Details
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Improvement
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Status: Open
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Minor
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Resolution: Unresolved
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None
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None
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None
Description
Currently there are 2 helper classes called Locked, that serve the same purpose:
one in jcr-commons http://jackrabbit.apache.org/api/2.2/org/apache/jackrabbit/util/Locked.html
and the other one in spi-commons http://jackrabbit.apache.org/api/2.2/org/apache/jackrabbit/spi/commons/lock/Locked.html
There was a discussion a while back about deprecating one of them. the issue affected JR 1.4 and it is now closed. I guess the old patches have not been applied: https://issues.apache.org/jira/browse/JCR-1169
Anyway, I propose to keep the one in jcr-commons and deprecate the other one.
Also, while we are on the matter, I'd like to propose some improvements to this class:
1. make the lock configurable, basically add a flag to say if it is session scoped or not (currently it is hard coded as a session wide lock).
2. upgrade the lock code to use the LockManager (http://www.day.com/maven/javax.jcr/javadocs/jcr-2.0/javax/jcr/lock/LockManager.html) - this means that the class will rely only on the JCR 2.0. this is a potentially breaking change, although a lot of the classes in this module depend directly on the 2.0 API
3. allow the Locked class to use generics. The biggest issue here is the timeout behavior: on timeout you get the TIMED_OUT token object, and you have to compare the response to that, to make sure that the code ran properly. I think the simplest solution would be to not touch the class directly and build a wrapper class that is generified, and throws a RepositoryException in case of a timeout.
This would turn this code( from the javadoc)
Node counter = ...;
Object ret = new Locked() {
protected Object run(Node counter) throws RepositoryException
}.with(counter, false);
if (ret == Locked.TIMED_OUT) { // do whatever you think is appropriate in this case } else { // get the value long nextValue = ((Long) ret).longValue(); }
into
Node counter = ...;
Long ret = new LockedWrapper<Long>() {
protected Object run(Node counter) throws RepositoryException { ... }
}.with(counter, false);
// handle the timeout as a RepositoryException
4. lock tests location? (this is more of an observation than an actual issue it came to me via 'find . -name *Lock*Test.java')
There are some lock tests in jackrabbit-core:
- jackrabbit-core/src/test/java/org/apache/jackrabbit/core/LockTest.java
- jackrabbit-core/src/test/java/org/apache/jackrabbit/core/lock/LockTimeoutTest.java
- jackrabbit-core/src/test/java/org/apache/jackrabbit/core/lock/ConcurrentLockingWithTransactionsTest.java
- jackrabbit-core/src/test/java/org/apache/jackrabbit/core/lock/ExtendedLockingTest.java
- jackrabbit-core/src/test/java/org/apache/jackrabbit/core/lock/ConcurrentLockingTest.java
...some in jackrabbit-jcr2spi:
- jackrabbit-jcr2spi/src/test/java/org/apache/jackrabbit/jcr2spi/lock/OpenScopedLockTest.java
- jackrabbit-jcr2spi/src/test/java/org/apache/jackrabbit/jcr2spi/lock/SessionScopedLockTest.java
- jackrabbit-jcr2spi/src/test/java/org/apache/jackrabbit/jcr2spi/lock/DeepLockTest.java
- jackrabbit-jcr2spi/src/test/java/org/apache/jackrabbit/jcr2spi/lock/AbstractLockTest.java
and others in jackrabbit-jcr-tests:
- jackrabbit-jcr-tests/src/main/java/org/apache/jackrabbit/test/api/observation/LockingTest.java
- jackrabbit-jcr-tests/src/main/java/org/apache/jackrabbit/test/api/lock/SetValueLockExceptionTest.java
- jackrabbit-jcr-tests/src/main/java/org/apache/jackrabbit/test/api/lock/LockManagerTest.java
- jackrabbit-jcr-tests/src/main/java/org/apache/jackrabbit/test/api/lock/OpenScopedLockTest.java
- jackrabbit-jcr-tests/src/main/java/org/apache/jackrabbit/test/api/lock/LockTest.java
- jackrabbit-jcr-tests/src/main/java/org/apache/jackrabbit/test/api/lock/SessionScopedLockTest.java
- jackrabbit-jcr-tests/src/main/java/org/apache/jackrabbit/test/api/lock/DeepLockTest.java
- jackrabbit-jcr-tests/src/main/java/org/apache/jackrabbit/test/api/lock/AbstractLockTest.java
I'd like to move this one: org.apache.jackrabbit.core.LockTest from the jackrabbit-core to the jackrabbit-jcr-commons where the implementation class lives.
I'll add a patch for 1 & 2, but the rest I need your opinion.