System.Metrics.Json

Encoding of ekg metrics as JSON. The encoding defined by the functions in this module are standardized and used by the ekg web UI. The purpose of this module is to let other web servers and frameworks than the one used by the ekg package expose ekg metrics.

Converting metrics to JSON values

sampleToJson :: Sample -> Value

Encode metrics as nested JSON objects. Each "." in the metric name introduces a new level of nesting. For example, the metrics [("foo.bar", 10), ("foo.baz", "label")] are encoded as

{
  "foo": {
    "bar": {
      "type:", "c",
      "val": 10
    },
    "baz": {
      "type": "l",
      "val": "label"
    }
  }
}

valueToJson :: Value -> Value

Encodes a single metric as a JSON object. Example:

{
  "type": "c",
  "val": 89460
}

Newtype wrappers with instances

newtype Sample

Newtype wrapper that provides a ToJSON instances for the underlying Sample without creating an orphan instance.

Constructors

Sample Sample

Instances

Show Sample

Methods

showsPrec :: Int -> Sample -> ShowS

show :: Sample -> String

showList :: [Sample] -> ShowS

ToJSON Sample

Uses sampleToJson.

Methods

toJSON :: Sample -> Value

toEncoding :: Sample -> Encoding

toJSONList :: [Sample] -> Value

toEncodingList :: [Sample] -> Encoding

newtype Value

Newtype wrapper that provides a ToJSON instances for the underlying Value without creating an orphan instance.

Constructors

Value Value

Instances

Show Value

Methods

showsPrec :: Int -> Value -> ShowS

show :: Value -> String

showList :: [Value] -> ShowS

ToJSON Value

Uses valueToJson.

Methods

toJSON :: Value -> Value

toEncoding :: Value -> Encoding

toJSONList :: [Value] -> Value

toEncodingList :: [Value] -> Encoding