            return newId( f.__oid() );

        case mongo::NumberDouble:
        case mongo::NumberInt:
            return v8::Number::New( f.number() );

        case mongo::Array:
        case mongo::Object:
            return mongoToV8( f.embeddedObject() , f.type() == mongo::Array );

        case mongo::Date:
            return v8::Date::New( f.date() );

        case mongo::Bool:
            return v8::Boolean::New( f.boolean() );

        case mongo::EOO:
        case mongo::jstNULL:
        case mongo::Undefined: // duplicate sm behavior
            return v8::Null();

        case mongo::RegEx: {
            v8::Function * regex = getNamedCons( "RegExp" );

            v8::Handle<v8::Value> argv[2];
            argv[0] = v8::String::New( f.regex() );
            argv[1] = v8::String::New( f.regexFlags() );

            return regex->NewInstance( 2 , argv );
            break;
        }

        case mongo::BinData: {
            int len;
            const char *data = f.binData( len );

            v8::Function* binData = getNamedCons( "BinData" );
            v8::Handle<v8::Value> argv[3];
            argv[0] = v8::Number::New( len );
            argv[1] = v8::Number::New( f.binDataType() );
            argv[2] = v8::String::New( data, len );
            return binData->NewInstance( 3, argv );
        };

        case mongo::Timestamp: {
            Local<v8::Object> sub = internalFieldObjects->NewInstance();

            sub->Set( v8::String::New( "t" ) , v8::Number::New( f.timestampTime() ) );
            sub->Set( v8::String::New( "i" ) , v8::Number::New( f.timestampInc() ) );
            sub->SetInternalField( 0, v8::Uint32::New( f.type() ) );

            return sub;
        }

        case mongo::NumberLong: {
            Local<v8::Object> sub = internalFieldObjects->NewInstance();
            unsigned long long val = f.numberLong();
            v8::Function* numberLong = getNamedCons( "NumberLong" );
            if ( (long long)val == (long long)(double)(long long)(val) ) {
                v8::Handle<v8::Value> argv[1];
                argv[0] = v8::Number::New( (double)(long long)( val ) );
                return numberLong->NewInstance( 1, argv );
            }
            else {
                v8::Handle<v8::Value> argv[3];
                argv[0] = v8::Number::New( (double)(long long)( val ) );
                argv[1] = v8::Integer::New( val >> 32 );
                argv[2] = v8::Integer::New( (unsigned long)(val & 0x00000000ffffffff) );
                return numberLong->NewInstance( 3, argv );
            }
        }

        case mongo::MinKey: {
            Local<v8::Object> sub = internalFieldObjects->NewInstance();
            sub->Set( v8::String::New( "$MinKey" ), v8::Boolean::New( true ) );
            sub->SetInternalField( 0, v8::Uint32::New( f.type() ) );
            return sub;
        }

        case mongo::MaxKey: {
            Local<v8::Object> sub = internalFieldObjects->NewInstance();
            sub->Set( v8::String::New( "$MaxKey" ), v8::Boolean::New( true ) );
            sub->SetInternalField( 0, v8::Uint32::New( f.type() ) );
            return sub;
        }

        case mongo::DBRef: {
            v8::Function* dbPointer = getNamedCons( "DBPointer" );
            v8::Handle<v8::Value> argv[2];
            argv[0] = v8::String::New( f.dbrefNS() );
            argv[1] = newId( f.dbrefOID() );
            return dbPointer->NewInstance(2, argv);
        }

        default:
            cout << "can't handle type: ";
            cout  << f.type() << " ";
            cout  << f.toString();
            cout  << endl;
            break;
        }

        return v8::Undefined();
    }

    void v8ToMongoElement( BSONObjBuilder & b , v8::Handle<v8::String> name , const string sname , v8::Handle<v8::Value> value , int depth ) {

        if ( value->IsString() ) {
            b.append( sname , toSTLString( value ).c_str() );
            return;
        }

        if ( value->IsFunction() ) {
            b.appendCode( sname , toSTLString( value ) );
            return;
        }

        if ( value->IsNumber() ) {
            if ( value->IsInt32() )
                b.append( sname, int( value->ToInt32()->Value() ) );
            else
                b.append( sname , value->ToNumber()->Value() );
            return;
        }

        if ( value->IsArray() ) {
            BSONObj sub = v8ToMongo( value->ToObject() , depth );
            b.appendArray( sname , sub );
            return;
        }

        if ( value->IsDate() ) {
            b.appendDate( sname , Date_t( (unsigned long long)(v8::Date::Cast( *value )->NumberValue())) );
            return;
        }

        if ( value->IsExternal() )
            return;

        if ( value->IsObject() ) {
            // The user could potentially modify the fields of these special objects,
            // wreaking havoc when we attempt to reinterpret them.  Not doing any validation
            // for now...
            Local< v8::Object > obj = value->ToObject();
            if ( obj->InternalFieldCount() && obj->GetInternalField( 0 )->IsNumber() ) {
                switch( obj->GetInternalField( 0 )->ToInt32()->Value() ) { // NOTE Uint32's Value() gave me a linking error, so going with this instead
                case Timestamp:
                    b.appendTimestamp( sname,
                                       Date_t( (unsigned long long)(obj->Get( v8::String::New( "t" ) )->ToNumber()->Value() )),
                                       obj->Get( v8::String::New( "i" ) )->ToInt32()->Value() );
                    return;
                case MinKey:
                    b.appendMinKey( sname );
                    return;
                case MaxKey:
                    b.appendMaxKey( sname );
                    return;
                default:
                    assert( "invalid internal field" == 0 );
                }
            }
            string s = toSTLString( value );
            if ( s.size() && s[0] == '/' ) {
                s = s.substr( 1 );
                string r = s.substr( 0 , s.rfind( "/" ) );
                string o = s.substr( s.rfind( "/" ) + 1 );
                b.appendRegex( sname , r , o );
            }
            else if ( value->ToObject()->GetPrototype()->IsObject() &&
                      value->ToObject()->GetPrototype()->ToObject()->HasRealNamedProperty( v8::String::New( "isObjectId" ) ) ) {
                OID oid;
                oid.init( toSTLString( value ) );
                b.appendOID( sname , &oid );
            }
            else if ( !value->ToObject()->GetHiddenValue( v8::String::New( "__NumberLong" ) ).IsEmpty() ) {
                // TODO might be nice to potentially speed this up with an indexed internal
                // field, but I don't yet know how to use an ObjectTemplate with a
                // constructor.
                v8::Handle< v8::Object > it = value->ToObject();
                long long val;
                if ( !it->Has( v8::String::New( "top" ) ) ) {
                    val = (long long)( it->Get( v8::String::New( "floatApprox" ) )->NumberValue() );
                }
                else {
                    val = (long long)
                          ( (unsigned long long)( it->Get( v8::String::New( "top" ) )->ToInt32()->Value() ) << 32 ) +
                          (unsigned)( it->Get( v8::String::New( "bottom" ) )->ToInt32()->Value() );
                }

                b.append( sname, val );
            }
            else if ( !value->ToObject()->GetHiddenValue( v8::String::New( "__DBPointer" ) ).IsEmpty() ) {
                OID oid;
                oid.init( toSTLString( value->ToObject()->Get( v8::String::New( "id" ) ) ) );
                string ns = toSTLString( value->ToObject()->Get( v8::String::New( "ns" ) ) );
                b.appendDBRef( sname, ns, oid );
            }
            else if ( !value->ToObject()->GetHiddenValue( v8::String::New( "__BinData" ) ).IsEmpty() ) {
                int len = obj->Get( v8::String::New( "len" ) )->ToInt32()->Value();
                v8::String::Utf8Value data( obj->Get( v8::String::New( "data" ) ) );
                const char *dataArray = *data;
                assert( data.length() == len );
                b.appendBinData( sname,
                                 len,
                                 mongo::BinDataType( obj->Get( v8::String::New( "type" ) )->ToInt32()->Value() ),
                                 dataArray );
            }
            else {
                BSONObj sub = v8ToMongo( value->ToObject() , depth );
                b.append( sname , sub );
            }
            return;
        }

        if ( value->IsBoolean() ) {
            b.appendBool( sname , value->ToBoolean()->Value() );
            return;
        }

        else if ( value->IsUndefined() ) {
            b.appendUndefined( sname );
            return;
        }

        else if ( value->IsNull() ) {
            b.appendNull( sname );
            return;
        }

        cout << "don't know how to convert to mongo field [" << name << "]\t" << value << endl;
    }

    BSONObj v8ToMongo( v8::Handle<v8::Object> o , int depth ) {
        BSONObjBuilder b;

        if ( depth == 0 ) {
            v8::Handle<v8::String> idName = v8::String::New( "_id" );
            if ( o->HasRealNamedProperty( idName ) ) {
                v8ToMongoElement( b , idName , "_id" , o->Get( idName ) );
            }
        }

        Local<v8::Array> names = o->GetPropertyNames();
        for ( unsigned int i=0; i<names->Length(); i++ ) {
            v8::Local<v8::String> name = names->Get(v8::Integer::New(i) )->ToString();

            if ( o->GetPrototype()->IsObject() &&
                    o->GetPrototype()->ToObject()->HasRealNamedProperty( name ) )
                continue;

            v8::Local<v8::Value> value = o->Get( name );

            const string sname = toSTLString( name );
            if ( depth == 0 && sname == "_id" )
                continue;

            v8ToMongoElement( b , name , sname , value , depth + 1 );
        }
        return b.obj();
    }

    // --- object wrapper ---

    class WrapperHolder {
    public:
        WrapperHolder( const BSONObj * o , bool readOnly , bool iDelete )
            : _o(o), _readOnly( readOnly ), _iDelete( iDelete ) {
        }

        ~WrapperHolder() {
            if ( _o && _iDelete ) {
                delete _o;
            }
            _o = 0;
        }

        v8::Handle<v8::Value> get( v8::Local<v8::String> name ) {
            const string& s = toSTLString( name );
            const BSONElement& e = _o->getField( s );
            return mongoToV8Element(e);
        }

        const BSONObj * _o;
        bool _readOnly;
        bool _iDelete;
    };

    WrapperHolder * createWrapperHolder( const BSONObj * o , bool readOnly , bool iDelete ) {
        return new WrapperHolder( o , readOnly , iDelete );
    }

#define WRAPPER_STRING (v8::String::New( "_wrapper" ) )

    WrapperHolder * getWrapper( v8::Handle<v8::Object> o ) {
        Handle<v8::Value> t = o->GetRealNamedProperty( WRAPPER_STRING );
        assert( t->IsExternal() );
        Local<External> c = External::Cast( *t );
        WrapperHolder * w = (WrapperHolder*)(c->Value());
        assert( w );
        return w;
    }


    Handle<Value> wrapperCons(const Arguments& args) {
        if ( ! ( args.Length() == 1 && args[0]->IsExternal() ) )
            return v8::ThrowException( v8::String::New( "wrapperCons needs 1 External arg" ) );

        args.This()->Set( WRAPPER_STRING , args[0] );

        return v8::Undefined();
    }

    v8::Handle<v8::Value> wrapperGetHandler( v8::Local<v8::String> name, const v8::AccessorInfo &info) {
        return getWrapper( info.This() )->get( name );
    }

    v8::Handle<v8::FunctionTemplate> getObjectWrapperTemplate() {
        v8::Local<v8::FunctionTemplate> t = newV8Function< wrapperCons >();
        t->InstanceTemplate()->SetNamedPropertyHandler( wrapperGetHandler );
        return t;
    }

    // --- random utils ----

    v8::Function * getNamedCons( const char * name ) {
        return v8::Function::Cast( *(v8::Context::GetCurrent()->Global()->Get( v8::String::New( name ) ) ) );
    }

    v8::Function * getObjectIdCons() {
        return getNamedCons( "ObjectId" );
    }

}