[async-await] Support for sending response headers via context #1262
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Signed-off-by: Si Beaumont <[email protected]>
Signed-off-by: Si Beaumont <[email protected]>
Signed-off-by: Si Beaumont <[email protected]>
simonjbeaumont
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Sep 13, 2021
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@glbrntt I guess it's obvious but this changes the semantics as seen from the client. It used to be they would get an instant "reply" with the initial metadata. Now they don't get anything until the first response which means that, in the event that the user handler doesn't return anything before the deadline, the client will timeout.
Just wanted to call this out and confirm we expect, and are happy with, these semantics?
glbrntt
requested changes
Sep 13, 2021
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@glbrntt I guess it's obvious but this changes the semantics as seen from the client. It used to be they would get an instant "reply" with the initial metadata. Now they don't get anything until the first response which means that, in the event that the user handler doesn't return anything before the deadline, the client will timeout.
Just wanted to call this out and confirm we expect, and are happy with, these semantics?
I think so, yes. This is what the C# and Go implementations do. Go also has a function to send headers directly.
As a follow up, I think we should add a note to initial metadata on the client to explain that it's not always the case that we'll receive them right away.
Sources/GRPC/AsyncAwaitSupport/GRPCAsyncServerCallContext.swift
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Sources/GRPC/AsyncAwaitSupport/GRPCAsyncServerCallContext.swift
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Signed-off-by: Si Beaumont <[email protected]>
Signed-off-by: Si Beaumont <[email protected]>
Signed-off-by: Si Beaumont <[email protected]>
Signed-off-by: Si Beaumont <[email protected]>
glbrntt
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Sep 16, 2021
…1262) The adopter may wish to set the response headers (aka "initial metadata") from their user handler. Until now this was not possible, even in the existing non–async-await API, and it was only possible for an adopter to set the trailers. This introduces a new mutable property to the context passed to the user handler that allows them to set the headers that should be sent back to the client before the first response message. * `let GRPCAsyncServerCallContext.headers` has been renamed to `requestHeaders` to disambiguate from newly introduced property. * `var GRPCAsyncServerCallContext.trailers` has been renamed to `responseTrailers` to better align with newly introduced property. * `var GRPCAsyncServerCallContext.responseHeaders` has been introduced.
glbrntt
pushed a commit
to glbrntt/grpc-swift
that referenced
this pull request
Sep 16, 2021
…1262) The adopter may wish to set the response headers (aka "initial metadata") from their user handler. Until now this was not possible, even in the existing non–async-await API, and it was only possible for an adopter to set the trailers. This introduces a new mutable property to the context passed to the user handler that allows them to set the headers that should be sent back to the client before the first response message. * `let GRPCAsyncServerCallContext.headers` has been renamed to `requestHeaders` to disambiguate from newly introduced property. * `var GRPCAsyncServerCallContext.trailers` has been renamed to `responseTrailers` to better align with newly introduced property. * `var GRPCAsyncServerCallContext.responseHeaders` has been introduced.
glbrntt
pushed a commit
that referenced
this pull request
Sep 16, 2021
The adopter may wish to set the response headers (aka "initial metadata") from their user handler. Until now this was not possible, even in the existing non–async-await API, and it was only possible for an adopter to set the trailers. This introduces a new mutable property to the context passed to the user handler that allows them to set the headers that should be sent back to the client before the first response message. * `let GRPCAsyncServerCallContext.headers` has been renamed to `requestHeaders` to disambiguate from newly introduced property. * `var GRPCAsyncServerCallContext.trailers` has been renamed to `responseTrailers` to better align with newly introduced property. * `var GRPCAsyncServerCallContext.responseHeaders` has been introduced.
glbrntt
pushed a commit
that referenced
this pull request
Nov 26, 2021
The adopter may wish to set the response headers (aka "initial metadata") from their user handler. Until now this was not possible, even in the existing non–async-await API, and it was only possible for an adopter to set the trailers. This introduces a new mutable property to the context passed to the user handler that allows them to set the headers that should be sent back to the client before the first response message. * `let GRPCAsyncServerCallContext.headers` has been renamed to `requestHeaders` to disambiguate from newly introduced property. * `var GRPCAsyncServerCallContext.trailers` has been renamed to `responseTrailers` to better align with newly introduced property. * `var GRPCAsyncServerCallContext.responseHeaders` has been introduced.
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The adopter may wish to set the response headers (aka "initial metadata") from their user handler. Until now this was not possible, even in the existing non–async-await API, and it was only possible for an adopter to set the trailers.
This introduces a new mutable property to the context passed to the user handler that allows them to set the headers that should be sent back to the client before the first response message.
let GRPCAsyncServerCallContext.headershas been renamed torequestHeadersto disambiguate from newly introduced property.var GRPCAsyncServerCallContext.trailershas been renamed toresponseTrailersto better align with newly introduced property.var GRPCAsyncServerCallContext.responseHeadershas been introduced.