chore: remove various useless code

- call expect directly on Result
lint message: called `ok().expect()` on a `Result` value
help: you can call `expect()` directly on the `Result`
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#ok_expect
- use assign operation instead of manual implementation
lint message: manual implementation of an assign operation
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#assign_op_pattern
- remove useless call to format
lint message: useless use of `format!`
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#useless_format
- remove useless `?Sized`
lint message: `?Sized` bound is ignored because of a `Sized` requirement
note: ...because `Deserialize` has the bound `Sized`
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#needless_maybe_sized
- use is_some instead of pattern maching with Some(_)
lint message: redundant pattern matching, consider using `is_some()`
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#redundant_pattern_matching
- remove unneeded unit return type
lint message: unneeded unit return type
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#unused_unit
- remove redundant closure
lint message: redundant closure
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#redundant_closure
- use derive Default instead of manual implementation
lint message: this `impl` can be derived
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#derivable_impls
- remove unneeded `return` statement
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#needless_return
- remove empty string from println call
lint message: empty string literal in `println!`
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#println_empty_string
- remove clone() on type than implement Copy
lint message: using `clone` on type `Option<ChecksumValue>` which implements the `Copy` trait
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#clone_on_copy
- remove useless let binding
lint message: this let-binding has unit value
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#let_unit_value
- remove useless len comparison to zero, already test of empty
lint message: length comparison to zero
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#len_zero
- remove useless `as_deref` call
lint message: derefed type is same as origin
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#needless_option_as_deref
- remove useless conversion of the same type
lint message: useless conversion to the same type: `replication_mode::ReplicationFactor`
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#useless_conversion
- remove useless bool_comparison
lint message: equality checks against false can be replaced by a negation
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#bool_comparison
- remove useless to_string
lint message: unnecessary use of `to_string`
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#unnecessary_to_owned

Signed-off-by: Gwen Lg <me@gwenlg.fr>

src/db/lmdb_adapter.rs

@@ -45,16 +45,14 @@ pub(crate) fn open_db(path: &PathBuf, opt: &OpenOpt) -> Result<Db> {
 		}
 	}
 	match env_builder.open(path) {
-		Err(heed::Error::Io(e)) if e.kind() == std::io::ErrorKind::OutOfMemory => {
-			return Err(Error(
-				"OutOfMemory error while trying to open LMDB database. This can happen \
+		Err(heed::Error::Io(e)) if e.kind() == std::io::ErrorKind::OutOfMemory => Err(Error(
+			"OutOfMemory error while trying to open LMDB database. This can happen \
                 if your operating system is not allowing you to use sufficient virtual \
                 memory address space. Please check that no limit is set (ulimit -v). \
                 You may also try to set a smaller `lmdb_map_size` configuration parameter. \
                 On 32-bit machines, you should probably switch to another database engine."
-					.into(),
-			))
-		}
+				.into(),
+		)),
 		Err(e) => Err(Error(format!("Cannot open LMDB database: {}", e).into())),
 		Ok(db) => Ok(LmdbDb::init(db)),
 	}

src/db/open.rs

@@ -68,22 +68,13 @@ impl std::str::FromStr for Engine {
 	}
 }
 
+#[derive(Default)]
 pub struct OpenOpt {
 	pub fsync: bool,
 	pub lmdb_map_size: Option<usize>,
 	pub fjall_block_cache_size: Option<usize>,
 }
 
-impl Default for OpenOpt {
-	fn default() -> Self {
-		Self {
-			fsync: false,
-			lmdb_map_size: None,
-			fjall_block_cache_size: None,
-		}
-	}
-}
-
 pub fn open_db(path: &PathBuf, engine: Engine, opt: &OpenOpt) -> Result<Db> {
 	match engine {
 		// ---- Sqlite DB ----

src/db/sqlite_adapter.rs

@@ -308,7 +308,7 @@ impl IDb for SqliteDb {
 
 		trace!("transaction done");
 		drop(lock);
-		return res;
+		res
 	}
 }