From 25458138a99132dc8444b5f54270d1b2f5eeb242 Mon Sep 17 00:00:00 2001
From: Rachel Hornung <rachelhornung@google.com>
Date: Wed, 17 May 2023 17:08:38 -0700
Subject: [PATCH] #MediaPipe Add ConcatenateStringVectorCalculator.

PiperOrigin-RevId: 532956844
---
 .../core/concatenate_vector_calculator.cc     |  4 +++
 .../concatenate_vector_calculator_test.cc     | 25 ++++++++++++++++---
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/mediapipe/calculators/core/concatenate_vector_calculator.cc b/mediapipe/calculators/core/concatenate_vector_calculator.cc
index 0079aa98d..4d0d66206 100644
--- a/mediapipe/calculators/core/concatenate_vector_calculator.cc
+++ b/mediapipe/calculators/core/concatenate_vector_calculator.cc
@@ -55,6 +55,10 @@ MEDIAPIPE_REGISTER_NODE(ConcatenateUInt64VectorCalculator);
 typedef ConcatenateVectorCalculator<bool> ConcatenateBoolVectorCalculator;
 MEDIAPIPE_REGISTER_NODE(ConcatenateBoolVectorCalculator);
 
+typedef ConcatenateVectorCalculator<std::string>
+    ConcatenateStringVectorCalculator;
+MEDIAPIPE_REGISTER_NODE(ConcatenateStringVectorCalculator);
+
 // Example config:
 // node {
 //   calculator: "ConcatenateTfLiteTensorVectorCalculator"
diff --git a/mediapipe/calculators/core/concatenate_vector_calculator_test.cc b/mediapipe/calculators/core/concatenate_vector_calculator_test.cc
index 5510b98a3..3fccf58fd 100644
--- a/mediapipe/calculators/core/concatenate_vector_calculator_test.cc
+++ b/mediapipe/calculators/core/concatenate_vector_calculator_test.cc
@@ -30,13 +30,15 @@ namespace mediapipe {
 typedef ConcatenateVectorCalculator<int> TestConcatenateIntVectorCalculator;
 MEDIAPIPE_REGISTER_NODE(TestConcatenateIntVectorCalculator);
 
-void AddInputVector(int index, const std::vector<int>& input, int64_t timestamp,
+template <typename T>
+void AddInputVector(int index, const std::vector<T>& input, int64_t timestamp,
                     CalculatorRunner* runner) {
   runner->MutableInputs()->Index(index).packets.push_back(
-      MakePacket<std::vector<int>>(input).At(Timestamp(timestamp)));
+      MakePacket<std::vector<T>>(input).At(Timestamp(timestamp)));
 }
 
-void AddInputVectors(const std::vector<std::vector<int>>& inputs,
+template <typename T>
+void AddInputVectors(const std::vector<std::vector<T>>& inputs,
                      int64_t timestamp, CalculatorRunner* runner) {
   for (int i = 0; i < inputs.size(); ++i) {
     AddInputVector(i, inputs[i], timestamp, runner);
@@ -382,6 +384,23 @@ TEST(ConcatenateFloatVectorCalculatorTest, OneEmptyStreamNoOutput) {
   EXPECT_EQ(0, outputs.size());
 }
 
+TEST(ConcatenateStringVectorCalculatorTest, OneTimestamp) {
+  CalculatorRunner runner("ConcatenateStringVectorCalculator",
+                          /*options_string=*/"", /*num_inputs=*/3,
+                          /*num_outputs=*/1, /*num_side_packets=*/0);
+
+  std::vector<std::vector<std::string>> inputs = {
+      {"a", "b"}, {"c"}, {"d", "e", "f"}};
+  AddInputVectors(inputs, /*timestamp=*/1, &runner);
+  MP_ASSERT_OK(runner.Run());
+
+  const std::vector<Packet>& outputs = runner.Outputs().Index(0).packets;
+  EXPECT_EQ(1, outputs.size());
+  EXPECT_EQ(Timestamp(1), outputs[0].Timestamp());
+  std::vector<std::string> expected_vector = {"a", "b", "c", "d", "e", "f"};
+  EXPECT_EQ(expected_vector, outputs[0].Get<std::vector<std::string>>());
+}
+
 typedef ConcatenateVectorCalculator<std::unique_ptr<int>>
     TestConcatenateUniqueIntPtrCalculator;
 MEDIAPIPE_REGISTER_NODE(TestConcatenateUniqueIntPtrCalculator);