Initial commit

velox/docs/functions/spark/json.rst

@@ -22,6 +22,8 @@ JSON Functions
 
 .. spark:function:: get_json_object(json, path) -> varchar
 
-    Extracts a json object from path::
+    Extracts a json object from ``path``. Returns NULL if it finds json string
+    is malformed. ::
 
-        SELECT get_json_object('{"a":"b"}', '$.a'); -- b
+        SELECT get_json_object('{"a":"b"}', '$.a'); -- 'b'
+        SELECT get_json_object('{"a":{"b":"c"}}', '$.a'); -- '{"b":"c"}'

velox/functions/sparksql/CMakeLists.txt

@@ -48,7 +48,8 @@ target_link_libraries(
   velox_functions_spark_specialforms
   velox_is_null_functions
   velox_functions_util
-  Folly::folly)
+  Folly::folly
+  simdjson)
 
 set_property(TARGET velox_functions_spark PROPERTY JOB_POOL_COMPILE
                                                    high_memory_pool)

velox/functions/sparksql/Register.cpp

@@ -22,7 +22,6 @@
 #include "velox/functions/lib/Re2Functions.h"
 #include "velox/functions/lib/RegistrationHelpers.h"
 #include "velox/functions/prestosql/DateTimeFunctions.h"
-#include "velox/functions/prestosql/JsonFunctions.h"
 #include "velox/functions/prestosql/StringFunctions.h"
 #include "velox/functions/sparksql/ArrayMinMaxFunction.h"
 #include "velox/functions/sparksql/ArraySort.h"
@@ -35,6 +34,7 @@
 #include "velox/functions/sparksql/RegexFunctions.h"
 #include "velox/functions/sparksql/RegisterArithmetic.h"
 #include "velox/functions/sparksql/RegisterCompare.h"
+#include "velox/functions/sparksql/SIMDJsonFunctions.h"
 #include "velox/functions/sparksql/Size.h"
 #include "velox/functions/sparksql/String.h"
 #include "velox/functions/sparksql/StringToMap.h"
@@ -124,7 +124,7 @@ void registerFunctions(const std::string& prefix) {
   // Register size functions
   registerSize(prefix + "size");
 
-  registerFunction<JsonExtractScalarFunction, Varchar, Varchar, Varchar>(
+  registerFunction<SIMDGetJsonObjectFunction, Varchar, Varchar, Varchar>(
       {prefix + "get_json_object"});
 
   // Register string functions.

velox/functions/sparksql/SIMDJsonFunctions.h

@@ -0,0 +1,182 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "velox/functions/prestosql/SIMDJsonFunctions.h"
+
+using namespace simdjson;
+
+namespace facebook::velox::functions::sparksql {
+
+template <typename T>
+struct SIMDGetJsonObjectFunction {
+  VELOX_DEFINE_FUNCTION_TYPES(T);
+  std::optional<std::string> formattedJsonPath_;
+
+  // ASCII input always produces ASCII result.
+  static constexpr bool is_default_ascii_behavior = true;
+
+  // Makes a conversion from spark's json path, e.g., converts
+  // "$.a.b" to "/a/b".
+  FOLLY_ALWAYS_INLINE std::string getFormattedJsonPath(
+      const arg_type<Varchar>& jsonPath) {
+    char formattedJsonPath[jsonPath.size() + 1];
+    int j = 0;
+    for (int i = 0; i < jsonPath.size(); i++) {
+      if (jsonPath.data()[i] == '$' || jsonPath.data()[i] == ']' ||
+          jsonPath.data()[i] == '\'') {
+        continue;
+      } else if (jsonPath.data()[i] == '[' || jsonPath.data()[i] == '.') {
+        formattedJsonPath[j] = '/';
+        j++;
+      } else {
+        formattedJsonPath[j] = jsonPath.data()[i];
+        j++;
+      }
+    }
+    formattedJsonPath[j] = '\0';
+    return std::string(formattedJsonPath, j + 1);
+  }
+
+  FOLLY_ALWAYS_INLINE void initialize(
+      const core::QueryConfig& config,
+      const arg_type<Varchar>* /*json*/,
+      const arg_type<Varchar>* jsonPath) {
+    if (jsonPath != nullptr) {
+      formattedJsonPath_ = getFormattedJsonPath(*jsonPath);
+    }
+  }
+
+  FOLLY_ALWAYS_INLINE simdjson::error_code extractStringResult(
+      simdjson_result<ondemand::value> rawResult,
+      out_type<Varchar>& result) {
+    simdjson::error_code error;
+    std::stringstream ss;
+    switch (rawResult.type()) {
+      // For number and bool types, we need to explicitly get the value
+      // for specific types instead of using `ss << rawResult`. Thus, we
+      // can make simdjson's internal parsing position moved and then we
+      // can check the validity of ending character.
+      case ondemand::json_type::number: {
+        switch (rawResult.get_number_type()) {
+          case ondemand::number_type::unsigned_integer: {
+            uint64_t numberResult;
+            error = rawResult.get_uint64().get(numberResult);
+            if (!error) {
+              ss << numberResult;
+              result.append(ss.str());
+            }
+            return error;
+          }
+          case ondemand::number_type::signed_integer: {
+            int64_t numberResult;
+            error = rawResult.get_int64().get(numberResult);
+            if (!error) {
+              ss << numberResult;
+              result.append(ss.str());
+            }
+            return error;
+          }
+          case ondemand::number_type::floating_point_number: {
+            double numberResult;
+            error = rawResult.get_double().get(numberResult);
+            if (!error) {
+              ss << numberResult;
+              result.append(ss.str());
+            }
+            return error;
+          }
+          default:
+            VELOX_UNREACHABLE();
+        }
+      }
+      case ondemand::json_type::boolean: {
+        bool boolResult;
+        error = rawResult.get_bool().get(boolResult);
+        if (!error) {
+          result.append(boolResult ? "true" : "false");
+        }
+        return error;
+      }
+      case ondemand::json_type::string: {
+        std::string_view stringResult;
+        error = rawResult.get_string().get(stringResult);
+        result.append(stringResult);
+        return error;
+      }
+      case ondemand::json_type::object: {
+        // For nested case, e.g., for "{"my": {"hello": 10}}", "$.my" will
+        // return an object type.
+        ss << rawResult;
+        result.append(ss.str());
+        return SUCCESS;
+      }
+      case ondemand::json_type::array: {
+        ss << rawResult;
+        result.append(ss.str());
+        return SUCCESS;
+      }
+      default: {
+        return UNSUPPORTED_ARCHITECTURE;
+      }
+    }
+  }
+
+  // This is a simple validation by checking whether the obtained result is
+  // followed by valid char. Because ondemand parsing we are using ignores json
+  // format validation for characters following the current parsing position.
+  bool isValidEndingCharacter(const char* currentPos) {
+    char endingChar = *currentPos;
+    if (endingChar == ',' || endingChar == '}' || endingChar == ']') {
+      return true;
+    }
+    if (endingChar == ' ' || endingChar == '\r' || endingChar == '\n' ||
+        endingChar == '\t') {
+      // These chars can be prior to a valid ending char.
+      return isValidEndingCharacter(currentPos++);
+    }
+    return false;
+  }
+
+  FOLLY_ALWAYS_INLINE bool call(
+      out_type<Varchar>& result,
+      const arg_type<Varchar>& json,
+      const arg_type<Varchar>& jsonPath) {
+    ParserContext ctx(json.data(), json.size());
+    try {
+      ctx.parseDocument();
+      simdjson_result<ondemand::value> rawResult =
+          formattedJsonPath_.has_value()
+          ? ctx.jsonDoc.at_pointer(formattedJsonPath_.value().data())
+          : ctx.jsonDoc.at_pointer(getFormattedJsonPath(jsonPath).data());
+      // Field not found.
+      if (rawResult.error() == NO_SUCH_FIELD) {
+        return false;
+      }
+      auto error = extractStringResult(rawResult, result);
+      if (error) {
+        return false;
+      }
+    } catch (simdjson_error& e) {
+      return false;
+    }
+
+    const char* currentPos;
+    ctx.jsonDoc.current_location().get(currentPos);
+    return isValidEndingCharacter(currentPos);
+  }
+};
+
+} // namespace facebook::velox::functions::sparksql

velox/functions/sparksql/tests/CMakeLists.txt

@@ -29,6 +29,7 @@ add_executable(
   ElementAtTest.cpp
   HashTest.cpp
   InTest.cpp
+  JsonFunctionsTest.cpp
   LeastGreatestTest.cpp
   MapTest.cpp
   MightContainTest.cpp

velox/functions/sparksql/tests/JsonFunctionsTest.cpp

@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "velox/functions/prestosql/types/JsonType.h"
+#include "velox/functions/sparksql/tests/SparkFunctionBaseTest.h"
+#include "velox/type/Type.h"
+
+#include <stdint.h>
+
+namespace facebook::velox::functions::sparksql::test {
+namespace {
+
+class JsonFunctionTest : public SparkFunctionBaseTest {
+ protected:
+  std::optional<std::string> getJsonObject(
+      const std::optional<std::string>& json,
+      const std::optional<std::string>& jsonPath) {
+    return evaluateOnce<std::string>("get_json_object(c0, c1)", json, jsonPath);
+  }
+};
+
+TEST_F(JsonFunctionTest, getJsonObject) {
+  EXPECT_EQ(getJsonObject(R"({"hello": "3.5"})", "$.hello"), "3.5");
+  EXPECT_EQ(getJsonObject(R"({"hello": 3.5})", "$.hello"), "3.5");
+  EXPECT_EQ(getJsonObject(R"({"hello": 292222730})", "$.hello"), "292222730");
+  EXPECT_EQ(getJsonObject(R"({"hello": -292222730})", "$.hello"), "-292222730");
+  EXPECT_EQ(getJsonObject(R"({"my": {"hello": 3.5}})", "$.my.hello"), "3.5");
+  EXPECT_EQ(getJsonObject(R"({"my": {"hello": true}})", "$.my.hello"), "true");
+  EXPECT_EQ(getJsonObject(R"({"hello": ""})", "$.hello"), "");
+  EXPECT_EQ(
+      getJsonObject(R"({"name": "Alice", "age": 5, "id": "001"})", "$.age"),
+      "5");
+  EXPECT_EQ(
+      getJsonObject(R"({"name": "Alice", "age": 5, "id": "001"})", "$.id"),
+      "001");
+  EXPECT_EQ(
+      getJsonObject(
+          R"([{"my": {"param": {"name": "Alice", "age": "5", "id": "001"}}}, {"other": "v1"}])",
+          "$[0]['my']['param']['age']"),
+      "5");
+  EXPECT_EQ(
+      getJsonObject(
+          R"([{"my": {"param": {"name": "Alice", "age": "5", "id": "001"}}}, {"other": "v1"}])",
+          "$[0].my.param.age"),
+      "5");
+
+  // Json object as result.
+  EXPECT_EQ(
+      getJsonObject(
+          R"({"my": {"param": {"name": "Alice", "age": "5", "id": "001"}}})",
+          "$.my.param"),
+      R"({"name": "Alice", "age": "5", "id": "001"})");
+  EXPECT_EQ(
+      getJsonObject(
+          R"({"my": {"param": {"name": "Alice", "age": "5", "id": "001"}}})",
+          "$['my']['param']"),
+      R"({"name": "Alice", "age": "5", "id": "001"})");
+
+  // Array as result.
+  EXPECT_EQ(
+      getJsonObject(
+          R"([{"my": {"param": {"name": "Alice"}}}, {"other": ["v1", "v2"]}])",
+          "$[1].other"),
+      R"(["v1", "v2"])");
+  // Array element as result.
+  EXPECT_EQ(
+      getJsonObject(
+          R"([{"my": {"param": {"name": "Alice"}}}, {"other": ["v1", "v2"]}])",
+          "$[1].other[0]"),
+      "v1");
+  EXPECT_EQ(
+      getJsonObject(
+          R"([{"my": {"param": {"name": "Alice"}}}, {"other": ["v1", "v2"]}])",
+          "$[1].other[1]"),
+      "v2");
+
+  // Field not found.
+  EXPECT_EQ(getJsonObject(R"({"hello": "3.5"})", "$.hi"), std::nullopt);
+  // Illegal json.
+  EXPECT_EQ(getJsonObject(R"({"hello"-3.5})", "$.hello"), std::nullopt);
+  // Illegal json path.
+  EXPECT_EQ(getJsonObject(R"({"hello": "3.5"})", "$hello"), std::nullopt);
+  EXPECT_EQ(getJsonObject(R"({"hello": "3.5"})", "$."), std::nullopt);
+  // Invalid ending character.
+  EXPECT_EQ(
+      getJsonObject(
+          R"([{"my": {"param": {"name": "Alice"quoted""}}}, {"other": ["v1", "v2"]}])",
+          "$[0].my.param.name"),
+      std::nullopt);
+}
+
+} // namespace
+} // namespace facebook::velox::functions::sparksql::test