com.google.enterprise.connector.util.diffing

Interface DocumentSnapshot

public interface DocumentSnapshot

Interface for a local copy of a document that is stored on the GSA. This represents both objects in the repository as well as serialized entries in the snapshot files (the implementations need not be the same concrete, although doing so is often convenient).

The diffing package depends on the ordering of snapshots, which must match the order of their appearance in the SnapshotRepository. By default the ordering of snapshots is determined by the lexicographic ordering of their document IDs (the natural order of Java String values).

Since version 3.0.6, the DocumentSnapshot implementation class can also implement Comparable. The diffing package will check for the Comparable implementation before comparing the document IDs. Reasons to implement Comparable to define the details of the ordering include the lexicographic ordering of the document IDs, and the encoding required to make the document IDs safe to use in URLs, which might not be an order-preserving encoding (e.g., Base64 is not order-preserving).

Since:

2.8

Method Summary

Modifier and Type	Method and Description
java.lang.String	getDocumentId() Returns the unique ID for the document.
DocumentHandle	getUpdate(DocumentSnapshot onGsa) Returns a DocumentHandle for updating the referenced document on the GSA or null if the document on the GSA does not need updating.
java.lang.String	toString() Returns a serialized String representation of this DocumentSnapshot suitable for deserialization with DocumentSnapshotFactory.fromString(String).

Method Detail

getDocumentId

java.lang.String getDocumentId()

Returns the unique ID for the document.

getUpdate

DocumentHandle getUpdate(DocumentSnapshot onGsa)
                  throws RepositoryException

Returns a DocumentHandle for updating the referenced document on the GSA or null if the document on the GSA does not need updating.

The diffing framework will call this before calling toString() to persist this DocumentSnapshot.

Parameters:

onGsa - a DocumentSnapshot representing the GSA's version of the document

Returns:

a DocumentHandle representing the change required by the GSA to bring the document up-to-date; or null if the GSA's knowledge of the document is up-to-date

Throws:

RepositoryException

toString

java.lang.String toString()

Returns a serialized String representation of this DocumentSnapshot suitable for deserialization with DocumentSnapshotFactory.fromString(String). The returned value must not be null.

Overrides:

toString in class java.lang.Object