29 lines
730 B
Kotlin
29 lines
730 B
Kotlin
package co.electriccoin.zcash.spackle
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import kotlinx.coroutines.sync.Mutex
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import kotlinx.coroutines.sync.withLock
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/**
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* Implements a coroutines-friendly lazy singleton pattern with an input argument.
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*
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* This class is thread-safe.
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*/
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class SuspendingLazy<in Input, out Output>(private val deferredCreator: suspend ((Input) -> Output)) {
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private var singletonInstance: Output? = null
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private val mutex = Mutex()
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suspend fun getInstance(input: Input): Output {
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mutex.withLock {
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singletonInstance?.let {
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return it
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}
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val newInstance = deferredCreator(input)
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singletonInstance = newInstance
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return newInstance
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}
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}
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}
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