refactor(storage): Reorganize storage code into a new module (#2109)

## Which issue does this PR close?

- Closes #.

## What changes are included in this PR?
- Add a new module `storage` within `io` and put traits there

## Are these changes tested?
Relying on the existing tests

Author: CTTY

crates/iceberg/src/io/file_io.rs

@@ -23,8 +23,7 @@ use std::sync::Arc;
 use bytes::Bytes;
 use url::Url;
 
-use super::opendal::OpenDalStorage;
-use super::storage::Storage;
+use super::storage::{OpenDalStorage, Storage};
 use crate::{Error, ErrorKind, Result};
 
 /// FileIO implementation, used to manipulate files in underlying storage.

crates/iceberg/src/io/mod.rs

@@ -66,19 +66,11 @@
 //! - `new_input`: Create input file for reading.
 //! - `new_output`: Create output file for writing.
 
-mod config;
 mod file_io;
-mod local_fs;
-mod memory;
-mod opendal;
 mod storage;
 
-pub use config::*;
 pub use file_io::*;
-#[cfg(feature = "storage-s3")]
-pub use opendal::CustomAwsCredentialLoader;
-pub use opendal::{OpenDalStorage, OpenDalStorageFactory};
-pub use storage::{Storage, StorageConfig, StorageFactory};
+pub use storage::*;
 
 pub(crate) mod object_cache;
 

crates/iceberg/src/io/config/azdls.rs …s/iceberg/src/io/storage/config/azdls.rscrates/iceberg/src/io/config/azdls.rs renamed to crates/iceberg/src/io/storage/config/azdls.rs crates/iceberg/src/io/config/azdls.rs renamed to crates/iceberg/src/io/storage/config/azdls.rs

@@ -31,7 +31,7 @@ use async_trait::async_trait;
 use bytes::Bytes;
 use serde::{Deserialize, Serialize};
 
-use super::{
+use crate::io::{
     FileMetadata, FileRead, FileWrite, InputFile, OutputFile, Storage, StorageConfig,
     StorageFactory,
 };

crates/iceberg/src/io/config/gcs.rs …tes/iceberg/src/io/storage/config/gcs.rscrates/iceberg/src/io/config/gcs.rs renamed to crates/iceberg/src/io/storage/config/gcs.rs crates/iceberg/src/io/config/gcs.rs renamed to crates/iceberg/src/io/storage/config/gcs.rs

@@ -30,7 +30,7 @@ use async_trait::async_trait;
 use bytes::Bytes;
 use serde::{Deserialize, Serialize};
 
-use super::{
+use crate::io::{
     FileMetadata, FileRead, FileWrite, InputFile, OutputFile, Storage, StorageConfig,
     StorageFactory,
 };

crates/iceberg/src/io/config/mod.rs …tes/iceberg/src/io/storage/config/mod.rscrates/iceberg/src/io/config/mod.rs renamed to crates/iceberg/src/io/storage/config/mod.rs crates/iceberg/src/io/config/mod.rs renamed to crates/iceberg/src/io/storage/config/mod.rs

@@ -17,15 +17,25 @@
 
 //! Storage interfaces for Iceberg.
 
+mod config;
+mod local_fs;
+mod memory;
+mod opendal;
+
 use std::fmt::Debug;
 use std::sync::Arc;
 
 use async_trait::async_trait;
 use bytes::Bytes;
+pub use config::*;
+pub use local_fs::{LocalFsStorage, LocalFsStorageFactory};
+pub use memory::{MemoryStorage, MemoryStorageFactory};
+#[cfg(feature = "storage-s3")]
+pub use opendal::CustomAwsCredentialLoader;
+pub use opendal::{OpenDalStorage, OpenDalStorageFactory};
 
 use super::{FileMetadata, FileRead, FileWrite, InputFile, OutputFile};
 use crate::Result;
-pub use crate::io::config::StorageConfig;
 
 /// Trait for storage operations in Iceberg.
 ///