Galsza commented on code in PR #4361: URL: https://github.com/apache/ozone/pull/4361#discussion_r1129554093
########## hadoop-ozone/ozonefs-hadoop2/src/main/java/org/apache/hadoop/fs/StreamCapabilities.java: ########## @@ -0,0 +1,122 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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. + */ + +package org.apache.hadoop.fs; + +import org.apache.hadoop.classification.InterfaceAudience; +import org.apache.hadoop.classification.InterfaceStability; + +/** + * Interface to query streams for supported capabilities. + * + * This is copied from Hadoop3 code to make Ozone compatible with Hadoop2.7 + * runtime dependency. Hadoop 2.7 does not support StreamCapabilities API. + * + * TODO: remove this interface once we drop Hadoop 2.7 support. + * + * Capability strings must be in lower case. + * + * Constant strings are chosen over enums in order to allow other file systems + * to define their own capabilities. + */ [email protected] [email protected] +public interface StreamCapabilities { + /** + * Stream hflush capability implemented by {@link Syncable#hflush()}. + * + * Use the {@link #HSYNC} probe to check for the support of Syncable; + * it's that presence of {@code hsync()} which matters. + */ + @Deprecated + String HFLUSH = "hflush"; + + /** + * Stream hsync capability implemented by {@link Syncable#hsync()}. + */ + String HSYNC = "hsync"; + + /** + * Stream setReadahead capability implemented by + * {@link CanSetReadahead#setReadahead(Long)}. + */ + String READAHEAD = "in:readahead"; + + /** + * Stream setDropBehind capability implemented by + * {@link CanSetDropBehind#setDropBehind(Boolean)}. + */ + String DROPBEHIND = "dropbehind"; + + /** + * Stream unbuffer capability implemented by {@link CanUnbuffer#unbuffer()}. + */ + String UNBUFFER = "in:unbuffer"; + + /** + * Stream read(ByteBuffer) capability implemented by + * {@link ByteBufferReadable#read(java.nio.ByteBuffer)}. + */ + String READBYTEBUFFER = "in:readbytebuffer"; + + /** + * Stream read(long, ByteBuffer) capability implemented by + * {@link ByteBufferPositionedReadable#read(long, java.nio.ByteBuffer)}. + */ + String PREADBYTEBUFFER = "in:preadbytebuffer"; + + /** + * IOStatisticsSource API. + */ + //String IOSTATISTICS = "iostatistics"; Review Comment: Is this supposed to be commented out? -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
