View source for Class Structure Hash

You do not have permission to edit this page, for the following reasons:

The action you have requested is limited to users in one of the groups: Autoconfirmed users, emailconfirmed, editors.
You must confirm your email address before editing pages. Please set and validate your email address through your user preferences.

You can view and copy the source of this page:

'''Purpose:'''<br/>
A request for comments on the notion of various equality tests for a class.  The tests can be used in areas such as serialization, proxy/stub calls, versioning, dynamic type loading, etc.

Hash value are a SHA256 hash

'''Class-text hash:'''<br/>
* Complete hash of the text of the class.  Any change including non-processed areas such as `note' or comments would cause the hash value to change.

'''Semantic-text hash:'''<br/>
* Hash value of the semantically-meaningful text of the class.  This would ignore the actual character contents of breaks and would ignore comments and note fields.  If a buggy version of a class is discovered, it could be rejected for serialization or connection by this hash value.

'''Attribute hash:'''<br/>
* Hash value of the attributes of the class.  This would essentially mean anything with an equal attribute hash could be deserialized/serialized without recovery.

'''Feature hash:'''<br/>
* Name, signature, and export hash for a feature

'''Interface-to-class hash:'''<br/>
* Hash value of feature names and signature exported to a specific class.  This would be useful for remote proxying.  A class would have a additional value for each class to which features are exported.  If class A exports features to {ANY}, {A}, {B}, and {NONE} it would have a hash value for each to say whether the interface exported to either ANY, A, or B has changed.  Changes to features exported to A would affect the hash code for {ANY} and {A} but not {B}.  Changes to features exported to NONE would not affect any hash values.

'''Contract hash:'''<br/>
* A hash value for a the contract of a feature.

'''Interface-to-class contract hash:'''<br/>
* A hash value for the contract of all features exported to a class.

'''Additional issues:'''<br/>
* Mutual recursive references.  In some cases two classes reference each other; this could lead to difficulty in creating a hash value for both.<br/>
* Some traditionally non-semantic areas such as `note' actually have semantic value.<br/>
* Are 256 bits needed?  Maybe truncate hash to 128 bits or 64 bits.

Return to Class Structure Hash.

Retrieved from "https://dev.eiffel.com/Class_Structure_Hash"

View source for Class Structure Hash

Navigation

Development

Wiki

Search

Tools