Metric stdout exporter to print timestamp in human readable format (#…

…1192)
open-telemetry · Aug 11, 2023 · 2d42766 · 2d42766
1 parent 1d4db15
commit 2d42766
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diff --git a/opentelemetry-stdout/CHANGELOG.md b/opentelemetry-stdout/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+## vNext
+
+- Timestamp is additionally exported in user-friendly format.
+  [#1192](https://github.com/open-telemetry/opentelemetry-rust/pull/1192).
+
 ## v0.1.0
 
 ### Added

diff --git a/opentelemetry-stdout/Cargo.toml b/opentelemetry-stdout/Cargo.toml
@@ -10,7 +10,7 @@ categories = [
     "development-tools::profiling",
     "asynchronous",
 ]
-keywords = ["opentelemetry", "tracing", "metrics"]
+keywords = ["opentelemetry", "tracing", "metrics", "logs"]
 license = "Apache-2.0"
 edition = "2021"
 rust-version = "1.60"
@@ -22,6 +22,7 @@ logs = ["opentelemetry_api/logs", "opentelemetry_sdk/logs", "async-trait", "this
 
 [dependencies]
 async-trait = { version = "0.1", optional = true }
+chrono = { version = "0.4.22", default-features = false, features = ["clock"] }
 thiserror = { version = "1", optional = true }
 futures-util = { version = "0.3", optional = true, default-features = false }
 opentelemetry_api = { version = "0.20", path = "../opentelemetry-api", default_features = false }

diff --git a/opentelemetry-stdout/src/metrics/transform.rs b/opentelemetry-stdout/src/metrics/transform.rs
@@ -1,3 +1,4 @@
+use chrono::{LocalResult, TimeZone, Utc};
 use opentelemetry_api::{global, metrics::MetricsError};
 use opentelemetry_sdk::metrics::data;
 use serde::{Serialize, Serializer};
@@ -223,6 +224,10 @@ impl<T: Into<DataValue> + Copy> From<&data::Sum<T>> for Sum {
 #[serde(rename_all = "camelCase")]
 struct DataPoint {
     attributes: AttributeSet,
+    #[serde(serialize_with = "as_opt_human_readable")]
+    start_time: Option<SystemTime>,
+    #[serde(serialize_with = "as_opt_human_readable")]
+    time: Option<SystemTime>,
     #[serde(serialize_with = "as_opt_unix_nano")]
     start_time_unix_nano: Option<SystemTime>,
     #[serde(serialize_with = "as_opt_unix_nano")]
@@ -244,6 +249,8 @@ impl<T: Into<DataValue> + Copy> From<&data::DataPoint<T>> for DataPoint {
             attributes: AttributeSet::from(&value.attributes),
             start_time_unix_nano: value.start_time,
             time_unix_nano: value.time,
+            start_time: value.start_time,
+            time: value.time,
             value: value.value.into(),
             exemplars: value.exemplars.iter().map(Into::into).collect(),
             flags: 0,
@@ -275,6 +282,10 @@ struct HistogramDataPoint {
     start_time_unix_nano: SystemTime,
     #[serde(serialize_with = "as_unix_nano")]
     time_unix_nano: SystemTime,
+    #[serde(serialize_with = "as_human_readable")]
+    start_time: SystemTime,
+    #[serde(serialize_with = "as_human_readable")]
+    time: SystemTime,
     count: u64,
     explicit_bounds: Vec<f64>,
     bucket_counts: Vec<u64>,
@@ -291,6 +302,8 @@ impl<T: Into<DataValue> + Copy> From<&data::HistogramDataPoint<T>> for Histogram
             attributes: AttributeSet::from(&value.attributes),
             start_time_unix_nano: value.start_time,
             time_unix_nano: value.time,
+            start_time: value.start_time,
+            time: value.time,
             count: value.count,
             explicit_bounds: value.bounds.clone(),
             bucket_counts: value.bucket_counts.clone(),
@@ -309,11 +322,43 @@ struct Exemplar {
     filtered_attributes: Vec<KeyValue>,
     #[serde(serialize_with = "as_unix_nano")]
     time_unix_nano: SystemTime,
+    #[serde(serialize_with = "as_human_readable")]
+    time: SystemTime,
     value: DataValue,
     span_id: String,
     trace_id: String,
 }
 
+fn as_human_readable<S>(time: &SystemTime, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+{
+    let duration_since_epoch = time.duration_since(UNIX_EPOCH).unwrap_or_default();
+
+    match Utc.timestamp_opt(
+        duration_since_epoch.as_secs() as i64,
+        duration_since_epoch.subsec_nanos(),
+    ) {
+        LocalResult::Single(datetime) => serializer.serialize_str(
+            datetime
+                .format("%Y-%m-%d %H:%M:%S.%3f")
+                .to_string()
+                .as_ref(),
+        ),
+        _ => Err(serde::ser::Error::custom("Invalid Timestamp.")),
+    }
+}
+
+fn as_opt_human_readable<S>(time: &Option<SystemTime>, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+{
+    match time {
+        None => serializer.serialize_none(),
+        Some(time) => as_human_readable(time, serializer),
+    }
+}
+
 fn as_unix_nano<S>(time: &SystemTime, serializer: S) -> Result<S::Ok, S::Error>
 where
     S: Serializer,
@@ -341,6 +386,7 @@ impl<T: Into<DataValue> + Copy> From<&data::Exemplar<T>> for Exemplar {
         Exemplar {
             filtered_attributes: value.filtered_attributes.iter().map(Into::into).collect(),
             time_unix_nano: value.time,
+            time: value.time,
             value: value.value.into(),
             span_id: format!("{:016x}", u64::from_be_bytes(value.span_id)),
             trace_id: format!("{:032x}", u128::from_be_bytes(value.trace_id)),