Difference between revisions of "Uno/Spec/Purpose Environment"

Revision as of 11:00, 15 June 2006

version: 12506
state: draft
type: specification

Purpose Environments

Feature

Environment type naming is extended by introducing a so called "purpose" part, actually changing the environment type name to become an Environment Descriptor, defining the environment ABI and the environment purpose.

Environments are descriped as

<ABI type>[:<purpose>]*

meaning that purposes can be chained. This allows to have different environments of the same ABI types to be globally visible, differing in their purpose. For example:

• "uno:affine"
• "uno:debug"
• "uno:log:affine"
• "gcc3:debug"
• "gcc3"

When requesting the above examples, every environment is globally visible, while partly representing the same type or purpose, every combination is unique. Semantically, the former string describing an environments ABI now becomes an Environment Descriptor.

Rationale

Currently every UNO environment is either annonymous or globally visible. All globally visible environments are uniquely identified by their ABI (type) name. That means, that every bridge specific environment (such as "gcc3") can only be visible once globally. To be able to use more than one ABI type specific environment in a global way, support for a differentiator is needed. Together with Cascaded Mappings purpose environments are a powerful instrument for isolating and controlling sets of objects.

API

String getTypeName(String envDcp);

String getPurpose (String envDcp);

Compatibility

The character ':' gets a special meaning in all environment ABI type names. All Runtime functions dealing with environment ABI names, e.g.

getEnvironment,

getRegisteredEnvironments,

createEnvironment,

dumpEnvironmentByName,

are to support Environment Descriptors. All parameter names are to reflect this semantics.

In case of not providing purposes in an environment descriptor, the env. descriptor degenerates to just an environment ABI name. This means, that the change is compatible with all former usages and bridges, in case it does not get utilized. To utilize this feature, bridges should use the appropriate accessor methods to get the ABI or purpose part from an environment descriptor.

Note: Purpose environments _must_ not be used with not purpose environment aware Language Bindings.

Dependencies

• Uno/Spec/Cascaded Mapping