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https://issues.apache.org/jira/browse/BEAM-4071?focusedWorklogId=92268&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-92268
]
ASF GitHub Bot logged work on BEAM-4071:
----------------------------------------
Author: ASF GitHub Bot
Created on: 18/Apr/18 22:51
Start Date: 18/Apr/18 22:51
Worklog Time Spent: 10m
Work Description: jkff commented on a change in pull request #5150:
[BEAM-4071] Add Portable Runner Job API shim
URL: https://github.com/apache/beam/pull/5150#discussion_r182591993
##########
File path:
runners/reference/java/src/main/java/org/apache/beam/runners/reference/CloseableResource.java
##########
@@ -0,0 +1,119 @@
+/*
+ * 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.beam.runners.reference;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkState;
+
+import javax.annotation.Nullable;
+
+/**
+ * An {@link AutoCloseable} that wraps a resource that needs to be cleaned up
but does not implement
+ * {@link AutoCloseable} itself.
+ *
+ * <p>Recipients of a {@link CloseableResource} are in general responsible for
cleanup. Ownership
+ * can be transferred from one context to another via {@link #transfer()}.
Transferring relinquishes
+ * ownership from the original resource. This allows resources to be safely
constructed and
+ * transferred within a try-with-resources block. For example:
+ *
+ * <pre>try (CloseableResource<Foo> resource =
CloseableResource.of(...)) {
+ * // Do something with resource.
+ * ...
+ * // Then transfer ownership to some consumer.
+ * resourceConsumer(resource.release());
+ * }</pre>
+ *
+ * <p>Not thread-safe.
+ */
+public class CloseableResource<T> implements AutoCloseable {
+
+ private final T resource;
+
+ /**
+ * {@link Closer } for the underlying resource. Closers are nullable to
allow transfer of
+ * ownership. However, newly-constructed {@link CloseableResource
CloseableResources} must always
+ * have non-null closers.
+ */
+ @Nullable private Closer<T> closer;
+
+ private boolean isClosed = false;
+
+ private CloseableResource(T resource, Closer<T> closer) {
+ this.resource = resource;
+ this.closer = closer;
+ }
+
+ /** Creates a {@link CloseableResource} with the given resource and closer.
*/
+ public static <T> CloseableResource<T> of(T resource, Closer<T> closer) {
+ checkArgument(resource != null, "Resource must be non-null");
+ checkArgument(closer != null, "%s must be non-null",
Closer.class.getName());
+ return new CloseableResource<>(resource, closer);
+ }
+
+ /** Gets the underlying resource. */
+ public T get() {
+ checkState(closer != null, "%s has transferred ownership",
CloseableResource.class.getName());
+ checkState(!isClosed, "% is closed", CloseableResource.class.getName());
+ return resource;
+ }
+
+ /**
+ * Returns a new {@link CloseableResource} that owns the underlying resource
and relinquishes
+ * ownership from this {@link CloseableResource}. {@link #close()} on the
original instance
+ * becomes a no-op.
+ */
+ public CloseableResource<T> transfer() {
Review comment:
<!--thread_id:cc_182519308_t;
commit:1196e2664330e9135b7d5fcc5b1fe75bf3f91bda; resolved:1-->
<!--section:context-quote-->
> **bsidhom** wrote:
> It would be really nice to have the compiler enforce that existing
`CloseableResource` references are never passed as arguments but that they are
instead always `transfer()`'d in. I'm envisioning something like safe RAII move
semantics in C++. Is there a FindBugs check that could enforce this?
<!--section:body-->
There's no findbugs check that can do that AFAIK. It should be possible to
write a check using a compiler plugin, but I think practically speaking we
won't :-/
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Issue Time Tracking
-------------------
Worklog Id: (was: 92268)
Time Spent: 9h 20m (was: 9h 10m)
> Portable Runner Job API shim
> ----------------------------
>
> Key: BEAM-4071
> URL: https://issues.apache.org/jira/browse/BEAM-4071
> Project: Beam
> Issue Type: New Feature
> Components: runner-core
> Reporter: Ben Sidhom
> Assignee: Ben Sidhom
> Priority: Minor
> Time Spent: 9h 20m
> Remaining Estimate: 0h
>
> There needs to be a way to execute Java-SDK pipelines against a portable job
> server. The job server itself is expected to be started up out-of-band. The
> "PortableRunner" should take an option indicating the Job API endpoint and
> defer other runner configurations to the backend itself.
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