Struct grpcio_sys::grpc_metadata_credentials_plugin

#[repr(C)]
pub struct grpc_metadata_credentials_plugin {
    pub get_metadata: Option<unsafe extern "C" fn(state: *mut c_void, context: grpc_auth_metadata_context, cb: grpc_credentials_plugin_metadata_cb, user_data: *mut c_void, creds_md: *mut grpc_metadata, num_creds_md: *mut usize, status: *mut Type, error_details: *mut *const c_char) -> c_int>,
    pub debug_string: Option<unsafe extern "C" fn(state: *mut c_void) -> *mut c_char>,
    pub destroy: Option<unsafe extern "C" fn(state: *mut c_void)>,
    pub state: *mut c_void,
    pub type_: *const c_char,
}

grpc_metadata_credentials plugin is an API user provided structure used to create grpc_credentials objects that can be set on a channel (composed) or a call. See grpc_credentials_metadata_create_from_plugin below. The grpc client stack will call the get_metadata method of the plugin for every call in scope for the credentials created from it.

Fields

get_metadata: Option<unsafe extern "C" fn(state: *mut c_void, context: grpc_auth_metadata_context, cb: grpc_credentials_plugin_metadata_cb, user_data: *mut c_void, creds_md: *mut grpc_metadata, num_creds_md: *mut usize, status: *mut Type, error_details: *mut *const c_char) -> c_int>

The implementation of this method has to be non-blocking, but can be performed synchronously or asynchronously.

If processing occurs synchronously, returns non-zero and populates creds_md, num_creds_md, status, and error_details. In this case, the caller takes ownership of the entries in creds_md and of error_details. Note that if the plugin needs to return more than GRPC_METADATA_CREDENTIALS_PLUGIN_SYNC_MAX entries in creds_md, it must return asynchronously.

If processing occurs asynchronously, returns zero and invokes \a cb when processing is completed. \a user_data will be passed as the first parameter of the callback. NOTE: \a cb MUST be invoked in a different thread, not from the thread in which \a get_metadata() is invoked.

\a context is the information that can be used by the plugin to create auth metadata.

debug_string: Option<unsafe extern "C" fn(state: *mut c_void) -> *mut c_char>

Implements debug string of the given plugin. This method returns an allocated string that the caller needs to free using gpr_free()

destroy: Option<unsafe extern "C" fn(state: *mut c_void)>

Destroys the plugin state.

state: *mut c_void

State that will be set as the first parameter of the methods above.

type_: *const c_char

Type of credentials that this plugin is implementing.

Trait Implementations

impl Clone for grpc_metadata_credentials_plugin

fn clone(&self) -> grpc_metadata_credentials_plugin

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for grpc_metadata_credentials_plugin

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for grpc_metadata_credentials_plugin