From c6217d5c40d61addd0aa30c130bbb91744691e56 Mon Sep 17 00:00:00 2001
From: Emmanuel Bosquet <bjokac@gmail.com>
Date: Thu, 8 Feb 2024 10:54:25 +0100
Subject: [PATCH] Add example in command lib to benchmark the logger

---
 command/examples/bench_logger.rs | 105 +++++++++++++++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 command/examples/bench_logger.rs

diff --git a/command/examples/bench_logger.rs b/command/examples/bench_logger.rs
new file mode 100644
index 000000000..5633f1532
--- /dev/null
+++ b/command/examples/bench_logger.rs
@@ -0,0 +1,105 @@
+//! This file is used to bench the logger of Sozu by logging random lines.
+//! You can change the number of logs, log target, log filter and if they are colored with env
+//! variables. 
+
+use std::time::Instant;
+
+use rand::{rngs::StdRng, Rng, RngCore, SeedableRng};
+
+#[macro_use]
+extern crate sozu_command_lib;
+use sozu_command_lib::logging::setup_logging;
+
+struct LogLine {
+    arg0: u32,
+    arg1: u32,
+    arg2: u32,
+    log_level: u32,
+}
+
+#[allow(dead_code)]
+fn random_string(rng: &mut StdRng) -> String {
+    (0..10)
+        .map(|_| rng.sample(rand::distributions::Alphanumeric) as char)
+        .collect()
+}
+
+fn random_log_line(rng: &mut StdRng) -> LogLine {
+    LogLine {
+        arg0: rng.next_u32(),
+        arg1: rng.next_u32(),
+        arg2: rng.next_u32(),
+        log_level: rng.next_u32(),
+    }
+}
+
+fn main() {
+    let mut rng: StdRng = SeedableRng::seed_from_u64(54321);
+
+    let n: usize = std::env::var("BENCH_LOG_ITERS")
+        .ok()
+        .and_then(|n| n.parse().ok())
+        .unwrap_or(1000);
+    let colored = std::env::var("BENCH_LOG_COLOR")
+        .map(|v| v == "true")
+        .unwrap_or(false);
+    let pre_generate = std::env::var("BENCH_LOG_PREGEN")
+        .map(|v| v == "true")
+        .unwrap_or(false);
+    let target = std::env::var("BENCH_LOG_TARGET").unwrap_or("stdout".to_string());
+    let filter = std::env::var("BENCH_LOG_FILTER").unwrap_or("trace".to_string());
+
+    eprintln!(
+        "n={n}, pre_generate={pre_generate}, target={target}, colored={colored}, filter={filter}"
+    );
+    setup_logging(&target, colored, None, None, None, &filter, "WRK-01");
+
+    let mut pre_generated_log_iterator;
+    let mut log_iterator = std::iter::repeat(())
+        .take(n)
+        .map(|_| random_log_line(&mut rng));
+
+    let log_iterator = if pre_generate {
+        // the pre generated iterator allocates all LogLines to avoid generating them on the fly
+        // generation takes between 15% and 20% of the time
+        pre_generated_log_iterator = log_iterator.collect::<Vec<_>>().into_iter();
+        &mut pre_generated_log_iterator as &mut dyn Iterator<Item = LogLine>
+    } else {
+        &mut log_iterator as &mut dyn Iterator<Item = LogLine>
+    };
+
+    let start = Instant::now();
+    for LogLine {
+        arg0,
+        arg1,
+        arg2,
+        log_level,
+    } in log_iterator.into_iter()
+    {
+        match log_level % 5 {
+            0 => error!(
+                "first argument: {}, second: {}, third: {}",
+                arg0, arg1, arg2
+            ),
+            1 => warn!(
+                "first argument: {}, second: {}, third: {}",
+                arg0, arg1, arg2
+            ),
+            2 => info!(
+                "first argument: {}, second: {}, third: {}",
+                arg0, arg1, arg2
+            ),
+            3 => debug!(
+                "first argument: {}, second: {}, third: {}",
+                arg0, arg1, arg2
+            ),
+            _ => trace!(
+                "first argument: {}, second: {}, third: {}",
+                arg0,
+                arg1,
+                arg2
+            ),
+        }
+    }
+    eprintln!("logs took {:?}", start.elapsed());
+}