Triggering on FileIO.toPath sink completion
I have an IO Source I'm multiplexing a file and handing off to another part of the system to execute like:
source.alsoTo(FileIO.toPath(path))
This is used for a cache, i.e. i'm writing a file passing through my system to a temporary cache location. Once the cache is written, I want to move it atomically to its final location.
The consumer of the source gets a Future and knows when it is done, but my side-channel writing to file to disk has no such facility that I can find. Is there some way of attaching a completion handler to a sink so that I can complete my manipulation of that file?
akka akka-stream
asked Nov 22 at 19:30
Arne Claassen
8,96334982
add a comment |
I have an IO Source I'm multiplexing a file and handing off to another part of the system to execute like:
source.alsoTo(FileIO.toPath(path))
This is used for a cache, i.e. i'm writing a file passing through my system to a temporary cache location. Once the cache is written, I want to move it atomically to its final location.
The consumer of the source gets a Future and knows when it is done, but my side-channel writing to file to disk has no such facility that I can find. Is there some way of attaching a completion handler to a sink so that I can complete my manipulation of that file?
akka akka-stream
asked Nov 22 at 19:30
Arne Claassen
8,96334982
add a comment |
I have an IO Source I'm multiplexing a file and handing off to another part of the system to execute like:
source.alsoTo(FileIO.toPath(path))
This is used for a cache, i.e. i'm writing a file passing through my system to a temporary cache location. Once the cache is written, I want to move it atomically to its final location.
The consumer of the source gets a Future and knows when it is done, but my side-channel writing to file to disk has no such facility that I can find. Is there some way of attaching a completion handler to a sink so that I can complete my manipulation of that file?
akka akka-stream
asked Nov 22 at 19:30
Arne Claassen
8,96334982
I have an IO Source I'm multiplexing a file and handing off to another part of the system to execute like:
source.alsoTo(FileIO.toPath(path))
This is used for a cache, i.e. i'm writing a file passing through my system to a temporary cache location. Once the cache is written, I want to move it atomically to its final location.
The consumer of the source gets a Future and knows when it is done, but my side-channel writing to file to disk has no such facility that I can find. Is there some way of attaching a completion handler to a sink so that I can complete my manipulation of that file?
akka akka-stream
akka akka-stream
asked Nov 22 at 19:30
Arne Claassen
8,96334982
asked Nov 22 at 19:30
Arne Claassen
8,96334982
asked Nov 22 at 19:30
Arne Claassen
8,96334982
asked Nov 22 at 19:30
Arne Claassen
8,96334982
asked Nov 22 at 19:30
Arne Claassen
8,96334982
8,96334982
add a comment |
add a comment |
1 Answer
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Instead of alsoTo, use alsoToMat and mapMaterializedValue to access the materialized value of the file Sink:
val source: Source[ByteString, _] = ???
val cachedSource =
source
.alsoToMat(FileIO.toPath(path))(Keep.right)
.mapMaterializedValue { fileResult => // fileResult is a Future[IOResult]
// do something with fileResult
}
answered Nov 23 at 13:38
Jeffrey Chung
13.6k62140
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
Instead of alsoTo, use alsoToMat and mapMaterializedValue to access the materialized value of the file Sink:
val source: Source[ByteString, _] = ???
val cachedSource =
source
.alsoToMat(FileIO.toPath(path))(Keep.right)
.mapMaterializedValue { fileResult => // fileResult is a Future[IOResult]
// do something with fileResult
}
answered Nov 23 at 13:38
Jeffrey Chung
13.6k62140
add a comment |
Instead of alsoTo, use alsoToMat and mapMaterializedValue to access the materialized value of the file Sink:
val source: Source[ByteString, _] = ???
val cachedSource =
source
.alsoToMat(FileIO.toPath(path))(Keep.right)
.mapMaterializedValue { fileResult => // fileResult is a Future[IOResult]
// do something with fileResult
}
answered Nov 23 at 13:38
Jeffrey Chung
13.6k62140
add a comment |
Instead of alsoTo, use alsoToMat and mapMaterializedValue to access the materialized value of the file Sink:
val source: Source[ByteString, _] = ???
val cachedSource =
source
.alsoToMat(FileIO.toPath(path))(Keep.right)
.mapMaterializedValue { fileResult => // fileResult is a Future[IOResult]
// do something with fileResult
}
answered Nov 23 at 13:38
Jeffrey Chung
13.6k62140
Instead of alsoTo, use alsoToMat and mapMaterializedValue to access the materialized value of the file Sink:
val source: Source[ByteString, _] = ???
val cachedSource =
source
.alsoToMat(FileIO.toPath(path))(Keep.right)
.mapMaterializedValue { fileResult => // fileResult is a Future[IOResult]
// do something with fileResult
}
answered Nov 23 at 13:38
Jeffrey Chung
13.6k62140
edited Nov 23 at 23:46
answered Nov 23 at 13:38
Jeffrey Chung
13.6k62140
answered Nov 23 at 13:38
Jeffrey Chung
13.6k62140
answered Nov 23 at 13:38
Jeffrey Chung
13.6k62140
13.6k62140
add a comment |
add a comment |
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