DATAREDIS-779 ReactiveValueOperations.set[ifPresent|ifAbsent](…) does not return a value if value was not set #317
Conversation
…f the return value is Mono.just (false)
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Thanks for a pull request. We should discuss the actual issue and the solution within the related ticket first before applying changes. This behavior is caused by Lettuce's suppression of |
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I want to use the setIfAbsent method to implement a distributed lock. The return value of setIfAbsent method is a Mono type data, I think the method will returns Mono.just(true) if the method succeeds, Otherwise Mono.just(false). But it's not so, Not quite sure why just emit the onComplete event when the setIfAbsent method failed. |
public void lock(String key) {
Retry<Boolean> retry = Retry
.<Boolean>onlyIf(rc -> rc.exception() instanceof LockHoldedException)
.randomBackoff(Duration.ofSeconds(1), Duration.ofSeconds(2))
.retryMax(MAX_NUM_OF_RETRY);
template.opsForValue()
.setIfAbsent(key, "1")
.switchIfEmpty(Mono.error(new LockHoldedException()))
.retryWhen(retry);
} |
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This needs to be fixed in |
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I'll fix it. |
… not return a value if value was not set
SystemOutPrint
changed the title
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Thanks a lot. I'll take the pull request from here. We will apply the change only to Lovelace since that's a breaking change. Users of Spring Data Redis 2.0 currently don't expect an element to be emitted and after the change, we will emit elements. |
…t(…) does not set a value. We now emit false when SET XX/SET NX complete without setting the value because the condition was evaluated to not set the value. Previously, we did not emit a value as Redis responds null (nil). This behavior becomes visible through ReactiveValueOperations.set[ifPresent|ifAbsent](…) methods. This is a breaking change in the sense that changes the character of ReactiveValueOperations.set[ifPresent|ifAbsent](…) from an optionally emitted element to always emit. Reactive sequences that currently resume operation with .switchIfEmpty(…) will no longer utilize the fallback publisher. Original pull request: #317.
Reformat code. Add ticket references to tests. Original pull request: #317.
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That's now merged and polished. |
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