grpc: Add Call Metadata (Headers and Trailers) #517
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Mr3zee
approved these changes
Oct 22, 2025
| * | ||
| * @param key the name of the metadata entry to retrieve (case-insensitive). Must not end with `-bin`. | ||
| * @return the last value associated with the key, or `null` if no values exist | ||
| * @throws IllegalArgumentException if the key ends with `-bin` |
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Probably also when the key doesn't conform to this:
Keys must contain only the following ASCII characters:
* - Digits: `0-9`
* - Lowercase letters: `a-z` (uppercase letters are normalized to lowercase)
* - Special characters: `-`, `_`, `.`
| * | ||
| * ## Example usage | ||
| * ```kotlin | ||
| * val metadata = GrpcMetadata().apply { |
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Let's also add buildGrpcMetadata(body) method, which does the same as GrpcMetadata().apply { body() }
| import libkgrpc.kgrpc_metadata_array_append | ||
| import kotlin.experimental.ExperimentalNativeApi | ||
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| private value class GrpcKey private constructor(val name: String) { |
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Probably better to call it GrpcMetadataKey even if it is private
| @InternalRpcApi | ||
| public actual typealias GrpcMetadata = io.grpc.Metadata | ||
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| public actual operator fun GrpcMetadata.get(key: String): String? { |
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Does java lib perform ascii validation?
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Subsystem
gRPC
Problem Description
Before this, we had no support for passing gRPC metadata between the client and the server.
Solution
This PR solves this on JVM and Native by providing a custom interface (
GrpcMetadata).