ringlog: make metrics optional (#118)

Updates ringlog to make metrics optional.
pelikan-io · Jun 26, 2024 · 09e8616 · 09e8616
1 parent 11f8aef
commit 09e8616
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Showing 7 changed files with 173 additions and 113 deletions.
diff --git a/ringlog/Cargo.toml b/ringlog/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ringlog"
-version = "0.7.0"
+version = "0.8.0"
 edition = "2021"
 license = "Apache-2.0"
 authors = ["Brian Martin <brian@pelikan.io>"]
@@ -11,6 +11,9 @@ repository = "https://github.com/pelikan-io/rustcommon"
 [dependencies]
 ahash = "0.8.0"
 clocksource = { version = "0.8.0", path = "../clocksource" }
-metriken = "0.7.0"
 log = { version = "0.4.17", features = ["std"] }
+metriken = { version = "0.7.0", optional = true }
 mpmc = "0.1.6"
+
+[features]
+metrics = ["metriken"]
diff --git a/ringlog/src/lib.rs b/ringlog/src/lib.rs
@@ -37,6 +37,8 @@
 pub use log::*;
 
 mod format;
+#[macro_use]
+mod macros;
 mod multi;
 mod nop;
 mod outputs;
@@ -52,88 +54,17 @@ pub use sampling::*;
 pub use single::*;
 pub use traits::*;
 
+#[cfg(feature = "metrics")]
+mod metrics;
+
+#[cfg(feature = "metrics")]
+use metrics::*;
+
 use clocksource::datetime::DateTime;
 use mpmc::Queue;
 
 pub(crate) type LogBuffer = Vec<u8>;
 
-use metriken::{metric, Counter, Gauge};
-
-#[metric(name = "log_create", description = "logging targets initialized")]
-pub static LOG_CREATE: Counter = Counter::new();
-
-#[metric(
-    name = "log_create_ex",
-    description = "number of exceptions while initializing logging targets"
-)]
-pub static LOG_CREATE_EX: Counter = Counter::new();
-
-#[metric(name = "log_destroy", description = "logging targets destroyed")]
-pub static LOG_DESTROY: Counter = Counter::new();
-
-#[metric(name = "log_curr", description = "current number of logging targets")]
-pub static LOG_CURR: Gauge = Gauge::new();
-
-#[metric(
-    name = "log_open",
-    description = "number of logging destinations which have been opened"
-)]
-pub static LOG_OPEN: Counter = Counter::new();
-
-#[metric(
-    name = "log_open_ex",
-    description = "number of exceptions while opening logging destinations"
-)]
-pub static LOG_OPEN_EX: Counter = Counter::new();
-
-#[metric(
-    name = "log_write",
-    description = "number of writes to all logging destinations"
-)]
-pub static LOG_WRITE: Counter = Counter::new();
-
-#[metric(
-    name = "log_write_byte",
-    description = "number of bytes written to all logging destinations"
-)]
-pub static LOG_WRITE_BYTE: Counter = Counter::new();
-
-#[metric(
-    name = "log_write_ex",
-    description = "number of exceptions while writing to logging destinations"
-)]
-pub static LOG_WRITE_EX: Counter = Counter::new();
-
-#[metric(
-    name = "log_skip",
-    description = "number of log messages skipped due to sampling policy"
-)]
-pub static LOG_SKIP: Counter = Counter::new();
-
-#[metric(
-    name = "log_drop",
-    description = "number of log messages dropped due to full queues"
-)]
-pub static LOG_DROP: Counter = Counter::new();
-
-#[metric(
-    name = "log_drop_byte",
-    description = "number of bytes dropped due to full queues"
-)]
-pub static LOG_DROP_BYTE: Counter = Counter::new();
-
-#[metric(
-    name = "log_flush",
-    description = "number of times logging destinations have been flushed"
-)]
-pub static LOG_FLUSH: Counter = Counter::new();
-
-#[metric(
-    name = "log_flush_ex",
-    description = "number of times logging destinations have been flushed"
-)]
-pub static LOG_FLUSH_EX: Counter = Counter::new();
-
 /// A type which implements an asynchronous logging backend.
 pub struct RingLog {
     pub(crate) logger: Box<dyn Log>,
@@ -152,19 +83,3 @@ impl RingLog {
         self.drain
     }
 }
-
-#[macro_export]
-macro_rules! fatal {
-    () => (
-        error!();
-        std::process::exit(1);
-        );
-    ($fmt:expr) => (
-        error!($fmt);
-        std::process::exit(1);
-        );
-    ($fmt:expr, $($arg:tt)*) => (
-        error!($fmt, $($arg)*);
-        std::process::exit(1);
-        );
-}
diff --git a/ringlog/src/macros.rs b/ringlog/src/macros.rs
@@ -0,0 +1,26 @@
+#[macro_export]
+/// Logs a fatal error and terminates the program.
+macro_rules! fatal {
+    () => (
+        error!();
+        std::process::exit(1);
+        );
+    ($fmt:expr) => (
+        error!($fmt);
+        std::process::exit(1);
+        );
+    ($fmt:expr, $($arg:tt)*) => (
+        error!($fmt, $($arg)*);
+        std::process::exit(1);
+        );
+}
+
+#[cfg(feature = "metrics")]
+macro_rules! metrics {
+    { $( $tt:tt )* } => { $( $tt )* }
+}
+
+#[cfg(not(feature = "metrics"))]
+macro_rules! metrics {
+    { $( $tt:tt)* } => {}
+}
diff --git a/ringlog/src/metrics.rs b/ringlog/src/metrics.rs
@@ -0,0 +1,76 @@
+use metriken::{metric, Counter, Gauge};
+
+#[metric(name = "log_create", description = "logging targets initialized")]
+pub static LOG_CREATE: Counter = Counter::new();
+
+#[metric(
+    name = "log_create_ex",
+    description = "number of exceptions while initializing logging targets"
+)]
+pub static LOG_CREATE_EX: Counter = Counter::new();
+
+#[metric(name = "log_destroy", description = "logging targets destroyed")]
+pub static LOG_DESTROY: Counter = Counter::new();
+
+#[metric(name = "log_curr", description = "current number of logging targets")]
+pub static LOG_CURR: Gauge = Gauge::new();
+
+#[metric(
+    name = "log_open",
+    description = "number of logging destinations which have been opened"
+)]
+pub static LOG_OPEN: Counter = Counter::new();
+
+#[metric(
+    name = "log_open_ex",
+    description = "number of exceptions while opening logging destinations"
+)]
+pub static LOG_OPEN_EX: Counter = Counter::new();
+
+#[metric(
+    name = "log_write",
+    description = "number of writes to all logging destinations"
+)]
+pub static LOG_WRITE: Counter = Counter::new();
+
+#[metric(
+    name = "log_write_byte",
+    description = "number of bytes written to all logging destinations"
+)]
+pub static LOG_WRITE_BYTE: Counter = Counter::new();
+
+#[metric(
+    name = "log_write_ex",
+    description = "number of exceptions while writing to logging destinations"
+)]
+pub static LOG_WRITE_EX: Counter = Counter::new();
+
+#[metric(
+    name = "log_skip",
+    description = "number of log messages skipped due to sampling policy"
+)]
+pub static LOG_SKIP: Counter = Counter::new();
+
+#[metric(
+    name = "log_drop",
+    description = "number of log messages dropped due to full queues"
+)]
+pub static LOG_DROP: Counter = Counter::new();
+
+#[metric(
+    name = "log_drop_byte",
+    description = "number of bytes dropped due to full queues"
+)]
+pub static LOG_DROP_BYTE: Counter = Counter::new();
+
+#[metric(
+    name = "log_flush",
+    description = "number of times logging destinations have been flushed"
+)]
+pub static LOG_FLUSH: Counter = Counter::new();
+
+#[metric(
+    name = "log_flush_ex",
+    description = "number of times logging destinations have been flushed"
+)]
+pub static LOG_FLUSH_EX: Counter = Counter::new();
diff --git a/ringlog/src/outputs.rs b/ringlog/src/outputs.rs
@@ -81,11 +81,17 @@ impl File {
     /// file. When the size of the live log is exceeded, it will automatically
     /// be rotated to the backup path.
     pub fn new<T: AsRef<Path>>(active: T, backup: T, max_size: u64) -> Result<Self, Error> {
-        LOG_OPEN.increment();
+        metrics! {
+            LOG_OPEN.increment();
+        }
+
         let file = match std::fs::File::create(active.as_ref()) {
             Ok(f) => f,
             Err(e) => {
-                LOG_OPEN_EX.increment();
+                metrics! {
+                    LOG_OPEN_EX.increment();
+                }
+
                 return Err(e);
             }
         };
@@ -111,11 +117,18 @@ impl File {
             std::fs::rename(&self.active, &self.backup)?;
 
             // create a new file for the live log
-            LOG_OPEN.increment();
+
+            metrics! {
+                LOG_OPEN.increment();
+            }
+
             let file = match std::fs::File::create(&self.active) {
                 Ok(f) => f,
                 Err(e) => {
-                    LOG_OPEN_EX.increment();
+                    metrics! {
+                        LOG_OPEN_EX.increment();
+                    }
+
                     return Err(e);
                 }
             };

diff --git a/ringlog/src/sampling.rs b/ringlog/src/sampling.rs
@@ -32,10 +32,13 @@ impl Log for SamplingLogger {
         let count = self.counter.fetch_add(1, Ordering::Relaxed);
 
         // if this is the Nth message, we should log it
+        #[allow(clippy::needless_else)]
         if (count % self.sample) == 0 {
             self.logger.log(record)
         } else {
-            LOG_SKIP.increment();
+            metrics! {
+                LOG_SKIP.increment();
+            }
         }
     }