http: add GetEmptyRegions API (tikv#7660)

ref tikv#7300

Signed-off-by: lance6716 <[email protected]>

client/http/interface.go

@@ -38,6 +38,7 @@ type Client interface {
 	GetRegions(context.Context) (*RegionsInfo, error)
 	GetRegionsByKeyRange(context.Context, *KeyRange, int) (*RegionsInfo, error)
 	GetRegionsByStoreID(context.Context, uint64) (*RegionsInfo, error)
+	GetEmptyRegions(context.Context) (*RegionsInfo, error)
 	GetRegionsReplicatedStateByKeyRange(context.Context, *KeyRange) (string, error)
 	GetHotReadRegions(context.Context) (*StoreHotPeersInfos, error)
 	GetHotWriteRegions(context.Context) (*StoreHotPeersInfos, error)
@@ -204,6 +205,20 @@ func (c *client) GetRegionsByStoreID(ctx context.Context, storeID uint64) (*Regi
 	return &regions, nil
 }
 
+// GetEmptyRegions gets the empty regions info.
+func (c *client) GetEmptyRegions(ctx context.Context) (*RegionsInfo, error) {
+	var regions RegionsInfo
+	err := c.request(ctx, newRequestInfo().
+		WithName(getEmptyRegionsName).
+		WithURI(EmptyRegions).
+		WithMethod(http.MethodGet).
+		WithResp(&regions))
+	if err != nil {
+		return nil, err
+	}
+	return &regions, nil
+}
+
 // GetRegionsReplicatedStateByKeyRange gets the regions replicated state info by key range.
 // The keys in the key range should be encoded in the hex bytes format (without encoding to the UTF-8 bytes).
 func (c *client) GetRegionsReplicatedStateByKeyRange(ctx context.Context, keyRange *KeyRange) (string, error) {

client/http/request_info.go

@@ -26,6 +26,7 @@ const (
 	getRegionsName                          = "GetRegions"
 	getRegionsByKeyRangeName                = "GetRegionsByKeyRange"
 	getRegionsByStoreIDName                 = "GetRegionsByStoreID"
+	getEmptyRegionsName                     = "GetEmptyRegions"
 	getRegionsReplicatedStateByKeyRangeName = "GetRegionsReplicatedStateByKeyRange"
 	getHotReadRegionsName                   = "GetHotReadRegions"
 	getHotWriteRegionsName                  = "GetHotWriteRegions"

tests/integrations/client/http_client_test.go

@@ -109,6 +109,10 @@ func (suite *httpClientTestSuite) TestMeta() {
 	re.NoError(err)
 	re.Equal(int64(2), regions.Count)
 	re.Len(regions.Regions, 2)
+	regions, err = suite.client.GetEmptyRegions(suite.ctx)
+	re.NoError(err)
+	re.Equal(int64(2), regions.Count)
+	re.Len(regions.Regions, 2)
 	state, err := suite.client.GetRegionsReplicatedStateByKeyRange(suite.ctx, pd.NewKeyRange([]byte("a1"), []byte("a3")))
 	re.NoError(err)
 	re.Equal("INPROGRESS", state)