steveloughran commented on a change in pull request #2168: URL: https://github.com/apache/hadoop/pull/2168#discussion_r557456802
########## File path: hadoop-common-project/hadoop-common/src/site/markdown/filesystem/openfile.md ########## @@ -0,0 +1,290 @@ +<!--- + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. See accompanying LICENSE file. +--> + +# `openFile()` + +Create a builder to open a file, supporting options +both standard and filesystem specific. The return +value of the `build()` call is a `Future<FSDataInputStream>`, +which must be waited on. The file opening may be +asynchronous, and it may actually be postponed (including +permission/existence checks) until reads are actually +performed. + +This API call was added to `FileSystem` and `FileContext` in +Hadoop 3.3.0; it was tuned in Hadoop 3.3.1 as follows. + +* Support `opt(key, long)` and `must(key, long)`. +* Declare that `withFileStatus(null)` is allowed. +* Declare that `withFileStatus(status)` only checks + the filename of the path, not the full path. + This is needed to support passthrough/mounted filesystems. + + +### <a name="openfile(path)"></a> `FSDataInputStreamBuilder openFile(Path path)` Review comment: oops. Will do. I won't rename the fsdatainputstreambuilder.md file though -it's already shipped and I don't want to break links across versions. Will change all text references ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
