Common Media Client Data (CMCD -- CTA-5004)

This cmcd crate provides functionality and types to read CMCD data from HTTP Header, Query Strings and JSON payloads, as specified by CTA-5004.

All you really need to checkout is the [Info] type. The following examples are taken from its documentation.

Example 1: Header Map

For now HTTP Headers are expected to be Key-Value String pairs. Check out the Planned Features if that may not satisfy your needs right now.

let header: HashMap<String, String> = HashMap::from([
    ("cmcd-object".into(), "br=123,d=456,ot=i".into()),
    ("CMCD-Session".into(), r#"sid="6e2fb550-c457-11e9-bb97-0800200c9a66",st=l,pr=1.5"#.into()),
    ("Cmcd-Status".into(), "custom-field=1.69"),
]);

let info = Info::from_header_map(&header).unwrap();

Example 2: Query String

Query parsing requires you to extract the query value from the query key CMCD and then pass it to either [Info::from_query_string] if the string is URL encoded or to [Info::from_raw_query_string] if it wasn't encoded.

let query: String =
    String::from(r#"br=123,custom-field=1.69,d=456,pr=1.5,ot=i,sid="6e2fb550-c457-11e9-bb97-0800200c9a66",st=l"#);

let info = Info::from_raw_query_string(&query).unwrap();
// or with an URL encoded query
let encoded = urlencoding::encode(&query);
let info = Info::from_query_string(&encoded).unwrap();

Example 3: JSON

JSON payloads can be parsed from either string with [Info::from_json] or from bytes with [Info::from_json_bytes].

let json = serde_json::json!(
    {
        "br": 123,
        "d": 456,
        "pr": 1.5,
        "ot": "i",
        "sid": "6e2fb550-c457-11e9-bb97-0800200c9a66",
        "st": "l",
        "custom-field": 1.69
    }
)
.to_string();

let info = Info::from_json(&json).unwrap();

Planned Features

Here is a list of additions I intend to add to this crate in the future:

• Support for specific HTTP framework type, like
  • axum
  • pingora
  • others if demand is there
  • each crate would be locked behind a feature, so you would be able to exclude those you have no need for
• Provide a builder pattern for creating new [Info] data

I am open to any other feature request and naturally contributions to the code base.