feat: support truncate collection restful api v2 (#47032)

issue: https://github.com/milvus-io/milvus/issues/47031

---------

Signed-off-by: sijie-ni-0214 <sijie.ni@zilliz.com>

internal/distributed/proxy/httpserver/constant.go

@@ -77,6 +77,7 @@ const (
 	CompactAction                   = "compact"
 	CompactionStateAction           = "get_compaction_state"
 	FlushAction                     = "flush"
+	TruncateAction                  = "truncate"
 	GetProgressAction               = "get_progress" // deprecated, keep it for compatibility, use `/v2/vectordb/jobs/import/describe` instead
 	AddPrivilegesToGroupAction      = "add_privileges_to_group"
 	RemovePrivilegesFromGroupAction = "remove_privileges_from_group"

internal/distributed/proxy/httpserver/handler_v2.go

@@ -77,6 +77,7 @@ func (h *HandlersV2) RegisterRoutesToV2(router gin.IRouter) {
 	router.POST(CollectionCategory+LoadStateAction, timeoutMiddleware(wrapperPost(func() any { return &CollectionNameReq{} }, wrapperTraceLog(h.getCollectionLoadState))))
 	router.POST(CollectionCategory+CreateAction, timeoutMiddleware(wrapperPost(func() any { return &CollectionReq{AutoID: DisableAutoID} }, wrapperTraceLog(h.createCollection))))
 	router.POST(CollectionCategory+DropAction, timeoutMiddleware(wrapperPost(func() any { return &CollectionNameReq{} }, wrapperTraceLog(h.dropCollection))))
+	router.POST(CollectionCategory+TruncateAction, timeoutMiddleware(wrapperPost(func() any { return &CollectionNameReq{} }, wrapperTraceLog(h.truncateCollection))))
 	router.POST(CollectionCategory+RenameAction, timeoutMiddleware(wrapperPost(func() any { return &RenameCollectionReq{} }, wrapperTraceLog(h.renameCollection))))
 	router.POST(CollectionCategory+LoadAction, timeoutMiddleware(wrapperPost(func() any { return &CollectionNameReq{} }, wrapperTraceLog(h.loadCollection))))
 	router.POST(CollectionCategory+RefreshLoadAction, timeoutMiddleware(wrapperPost(func() any { return &CollectionNameReq{} }, wrapperTraceLog(h.refreshLoadCollection))))
@@ -623,6 +624,22 @@ func (h *HandlersV2) dropCollection(ctx context.Context, c *gin.Context, anyReq
 	return resp, err
 }
 
+func (h *HandlersV2) truncateCollection(ctx context.Context, c *gin.Context, anyReq any, dbName string) (interface{}, error) {
+	getter, _ := anyReq.(requestutil.CollectionNameGetter)
+	req := &milvuspb.TruncateCollectionRequest{
+		DbName:         dbName,
+		CollectionName: getter.GetCollectionName(),
+	}
+	c.Set(ContextRequest, req)
+	resp, err := wrapperProxyWithLimit(ctx, c, req, h.checkAuth, false, "/milvus.proto.milvus.MilvusService/TruncateCollection", true, h.proxy, func(reqCtx context.Context, req any) (interface{}, error) {
+		return h.proxy.TruncateCollection(reqCtx, req.(*milvuspb.TruncateCollectionRequest))
+	})
+	if err == nil {
+		HTTPReturn(c, http.StatusOK, wrapperReturnDefault())
+	}
+	return resp, err
+}
+
 func (h *HandlersV2) renameCollection(ctx context.Context, c *gin.Context, anyReq any, dbName string) (interface{}, error) {
 	httpReq := anyReq.(*RenameCollectionReq)
 	req := &milvuspb.RenameCollectionRequest{

internal/distributed/proxy/httpserver/handler_v2_test.go

@@ -2983,3 +2983,46 @@ func (s *CollectionFunctionSuite) TestDropCollectionFunctionNormal() {
 		validateRequestBodyTestCases(s.T(), s.testEngine, addFunctionTestCases, false)
 	})
 }
+
+func TestTruncateCollection(t *testing.T) {
+	paramtable.Init()
+	// disable rate limit
+	paramtable.Get().Save(paramtable.Get().QuotaConfig.QuotaAndLimitsEnabled.Key, "false")
+	defer paramtable.Get().Reset(paramtable.Get().QuotaConfig.QuotaAndLimitsEnabled.Key)
+	mp := mocks.NewMockProxy(t)
+	mp.EXPECT().TruncateCollection(mock.Anything, mock.Anything).Return(&milvuspb.TruncateCollectionResponse{
+		Status: commonSuccessStatus,
+	}, nil).Times(2)
+	testEngine := initHTTPServerV2(mp, false)
+
+	testCases := []requestBodyTestCase{
+		{
+			path:        versionalV2(CollectionCategory, TruncateAction),
+			requestBody: []byte(`{"dbName": "default", "collectionName": "` + DefaultCollectionName + `"}`),
+			errCode:     0,
+			errMsg:      "",
+		},
+		{
+			path:        versionalV2(CollectionCategory, TruncateAction),
+			requestBody: []byte(`{"collectionName": "` + DefaultCollectionName + `"}`),
+			errCode:     0,
+			errMsg:      "",
+		},
+		{
+			path:        versionalV2(CollectionCategory, TruncateAction),
+			requestBody: []byte(`{"dbName": "db", "collectionName": ""}`),
+			errCode:     1802,
+			errMsg:      "missing required parameters",
+		},
+		{
+			path:        versionalV2(CollectionCategory, TruncateAction),
+			requestBody: []byte(`invalid json`),
+			errCode:     1801,
+			errMsg:      "can only accept json format request",
+		},
+	}
+
+	for _, testcase := range testCases {
+		sendReqAndVerify(t, testEngine, testcase.path, http.MethodPost, testcase)
+	}
+}