database: use rayon for service's reader thread-pool (#93)

* add `rayon 1.9.0`

* service: re-impl reader threadpool with `rayon`

* service: impl `tower::Service` for writer

* backend: create db dir in `Env::open`

* service: read + write request/response tests

* docs, name changes

* service: always return `Poll::Ready` in writer

* service: use `spawn()` instead of `install()`

* service: replace `DatabaseReader` with free functions

* cargo: add `tokio-utils`

* service: acquire permit before `call()` for read requests

* service: acquire permit in tests

* docs

* service: use loop for write request tests

* service: use `ready!()`

Cargo.toml

@@ -58,7 +58,7 @@ paste                 = { version = "1.0.14", default-features = false }
 pin-project           = { version = "1.1.3", default-features = false }
 randomx-rs            = { git = "https://github.com/Cuprate/randomx-rs.git", rev = "0028464", default-features = false }
 rand                  = { version = "0.8.5", default-features = false }
-rayon                 = { version = "1.8.0", default-features = false }
+rayon                 = { version = "1.9.0", default-features = false }
 serde_bytes           = { version = "0.11.12", default-features = false }
 serde_json            = { version = "1.0.108", default-features = false }
 serde                 = { version = "1.0.190", default-features = false }

database/Cargo.toml

@@ -9,11 +9,11 @@ repository  = "https://github.com/Cuprate/cuprate/tree/main/database"
 keywords    = ["cuprate", "database"]
 
 [features]
-default   = ["heed", "redb", "service"]
-# default   = ["redb", "service"]
+# default   = ["heed", "redb", "service"]
+default   = ["redb", "service"]
 heed    = ["dep:heed"]
 redb    = ["dep:redb"]
-service = ["dep:crossbeam", "dep:tokio", "dep:tower"]
+service = ["dep:crossbeam", "dep:futures", "dep:tokio", "dep:tokio-util", "dep:tower", "dep:rayon"]
 
 [dependencies]
 bytemuck = { version = "1.14.3", features = ["must_cast", "derive", "min_const_generics", "extern_crate_alloc"] }
@@ -27,9 +27,12 @@ page_size      = { version = "0.6.0" } # Needed for database resizes, they must
 thiserror      = { workspace = true }
 
 # `service` feature.
-crossbeam = { workspace = true, features = ["std"], optional = true }
-tokio     = { workspace = true, features = ["full"], optional = true }
-tower     = { workspace = true, features = ["full"], optional = true }
+crossbeam  = { workspace = true, features = ["std"], optional = true }
+futures    = { workspace = true, optional = true }
+tokio      = { workspace = true, features = ["full"], optional = true }
+tokio-util = { workspace = true, features = ["full"], optional = true }
+tower      = { workspace = true, features = ["full"], optional = true }
+rayon      = { workspace = true, optional = true }
 
 # Optional features.
 heed  = { version = "0.20.0-alpha.9", optional = true }

database/src/backend/heed/env.rs

@@ -164,6 +164,8 @@ impl Env for ConcreteEnv {
             reader_threads + 16
         });
 
+        // Create the database directory if it doesn't exist.
+        std::fs::create_dir_all(config.db_directory())?;
         // Open the environment in the user's PATH.
         let env = env_open_options.open(config.db_directory())?;
 

database/src/backend/redb/env.rs

@@ -72,6 +72,9 @@ impl Env for ConcreteEnv {
         // TODO: we can set cache sizes with:
         // env_builder.set_cache(bytes);
 
+        // Create the database directory if it doesn't exist.
+        std::fs::create_dir_all(config.db_directory())?;
+
         // Open the database file, create if needed.
         let db_file = std::fs::OpenOptions::new()
             .read(true)

database/src/lib.rs

@@ -142,7 +142,6 @@
 	keyword_idents,
 	non_ascii_idents,
 	variant_size_differences,
-	unused_mut, // Annoying when debugging, maybe put in allow.
 
 	// Probably can be put into `#[deny]`.
 	future_incompatible,
@@ -168,6 +167,7 @@
     clippy::pedantic,
     clippy::nursery,
     clippy::cargo,
+    unused_mut,
     missing_docs,
     deprecated,
     unused_comparisons,

database/src/service/free.rs

@@ -6,9 +6,7 @@ use std::sync::Arc;
 use crate::{
     config::Config,
     error::InitError,
-    service::{
-        read::DatabaseReader, write::DatabaseWriter, DatabaseReadHandle, DatabaseWriteHandle,
-    },
+    service::{write::DatabaseWriter, DatabaseReadHandle, DatabaseWriteHandle},
     ConcreteEnv, Env,
 };
 
@@ -39,11 +37,10 @@ pub fn init(config: Config) -> Result<(DatabaseReadHandle, DatabaseWriteHandle),
     let db: Arc<ConcreteEnv> = Arc::new(ConcreteEnv::open(config)?);
 
     // Spawn the Reader thread pool and Writer.
-    let readers = DatabaseReader::init(&db, reader_threads);
-    let writers = DatabaseWriter::init(db);
+    let readers = DatabaseReadHandle::init(&db, reader_threads);
+    let writer = DatabaseWriteHandle::init(db);
 
-    // Return the handles to those pools.
-    Ok((readers, writers))
+    Ok((readers, writer))
 }
 
 //---------------------------------------------------------------------------------------------------- Tests

database/src/service/mod.rs

@@ -38,7 +38,7 @@
 //!
 //! Upon dropping the [`crate::ConcreteEnv`]:
 //! - All un-processed database transactions are completed
-//! - All data gets flushed to disk (caused by [`Drop::drop`] impl of [`crate::ConcreteEnv`])
+//! - All data gets flushed to disk (caused by [`Drop::drop`] impl on [`crate::ConcreteEnv`])
 //!
 //! ## Request and Response
 //! To interact with the database (whether reading or writing data),