diff --git a/Cargo.lock b/Cargo.lock
index aa7eb276e28..280ea82193b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1617,6 +1617,7 @@ dependencies = [
  "prometheus",
  "prometheus-static-metric",
  "protobuf",
+ "proxy_ffi",
  "raft",
  "raft-proto",
  "raftstore",
@@ -4420,6 +4421,26 @@ dependencies = [
  "protobuf-codegen",
 ]
 
+[[package]]
+name = "proxy_ffi"
+version = "0.0.1"
+dependencies = [
+ "engine_rocks",
+ "engine_traits",
+ "fail",
+ "futures 0.3.15",
+ "futures-util",
+ "keys",
+ "kvproto",
+ "lazy_static",
+ "protobuf",
+ "slog",
+ "slog-global",
+ "tikv_util",
+ "tokio",
+ "tokio-timer",
+]
+
 [[package]]
 name = "proxy_server"
 version = "0.0.1"
diff --git a/Cargo.toml b/Cargo.toml
index 6235d1d9c8a..4e407a30b25 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -301,6 +301,7 @@ members = [
   "fuzz/fuzzer-honggfuzz",
   "fuzz/fuzzer-libfuzzer",
   "gen-proxy-ffi",
+  "proxy_ffi",
   "proxy_tests",
   "raftstore-proxy",
   "tests",
@@ -388,6 +389,7 @@ engine_store_ffi = { path = "engine_store_ffi", default-features = false }
 new-mock-engine-store = { path = "new-mock-engine-store", default-features = false }
 proxy_server = { path = "proxy_server", default-features = false }
 engine_tiflash = { path = "engine_tiflash", default-features = false }
+proxy_ffi = { path = "proxy_ffi", default-features = false }
 
 [profile.dev.package.grpcio-sys]
 debug = false
diff --git a/engine_store_ffi/Cargo.toml b/engine_store_ffi/Cargo.toml
index f24a69afae2..291365e9b88 100644
--- a/engine_store_ffi/Cargo.toml
+++ b/engine_store_ffi/Cargo.toml
@@ -37,7 +37,6 @@ collections = { workspace = true }
 crossbeam = "0.8"
 derivative = "2"
 encryption = { workspace = true, default-features = false }
-
 engine_rocks = { workspace = true, default-features = false }
 # Should be [dev-dependencies] but we need to control the features
 # https://github.com/rust-lang/cargo/issues/6915
@@ -67,6 +66,7 @@ portable-atomic = "0.3"
 prometheus = { version = "0.13", features = ["nightly"] }
 prometheus-static-metric = "0.5"
 protobuf = { version = "2.8", features = ["bytes"] }
+proxy_ffi = { workspace = true, default-features = false }
 raft = { version = "0.7.0", default-features = false, features = ["protobuf-codec"] }
 raft-proto = { version = "0.7.0", default-features = false }
 raftstore = { workspace = true, default-features = false }
diff --git a/engine_store_ffi/src/ffi/mod.rs b/engine_store_ffi/src/ffi/mod.rs
index 4f63dbd8e53..3b1218ea564 100644
--- a/engine_store_ffi/src/ffi/mod.rs
+++ b/engine_store_ffi/src/ffi/mod.rs
@@ -3,38 +3,17 @@
 /// All mods end up with `_impls` impl structs defined in interface.
 /// Other mods which define and impl structs should not end up with name
 /// `_impls`.
-
-#[allow(dead_code)]
-pub mod interfaces;
-// All ffi impls that without raft domain.
-pub mod basic_ffi_impls;
-// All ffi impls that within raft domain, but without proxy helper context.
-pub mod domain_impls;
-// All ffi impls that within proxy helper context.
-pub mod context_impls;
-pub mod encryption_impls;
-// FFI directly related with EngineStoreServerHelper.
-pub mod engine_store_helper_impls;
 pub(crate) mod lock_cf_reader;
 // FFI directly related with RaftStoreProxyFFIHelper.
+pub mod encryption_impls;
+pub mod raftstore_proxy;
 pub mod raftstore_proxy_helper_impls;
-pub mod sst_reader_impls;
+pub mod read_index_helper;
 
 pub use engine_tiflash::EngineStoreConfig;
+pub use proxy_ffi::*;
 
 pub use self::{
-    basic_ffi_impls::*, domain_impls::*, encryption_impls::*, engine_store_helper_impls::*,
-    interfaces::root::DB as interfaces_ffi, lock_cf_reader::*, raftstore_proxy_helper_impls::*,
+    encryption_impls::*, lock_cf_reader::*, raftstore_proxy::*, raftstore_proxy_helper_impls::*,
     sst_reader_impls::*,
 };
-
-#[allow(clippy::wrong_self_convention)]
-pub trait UnwrapExternCFunc<T> {
-    unsafe fn into_inner(&self) -> &T;
-}
-
-impl<T> UnwrapExternCFunc<T> for std::option::Option<T> {
-    unsafe fn into_inner(&self) -> &T {
-        std::mem::transmute::<&Self, &T>(self)
-    }
-}
diff --git a/engine_store_ffi/src/ffi/raftstore_proxy.rs b/engine_store_ffi/src/ffi/raftstore_proxy.rs
new file mode 100644
index 00000000000..9f075f22c77
--- /dev/null
+++ b/engine_store_ffi/src/ffi/raftstore_proxy.rs
@@ -0,0 +1,92 @@
+// Copyright 2022 TiKV Project Authors. Licensed under Apache-2.0.
+
+use std::sync::{
+    atomic::{AtomicU8, Ordering},
+    Arc,
+};
+
+use encryption::DataKeyManager;
+use engine_traits::Peekable;
+
+use super::{
+    interfaces_ffi::{ConstRawVoidPtr, RaftProxyStatus, RaftStoreProxyPtr},
+    raftstore_proxy_helper_impls::*,
+    read_index_helper,
+};
+use crate::TiFlashEngine;
+
+pub struct RaftStoreProxy {
+    pub status: AtomicU8,
+    pub key_manager: Option<Arc<DataKeyManager>>,
+    pub read_index_client: Option<Box<dyn read_index_helper::ReadIndex>>,
+    pub kv_engine: std::sync::RwLock<Option<TiFlashEngine>>,
+}
+
+impl RaftStoreProxy {
+    pub fn new(
+        status: AtomicU8,
+        key_manager: Option<Arc<DataKeyManager>>,
+        read_index_client: Option<Box<dyn read_index_helper::ReadIndex>>,
+        kv_engine: std::sync::RwLock<Option<TiFlashEngine>>,
+    ) -> Self {
+        RaftStoreProxy {
+            status,
+            key_manager,
+            read_index_client,
+            kv_engine,
+        }
+    }
+}
+
+impl RaftStoreProxyFFI<TiFlashEngine> for RaftStoreProxy {
+    fn set_kv_engine(&mut self, kv_engine: Option<TiFlashEngine>) {
+        let mut lock = self.kv_engine.write().unwrap();
+        *lock = kv_engine;
+    }
+
+    fn set_status(&mut self, s: RaftProxyStatus) {
+        self.status.store(s as u8, Ordering::SeqCst);
+    }
+
+    fn get_value_cf<F>(&self, cf: &str, key: &[u8], cb: F)
+    where
+        F: FnOnce(Result<Option<&[u8]>, String>),
+    {
+        let kv_engine_lock = self.kv_engine.read().unwrap();
+        let kv_engine = kv_engine_lock.as_ref();
+        if kv_engine.is_none() {
+            cb(Err("KV engine is not initialized".to_string()));
+            return;
+        }
+        let value = kv_engine.unwrap().get_value_cf(cf, key);
+        match value {
+            Ok(v) => {
+                if let Some(x) = v {
+                    cb(Ok(Some(&x)));
+                } else {
+                    cb(Ok(None));
+                }
+            }
+            Err(e) => {
+                cb(Err(format!("{}", e)));
+            }
+        }
+    }
+}
+
+impl RaftStoreProxyPtr {
+    pub unsafe fn as_ref(&self) -> &RaftStoreProxy {
+        &*(self.inner as *const RaftStoreProxy)
+    }
+    pub fn is_null(&self) -> bool {
+        self.inner.is_null()
+    }
+}
+
+impl From<&RaftStoreProxy> for RaftStoreProxyPtr {
+    fn from(ptr: &RaftStoreProxy) -> Self {
+        Self {
+            inner: ptr as *const _ as ConstRawVoidPtr,
+        }
+    }
+}
diff --git a/engine_store_ffi/src/ffi/raftstore_proxy_helper_impls.rs b/engine_store_ffi/src/ffi/raftstore_proxy_helper_impls.rs
index 4e976b2d25f..42a5a4ff391 100644
--- a/engine_store_ffi/src/ffi/raftstore_proxy_helper_impls.rs
+++ b/engine_store_ffi/src/ffi/raftstore_proxy_helper_impls.rs
@@ -2,15 +2,10 @@
 
 use std::{
     pin::Pin,
-    sync::{
-        atomic::{AtomicU8, Ordering},
-        Arc,
-    },
+    sync::{atomic::Ordering, Arc},
     time,
 };
 
-use encryption::DataKeyManager;
-use engine_traits::Peekable;
 use kvproto::kvrpcpb;
 use protobuf::Message;
 
@@ -21,98 +16,13 @@ use super::{
     engine_store_helper_impls::*,
     interfaces_ffi,
     interfaces_ffi::{
-        BaseBuffView, ConstRawVoidPtr, CppStrVecView, KVGetStatus, RaftProxyStatus,
-        RaftStoreProxyFFIHelper, RaftStoreProxyPtr, RawCppPtr, RawCppStringPtr, RawRustPtr,
-        RawVoidPtr, SSTReaderInterfaces,
+        BaseBuffView, CppStrVecView, KVGetStatus, RaftProxyStatus, RaftStoreProxyFFIHelper,
+        RaftStoreProxyPtr, RawCppPtr, RawCppStringPtr, RawRustPtr, RawVoidPtr, SSTReaderInterfaces,
     },
+    read_index_helper,
     sst_reader_impls::*,
-    UnwrapExternCFunc,
+    utils, UnwrapExternCFunc,
 };
-use crate::{read_index_helper, utils, TiFlashEngine};
-
-pub trait RaftStoreProxyFFI: Sync {
-    fn set_status(&mut self, s: RaftProxyStatus);
-    fn get_value_cf<F>(&self, cf: &str, key: &[u8], cb: F)
-    where
-        F: FnOnce(Result<Option<&[u8]>, String>);
-    fn set_kv_engine(&mut self, kv_engine: Option<TiFlashEngine>);
-}
-
-pub struct RaftStoreProxy {
-    pub status: AtomicU8,
-    pub key_manager: Option<Arc<DataKeyManager>>,
-    pub read_index_client: Option<Box<dyn read_index_helper::ReadIndex>>,
-    pub kv_engine: std::sync::RwLock<Option<TiFlashEngine>>,
-}
-
-impl RaftStoreProxy {
-    pub fn new(
-        status: AtomicU8,
-        key_manager: Option<Arc<DataKeyManager>>,
-        read_index_client: Option<Box<dyn read_index_helper::ReadIndex>>,
-        kv_engine: std::sync::RwLock<Option<TiFlashEngine>>,
-    ) -> Self {
-        RaftStoreProxy {
-            status,
-            key_manager,
-            read_index_client,
-            kv_engine,
-        }
-    }
-}
-
-impl RaftStoreProxyFFI for RaftStoreProxy {
-    fn set_kv_engine(&mut self, kv_engine: Option<TiFlashEngine>) {
-        let mut lock = self.kv_engine.write().unwrap();
-        *lock = kv_engine;
-    }
-
-    fn set_status(&mut self, s: RaftProxyStatus) {
-        self.status.store(s as u8, Ordering::SeqCst);
-    }
-
-    fn get_value_cf<F>(&self, cf: &str, key: &[u8], cb: F)
-    where
-        F: FnOnce(Result<Option<&[u8]>, String>),
-    {
-        let kv_engine_lock = self.kv_engine.read().unwrap();
-        let kv_engine = kv_engine_lock.as_ref();
-        if kv_engine.is_none() {
-            cb(Err("KV engine is not initialized".to_string()));
-            return;
-        }
-        let value = kv_engine.unwrap().get_value_cf(cf, key);
-        match value {
-            Ok(v) => {
-                if let Some(x) = v {
-                    cb(Ok(Some(&x)));
-                } else {
-                    cb(Ok(None));
-                }
-            }
-            Err(e) => {
-                cb(Err(format!("{}", e)));
-            }
-        }
-    }
-}
-
-impl RaftStoreProxyPtr {
-    pub unsafe fn as_ref(&self) -> &RaftStoreProxy {
-        &*(self.inner as *const RaftStoreProxy)
-    }
-    pub fn is_null(&self) -> bool {
-        self.inner.is_null()
-    }
-}
-
-impl From<&RaftStoreProxy> for RaftStoreProxyPtr {
-    fn from(ptr: &RaftStoreProxy) -> Self {
-        Self {
-            inner: ptr as *const _ as ConstRawVoidPtr,
-        }
-    }
-}
 
 impl Clone for RaftStoreProxyPtr {
     fn clone(&self) -> RaftStoreProxyPtr {
@@ -124,8 +34,16 @@ impl Clone for RaftStoreProxyPtr {
 
 impl Copy for RaftStoreProxyPtr {}
 
+pub trait RaftStoreProxyFFI<EK: engine_traits::KvEngine>: Sync {
+    fn set_status(&mut self, s: RaftProxyStatus);
+    fn get_value_cf<F>(&self, cf: &str, key: &[u8], cb: F)
+    where
+        F: FnOnce(Result<Option<&[u8]>, String>);
+    fn set_kv_engine(&mut self, kv_engine: Option<EK>);
+}
+
 impl RaftStoreProxyFFIHelper {
-    pub fn new(proxy: &RaftStoreProxy) -> Self {
+    pub fn new(proxy: RaftStoreProxyPtr) -> Self {
         RaftStoreProxyFFIHelper {
             proxy_ptr: proxy.into(),
             fn_handle_get_proxy_status: Some(ffi_handle_get_proxy_status),
@@ -353,3 +271,60 @@ pub unsafe extern "C" fn ffi_poll_timer_task(task_ptr: RawVoidPtr, waker: RawVoi
         0
     }
 }
+
+#[repr(u32)]
+#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
+pub enum RawRustPtrType {
+    None = 0,
+    ReadIndexTask = 1,
+    ArcFutureWaker = 2,
+    TimerTask = 3,
+}
+
+impl From<u32> for RawRustPtrType {
+    fn from(x: u32) -> Self {
+        unsafe { std::mem::transmute(x) }
+    }
+}
+
+// TODO remove this warn.
+#[allow(clippy::from_over_into)]
+impl Into<u32> for RawRustPtrType {
+    fn into(self) -> u32 {
+        unsafe { std::mem::transmute(self) }
+    }
+}
+
+pub extern "C" fn ffi_gc_rust_ptr(data: RawVoidPtr, type_: interfaces_ffi::RawRustPtrType) {
+    if data.is_null() {
+        return;
+    }
+    let type_: RawRustPtrType = type_.into();
+    match type_ {
+        RawRustPtrType::ReadIndexTask => unsafe {
+            drop(Box::from_raw(data as *mut read_index_helper::ReadIndexTask));
+        },
+        RawRustPtrType::ArcFutureWaker => unsafe {
+            drop(Box::from_raw(data as *mut utils::ArcNotifyWaker));
+        },
+        RawRustPtrType::TimerTask => unsafe {
+            drop(Box::from_raw(data as *mut utils::TimerTask));
+        },
+        _ => unreachable!(),
+    }
+}
+
+impl Default for RawRustPtr {
+    fn default() -> Self {
+        Self {
+            ptr: std::ptr::null_mut(),
+            type_: RawRustPtrType::None.into(),
+        }
+    }
+}
+
+impl RawRustPtr {
+    pub fn is_null(&self) -> bool {
+        self.ptr.is_null()
+    }
+}
diff --git a/engine_store_ffi/src/read_index_helper.rs b/engine_store_ffi/src/ffi/read_index_helper.rs
similarity index 100%
rename from engine_store_ffi/src/read_index_helper.rs
rename to engine_store_ffi/src/ffi/read_index_helper.rs
diff --git a/engine_store_ffi/src/lib.rs b/engine_store_ffi/src/lib.rs
index d068baacf8f..b98bf686af0 100644
--- a/engine_store_ffi/src/lib.rs
+++ b/engine_store_ffi/src/lib.rs
@@ -6,8 +6,6 @@ pub mod core;
 pub mod engine;
 pub mod ffi;
 pub mod observer;
-pub mod read_index_helper;
-mod utils;
 
 // Be discreet when expose inner mods by pub use.
 // engine_store_ffi crate includes too many mods here.
diff --git a/new-mock-engine-store/src/mock_cluster.rs b/new-mock-engine-store/src/mock_cluster.rs
index bf98252a34c..0d20736c11a 100644
--- a/new-mock-engine-store/src/mock_cluster.rs
+++ b/new-mock-engine-store/src/mock_cluster.rs
@@ -16,7 +16,7 @@ pub use engine_store_ffi::ffi::{
     interfaces_ffi::{
         EngineStoreServerHelper, RaftProxyStatus, RaftStoreProxyFFIHelper, RawCppPtr,
     },
-    UnwrapExternCFunc,
+    RaftStoreProxy, UnwrapExternCFunc,
 };
 pub use engine_store_ffi::TiFlashEngine;
 use engine_tiflash::DB;
@@ -180,7 +180,7 @@ impl<T: Simulator<TiFlashEngine>> Cluster<T> {
             key_manager: key_mgr.clone(),
             read_index_client: match router {
                 Some(r) => Some(Box::new(
-                    engine_store_ffi::read_index_helper::ReadIndexClient::new(
+                    engine_store_ffi::ffi::read_index_helper::ReadIndexClient::new(
                         r.clone(),
                         SysQuota::cpu_cores_quota() as usize * 2,
                     ),
@@ -190,7 +190,8 @@ impl<T: Simulator<TiFlashEngine>> Cluster<T> {
             kv_engine: std::sync::RwLock::new(Some(engines.kv.clone())),
         });
 
-        let mut proxy_helper = Box::new(RaftStoreProxyFFIHelper::new(&proxy));
+        let proxy_ref = proxy.as_ref();
+        let mut proxy_helper = Box::new(RaftStoreProxyFFIHelper::new(proxy_ref.into()));
         let mut engine_store_server = Box::new(EngineStoreServer::new(id, Some(engines)));
         engine_store_server.proxy_compat = proxy_compat;
         engine_store_server.mock_cfg = mock_cfg;
@@ -418,7 +419,7 @@ impl<T: Simulator<TiFlashEngine>> Cluster<T> {
             let mut lock = self.ffi_helper_set.lock().unwrap();
             let ffi_helper_set = lock.get_mut(&node_id).unwrap();
             ffi_helper_set.proxy.read_index_client = Some(Box::new(
-                engine_store_ffi::read_index_helper::ReadIndexClient::new(
+                engine_store_ffi::ffi::read_index_helper::ReadIndexClient::new(
                     router.clone(),
                     SysQuota::cpu_cores_quota() as usize * 2,
                 ),
diff --git a/proxy_ffi/Cargo.toml b/proxy_ffi/Cargo.toml
new file mode 100644
index 00000000000..ddd87380ab8
--- /dev/null
+++ b/proxy_ffi/Cargo.toml
@@ -0,0 +1,29 @@
+[package]
+name = "proxy_ffi"
+version = "0.0.1"
+authors = ["The TiKV Authors"]
+license = "Apache-2.0"
+edition = "2018"
+publish = false
+
+[features]
+default = []
+failpoints = ["fail/failpoints"]
+testexport = []
+
+[dependencies]
+encryption = { workspace = true, default-features = false }
+engine_rocks = { workspace = true, default-features = false }
+engine_traits = { workspace = true, default-features = false }
+fail = "0.5"
+futures = "0.3"
+futures-util = { version = "0.3.1", default-features = false, features = ["io"] }
+keys = { workspace = true, default-features = false }
+kvproto = { git = "https://github.com/pingcap/kvproto.git" }
+lazy_static = "1.3"
+protobuf = { version = "2.8", features = ["bytes"] }
+slog = { version = "2.3", features = ["max_level_trace", "release_max_level_debug"] }
+slog-global = { version = "0.1", git = "https://github.com/breeswish/slog-global.git", rev = "d592f88e4dbba5eb439998463054f1a44fbf17b9" }
+tikv_util = { workspace = true, default-features = false }
+tokio = { version = "1.5", features = ["sync", "rt-multi-thread"] }
+tokio-timer = { git = "https://github.com/tikv/tokio", branch = "tokio-timer-hotfix" }
diff --git a/engine_store_ffi/src/ffi/basic_ffi_impls.rs b/proxy_ffi/src/basic_ffi_impls.rs
similarity index 78%
rename from engine_store_ffi/src/ffi/basic_ffi_impls.rs
rename to proxy_ffi/src/basic_ffi_impls.rs
index 3c756e115f8..8aed6197908 100644
--- a/engine_store_ffi/src/ffi/basic_ffi_impls.rs
+++ b/proxy_ffi/src/basic_ffi_impls.rs
@@ -1,7 +1,18 @@
 // Copyright 2022 TiKV Project Authors. Licensed under Apache-2.0.
 use std::pin::Pin;
 
-pub use super::interfaces_ffi::BaseBuffView;
+use super::interfaces_ffi::BaseBuffView;
+
+#[allow(clippy::wrong_self_convention)]
+pub trait UnwrapExternCFunc<T> {
+    unsafe fn into_inner(&self) -> &T;
+}
+
+impl<T> UnwrapExternCFunc<T> for std::option::Option<T> {
+    unsafe fn into_inner(&self) -> &T {
+        std::mem::transmute::<&Self, &T>(self)
+    }
+}
 
 impl From<&[u8]> for BaseBuffView {
     fn from(s: &[u8]) -> Self {
diff --git a/engine_store_ffi/src/ffi/context_impls.rs b/proxy_ffi/src/context_impls.rs
similarity index 100%
rename from engine_store_ffi/src/ffi/context_impls.rs
rename to proxy_ffi/src/context_impls.rs
diff --git a/engine_store_ffi/src/ffi/domain_impls.rs b/proxy_ffi/src/domain_impls.rs
similarity index 58%
rename from engine_store_ffi/src/ffi/domain_impls.rs
rename to proxy_ffi/src/domain_impls.rs
index ca49e8a4e0c..04e8f424059 100644
--- a/engine_store_ffi/src/ffi/domain_impls.rs
+++ b/proxy_ffi/src/domain_impls.rs
@@ -1,15 +1,33 @@
 // Copyright 2022 TiKV Project Authors. Licensed under Apache-2.0.
 
+use std::pin::Pin;
+
 use engine_traits::{CF_DEFAULT, CF_LOCK, CF_WRITE};
 
-use super::{
-    interfaces_ffi,
-    interfaces_ffi::{
-        BaseBuffView, ColumnFamilyType, RaftCmdHeader, RawRustPtr, RawVoidPtr, WriteCmdType,
-        WriteCmdsView,
-    },
+use super::interfaces_ffi::{
+    BaseBuffView, ColumnFamilyType, RaftCmdHeader, SSTView, SSTViewVec, WriteCmdType, WriteCmdsView,
 };
 
+pub fn into_sst_views(snaps: Vec<(&[u8], ColumnFamilyType)>) -> Vec<SSTView> {
+    let mut snaps_view = vec![];
+    for (path, cf) in snaps {
+        snaps_view.push(SSTView {
+            type_: cf,
+            path: path.into(),
+        })
+    }
+    snaps_view
+}
+
+impl From<Pin<&Vec<SSTView>>> for SSTViewVec {
+    fn from(snaps_view: Pin<&Vec<SSTView>>) -> Self {
+        Self {
+            views: snaps_view.as_ptr(),
+            len: snaps_view.len() as u64,
+        }
+    }
+}
+
 pub fn name_to_cf(cf: &str) -> ColumnFamilyType {
     if cf.is_empty() {
         return ColumnFamilyType::Default;
@@ -92,62 +110,3 @@ impl RaftCmdHeader {
         }
     }
 }
-
-#[repr(u32)]
-#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
-pub enum RawRustPtrType {
-    None = 0,
-    ReadIndexTask = 1,
-    ArcFutureWaker = 2,
-    TimerTask = 3,
-}
-
-impl From<u32> for RawRustPtrType {
-    fn from(x: u32) -> Self {
-        unsafe { std::mem::transmute(x) }
-    }
-}
-
-// TODO remove this warn.
-#[allow(clippy::from_over_into)]
-impl Into<u32> for RawRustPtrType {
-    fn into(self) -> u32 {
-        unsafe { std::mem::transmute(self) }
-    }
-}
-
-pub extern "C" fn ffi_gc_rust_ptr(data: RawVoidPtr, type_: interfaces_ffi::RawRustPtrType) {
-    if data.is_null() {
-        return;
-    }
-    let type_: RawRustPtrType = type_.into();
-    match type_ {
-        RawRustPtrType::ReadIndexTask => unsafe {
-            drop(Box::from_raw(
-                data as *mut crate::read_index_helper::ReadIndexTask,
-            ));
-        },
-        RawRustPtrType::ArcFutureWaker => unsafe {
-            drop(Box::from_raw(data as *mut crate::utils::ArcNotifyWaker));
-        },
-        RawRustPtrType::TimerTask => unsafe {
-            drop(Box::from_raw(data as *mut crate::utils::TimerTask));
-        },
-        _ => unreachable!(),
-    }
-}
-
-impl Default for RawRustPtr {
-    fn default() -> Self {
-        Self {
-            ptr: std::ptr::null_mut(),
-            type_: RawRustPtrType::None.into(),
-        }
-    }
-}
-
-impl RawRustPtr {
-    pub fn is_null(&self) -> bool {
-        self.ptr.is_null()
-    }
-}
diff --git a/engine_store_ffi/src/ffi/engine_store_helper_impls.rs b/proxy_ffi/src/engine_store_helper_impls.rs
similarity index 99%
rename from engine_store_ffi/src/ffi/engine_store_helper_impls.rs
rename to proxy_ffi/src/engine_store_helper_impls.rs
index b92eed0db02..f4aea0fdb1e 100644
--- a/engine_store_ffi/src/ffi/engine_store_helper_impls.rs
+++ b/proxy_ffi/src/engine_store_helper_impls.rs
@@ -5,6 +5,7 @@ use kvproto::{kvrpcpb, metapb, raft_cmdpb};
 
 use super::{
     basic_ffi_impls::*,
+    domain_impls::*,
     interfaces_ffi,
     interfaces_ffi::{
         BaseBuffView, ColumnFamilyType, CppStrWithView, EngineStoreApplyRes,
@@ -13,7 +14,6 @@ use super::{
         RawCppStringPtr, RawVoidPtr, SpecialCppPtrType, StoreStats, RAFT_STORE_PROXY_MAGIC_NUMBER,
         RAFT_STORE_PROXY_VERSION,
     },
-    sst_reader_impls::*,
     UnwrapExternCFunc, WriteCmds,
 };
 
diff --git a/engine_store_ffi/src/ffi/interfaces.rs b/proxy_ffi/src/interfaces.rs
similarity index 100%
rename from engine_store_ffi/src/ffi/interfaces.rs
rename to proxy_ffi/src/interfaces.rs
diff --git a/proxy_ffi/src/lib.rs b/proxy_ffi/src/lib.rs
new file mode 100644
index 00000000000..ab15451f1c3
--- /dev/null
+++ b/proxy_ffi/src/lib.rs
@@ -0,0 +1,24 @@
+// Copyright 2022 TiKV Project Authors. Licensed under Apache-2.0.
+
+#[allow(dead_code)]
+pub mod interfaces;
+
+/// All mods end up with `_impls` impl structs defined in interface.
+/// Other mods which define and impl structs should not end up with name
+/// `_impls`.
+// All ffi impls that without raft domain.
+pub mod basic_ffi_impls;
+// All ffi impls that within raft domain, but without proxy helper context.
+pub mod domain_impls;
+// FFI directly related with EngineStoreServerHelper.
+pub mod engine_store_helper_impls;
+// All ffi impls that within engine store helper context.
+pub mod context_impls;
+
+pub mod sst_reader_impls;
+pub mod utils;
+
+pub use self::{
+    basic_ffi_impls::*, context_impls::*, domain_impls::*, engine_store_helper_impls::*,
+    interfaces::root::DB as interfaces_ffi, sst_reader_impls::*, utils::*,
+};
diff --git a/engine_store_ffi/src/ffi/sst_reader_impls.rs b/proxy_ffi/src/sst_reader_impls.rs
similarity index 91%
rename from engine_store_ffi/src/ffi/sst_reader_impls.rs
rename to proxy_ffi/src/sst_reader_impls.rs
index 17dd4d81a21..dd2fd9ac920 100644
--- a/engine_store_ffi/src/ffi/sst_reader_impls.rs
+++ b/proxy_ffi/src/sst_reader_impls.rs
@@ -1,5 +1,5 @@
 // Copyright 2022 TiKV Project Authors. Licensed under Apache-2.0.
-use std::{cell::RefCell, pin::Pin, sync::Arc};
+use std::{cell::RefCell, sync::Arc};
 
 use encryption::DataKeyManager;
 use engine_rocks::{get_env, RocksSstIterator, RocksSstReader};
@@ -8,7 +8,7 @@ use engine_traits::{IterOptions, Iterator, RefIterable, SstReader};
 use super::{
     interfaces_ffi::{
         BaseBuffView, ColumnFamilyType, RaftStoreProxyPtr, RawVoidPtr, SSTReaderInterfaces,
-        SSTReaderPtr, SSTView, SSTViewVec,
+        SSTReaderPtr, SSTView,
     },
     LockCFFileReader,
 };
@@ -124,26 +124,6 @@ pub unsafe extern "C" fn ffi_gc_sst_reader(reader: SSTReaderPtr, type_: ColumnFa
     }
 }
 
-pub fn into_sst_views(snaps: Vec<(&[u8], ColumnFamilyType)>) -> Vec<SSTView> {
-    let mut snaps_view = vec![];
-    for (path, cf) in snaps {
-        snaps_view.push(SSTView {
-            type_: cf,
-            path: path.into(),
-        })
-    }
-    snaps_view
-}
-
-impl From<Pin<&Vec<SSTView>>> for SSTViewVec {
-    fn from(snaps_view: Pin<&Vec<SSTView>>) -> Self {
-        Self {
-            views: snaps_view.as_ptr(),
-            len: snaps_view.len() as u64,
-        }
-    }
-}
-
 pub struct SSTFileReader<'a> {
     iter: RefCell<Option<RocksSstIterator<'a>>>,
     remained: RefCell<bool>,
diff --git a/engine_store_ffi/src/utils.rs b/proxy_ffi/src/utils.rs
similarity index 100%
rename from engine_store_ffi/src/utils.rs
rename to proxy_ffi/src/utils.rs
diff --git a/proxy_server/src/run.rs b/proxy_server/src/run.rs
index 9c6e68d0b62..21a6190a491 100644
--- a/proxy_server/src/run.rs
+++ b/proxy_server/src/run.rs
@@ -35,9 +35,9 @@ use engine_store_ffi::{
             EngineStoreServerHelper, EngineStoreServerStatus, RaftProxyStatus,
             RaftStoreProxyFFIHelper,
         },
+        read_index_helper::ReadIndexClient,
         RaftStoreProxy, RaftStoreProxyFFI,
     },
-    read_index_helper::ReadIndexClient,
     TiFlashEngine,
 };
 use engine_traits::{
@@ -149,8 +149,9 @@ pub fn run_impl<CER: ConfiguredRaftEngine, F: KvFormat>(
         std::sync::RwLock::new(None),
     );
 
+    let proxy_ref = &proxy;
     let proxy_helper = {
-        let mut proxy_helper = RaftStoreProxyFFIHelper::new(&proxy);
+        let mut proxy_helper = RaftStoreProxyFFIHelper::new(proxy_ref.into());
         proxy_helper.fn_server_info = Some(ffi_server_info);
         proxy_helper
     };
@@ -254,8 +255,9 @@ fn run_impl_only_for_decryption<CER: ConfiguredRaftEngine, F: KvFormat>(
         std::sync::RwLock::new(None),
     );
 
+    let proxy_ref = &proxy;
     let proxy_helper = {
-        let mut proxy_helper = RaftStoreProxyFFIHelper::new(&proxy);
+        let mut proxy_helper = RaftStoreProxyFFIHelper::new(proxy_ref.into());
         proxy_helper.fn_server_info = Some(ffi_server_info);
         proxy_helper
     };
diff --git a/proxy_tests/proxy/replica_read.rs b/proxy_tests/proxy/replica_read.rs
index 3c484240955..e182b6ec0e4 100644
--- a/proxy_tests/proxy/replica_read.rs
+++ b/proxy_tests/proxy/replica_read.rs
@@ -191,7 +191,6 @@ fn test_read_index() {
     cluster.must_put(b"k0", b"v0");
     cluster.pd_client.must_none_pending_peer(p2.clone());
     cluster.pd_client.must_none_pending_peer(p3.clone());
-
     let region = cluster.get_region(b"k0");
     assert_eq!(cluster.leader_of_region(region.get_id()).unwrap(), p1);