hadoop/hadoop-hdfs-project/hadoop-hdfs-client
Steve Loughran e346e3638c HADOOP-15691 Add PathCapabilities to FileSystem and FileContext.
Contributed by Steve Loughran.

This complements the StreamCapabilities Interface by allowing applications to probe for a specific path on a specific instance of a FileSystem client
to offer a specific capability.

This is intended to allow applications to determine

* Whether a method is implemented before calling it and dealing with UnsupportedOperationException.
* Whether a specific feature is believed to be available in the remote store.

As well as a common set of capabilities defined in CommonPathCapabilities,
file systems are free to add their own capabilities, prefixed with
 fs. + schema + .

The plan is to identify and document more capabilities -and for file systems which add new features, for a declaration of the availability of the feature to always be available.

Note

* The remote store is not expected to be checked for the feature;
  It is more a check of client API and the client's configuration/knowledge
  of the state of the remote system.
* Permissions are not checked.

Change-Id: I80bfebe94f4a8bdad8f3ac055495735b824968f5
2019-09-25 12:16:41 +01:00
..
dev-support HDFS-13601. Optimize ByteString conversions in PBHelper. 2018-05-22 23:55:20 -07:00
src HADOOP-15691 Add PathCapabilities to FileSystem and FileContext. 2019-09-25 12:16:41 +01:00
pom.xml HADOOP-16558. [COMMON+HDFS] use protobuf-maven-plugin to generate protobuf classes (#1494). Contributed by Vinayakumar B. 2019-09-23 12:37:47 +05:30