pub fn read_header_value(
name: String,
source: impl Read,
max_len: usize,
) -> Result<HealthCheckHeaderValue, HeaderValueReadError>Expand description
Read one health-check header value from source (a file or stdin) into a
protected ingress carrier.
At most max_len + 3 bytes are read: the value, a possible terminal CRLF
and one byte that proves an overflow. The bytes are kept exactly, except one
terminal LF and the CR right before it, which a text editor or echo adds.
Nothing else is trimmed, and an empty value is a value. The value is
validated later, where the carrier is turned into a SecretValue.
The read buffer is allocated once at its final size, so no earlier, unwiped copy is left behind by a reallocation, and it is zeroed on every return. Neither the bytes nor any length of them appears in an error.