feat: router impl (#363)

* feat: heartbeat lease & route api

* feat: batchput&cas

* chore: demo&ut

* chore: by cr

* chore: datanode selector

* chore: rename with_key_range to with_range

* chore: ut

src/api/greptime/v1/meta/store.proto

@@ -11,6 +11,13 @@ service Store {
   // Put puts the given key into the key-value store.
   rpc Put(PutRequest) returns (PutResponse);
 
+  // BatchPut atomically puts the given keys into the key-value store.
+  rpc BatchPut(BatchPutRequest) returns (BatchPutResponse);
+
+  // CompareAndPut atomically puts the value to the given updated
+  // value if the current value == the expected value.
+  rpc CompareAndPut(CompareAndPutRequest) returns (CompareAndPutResponse);
+
   // DeleteRange deletes the given range from the key-value store.
   rpc DeleteRange(DeleteRangeRequest) returns (DeleteRangeResponse);
 }
@@ -64,6 +71,42 @@ message PutResponse {
   KeyValue prev_kv = 2;
 }
 
+message BatchPutRequest {
+  RequestHeader header = 1;
+
+  repeated KeyValue kvs = 2;
+  // If prev_kv is set, gets the previous key-value pairs before changing it.
+  // The previous key-value pairs will be returned in the batch put response.
+  bool prev_kv = 3;
+}
+
+message BatchPutResponse {
+  ResponseHeader header = 1;
+
+  // If prev_kv is set in the request, the previous key-value pairs will be
+  // returned.
+  repeated KeyValue prev_kvs = 2;
+}
+
+message CompareAndPutRequest {
+  RequestHeader header = 1;
+
+  // key is the key, in bytes, to put into the key-value store.
+  bytes key = 2;
+  // expect is the previous value, in bytes
+  bytes expect = 3;
+  // value is the value, in bytes, to associate with the key in the
+  // key-value store.
+  bytes value = 4; 
+}
+
+message CompareAndPutResponse {
+  ResponseHeader header = 1;
+
+  bool success = 2;
+  KeyValue prev_kv = 3;
+}
+
 message DeleteRangeRequest {
   RequestHeader header = 1;
 

src/api/src/v1/meta.rs

@@ -2,18 +2,34 @@ tonic::include_proto!("greptime.v1.meta");
 
 pub const PROTOCOL_VERSION: u64 = 1;
 
-pub const fn request_header((cluster_id, member_id): (u64, u64)) -> Option<RequestHeader> {
-    Some(RequestHeader::new((cluster_id, member_id)))
-}
-
 impl RequestHeader {
     #[inline]
-    pub const fn new((cluster_id, member_id): (u64, u64)) -> Self {
-        Self {
+    pub fn new((cluster_id, member_id): (u64, u64)) -> Option<Self> {
+        Some(Self {
             protocol_version: PROTOCOL_VERSION,
             cluster_id,
             member_id,
-        }
+        })
+    }
+}
+
+impl ResponseHeader {
+    #[inline]
+    pub fn success(cluster_id: u64) -> Option<Self> {
+        Some(Self {
+            protocol_version: PROTOCOL_VERSION,
+            cluster_id,
+            ..Default::default()
+        })
+    }
+
+    #[inline]
+    pub fn failed(cluster_id: u64, error: Error) -> Option<Self> {
+        Some(Self {
+            protocol_version: PROTOCOL_VERSION,
+            cluster_id,
+            error: Some(error),
+        })
     }
 }