diff --git a/velox/docs/functions/json.rst b/velox/docs/functions/json.rst index 873239dc84b9c..031272e44d2d8 100644 --- a/velox/docs/functions/json.rst +++ b/velox/docs/functions/json.rst @@ -124,6 +124,13 @@ JSON Functions SELECT json_array_contains('[1, 2, 3]', 2); +.. function:: json_format(json) -> varchar + + Serializes the input JSON value to JSON text conforming to RFC 7159. + The JSON value can be a JSON object, a JSON array, a JSON string, a JSON number, true, false or null + + SELECT json_format('{"k1":1,"k2":23,"k3":456}'); + ============ JSON Vectors ============ diff --git a/velox/functions/prestosql/JsonFunctions.h b/velox/functions/prestosql/JsonFunctions.h index a2a3c2d2c28ca..36513e9b2fbe3 100644 --- a/velox/functions/prestosql/JsonFunctions.h +++ b/velox/functions/prestosql/JsonFunctions.h @@ -20,6 +20,17 @@ namespace facebook::velox::functions { +template +struct JsonFormatFunction { + VELOX_DEFINE_FUNCTION_TYPES(T); + + FOLLY_ALWAYS_INLINE void call( + out_type& result, + const arg_type& json) { + UDFOutputString::assign(result, folly::toJson(folly::parseJson(json))); + } +}; + template struct IsJsonScalarFunction { VELOX_DEFINE_FUNCTION_TYPES(T); diff --git a/velox/functions/prestosql/registration/JsonFunctionsRegistration.cpp b/velox/functions/prestosql/registration/JsonFunctionsRegistration.cpp index 8fb7bec3eec23..3a806cd1f255f 100644 --- a/velox/functions/prestosql/registration/JsonFunctionsRegistration.cpp +++ b/velox/functions/prestosql/registration/JsonFunctionsRegistration.cpp @@ -34,6 +34,7 @@ void registerJsonFunctions() { {"json_array_contains"}); registerFunction( {"json_array_contains"}); + registerFunction({"json_format"}); } } // namespace facebook::velox::functions diff --git a/velox/functions/prestosql/tests/JsonFunctionsTest.cpp b/velox/functions/prestosql/tests/JsonFunctionsTest.cpp index 570bc59adaf44..1f02e88d6c348 100644 --- a/velox/functions/prestosql/tests/JsonFunctionsTest.cpp +++ b/velox/functions/prestosql/tests/JsonFunctionsTest.cpp @@ -24,6 +24,10 @@ namespace { class JsonFunctionsTest : public functions::test::FunctionBaseTest { public: + std::optional json_format(std::optional json) { + return evaluateOnce("json_format(c0)", json); + } + std::optional is_json_scalar(std::optional json) { return evaluateOnce("is_json_scalar(c0)", json); } @@ -52,6 +56,42 @@ class JsonFunctionsTest : public functions::test::FunctionBaseTest { } }; +TEST_F(JsonFunctionsTest, JsonFormatSignatures) { + auto signatures = getSignatureStrings("json_format"); + ASSERT_EQ(1, signatures.size()); + ASSERT_EQ(1, signatures.count("(json) -> varchar")); +} + +TEST_F(JsonFunctionsTest, JsonFormat) { + EXPECT_EQ(json_format(R"(true)"), "true"); + EXPECT_EQ(json_format(R"(null)"), "null"); + EXPECT_EQ(json_format(R"(42)"), "42"); + EXPECT_EQ(json_format(R"("abc")"), "\"abc\""); + EXPECT_EQ(json_format(R"([1, 2, 3])"), "[1,2,3]"); + EXPECT_EQ(json_format(R"({"k1":"v1"})"), "{\"k1\":\"v1\"}"); + + // check keys and values are there + std::optional jsonStr = json_format(R"({"k1":"v1","k2":"v1"})"); + folly::dynamic object = folly::parseJson(jsonStr.value()); + + std::set keys; + keys.insert("k1"); + keys.insert("k2"); + + for (auto begin = object.keys().begin(); begin != object.keys().end(); + ++begin) { + EXPECT_EQ(keys.find(begin->getString()) != keys.end(), true); + } + + std::set values; + values.insert("v1"); + + for (auto begin = object.values().begin(); begin != object.values().end(); + ++begin) { + EXPECT_EQ(values.find(begin->getString()) != values.end(), true); + } +} + TEST_F(JsonFunctionsTest, isJsonScalarSignatures) { auto signatures = getSignatureStrings("is_json_scalar"); ASSERT_EQ(1, signatures.size());