formatHttpHeaders top-level constant
String
const formatHttpHeaders
Represents SpanContexts using a character-restricted Map<String, String> as a carrier.
Keys and values in the formatHttpHeaders carrier must be suitable for use as HTTP headers (without modification or further escaping). That is, the keys have a greatly restricted character set, casing for the keys may not be preserved by various intermediaries, and the values should be URL-escaped.
The formatHttpHeaders carrier map may contain unrelated data (e.g.,
arbitrary HTTP headers); as such, the Tracer
implementation should use a
prefix or other convention to distinguish Tracer
-specific key:value
pairs.
Implementation
const String formatHttpHeaders = 'http_headers';