#![deny(clippy::all)]
#![deny(clippy::pedantic)]
#![allow(clippy::missing_errors_doc)]
mod error;
mod key;
mod label;
mod value;
pub use crate::error::Error;
use crate::key::{Serializer as KeySerializer};
use crate::label::{Serializer as LabelSerializer};
use crate::value::{Serializer as ValueSerializer};
use std::collections::HashMap;
use std::convert::TryFrom;
use std::str::FromStr;
use std::fmt::Display;
use std::borrow::Cow;
use serde::{Serialize, ser::{Impossible, SerializeMap, SerializeStruct, SerializeSeq}};
use snafu::ResultExt;
pub enum TypeHint {
Counter = 1337,
Guage = 1338,
Histogram = 1339,
Summary = 1340,
}
impl TryFrom<u32> for TypeHint {
type Error = Error;
fn try_from(x: u32) -> Result<Self, Self::Error> {
match x {
x if x == TypeHint::Counter as u32 => Ok(TypeHint::Counter),
x if x == TypeHint::Guage as u32 => Ok(TypeHint::Guage),
x if x == TypeHint::Histogram as u32 => Ok(TypeHint::Histogram),
x if x == TypeHint::Summary as u32 => Ok(TypeHint::Summary),
_ => Err(Error::UnsupportedValue { kind: "TypeHint".to_string() }),
}
}
}
impl FromStr for TypeHint {
type Err = Error;
fn from_str(v: &str) -> std::result::Result<Self, Self::Err> {
match v {
"counter" => Ok(TypeHint::Counter),
"guage" => Ok(TypeHint::Guage),
"histogram" => Ok(TypeHint::Histogram),
"summary" => Ok(TypeHint::Summary),
_ => Err(Error::UnknownHint),
}
}
}
impl Display for TypeHint {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.write_str(match self {
TypeHint::Counter => "counter",
TypeHint::Guage => "guage",
TypeHint::Histogram => "histogram",
TypeHint::Summary => "summary",
})
}
}
struct Serializer<'a, T: std::io::Write, S: std::hash::BuildHasher> {
namespace: Option<&'a str>,
path: Vec<String>,
global_labels: HashMap<&'a str, &'a str, S>,
output: T,
}
pub fn to_string<T, S>(
value: &T,
namespace: Option<&str>,
global_labels: HashMap<&str, &str, S>,
) -> Result<String, Error>
where
T: ?Sized + Serialize,
S: std::hash::BuildHasher,
{
let mut serializer = Serializer {
namespace,
path: vec![],
global_labels,
output: Vec::with_capacity(std::mem::size_of_val(value) * 4 * 12),
};
value.serialize(&mut serializer)?;
Ok(String::from_utf8(serializer.output).unwrap())
}
impl<T: std::io::Write, S: std::hash::BuildHasher> Serializer<'_, T, S> {
fn write_key<'a>(&mut self, hint: Option<TypeHint>, key: Option<Cow<'a, str>>) -> Result<(), Error> {
let path = self.path.last();
let key = match (path, key) {
(Some(path), Some(key)) => format!("{}_{}", path, key.as_ref()),
(_, Some(key)) => key.into_owned(),
(Some(path), _) => path.to_string(),
(_, _) => return Err(error::Error::NoMetricName),
};
let key = match self.namespace {
Some(namespace) => format!("{}_{}", namespace, key),
None => key,
};
if let Some(typ) = hint {
writeln!(self.output, "# TYPE {} {}", key, typ)?;
}
key.serialize(&mut KeySerializer {
output: &mut self.output,
})?;
Ok(())
}
fn write_labels(&mut self, extras: Option<HashMap<&str, &str>>) -> Result<(), Error> {
let mut map = extras.unwrap_or_default();
let path = if self.path.is_empty() {
None
} else {
Some(self.path[..self.path.len() - 1].join("/"))
};
if let Some(path) = path.as_ref() {
map.insert("path", path);
}
for (key, value) in &self.global_labels {
map.insert(key, value);
}
if !map.is_empty() {
map.serialize(&mut LabelSerializer {
output: &mut self.output,
remaining: 0,
})?;
}
Ok(())
}
fn write_value<V: Serialize>(&mut self, value: V) -> Result<(), Error> {
self.output.write_all(b" ")?;
value.serialize(&mut ValueSerializer {
output: &mut self.output,
})?;
self.output.write_all(b"\n")?;
Ok(())
}
}
impl<W: std::io::Write, S: std::hash::BuildHasher> serde::Serializer for &mut Serializer<'_, W, S> {
type Ok = ();
type Error = Error;
type SerializeSeq = Self;
type SerializeTuple = Impossible<Self::Ok, Self::Error>;
type SerializeTupleStruct = Impossible<Self::Ok, Self::Error>;
type SerializeTupleVariant = Impossible<Self::Ok, Self::Error>;
type SerializeMap = Self;
type SerializeStruct = Self;
type SerializeStructVariant = Impossible<Self::Ok, Self::Error>;
fn serialize_unit_struct(self, name: &'static str) -> Result<Self::Ok, Self::Error> {
self.write_key(None, Some(Cow::Borrowed(name)))?;
self.write_labels(None)?;
self.write_value(0)
}
fn serialize_newtype_struct<T: ?Sized>(
self,
type_name: &'static str,
value: &T,
) -> Result<Self::Ok, Self::Error>
where
T: Serialize,
{
let (modifiers, labels) = if type_name.contains('|') {
let mut split = type_name.splitn(2, '|');
(split.next().filter(|v| !v.is_empty()), split.next().filter(|v| !v.is_empty()))
} else {
(None, Some(type_name).filter(|v| !v.is_empty() && v.contains('=')))
};
let original = self.path.clone();
let mut key = Vec::new();
if let Some(modifiers) = modifiers {
for modifier in modifiers.chars() {
match modifier {
'<' => key.insert(0, self.path.pop().expect("no path to pop!!")),
'!' => { self.path.pop(); },
_ => return Err(Error::InvalidModifier)
}
}
}
let key = if key.is_empty() {
None
} else {
Some(Cow::Owned(key.join("_")))
};
self.write_key(None, key)?;
self.write_labels(if let Some(label) = labels {
let mut labels = HashMap::new();
let pairs = label
.split(',')
.map(|pair| pair.splitn(2, '='))
.map(|mut v| (v.next(), v.next()));
for (key, value) in pairs {
labels.insert(
key.ok_or(Error::InvalidLabel)?,
value.ok_or(Error::InvalidLabel)?,
);
}
Some(labels)
} else {
None
})?;
self.write_value(value)?;
self.path = original;
Ok(())
}
fn serialize_newtype_variant<T: ?Sized>(
self,
name: &'static str,
variant_index: u32,
variant: &'static str,
value: &T,
) -> Result<Self::Ok, Self::Error>
where
T: Serialize,
{
let name = match name {
"" => None,
x => Some(Cow::Borrowed(x)),
};
let hint = match variant_index {
0 => None,
x => Some(TypeHint::try_from(x)?),
};
self.write_key(hint, name)?;
self.write_labels(if variant.contains('=') {
let mut labels = HashMap::new();
let pairs = variant
.split(',')
.map(|pair| pair.splitn(2, '='))
.map(|mut v| (v.next(), v.next()));
for (key, value) in pairs {
labels.insert(
key.ok_or(Error::InvalidLabel)?,
value.ok_or(Error::InvalidLabel)?,
);
}
Some(labels)
} else {
None
})?;
self.write_value(value)?;
Ok(())
}
fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
Ok(self)
}
fn serialize_struct(
self,
_name: &'static str,
_len: usize,
) -> Result<Self::SerializeStruct, Self::Error> {
Ok(self)
}
fn serialize_i8(self, value: i8) -> Result<Self::Ok, Self::Error> {
self.write_key(None, None)?;
self.write_labels(None)?;
self.write_value(value)?;
Ok(())
}
fn serialize_i16(self, value: i16) -> Result<Self::Ok, Self::Error> {
self.write_key(None, None)?;
self.write_labels(None)?;
self.write_value(value)?;
Ok(())
}
fn serialize_i32(self, value: i32) -> Result<Self::Ok, Self::Error> {
self.write_key(None, None)?;
self.write_labels(None)?;
self.write_value(value)?;
Ok(())
}
fn serialize_i64(self, value: i64) -> Result<Self::Ok, Self::Error> {
self.write_key(None, None)?;
self.write_labels(None)?;
self.write_value(value)?;
Ok(())
}
fn serialize_u8(self, value: u8) -> Result<Self::Ok, Self::Error> {
self.write_key(None, None)?;
self.write_labels(None)?;
self.write_value(value)?;
Ok(())
}
fn serialize_u16(self, value: u16) -> Result<Self::Ok, Self::Error> {
self.write_key(None, None)?;
self.write_labels(None)?;
self.write_value(value)?;
Ok(())
}
fn serialize_u32(self, value: u32) -> Result<Self::Ok, Self::Error> {
self.write_key(None, None)?;
self.write_labels(None)?;
self.write_value(value)?;
Ok(())
}
fn serialize_u64(self, value: u64) -> Result<Self::Ok, Self::Error> {
self.write_key(None, None)?;
self.write_labels(None)?;
self.write_value(value)?;
Ok(())
}
fn serialize_f32(self, value: f32) -> Result<Self::Ok, Self::Error> {
self.write_key(None, None)?;
self.write_labels(None)?;
self.write_value(value)?;
Ok(())
}
fn serialize_f64(self, value: f64) -> Result<Self::Ok, Self::Error> {
self.write_key(None, None)?;
self.write_labels(None)?;
self.write_value(value)?;
Ok(())
}
fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
Ok(())
}
fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
where
T: Serialize,
{
value.serialize(&mut *self)?;
Ok(())
}
fn serialize_unit_variant(
self,
name: &'static str,
_variant_index: u32,
variant: &'static str,
) -> Result<Self::Ok, Self::Error> {
Err(Error::UnsupportedValue { kind: format!("Unit Variant ({}::{})", name, variant) })
}
fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
Ok(self)
}
fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
Err(Error::UnsupportedValue { kind: "Tuple".to_string() })
}
fn serialize_tuple_struct(
self,
name: &'static str,
_len: usize,
) -> Result<Self::SerializeTupleStruct, Self::Error> {
Err(Error::UnsupportedValue { kind: format!("Tuple Struct ({})", name) })
}
fn serialize_tuple_variant(
self,
name: &'static str,
_variant_index: u32,
variant: &'static str,
_len: usize,
) -> Result<Self::SerializeTupleVariant, Self::Error> {
Err(Error::UnsupportedValue { kind: format!("Tuple Variant ({}::{})", name, variant) })
}
fn serialize_struct_variant(
self,
name: &'static str,
_variant_index: u32,
variant: &'static str,
_len: usize,
) -> Result<Self::SerializeStructVariant, Self::Error> {
Err(Error::UnsupportedValue { kind: format!("Struct Variant ({}::{})", name, variant) })
}
fn collect_str<T: ?Sized>(self, _value: &T) -> Result<Self::Ok, Self::Error>
where
T: Display,
{
Err(Error::UnsupportedValue { kind: "collect_str".to_string() })
}
fn serialize_str(self, _v: &str) -> Result<Self::Ok, Self::Error> {
Err(Error::UnsupportedValue { kind: "str".to_string() })
}
fn serialize_char(self, _v: char) -> Result<Self::Ok, Self::Error> {
Err(Error::UnsupportedValue { kind: "char".to_string() })
}
fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Self::Error> {
Err(Error::UnsupportedValue { kind: "bytes".to_string() })
}
fn serialize_bool(self, _v: bool) -> Result<Self::Ok, Self::Error> {
Err(Error::UnsupportedValue { kind: "bool".to_string() })
}
fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
Err(Error::UnsupportedValue { kind: "()".to_string() })
}
}
impl<W: std::io::Write, S: std::hash::BuildHasher> SerializeMap for &mut Serializer<'_, W, S> {
type Ok = ();
type Error = Error;
fn serialize_key<T: ?Sized + Serialize>(&mut self, key: &T) -> Result<(), Self::Error> {
let key_bytes = key.serialize(MapKeySerializer)?;
self.path.push(std::str::from_utf8(key_bytes.as_bytes()).context(error::MetricNameMustBeUtf8)?.to_owned());
Ok(())
}
fn serialize_value<T: ?Sized + Serialize>(&mut self, value: &T) -> Result<(), Self::Error> {
value.serialize(&mut **self)?;
self.path.pop();
Ok(())
}
fn end(self) -> Result<Self::Ok, Self::Error> {
Ok(())
}
}
impl<W: std::io::Write, S: std::hash::BuildHasher> SerializeStruct for &mut Serializer<'_, W, S> {
type Ok = ();
type Error = Error;
fn serialize_field<T: ?Sized + Serialize>(
&mut self,
key: &'static str,
value: &T,
) -> Result<(), Self::Error> {
self.path.push(key.to_owned());
value.serialize(&mut **self)?;
self.path.pop();
Ok(())
}
fn end(self) -> Result<Self::Ok, Self::Error> {
Ok(())
}
}
impl<W: std::io::Write, S: std::hash::BuildHasher> SerializeSeq for &mut Serializer<'_, W, S> {
type Ok = ();
type Error = Error;
fn serialize_element<T: ?Sized + Serialize>(
&mut self,
value: &T
) -> Result<(), Self::Error> {
value.serialize(&mut **self)?;
Ok(())
}
fn end(self) -> Result<Self::Ok, Self::Error> {
Ok(())
}
}
struct MapKeySerializer;
impl serde::Serializer for MapKeySerializer {
type Ok = String;
type Error = Error;
type SerializeSeq = Impossible<String, Error>;
type SerializeTuple = Impossible<String, Error>;
type SerializeTupleStruct = Impossible<String, Error>;
type SerializeTupleVariant = Impossible<String, Error>;
type SerializeMap = Impossible<String, Error>;
type SerializeStruct = Impossible<String, Error>;
type SerializeStructVariant = Impossible<String, Error>;
fn serialize_bool(self, _value: bool) -> Result<Self::Ok, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_i8(self, value: i8) -> Result<Self::Ok, Self::Error> {
Ok(value.to_string())
}
fn serialize_i16(self, value: i16) -> Result<Self::Ok, Self::Error> {
Ok(value.to_string())
}
fn serialize_i32(self, value: i32) -> Result<Self::Ok, Self::Error> {
Ok(value.to_string())
}
fn serialize_i64(self, value: i64) -> Result<Self::Ok, Self::Error> {
Ok(value.to_string())
}
fn serialize_u8(self, value: u8) -> Result<Self::Ok, Self::Error> {
Ok(value.to_string())
}
fn serialize_u16(self, value: u16) -> Result<Self::Ok, Self::Error> {
Ok(value.to_string())
}
fn serialize_u32(self, value: u32) -> Result<Self::Ok, Self::Error> {
Ok(value.to_string())
}
fn serialize_u64(self, value: u64) -> Result<Self::Ok, Self::Error> {
Ok(value.to_string())
}
fn serialize_f32(self, _value: f32) -> Result<Self::Ok, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_f64(self, _value: f64) -> Result<Self::Ok, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_char(self, value: char) -> Result<Self::Ok, Self::Error> {
let mut buf = [0; 4];
self.serialize_str(value.encode_utf8(&mut buf))
}
fn serialize_str(self, value: &str) -> Result<Self::Ok, Self::Error> {
Ok(value.to_string())
}
fn serialize_bytes(self, _value: &[u8]) -> Result<Self::Ok, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_none(self) -> Result<Self::Ok, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_some<T>(self, _value: &T) -> Result<Self::Ok, Self::Error>
where
T: ?Sized + Serialize,
{
Err(Error::MapKeyMustBeString)
}
fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_unit_variant(
self,
_name: &'static str,
_variant_index: u32,
variant: &'static str,
) -> Result<Self::Ok, Self::Error> {
Ok(variant.to_string())
}
#[inline]
fn serialize_newtype_struct<T>(
self,
_name: &'static str,
value: &T,
) -> Result<Self::Ok, Self::Error>
where
T: ?Sized + Serialize,
{
value.serialize(self)
}
fn serialize_newtype_variant<T>(
self,
_name: &'static str,
_variant_index: u32,
_variant: &'static str,
_value: &T,
) -> Result<Self::Ok, Self::Error>
where
T: ?Sized + Serialize,
{
Err(Error::MapKeyMustBeString)
}
fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_tuple_struct(
self,
_name: &'static str,
_len: usize,
) -> Result<Self::SerializeTupleStruct, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_tuple_variant(
self,
_name: &'static str,
_variant_index: u32,
_variant: &'static str,
_len: usize,
) -> Result<Self::SerializeTupleVariant, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_struct(
self,
_name: &'static str,
_len: usize,
) -> Result<Self::SerializeStruct, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn serialize_struct_variant(
self,
_name: &'static str,
_variant_index: u32,
_variant: &'static str,
_len: usize,
) -> Result<Self::SerializeStructVariant, Self::Error> {
Err(Error::MapKeyMustBeString)
}
fn collect_str<T: ?Sized>(self, value: &T) -> Result<Self::Ok, Self::Error>
where
T: Display,
{
Ok(value.to_string())
}
}
#[cfg(test)]
mod tests {
use metered::{metered, HitCount, ResponseTime, Throughput};
use std::collections::HashMap;
#[derive(serde::Serialize)]
pub struct ServiceMetricRegistry<'a> {
biz: &'a BizMetrics,
baz: &'a BazMetrics,
}
#[derive(Default)]
pub struct Biz {
metrics: BizMetrics,
}
#[metered(registry = BizMetrics)]
impl Biz {
#[measure([HitCount, Throughput, ResponseTime])]
pub fn bizle(&self) {}
}
#[derive(Default)]
pub struct Baz {
metrics: BazMetrics,
}
#[metered(registry = BazMetrics)]
impl Baz {
#[measure([HitCount, Throughput, ResponseTime])]
pub fn bazle(&self) {}
}
#[test]
fn normal_registry() {
let biz = Biz::default();
let baz = Baz::default();
let ret = crate::to_string(
&ServiceMetricRegistry {
biz: &biz.metrics,
baz: &baz.metrics,
},
None,
HashMap::new(),
)
.unwrap();
let split: Vec<&str> = ret.split("\n").collect();
assert_eq!(split[0], "hit_count{path = \"biz/bizle\"} 0");
if !split.contains(&"throughput{quantile = \"0.95\", path = \"biz/bizle\"} 0")
&& !split.contains(&"throughput{path = \"biz/bizle\", quantile = \"0.95\"} 0")
{
assert!(split.contains(&"throughput{quantile = \"0.95\", path = \"biz/bizle\"} 0"));
}
}
#[test]
fn wrapped_registry() {
#[derive(serde::Serialize)]
pub struct MyWrapperRegistry<'a> {
wrapper: ServiceMetricRegistry<'a>,
}
let biz = Biz::default();
let baz = Baz::default();
let mut labels = HashMap::new();
labels.insert("service", "my_cool_service");
let ret = crate::to_string(
&MyWrapperRegistry {
wrapper: ServiceMetricRegistry {
biz: &biz.metrics,
baz: &baz.metrics,
},
},
Some("global"),
labels,
)
.unwrap();
let split: Vec<&str> = ret.split("\n").collect();
if split[0] != "global_hit_count{service = \"my_cool_service\", path = \"wrapper/biz/bizle\"} 0"
&& split[0] != "global_hit_count{path = \"wrapper/biz/bizle\", service = \"my_cool_service\"} 0"
{
assert_eq!(split[0], "global_hit_count{service = \"my_cool_service\", path = \"wrapper/biz/bizle\"} 0");
}
if !split.contains(&"global_response_time_count{path = \"wrapper/baz/bazle\", service = \"my_cool_service\"} 0")
&& !split.contains(&"global_response_time_count{service = \"my_cool_service\", path = \"wrapper/baz/bazle\"} 0")
{
assert!(split.contains(&"global_response_time_count{service = \"my_cool_service\", path = \"wrapper/biz/bizle\"} 0"));
}
}
}