From 10b564a4db8a46046bd405de95232235520bc0a1 Mon Sep 17 00:00:00 2001
From: Maaz Ahmed <maaz.a@subcom.tech>
Date: Fri, 15 Dec 2023 11:23:11 +0530
Subject: [PATCH] refactor: replace external error type with an internal one in
pub API
---
src/lib.rs | 15 ++--
src/result.rs | 189 +++++++++++++++++++++++++++++++++++++++++++++++++
tests/utils.rs | 4 +-
3 files changed, 199 insertions(+), 9 deletions(-)
create mode 100644 src/result.rs
diff --git a/src/lib.rs b/src/lib.rs
index baaef71..dbefb59 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,8 +1,9 @@
#![doc = include_str!("../README.md")]
pub mod query;
+pub mod result;
-use prometheus_http_query::{response::PromqlResult, Client, Error};
+use prometheus_http_query::{response::PromqlResult, Client};
use query::IntoQuery;
use reqwest::header::HeaderValue;
use url::Url;
@@ -65,7 +66,7 @@ impl QueryManager {
/// The trait is implemented for `&str`, `String`, `&String`, and __mquery's__
/// internal types such as [`query::Metric`], [`query::Scalar`] and others that result
/// from the query builder API.
- pub async fn query<Q: IntoQuery>(&self, query: Q) -> Result<PromqlResult, Error> {
+ pub async fn query<Q: IntoQuery>(&self, query: Q) -> Result<PromqlResult, result::Error> {
let mut builder = self.client.query(query.into_query().as_ref());
if let Some((name, val)) = self.auth.get_header() {
builder = builder.header(name, val);
@@ -74,8 +75,8 @@ impl QueryManager {
builder = builder.timeout(*timeout);
}
match self.method {
- Method::Get => builder.get().await,
- Method::Post => builder.post().await,
+ Method::Get => builder.get().await.map_err(|e| e.into()),
+ Method::Post => builder.post().await.map_err(|e| e.into()),
}
}
@@ -91,7 +92,7 @@ impl QueryManager {
start: i64,
end: i64,
step: f64,
- ) -> Result<PromqlResult, Error> {
+ ) -> Result<PromqlResult, result::Error> {
let mut builder = self
.client
.query_range(query.into_query().as_ref(), start, end, step);
@@ -102,8 +103,8 @@ impl QueryManager {
builder = builder.timeout(*timeout);
}
match self.method {
- Method::Get => builder.get().await,
- Method::Post => builder.post().await,
+ Method::Get => builder.get().await.map_err(|e| e.into()),
+ Method::Post => builder.post().await.map_err(|e| e.into()),
}
}
}
diff --git a/src/result.rs b/src/result.rs
new file mode 100644
index 0000000..fac15e8
--- /dev/null
+++ b/src/result.rs
@@ -0,0 +1,189 @@
+//! `PromqlResult` and the `Error` types which are essentially clones of the types
+//! with the same name from the `prometheus-http-query` crate with slight modifications
+//! to suit the needs of `mqeury`.
+//!
+//! The reason why this crate maintains its own types which are the same (almost) as the ones
+//! provided by the other crate that is used internally, is to ensure that the public
+//! API remains stable even if the internal crate API changes.
+
+use prometheus_http_query::error;
+use std::fmt::{self, Display};
+
+/// A global error enum that contains all errors that are returned by this
+/// library. Some errors are wrappers for errors from underlying libraries.
+/// All errors (this enum as well as all contained structs) implement [`std::error::Error`].
+#[non_exhaustive]
+#[derive(Debug, Clone)]
+pub enum Error {
+ /// Wraps errors from the underlying [`reqwest::Client`] that cannot be mapped
+ /// to a more specific error type. Deserialization errors also fall into this
+ /// category.
+ Client(ClientError),
+ /// Occurs when Prometheus responds with e.g. HTTP 4xx (e.g. due to a syntax error in a PromQL query).<br>
+ /// Details on the error as reported by Prometheus are included in [`PrometheusError`].
+ Prometheus(PrometheusError),
+ /// Occurs when the [`Client::series`](crate::Client::series) method is called with an empty set of
+ /// series [`Selector`](crate::selector::Selector)s. According to the Prometheus API description at least one
+ /// [`Selector`](crate::selector::Selector) must be provided.
+ EmptySeriesSelector,
+}
+
+impl Display for Error {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Self::Client(e) => e.fmt(f),
+ Self::Prometheus(e) => e.fmt(f),
+ Self::EmptySeriesSelector => f.write_str("at least one series selector must be provided in order to query the series endpoint"),
+ }
+ }
+}
+
+impl std::error::Error for Error {
+ fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+ match self {
+ Self::Client(e) => e.source(),
+ Self::Prometheus(p) => p.source(),
+ Self::EmptySeriesSelector => None,
+ }
+ }
+}
+
+impl From<prometheus_http_query::Error> for Error {
+ fn from(value: prometheus_http_query::Error) -> Self {
+ match value {
+ prometheus_http_query::Error::Client(c) => Self::Client(c.into()),
+ prometheus_http_query::Error::Prometheus(p) => Self::Prometheus(p.into()),
+ prometheus_http_query::Error::EmptySeriesSelector => Self::EmptySeriesSelector,
+ _ => unreachable!(),
+ }
+ }
+}
+
+/// This error is thrown when the JSON response's `status` field contains `error`.<br>
+/// The error-related information from the JSON body is included in this error.
+#[derive(Debug, Clone, PartialEq)]
+pub struct PrometheusError {
+ pub(crate) error_type: PrometheusErrorType,
+ pub(crate) message: String,
+}
+
+impl std::error::Error for PrometheusError {}
+
+impl fmt::Display for PrometheusError {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ write!(f, "{}: {}", self.error_type, self.message)
+ }
+}
+
+impl From<error::PrometheusError> for PrometheusError {
+ fn from(value: error::PrometheusError) -> Self {
+ let error_type = PrometheusErrorType::from(value.error_type());
+ let message = value.message().to_owned();
+ PrometheusError {
+ error_type,
+ message,
+ }
+ }
+}
+
+impl PrometheusError {
+ /// Returns the parsed version of the error type that was given by the Prometheus API.
+ pub fn error_type(&self) -> PrometheusErrorType {
+ self.error_type
+ }
+
+ /// Returns the error message that was given by the Prometheus API.
+ pub fn message(&self) -> &str {
+ &self.message
+ }
+
+ pub fn is_timeout(&self) -> bool {
+ self.error_type == PrometheusErrorType::Timeout
+ }
+
+ pub fn is_canceled(&self) -> bool {
+ self.error_type == PrometheusErrorType::Canceled
+ }
+
+ pub fn is_execution(&self) -> bool {
+ self.error_type == PrometheusErrorType::Execution
+ }
+
+ pub fn is_bad_data(&self) -> bool {
+ self.error_type == PrometheusErrorType::BadData
+ }
+
+ pub fn is_internal(&self) -> bool {
+ self.error_type == PrometheusErrorType::Internal
+ }
+
+ pub fn is_unavailable(&self) -> bool {
+ self.error_type == PrometheusErrorType::Unavailable
+ }
+
+ pub fn is_not_found(&self) -> bool {
+ self.error_type == PrometheusErrorType::NotFound
+ }
+}
+
+/// The parsed error type as returned by the Prometheus API.
+#[non_exhaustive]
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum PrometheusErrorType {
+ Timeout,
+ Canceled,
+ Execution,
+ BadData,
+ Internal,
+ Unavailable,
+ NotFound,
+}
+
+impl From<error::PrometheusErrorType> for PrometheusErrorType {
+ fn from(value: error::PrometheusErrorType) -> Self {
+ match value {
+ error::PrometheusErrorType::Timeout => PrometheusErrorType::Timeout,
+ error::PrometheusErrorType::Canceled => PrometheusErrorType::Canceled,
+ error::PrometheusErrorType::Execution => PrometheusErrorType::Execution,
+ error::PrometheusErrorType::BadData => PrometheusErrorType::BadData,
+ error::PrometheusErrorType::Internal => PrometheusErrorType::Internal,
+ error::PrometheusErrorType::Unavailable => PrometheusErrorType::Unavailable,
+ error::PrometheusErrorType::NotFound => PrometheusErrorType::NotFound,
+ _ => unreachable!(),
+ }
+ }
+}
+
+impl fmt::Display for PrometheusErrorType {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ match self {
+ Self::Timeout => f.write_str("timeout"),
+ Self::Canceled => f.write_str("canceled"),
+ Self::Execution => f.write_str("execution"),
+ Self::BadData => f.write_str("bad_data"),
+ Self::Internal => f.write_str("internal"),
+ Self::Unavailable => f.write_str("unavailable"),
+ Self::NotFound => f.write_str("not_found"),
+ }
+ }
+}
+
+/// Is thrown when the [`Client`](crate::Client) or the underlying
+/// [`reqwest::Error`] fail to build or execute a request.
+#[derive(Debug, Clone)]
+pub struct ClientError(String);
+
+impl From<prometheus_http_query::error::ClientError> for ClientError {
+ fn from(value: prometheus_http_query::error::ClientError) -> Self {
+ let message = value.to_string();
+ ClientError(message)
+ }
+}
+
+impl fmt::Display for ClientError {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ f.write_str(&self.0)
+ }
+}
+
+impl std::error::Error for ClientError {}
diff --git a/tests/utils.rs b/tests/utils.rs
index dbaa3a8..12303de 100644
--- a/tests/utils.rs
+++ b/tests/utils.rs
@@ -1,9 +1,9 @@
use mquery::{query::IntoQuery, QueryManager};
-use prometheus_http_query::{response::PromqlResult, Error};
+use prometheus_http_query::response::PromqlResult;
// local victoria metrics server
pub static URL: &str = "http://localhost:8428";
-pub async fn send_query(query: impl IntoQuery) -> Result<PromqlResult, Error> {
+pub async fn send_query(query: impl IntoQuery) -> Result<PromqlResult, mquery::result::Error> {
QueryManager::new(URL.parse().unwrap()).query(query).await
}
--
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