support optional logger (#302)

Signed-off-by: Ana Hobden <[email protected]>

Cargo.toml

@@ -16,16 +16,20 @@ edition = "2018"
 members = ["proto", "harness"]
 
 [features]
-default = ["protobuf-codec"]
+default = ["protobuf-codec", "default-logger"]
 # Enable failpoints
 failpoints = ["fail/failpoints"]
 protobuf-codec = ["raft-proto/protobuf-codec"]
 prost-codec = ["raft-proto/prost-codec"]
+default-logger = ["slog-stdlog", "slog-envlogger", "slog-term"]
 
 # Make sure to synchronize updates with Harness.
 [dependencies]
 protobuf = "2"
 slog = "2.2"
+slog-stdlog = { version = "4", optional = true }
+slog-envlogger = { version = "2.1.0", optional = true }
+slog-term = { version = "2.4.0", optional = true }
 quick-error = "1.2.2"
 raft-proto = { path = "proto", version = "0.6.0-alpha", default-features = false }
 # Stick with 0.6 (rather than 0.7) for now, since most of the ecosystem has not

benches/benches.rs

@@ -1,45 +1,13 @@
 #![allow(dead_code)] // Due to criterion we need this to avoid warnings.
 #![cfg_attr(feature = "cargo-clippy", allow(clippy::let_and_return))] // Benches often artificially return values. Allow it.
 
-#[macro_use]
-extern crate slog;
-
 use criterion::Criterion;
 use std::time::Duration;
 
 mod suites;
 
 pub const DEFAULT_RAFT_SETS: [(usize, usize); 4] = [(0, 0), (3, 1), (5, 2), (7, 3)];
 
-/// The default logger we fall back to when passed `None` in external facing constructors.
-///
-/// Currently, this is a `log` adaptor behind a `Once` to ensure there is no clobbering.
-fn default_logger() -> slog::Logger {
-    use slog::Drain;
-    use std::sync::{Mutex, Once};
-
-    static LOGGER_INITIALIZED: Once = Once::new();
-    static mut LOGGER: Option<slog::Logger> = None;
-
-    let logger = unsafe {
-        LOGGER_INITIALIZED.call_once(|| {
-            let decorator = slog_term::TermDecorator::new().build();
-            let drain = slog_term::CompactFormat::new(decorator).build();
-            let drain = slog_envlogger::new(drain);
-            LOGGER = Some(slog::Logger::root(Mutex::new(drain).fuse(), o!()));
-        });
-        LOGGER.as_ref().unwrap()
-    };
-    let case = std::thread::current()
-        .name()
-        .unwrap()
-        .split(':')
-        .last()
-        .unwrap()
-        .to_string();
-    logger.new(o!("case" => case))
-}
-
 fn main() {
     let mut c = Criterion::default()
         // Configure defaults before overriding with args.

benches/suites/progress_set.rs

@@ -16,7 +16,7 @@ pub fn bench_progress_set(c: &mut Criterion) {
 }
 
 fn quick_progress_set(voters: usize, learners: usize) -> ProgressSet {
-    let mut set = ProgressSet::with_capacity(voters, learners, crate::default_logger());
+    let mut set = ProgressSet::with_capacity(voters, learners, raft::default_logger());
     (0..voters).for_each(|id| {
         set.insert_voter(id as u64, Progress::new(0, 10)).ok();
     });
@@ -29,7 +29,7 @@ fn quick_progress_set(voters: usize, learners: usize) -> ProgressSet {
 pub fn bench_progress_set_new(c: &mut Criterion) {
     let bench = |b: &mut Bencher| {
         // No setup.
-        b.iter(|| ProgressSet::new(crate::default_logger()));
+        b.iter(|| ProgressSet::new(raft::default_logger()));
     };
 
     c.bench_function("ProgressSet::new", bench);
@@ -39,7 +39,7 @@ pub fn bench_progress_set_with_capacity(c: &mut Criterion) {
     let bench = |voters, learners| {
         move |b: &mut Bencher| {
             // No setup.
-            b.iter(|| ProgressSet::with_capacity(voters, learners, crate::default_logger()));
+            b.iter(|| ProgressSet::with_capacity(voters, learners, raft::default_logger()));
         }
     };
 

benches/suites/raft.rs

@@ -24,7 +24,7 @@ fn quick_raft(voters: usize, learners: usize, logger: &slog::Logger) -> Raft<Mem
 pub fn bench_raft_new(c: &mut Criterion) {
     DEFAULT_RAFT_SETS.iter().for_each(|(voters, learners)| {
         c.bench_function(&format!("Raft::new ({}, {})", voters, learners), move |b| {
-            let logger = crate::default_logger();
+            let logger = raft::default_logger();
             b.iter(|| quick_raft(*voters, *learners, &logger))
         });
     });
@@ -46,7 +46,7 @@ pub fn bench_raft_campaign(c: &mut Criterion) {
                 c.bench_function(
                     &format!("Raft::campaign ({}, {}, {})", voters, learners, msg),
                     move |b| {
-                        let logger = crate::default_logger();
+                        let logger = raft::default_logger();
                         b.iter(|| {
                             let mut raft = quick_raft(*voters, *learners, &logger);
                             raft.campaign(msg.as_bytes());

benches/suites/raw_node.rs

@@ -14,7 +14,7 @@ fn quick_raw_node(logger: &slog::Logger) -> RawNode<MemStorage> {
 
 pub fn bench_raw_node_new(c: &mut Criterion) {
     let bench = |b: &mut Bencher| {
-        let logger = crate::default_logger();
+        let logger = raft::default_logger();
         b.iter(|| quick_raw_node(&logger));
     };
 

harness/Cargo.toml

@@ -12,7 +12,7 @@ categories = []
 edition = "2018"
 
 [features]
-default = ["protobuf-codec"]
+default = ["protobuf-codec", "raft/default-logger"]
 protobuf-codec = ["raft/protobuf-codec"]
 prost-codec = ["raft/prost-codec"]
 
@@ -21,13 +21,10 @@ prost-codec = ["raft/prost-codec"]
 raft = { path = "..", default-features = false }
 rand = "0.6.5"
 slog = "2.2"
-slog-term = "2.4.0"
-slog-envlogger = "2.1.0"
 
 [dev-dependencies]
 criterion = ">0.2.4"
 hashbrown = "0.5"
 lazy_static = "1.0"
 protobuf = "2"
 regex = "1.1"
-slog-async = "2.3.0"

harness/src/lib.rs

@@ -33,40 +33,7 @@ This module contains various testing harness utilities for Raft.
 
 */
 
-#[macro_use]
-extern crate slog;
-
 mod interface;
 mod network;
 
 pub use self::{interface::Interface, network::Network};
-use slog::{Drain, Logger};
-
-/// Build a logger for tests.
-///
-/// Currently, this is a terminal log. It ensures it is only initialized once to prevent clobbering.
-// This is `pub` so that testing and benching functions can use it.
-// `#[cfg(test)]` doesn't work for benching.
-pub fn testing_logger() -> Logger {
-    use std::sync::{Mutex, Once};
-    static LOGGER_INITIALIZED: Once = Once::new();
-    static mut LOGGER: Option<Logger> = None;
-
-    let logger = unsafe {
-        LOGGER_INITIALIZED.call_once(|| {
-            let decorator = slog_term::TermDecorator::new().build();
-            let drain = slog_term::CompactFormat::new(decorator).build();
-            let drain = slog_envlogger::new(drain);
-            LOGGER = Some(slog::Logger::root(Mutex::new(drain).fuse(), o!()));
-        });
-        LOGGER.as_ref().unwrap()
-    };
-    let case = std::thread::current()
-        .name()
-        .unwrap()
-        .split(':')
-        .last()
-        .unwrap()
-        .to_string();
-    logger.new(o!("case" => case))
-}

harness/tests/failpoints_cases/mod.rs

@@ -12,9 +12,8 @@
 // limitations under the License.
 
 use crate::test_util::*;
-use crate::testing_logger;
 use fail;
-use raft::eraftpb::MessageType;
+use raft::{eraftpb::MessageType, util::default_logger};
 use std::sync::*;
 
 // test_reject_stale_term_message tests that if a server receives a request with
@@ -24,7 +23,7 @@ use std::sync::*;
 #[test]
 fn test_reject_stale_term_message() {
     let scenario = fail::FailScenario::setup();
-    let l = testing_logger();
+    let l = default_logger();
     let mut r = new_test_raft(1, vec![1, 2, 3], 10, 1, new_storage(), &l);
     fail::cfg("before_step", "panic").unwrap();
     r.load_state(&hard_state(2, 1, 0));
@@ -40,7 +39,7 @@ fn test_reject_stale_term_message() {
 #[test]
 fn test_step_ignore_old_term_msg() {
     let scenario = fail::FailScenario::setup();
-    let l = testing_logger();
+    let l = default_logger();
     let mut sm = new_test_raft(1, vec![1], 10, 1, new_storage(), &l);
     fail::cfg("before_step", "panic").unwrap();
     sm.term = 2;