diff --git a/src/raw/requests.rs b/src/raw/requests.rs
index bc91d0c..75d5fe4 100644
--- a/src/raw/requests.rs
+++ b/src/raw/requests.rs
@@ -3,11 +3,11 @@
 use super::RawRpcRequest;
 use crate::{
     pd::PdClient,
-    request::{
+    request::KvRequest,
+    store::{
         store_stream_for_key, store_stream_for_keys, store_stream_for_range,
-        store_stream_for_ranges, KvRequest,
+        store_stream_for_ranges, Store,
     },
-    store::Store,
     transaction::HasLocks,
     BoundRange, ColumnFamily, Key, KvPair, Result, Value,
 };
diff --git a/src/request.rs b/src/request.rs
index 299f5a6..4b183de 100644
--- a/src/request.rs
+++ b/src/request.rs
@@ -6,15 +6,12 @@ use crate::{
     stats::tikv_stats,
     store::Store,
     transaction::{resolve_locks, HasLocks},
-    BoundRange, Error, Key, Result,
+    Error, Result,
 };
 use async_trait::async_trait;
 use derive_new::new;
 use futures::{prelude::*, stream::BoxStream};
-use std::{
-    cmp::{max, min},
-    sync::Arc,
-};
+use std::sync::Arc;
 use tikv_client_store::{HasError, HasRegionError, Request};
 
 const DEFAULT_REGION_BACKOFF: Backoff = Backoff::no_jitter_backoff(2, 500, 10);
@@ -179,93 +176,14 @@ impl RetryOptions {
     }
 }
 
-pub fn store_stream_for_key<KeyData, PdC>(
-    key_data: KeyData,
-    pd_client: Arc<PdC>,
-) -> BoxStream<'static, Result<(KeyData, Store)>>
-where
-    KeyData: AsRef<Key> + Send + 'static,
-    PdC: PdClient,
-{
-    pd_client
-        .store_for_key(key_data.as_ref().clone())
-        .map_ok(move |store| (key_data, store))
-        .into_stream()
-        .boxed()
-}
-
-/// Maps keys to a stream of stores. `key_data` must be sorted in increasing order
-pub fn store_stream_for_keys<KeyData, IntoKey, I, PdC>(
-    key_data: I,
-    pd_client: Arc<PdC>,
-) -> BoxStream<'static, Result<(Vec<KeyData>, Store)>>
-where
-    KeyData: AsRef<Key> + Send + Sync + 'static,
-    IntoKey: Into<KeyData> + 'static,
-    I: IntoIterator<Item = IntoKey>,
-    I::IntoIter: Send + Sync + 'static,
-    PdC: PdClient,
-{
-    pd_client
-        .clone()
-        .group_keys_by_region(key_data.into_iter().map(Into::into))
-        .and_then(move |(region_id, key)| {
-            pd_client
-                .clone()
-                .store_for_id(region_id)
-                .map_ok(move |store| (key, store))
-        })
-        .boxed()
-}
-
-pub fn store_stream_for_range<PdC: PdClient>(
-    range: BoundRange,
-    pd_client: Arc<PdC>,
-) -> BoxStream<'static, Result<((Key, Key), Store)>> {
-    pd_client
-        .stores_for_range(range.clone())
-        .map_ok(move |store| {
-            let region_range = store.region.range();
-            (bound_range(region_range, range.clone()), store)
-        })
-        .into_stream()
-        .boxed()
-}
-
-/// The range used for request should be the intersection of `region_range` and `range`.
-fn bound_range(region_range: (Key, Key), range: BoundRange) -> (Key, Key) {
-    let (lower, upper) = region_range;
-    let (lower_bound, upper_bound) = range.into_keys();
-    let up = match (upper.is_empty(), upper_bound) {
-        (_, None) => upper,
-        (true, Some(ub)) => ub,
-        (_, Some(ub)) if ub.is_empty() => upper,
-        (_, Some(ub)) => min(upper, ub),
-    };
-    (max(lower, lower_bound), up)
-}
-
-pub fn store_stream_for_ranges<PdC: PdClient>(
-    ranges: Vec<BoundRange>,
-    pd_client: Arc<PdC>,
-) -> BoxStream<'static, Result<(Vec<BoundRange>, Store)>> {
-    pd_client
-        .clone()
-        .group_ranges_by_region(ranges)
-        .and_then(move |(region_id, range)| {
-            pd_client
-                .clone()
-                .store_for_id(region_id)
-                .map_ok(move |store| (range, store))
-        })
-        .into_stream()
-        .boxed()
-}
-
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::mock::{MockKvClient, MockPdClient};
+    use crate::{
+        mock::{MockKvClient, MockPdClient},
+        store::store_stream_for_key,
+        Key,
+    };
     use futures::executor;
     use grpcio::CallOption;
     use std::{any::Any, sync::Mutex};
diff --git a/src/store.rs b/src/store.rs
index d6d395e..5b96f6f 100644
--- a/src/store.rs
+++ b/src/store.rs
@@ -1,6 +1,13 @@
-use crate::{Region, Result};
+// Copyright 2019 TiKV Project Authors. Licensed under Apache-2.0.
+
+use crate::{pd::PdClient, BoundRange, Key, Region, Result};
 use derive_new::new;
-use std::any::Any;
+use futures::{prelude::*, stream::BoxStream};
+use std::{
+    any::Any,
+    cmp::{max, min},
+    sync::Arc,
+};
 use tikv_client_store::{KvClient, KvConnect, Request, TikvConnect};
 
 #[derive(new)]
@@ -29,3 +36,86 @@ pub trait KvConnectStore: KvConnect {
 }
 
 impl KvConnectStore for TikvConnect {}
+
+pub fn store_stream_for_key<KeyData, PdC>(
+    key_data: KeyData,
+    pd_client: Arc<PdC>,
+) -> BoxStream<'static, Result<(KeyData, Store)>>
+where
+    KeyData: AsRef<Key> + Send + 'static,
+    PdC: PdClient,
+{
+    pd_client
+        .store_for_key(key_data.as_ref().clone())
+        .map_ok(move |store| (key_data, store))
+        .into_stream()
+        .boxed()
+}
+
+/// Maps keys to a stream of stores. `key_data` must be sorted in increasing order
+pub fn store_stream_for_keys<KeyData, IntoKey, I, PdC>(
+    key_data: I,
+    pd_client: Arc<PdC>,
+) -> BoxStream<'static, Result<(Vec<KeyData>, Store)>>
+where
+    KeyData: AsRef<Key> + Send + Sync + 'static,
+    IntoKey: Into<KeyData> + 'static,
+    I: IntoIterator<Item = IntoKey>,
+    I::IntoIter: Send + Sync + 'static,
+    PdC: PdClient,
+{
+    pd_client
+        .clone()
+        .group_keys_by_region(key_data.into_iter().map(Into::into))
+        .and_then(move |(region_id, key)| {
+            pd_client
+                .clone()
+                .store_for_id(region_id)
+                .map_ok(move |store| (key, store))
+        })
+        .boxed()
+}
+
+pub fn store_stream_for_range<PdC: PdClient>(
+    range: BoundRange,
+    pd_client: Arc<PdC>,
+) -> BoxStream<'static, Result<((Key, Key), Store)>> {
+    pd_client
+        .stores_for_range(range.clone())
+        .map_ok(move |store| {
+            let region_range = store.region.range();
+            (bound_range(region_range, range.clone()), store)
+        })
+        .into_stream()
+        .boxed()
+}
+
+/// The range used for request should be the intersection of `region_range` and `range`.
+fn bound_range(region_range: (Key, Key), range: BoundRange) -> (Key, Key) {
+    let (lower, upper) = region_range;
+    let (lower_bound, upper_bound) = range.into_keys();
+    let up = match (upper.is_empty(), upper_bound) {
+        (_, None) => upper,
+        (true, Some(ub)) => ub,
+        (_, Some(ub)) if ub.is_empty() => upper,
+        (_, Some(ub)) => min(upper, ub),
+    };
+    (max(lower, lower_bound), up)
+}
+
+pub fn store_stream_for_ranges<PdC: PdClient>(
+    ranges: Vec<BoundRange>,
+    pd_client: Arc<PdC>,
+) -> BoxStream<'static, Result<(Vec<BoundRange>, Store)>> {
+    pd_client
+        .clone()
+        .group_ranges_by_region(ranges)
+        .and_then(move |(region_id, range)| {
+            pd_client
+                .clone()
+                .store_for_id(region_id)
+                .map_ok(move |store| (range, store))
+        })
+        .into_stream()
+        .boxed()
+}
diff --git a/src/transaction/requests.rs b/src/transaction/requests.rs
index 9f89e58..fb4672e 100644
--- a/src/transaction/requests.rs
+++ b/src/transaction/requests.rs
@@ -2,11 +2,8 @@
 
 use crate::{
     pd::PdClient,
-    request::{
-        store_stream_for_key, store_stream_for_keys, store_stream_for_range, KvRequest,
-        RetryOptions,
-    },
-    store::Store,
+    request::{KvRequest, RetryOptions},
+    store::{store_stream_for_key, store_stream_for_keys, store_stream_for_range, Store},
     timestamp::TimestampExt,
     transaction::HasLocks,
     BoundRange, Error, Key, KvPair, Result, Value,