Module metadata

Available on crate features http and grpc only.

Expand description

Contains data structures and utilities for handling gRPC custom metadata.

Modules§

errors: The metadata::errors module contains types for errors that can occur while handling gRPC custom metadata.

GetAll: A view to all values stored in a single entry.
Iter: MetadataMap entry iterator.
IterMut: MetadataMap entry iterator.
Keys: An iterator over MetadataMap keys.
MetadataKey: Represents a custom metadata field name.
MetadataMap: A set of gRPC custom metadata entries.
MetadataValue: Represents a custom metadata field value.
OccupiedEntry: A view into a single occupied location in a MetadataMap.
VacantEntry: A view into a single empty location in a MetadataMap.
ValueDrain: A drain iterator of all values associated with a single metadata key.
ValueIter: An iterator of all values associated with a single metadata key.
Values: MetadataMap value iterator.
ValuesMut: MetadataMap value iterator.

Ascii: gRPC metadata values can be either ASCII strings or binary. Note that only visible ASCII characters (32-127) are permitted. This type should never be instantiated – in fact, it’s impossible to, because there’s no variants to instantiate. Instead, it’s just used as a type parameter for MetadataKey and MetadataValue.
Binary: gRPC metadata values can be either ASCII strings or binary. This type should never be instantiated – in fact, it’s impossible to, because there’s no variants to instantiate. Instead, it’s just used as a type parameter for MetadataKey and MetadataValue.
Entry: A view into a single location in a MetadataMap, which may be vacant or occupied.
KeyAndMutValueRef: Reference to a key and an associated value in a MetadataMap. It can point to either an ascii or a binary (“*-bin”) key.
KeyAndValueRef: Reference to a key and an associated value in a MetadataMap. It can point to either an ascii or a binary (“*-bin”) key.
KeyRef: Reference to a key in a MetadataMap. It can point to either an ascii or a binary (“*-bin”) key.
ValueRef: Reference to a value in a MetadataMap. It can point to either an ascii or a binary (“*-bin” key) value.
ValueRefMut: Reference to a value in a MetadataMap. It can point to either an ascii or a binary (“*-bin” key) value.