Benchmark metadata and payload cache updates

Cargo.toml

@@ -176,17 +176,24 @@ harness = false
 name = "cache_ingest"
 harness = false
 
+[[bench]]
+name = "cache_metadata_payload"
+harness = false
+
 [[bench]]
 name = "end_to_end_proxy"
 harness = false
 
 [profile.dev]
+debug = 0             # Use the profiling/bench profiles when symbols are needed
+incremental = false   # Avoid retaining a second full set of object files
 split-debuginfo = "unpacked"  # Faster linking — don't bundle debuginfo into binary
 
 [profile.dev.package."*"]
 opt-level = 1  # Compile dependencies with optimizations in dev mode
                # Huge runtime speedup for rustls/ring/foyer/moka
                # Minimal compile-time cost (deps cached after first build)
+debug = 0      # Keep dependency artifacts compact in the dev profile
 
 [profile.release]
 debug = false          # No debug symbols for smaller binaries

benches/cache_metadata_payload.rs

@@ -0,0 +1,120 @@
+//! Mixed hybrid-cache workload for metadata and retained-payload updates.
+//!
+//! Run with: `cargo bench --bench cache_metadata_payload`
+
+use divan::Bencher;
+use nntp_proxy::cache::{HybridCacheConfig, UnifiedCache};
+use nntp_proxy::protocol::StatusCode;
+use nntp_proxy::types::{BackendId, MessageId};
+use std::sync::atomic::{AtomicU64, Ordering};
+use std::time::Duration;
+use tempfile::{TempDir, tempdir};
+
+const ARTICLE_BODY: &str = "x";
+
+fn main() {
+    divan::main();
+}
+
+fn benchmark_cache() -> (tokio::runtime::Runtime, TempDir, UnifiedCache) {
+    let runtime = tokio::runtime::Runtime::new().expect("benchmark runtime");
+    let directory = tempdir().expect("benchmark cache directory");
+    let config = HybridCacheConfig {
+        memory_capacity: 4 * 1024 * 1024,
+        disk_capacity: 64 * 1024 * 1024,
+        disk_path: directory.path().to_path_buf(),
+        ttl: Duration::from_secs(300),
+        compression: nntp_proxy::config::CompressionCodec::None,
+        shards: 16,
+    };
+    let cache = runtime
+        .block_on(UnifiedCache::hybrid(config))
+        .expect("hybrid cache");
+    (runtime, directory, cache)
+}
+
+fn message_id(sequence: u64) -> MessageId<'static> {
+    MessageId::new(format!("<bench-{sequence}@example.com>")).expect("benchmark message ID")
+}
+
+fn article_response(sequence: u64) -> Vec<u8> {
+    format!(
+        "220 42 <bench-{sequence}@example.com>\r\nSubject: Benchmark\r\n\r\n{ARTICLE_BODY}\r\n.\r\n"
+    )
+    .into_bytes()
+}
+
+#[divan::bench(sample_count = 20, sample_size = 1)]
+fn metadata_only_updates(bencher: Bencher) {
+    let (runtime, _directory, cache) = benchmark_cache();
+    let sequence = AtomicU64::new(0);
+
+    bencher
+        .with_inputs(|| message_id(sequence.fetch_add(1, Ordering::Relaxed)))
+        .bench_values(|id| {
+            runtime.block_on(cache.record_backend_has_status(
+                id,
+                StatusCode::new(223),
+                BackendId::from_index(0),
+                0.into(),
+            ));
+        });
+
+    runtime
+        .block_on(cache.close())
+        .expect("close benchmark cache");
+}
+
+#[divan::bench(sample_count = 20, sample_size = 1)]
+fn retained_payload_updates(bencher: Bencher) {
+    let (runtime, _directory, cache) = benchmark_cache();
+    let sequence = AtomicU64::new(0);
+
+    bencher
+        .with_inputs(|| {
+            let sequence = sequence.fetch_add(1, Ordering::Relaxed);
+            (message_id(sequence), article_response(sequence))
+        })
+        .bench_values(|(id, response)| {
+            runtime.block_on(cache.upsert_ingest(id, response, BackendId::from_index(0), 0.into()));
+        });
+
+    runtime
+        .block_on(cache.close())
+        .expect("close benchmark cache");
+}
+
+#[divan::bench(sample_count = 20, sample_size = 1)]
+fn mixed_metadata_and_payload_updates(bencher: Bencher) {
+    let (runtime, _directory, cache) = benchmark_cache();
+    let sequence = AtomicU64::new(0);
+
+    bencher
+        .with_inputs(|| {
+            let sequence = sequence.fetch_add(2, Ordering::Relaxed);
+            (
+                message_id(sequence),
+                message_id(sequence + 1),
+                article_response(sequence + 1),
+            )
+        })
+        .bench_values(|(metadata_id, payload_id, response)| {
+            runtime.block_on(async {
+                cache
+                    .record_backend_has_status(
+                        metadata_id,
+                        StatusCode::new(223),
+                        BackendId::from_index(0),
+                        0.into(),
+                    )
+                    .await;
+                cache
+                    .upsert_ingest(payload_id, response, BackendId::from_index(0), 0.into())
+                    .await;
+            });
+        });
+
+    runtime
+        .block_on(cache.close())
+        .expect("close benchmark cache");
+}