enable unreachable_pub lint

This causes some other lints to start firing too (which is good), but
I'm going to fix them in follow-up commits to keep things organized.

src/database/abstraction.rs

@@ -4,15 +4,15 @@ use crate::Result;
 use std::{future::Future, pin::Pin, sync::Arc};
 
 #[cfg(feature = "sqlite")]
-pub mod sqlite;
+pub(crate) mod sqlite;
 
 #[cfg(feature = "rocksdb")]
-pub mod rocksdb;
+pub(crate) mod rocksdb;
 
 #[cfg(any(feature = "sqlite", feature = "rocksdb",))]
-pub mod watchers;
+pub(crate) mod watchers;
 
-pub trait KeyValueDatabaseEngine: Send + Sync {
+pub(crate) trait KeyValueDatabaseEngine: Send + Sync {
     fn open(config: &Config) -> Result<Self>
     where
         Self: Sized;
@@ -27,7 +27,7 @@ pub trait KeyValueDatabaseEngine: Send + Sync {
     fn clear_caches(&self) {}
 }
 
-pub trait KvTree: Send + Sync {
+pub(crate) trait KvTree: Send + Sync {
     fn get(&self, key: &[u8]) -> Result<Option<Vec<u8>>>;
 
     fn insert(&self, key: &[u8], value: &[u8]) -> Result<()>;

src/database/abstraction/rocksdb.rs

@@ -6,14 +6,14 @@ use std::{
     sync::{Arc, RwLock},
 };
 
-pub struct Engine {
+pub(crate) struct Engine {
     rocks: rocksdb::DBWithThreadMode<rocksdb::MultiThreaded>,
     max_open_files: i32,
     cache: rocksdb::Cache,
     old_cfs: Vec<String>,
 }
 
-pub struct RocksDbEngineTree<'a> {
+pub(crate) struct RocksDbEngineTree<'a> {
     db: Arc<Engine>,
     name: &'a str,
     watchers: Watchers,

src/database/abstraction/sqlite.rs

@@ -18,8 +18,8 @@ thread_local! {
 }
 
 struct PreparedStatementIterator<'a> {
-    pub iterator: Box<dyn Iterator<Item = TupleOfBytes> + 'a>,
-    pub _statement_ref: NonAliasingBox<rusqlite::Statement<'a>>,
+    pub(crate) iterator: Box<dyn Iterator<Item = TupleOfBytes> + 'a>,
+    pub(crate) _statement_ref: NonAliasingBox<rusqlite::Statement<'a>>,
 }
 
 impl Iterator for PreparedStatementIterator<'_> {
@@ -37,7 +37,7 @@ impl<T> Drop for NonAliasingBox<T> {
     }
 }
 
-pub struct Engine {
+pub(crate) struct Engine {
     writer: Mutex<Connection>,
     read_conn_tls: ThreadLocal<Connection>,
     read_iterator_conn_tls: ThreadLocal<Connection>,
@@ -73,7 +73,7 @@ impl Engine {
             .get_or(|| Self::prepare_conn(&self.path, self.cache_size_per_thread).unwrap())
     }
 
-    pub fn flush_wal(self: &Arc<Self>) -> Result<()> {
+    pub(crate) fn flush_wal(self: &Arc<Self>) -> Result<()> {
         self.write_lock()
             .pragma_update(Some(Main), "wal_checkpoint", "RESTART")?;
         Ok(())
@@ -125,7 +125,7 @@ impl KeyValueDatabaseEngine for Arc<Engine> {
     }
 }
 
-pub struct SqliteTable {
+pub(crate) struct SqliteTable {
     engine: Arc<Engine>,
     name: String,
     watchers: Watchers,
@@ -153,7 +153,7 @@ impl SqliteTable {
         Ok(())
     }
 
-    pub fn iter_with_guard<'a>(
+    pub(crate) fn iter_with_guard<'a>(
         &'a self,
         guard: &'a Connection,
     ) -> Box<dyn Iterator<Item = TupleOfBytes> + 'a> {

src/database/key_value/globals.rs

@@ -11,7 +11,7 @@ use ruma::{
 
 use crate::{database::KeyValueDatabase, service, services, utils, Error, Result};
 
-pub const COUNTER: &[u8] = b"c";
+pub(crate) const COUNTER: &[u8] = b"c";
 
 #[async_trait]
 impl service::globals::Data for KeyValueDatabase {