xref: /openjdk10/corba/src/java.corba/share/classes/com/sun/corba/se/impl/ior/notes

Notes on IOR implementation

1. Writeable is an interface that can write itself to an OutputStream.

2. IdEncapsulation is  a particular kind of Writeable that has an Id and
   an Encapsulation (a sequence of bytes) representing some other structure
   in a CDR encapsulation.

3. ContainerBase is a base class for containers of IdEncapsulations.

4. An IOR is a ContainerBase.

5. A TaggedComponent is not a ContainerBase.

6. Some (not all) Profiles are ContainerBases.

7. IIOPAddress contains (host, port)
    IIOPServerLocation contains:
	- A primary IIOPAddress
	- 0 or more secondary IIOPAddresses (these get placed in 
	  TAG_ALTERNATE_IIOP_ADDRESS components)

8. IIOPProfileTemplate:
    - major, minor version
    - 0 or more TaggedComponents
    - ObjectKeyTemplate

9. ObjectKeyTemplate:
    - contains only wire data, not internal structures

    write( object id, output stream ): write the object key out 
	to the output stream with the given object id
	
10. Significant problem: must of the dispatch path code is written in terms of
    IORs when it should be based on profiles.  Only a single profile is used in 
    a request, and that is what should be passed around.  This needs fixing soon
    to accommodate the eventual implementation of CORBA FT, and also to work
    properly with the new IOR.

11. Another question: since profile contains key which contains scid, what if 
    we have multiple profiles with different scids?
    One answer: create a cluster subcontract that invokes the individual 
    profiles for FT.  This may not mesh well with the FT spec.

12. Uses of IORs in the ORB:

Activation/ServerManagerImpl.java
    - Construct IOR for bad ID handler location forward
corba/ClientDelegate.java
    - marshal, getIOR, unmarshal are all questionable and make
      poor use of IOR.
    - gets forwarded IOR from response
    - IORs handled in some service contexts
    - createRequest needs to parse IOR
	- gets the (one) IIOP profile that we care about
	- gets the object key
corba/InitialNamingClient.java
    - constructs IOR from address info, object key
    - current implementation should use AlternateIIOPAddress components
    - constructs IOR with key "INIT" for old bootstrap
corba/ORB.java
    - stringify and destringify IOR
corba/ServerDelegate.java
    - access IOR from sending context service context
    - destroyObjref directly access transient key from a known offset.
    - creation sets up key inline with known offsets
core/IOR.java
    - IOR sometimes stores a servant
    - IOR contains the following
	- Object servant
	- Endpoint ep
	- String codebase
	- boolean cachedCodebase
	- TaggedComponent localCodeBaseTC
	- InternetIOPTag
    - The two constructors that take full args also
      construct tagged components
    - will need alternate address components for INS
core/SendingContextServiceContext.java
    - reads IOR from input stream
iiop/CDRInputStream.java
    - needs type id, code base from IOR
iiop/IIOPOutputStream.java
    - needs to access objkey as a sequence of bytes to realing requests.
POA/GenericPOAClientSC.java
    - needs to pull POA ID out of object key
    - needs to created a new IOR that has an updated scid
POA/GenericPOAServerSC.java
    - creates IORs
TransactionalPOA/TransactionalServerSC.java
    - inline access to known offset in object key to
      determine whether transactional

Guide to the files:

Basic Interfaces:
    Identifiable.java (Object has an Id)
    Writeable.java (Object can write to OutputStream)
    IdEncapsulation.java (Writeable, Identifiable interface)
    IdEncapsulationFactory.java (Factory interface for IdEncapsulation)
    IdEncapsulationFactoryFinder.java (Finder interface for IdEncapsulationFactoryFinder)

    IIOPAddress.java (class containing host and port for IIOP)

Basic support for IdEncapsulations (shared for components and profiles):
    GenericIdEncapsulation.java (Has id, octet sequence: used for generic
	TaggedComponent and TaggedProfile objects)
    FreezableList.java (Delegated implementation of List that can be made 
	immutable after construction)
    IdentifiableContainerBase.java (extends FreezableList: container of Identifiable: 
	supports iteratorById.)
    IdEncapsulationContainerBase.java (extends IdenitifableContainerBase:
	container of IdEncapsulation: supports read/write IdEncapsulationSequence)

Object Keys:
    ObjectKeyFactory.java
    ObjectKeyTemplate.java (interface for the following:)
	JIDLObjectKeyTemplate.java (object key used in *Delegate)
	POAObjectKeyTemplate.java (object key used in GenericPOA*SC)
	WireObjectKeyTemplate.java (used for non-Sun ORB IORs)
    ObjectId.java (a simple wrapper for byte[])
    ObjectKey.java (contains ObjectId and ObjectKeyTemplate)

Components:
    TaggedComponentFactories.java (contains method for registering factories)
    TaggedComponentFactoryFinder.java (contains registered factories)
    TaggedComponent.java (interface of all tagged components)
	AlternateIIOPAddressComponent.java
	CodeSetsComponent.java
	JavaCodebaseComponent.java
	ORBTypeComponent.java
	PoliciesComponent.java

Profiles:
    IIOPProfile.java (IIOPProfileTemplate and ObjectId)
    IIOPProfileTemplate.java (contains version, address, ObjectKeyTemplate, 
	list of TaggedComponent)
    TaggedProfile.java (interface for all TaggedProfiles)
    TaggedProfileFactoryFinder.java
    TaggedProfileTemplate.java

IOR:
    IOR.java
    IORTemplate.java (List of IIOPProfileTemplate
    ObjectIds.java (List of ObjectId: needed for an IOR constructor)

Notes from integration code review:

General:
    - Look at making IOR API public, or
      move everything into com.sun.corba.se.impl.ior
      (don't hold up putback for this)
    Making public:
	- Writeable needs getBytes() as well as write()
	  methods.
	- codec can be used with an Any to convert between
	  IDL data type and sequence of bytes.
	- write() needs to use getBytes, then write id, length,
	  octets to output stream.
	- getBytes() method needs to get typecode from IDL
	  then create Any.
	- IdEncapsulations need to have constructor that takes
	  byte[] (encapsulation of value).
    Why not?
	- Unencapsulated object keys can't be made portable
	- Lots of dependencies on ORB code in ObjectKey support
    Conclusion: 
	- move to internal (DONE)
    - JAVA_MAGIC should move to ObjectKeyTemplates (DONE)
    - check for intToBytes/bytesToInt related to object key
	corba/ServerDelegate (DONE)
	POA/GenericPOAServerSC (DONE)
	POA/SubcontractResponseHandler (DONE)
	TransactionalPOA/TransactionalClientSC.java (DONE)
	TransactionalPOA/TransactionalServerSC.java (DONE)

./com/sun/corba/se/impl/cosnaming/BootstrapServer.java
    - remove sc_init_key_* (DONE)

./com/sun/corba/se/impl/poa/POAImpl.java
    - remove line 130: comment on other endpoints, e.g. SSL (DONE)
    - add revisit comment on line 133: use multiple server port API (DONE)

./com/sun/corba/se/impl/corba/ORB.java
    - object_to_string: add comment that connect only takes place in
      non-POA cases. (DONE)

./com/sun/corba/se/impl/corba/ServerDelegate.java
    - chase down the object key offsets  (DONE)
      (search for bytesToInt and intToBytes)

./com/sun/corba/se/impl/core/SubcontractRegistry.java
    - getServerSubcontract: add b-e l-e comment and history on INIT, TINI (DONE)
    - getServerSubcontract: reference to constants (May not do this?)
    - getServerSubcontract: return null at end IS reachable, in the
      case where we have essentially a name in the key that isn't
      one of the ones we support.  Throw an exception? (DONE)
    - add minor code for INTERNAL (and string) (DONE)
    - remove setId calls in callers to getClientSubcontract (DONE)
    - throw INTERNAL exception for temp.size() != 1 case (DONE)
      Think about INST corbaloc problems (multi-profile IORs)
      both return nulls should throw exceptions (DONE)

./com/sun/corba/se/impl/core/IOR.java
    - Add some comments to getIORfromString about 4/2 constants (DONE)
    - fix name: should be getIORFromString (DONE)
    - IOR( InputStream ) has a problem with cachedCodeBase:
      is should not call getCodeBase: must refactor to 
      an internal implementation method. (DONE)
    - isEquivalent and isLocal should assert failure 
      if multiple profiles (through exception in getProfile) (DONE)
      (add comments about multi case)

./com/sun/corba/se/impl/iiop/CDRInputStream_1_0.java
    - read_Object: add assert in case servant is not Tie or objref (DONE)

./com/sun/corba/se/internal/TransactionalPOA/TransactionalPOAImpl.java
    - add comment about transactionalIortemplate: goes away after
      we get to OTS 1.2 transactional policy. (DONE)
    - change transactionalClone( ObjectKeyTemplate ) so that
      we get an error (INTERNAL) if NOT POAObjectKeyTemplate (DONE)
    - line 138: get string constant from 
      org.omg.CosTransactions.TransactionalObject (DONE)
    - remove Delegate d decl. (DONE)

We need to assign minor codes for all exceptions!

We need to clean up the minor code base usage! (DONE)

Add equals/toString to:
    Do not try to develop a reflective universal equals: too slow!
    Do we really want equals on lists?  
	If we do, define collectionEqual on FreezableList

CodeSetsComponent: toString
FreezableList: basic toString, equals methods
IIOPProfile: toString
IIOPProfileTemplate: toString
IOR: toString
IORTemplate.java: toString, equals (inherit?)
IdEncapsulationContainerBase.java: make abstract, but provide base toString/equals
IdentifiableContainerBase.java: make abstract (no other changes)
    (ContainerBase classes need some explanation)
ObjectIds.java needs toString, equals (use FreezableList?)
ObjectKey: toString
ObjectKeyFactory.java: singleton: don't add toString or equals
PoliciesComponent.java: should finish this sometime (after we figure out
    exactly what to do with it)
TaggedComponentBase.java: should be abstract
TaggedComponentFactories.java: a singelton
TaggedComponentFactoryFinder.java: a singleton
TaggedProfileFactoryFinder.java: a singleton
JIDLObjectKeyTemplate: toString
POAObjectKeyTemplate: toString
WireObjectKeyTemplate: toString uninteresting: no data, equals not useful

use util/Utility.objectToString to implement toString methods.

Other changes:

    IIOPAddress.toString should include class name (DONE)

    New tests needed:
	IIOPProfile.getIOPComponents 
	IIOPProfile.getIOPProfile
	GenericTaggedProfile.getIOPComponents
	GenericTaggedProfile.getIOPProfile
	GenericTaggedComponent.getIOPComponent
	ObjectKeyTemplate.getAdapterId

    Plus, do a read/write test for IOP stuff:
	construct profile
	convert to IOP.TaggedProfile
	write to stream
	get input stream
	construct profile
	check for equal

    do some tests on IOR.toString() just to see what gets printed.

    Add getAdapterId to *ObjectKeyTemplate.java (DONE)
    Add some tests for this:
	- WireObjectKeyTemplate throws an exception
	- Identically constructed ObjectKeyTemplates produce identical Adapter Ids.
	- Different OKTs produce different adapter IDs.

New tests for versioning support:

ORBVersionFactory:
    - for create array methods (DONE)
	- returns expected values for version encodings
	- throws INTERNAL for negative version
    - test one case for create stream method (DONE)
    - getORBVersion returns correct version (DONE)
ORBVersionImpl:
    - check equals on some ORBVersions (DONE)
    - check that each ORBVersion returns correct orbtype (DONE)
JIDLObjectKeyTemplate:
    - non-key constructor gives NEWER version (DONE)
POAObjectKeyTemplate:
    - non-key constructor gives NEWER version (DONE)
OldJIDLObjectKeyTemplate: (DONE)
    - non-key constructor with OLD, NEW MAGIC and check version
    - other values throw exception
OldPOAObjectKeyTemplate: (DONE)
    - non-key constructor with OLD, NEW MAGIC and check version (DONE)
    - other values throw exception (DONE)
WireObjectKeyTemplate (DONE)
    - version is FOREIGN
ObjectKeyFactory (DONE)
    create the following keys and check results:
	JIDL OLD	OldJIDL with correct magic, version
	JIDL NEW	OldJIDL
	JIDL NEWER	JIDL
	POA OLD		OldPOA
	POA NEW		OldPOA
	POA NEWER	POA