feat: add respective json_is UDFs for JSON type

src/common/function/src/scalars/json.rs

@@ -14,12 +14,16 @@
 
 use std::sync::Arc;
 mod json_get;
+mod json_is;
 mod json_to_string;
-mod to_json;
+mod parse_json;
 
 use json_get::{JsonGetBool, JsonGetFloat, JsonGetInt, JsonGetString};
+use json_is::{
+    JsonIsArray, JsonIsBool, JsonIsFloat, JsonIsInt, JsonIsNull, JsonIsObject, JsonIsString,
+};
 use json_to_string::JsonToStringFunction;
-use to_json::ToJsonFunction;
+use parse_json::ParseJsonFunction;
 
 use crate::function_registry::FunctionRegistry;
 
@@ -28,11 +32,19 @@ pub(crate) struct JsonFunction;
 impl JsonFunction {
     pub fn register(registry: &FunctionRegistry) {
         registry.register(Arc::new(JsonToStringFunction));
-        registry.register(Arc::new(ToJsonFunction));
+        registry.register(Arc::new(ParseJsonFunction));
 
         registry.register(Arc::new(JsonGetInt));
         registry.register(Arc::new(JsonGetFloat));
         registry.register(Arc::new(JsonGetString));
         registry.register(Arc::new(JsonGetBool));
+
+        registry.register(Arc::new(JsonIsNull));
+        registry.register(Arc::new(JsonIsInt));
+        registry.register(Arc::new(JsonIsFloat));
+        registry.register(Arc::new(JsonIsString));
+        registry.register(Arc::new(JsonIsBool));
+        registry.register(Arc::new(JsonIsArray));
+        registry.register(Arc::new(JsonIsObject));
     }
 }

src/common/function/src/scalars/json/json_get.rs

@@ -47,7 +47,7 @@ fn get_json_by_path(json: &[u8], path: &str) -> Option<Vec<u8>> {
 /// If the path does not exist or the value is not the type specified, return `NULL`.
 macro_rules! json_get {
     // e.g. name = JsonGetInt, type = Int64, rust_type = i64, doc = "Get the value from the JSONB by the given path and return it as an integer."
-    ($name: ident, $type: ident, $rust_type: ident, $doc:expr) => {
+    ($name:ident, $type:ident, $rust_type:ident, $doc:expr) => {
         paste::paste! {
             #[doc = $doc]
             #[derive(Clone, Debug, Default)]

src/common/function/src/scalars/json/json_is.rs

@@ -0,0 +1,215 @@
+// Copyright 2023 Greptime Team
+//
+// 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.
+
+use std::fmt::{self, Display};
+
+use common_query::error::{InvalidFuncArgsSnafu, Result, UnsupportedInputDataTypeSnafu};
+use common_query::prelude::Signature;
+use datafusion::logical_expr::Volatility;
+use datatypes::data_type::ConcreteDataType;
+use datatypes::prelude::VectorRef;
+use datatypes::scalars::ScalarVectorBuilder;
+use datatypes::vectors::{BooleanVectorBuilder, MutableVector};
+use snafu::ensure;
+
+use crate::function::{Function, FunctionContext};
+
+/// Checks if the input is a JSON object of the given type.
+macro_rules! json_is {
+    ($name:ident, $json_type:ident, $doc:expr) => {
+        paste::paste! {
+            #[derive(Clone, Debug, Default)]
+            pub struct $name;
+
+            impl Function for $name {
+                fn name(&self) -> &str {
+                    stringify!([<$name:snake>])
+                }
+
+                fn return_type(&self, _input_types: &[ConcreteDataType]) -> Result<ConcreteDataType> {
+                    Ok(ConcreteDataType::boolean_datatype())
+                }
+
+                fn signature(&self) -> Signature {
+                    Signature::exact(vec![ConcreteDataType::json_datatype()], Volatility::Immutable)
+                }
+
+                fn eval(&self, _func_ctx: FunctionContext, columns: &[VectorRef]) -> Result<VectorRef> {
+                    ensure!(
+                        columns.len() == 1,
+                        InvalidFuncArgsSnafu {
+                            err_msg: format!(
+                                "The length of the args is not correct, expect exactly one, have: {}",
+                                columns.len()
+                            ),
+                        }
+                    );
+
+                    let jsons = &columns[0];
+                    let size = jsons.len();
+                    let datatype = jsons.data_type();
+                    let mut results = BooleanVectorBuilder::with_capacity(size);
+
+                    match datatype {
+                        // JSON data type uses binary vector
+                        ConcreteDataType::Binary(_) => {
+                            for i in 0..size {
+                                let json = jsons.get_ref(i);
+                                let json = json.as_binary();
+                                let result = match json {
+                                    Ok(Some(json)) => {
+                                        Some(jsonb::[<is_ $json_type>](json))
+                                    }
+                                    _ => None,
+                                };
+                                results.push(result);
+                            }
+                        }
+                        _ => {
+                            return UnsupportedInputDataTypeSnafu {
+                                function: stringify!([<$name:snake>]),
+                                datatypes: columns.iter().map(|c| c.data_type()).collect::<Vec<_>>(),
+                            }
+                            .fail();
+                        }
+                    }
+
+                    Ok(results.to_vector())
+                }
+            }
+
+            impl Display for $name {
+                fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                    write!(f, "{}", stringify!([<$name:snake>]).to_ascii_uppercase())
+                }
+            }
+        }
+    }
+}
+
+json_is!(JsonIsNull, null, "Checks if the input JSONB is null");
+json_is!(
+    JsonIsBool,
+    boolean,
+    "Checks if the input JSONB is a boolean type JSON value"
+);
+json_is!(
+    JsonIsInt,
+    i64,
+    "Checks if the input JSONB is a integer type JSON value"
+);
+json_is!(
+    JsonIsFloat,
+    number,
+    "Checks if the input JSONB is a JSON float"
+);
+json_is!(
+    JsonIsString,
+    string,
+    "Checks if the input JSONB is a JSON string"
+);
+json_is!(
+    JsonIsArray,
+    array,
+    "Checks if the input JSONB is a JSON array"
+);
+json_is!(
+    JsonIsObject,
+    object,
+    "Checks if the input JSONB is a JSON object"
+);
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+
+    use datatypes::scalars::ScalarVector;
+    use datatypes::vectors::BinaryVector;
+
+    use super::*;
+
+    #[test]
+    fn test_json_is_functions() {
+        let json_is_functions: [&dyn Function; 6] = [
+            &JsonIsBool,
+            &JsonIsInt,
+            &JsonIsFloat,
+            &JsonIsString,
+            &JsonIsArray,
+            &JsonIsObject,
+        ];
+        let expected_names = [
+            "json_is_bool",
+            "json_is_int",
+            "json_is_float",
+            "json_is_string",
+            "json_is_array",
+            "json_is_object",
+        ];
+        for (func, expected_name) in json_is_functions.iter().zip(expected_names.iter()) {
+            assert_eq!(func.name(), *expected_name);
+            assert_eq!(
+                func.return_type(&[ConcreteDataType::json_datatype()])
+                    .unwrap(),
+                ConcreteDataType::boolean_datatype()
+            );
+            assert_eq!(
+                func.signature(),
+                Signature::exact(
+                    vec![ConcreteDataType::json_datatype()],
+                    Volatility::Immutable
+                )
+            );
+        }
+
+        let json_strings = [
+            r#"true"#,
+            r#"1"#,
+            r#"1.0"#,
+            r#""The pig fly through a castle, and has been attracted by the princess.""#,
+            r#"[1, 2]"#,
+            r#"{"a": 1}"#,
+        ];
+        let expected_results = [
+            [true, false, false, false, false, false],
+            [false, true, false, false, false, false],
+            // Integers are also floats
+            [false, true, true, false, false, false],
+            [false, false, false, true, false, false],
+            [false, false, false, false, true, false],
+            [false, false, false, false, false, true],
+        ];
+
+        let jsonbs = json_strings
+            .iter()
+            .map(|s| {
+                let value = jsonb::parse_value(s.as_bytes()).unwrap();
+                value.to_vec()
+            })
+            .collect::<Vec<_>>();
+        let json_vector = BinaryVector::from_vec(jsonbs);
+        let args: Vec<VectorRef> = vec![Arc::new(json_vector)];
+
+        for (func, expected_result) in json_is_functions.iter().zip(expected_results.iter()) {
+            let vector = func.eval(FunctionContext::default(), &args).unwrap();
+            assert_eq!(vector.len(), json_strings.len());
+
+            for (i, expected) in expected_result.iter().enumerate() {
+                let result = vector.get_ref(i);
+                let result = result.as_boolean().unwrap().unwrap();
+                assert_eq!(result, *expected);
+            }
+        }
+    }
+}

src/common/function/src/scalars/json/json_to_string.rs

@@ -119,7 +119,7 @@ mod tests {
     use super::*;
 
     #[test]
-    fn test_get_by_path_function() {
+    fn test_json_to_string_function() {
         let json_to_string = JsonToStringFunction;
 
         assert_eq!("json_to_string", json_to_string.name());

src/common/function/src/scalars/json/to_json.rs → src/common/function/src/scalars/json/parse_json.rs

@@ -27,11 +27,11 @@ use crate::function::{Function, FunctionContext};
 
 /// Parses the `String` into `JSONB`.
 #[derive(Clone, Debug, Default)]
-pub struct ToJsonFunction;
+pub struct ParseJsonFunction;
 
-const NAME: &str = "to_json";
+const NAME: &str = "parse_json";
 
-impl Function for ToJsonFunction {
+impl Function for ParseJsonFunction {
     fn name(&self) -> &str {
         NAME
     }
@@ -101,9 +101,9 @@ impl Function for ToJsonFunction {
     }
 }
 
-impl Display for ToJsonFunction {
+impl Display for ParseJsonFunction {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "TO_JSON")
+        write!(f, "PARSE_JSON")
     }
 }
 
@@ -119,17 +119,17 @@ mod tests {
 
     #[test]
     fn test_get_by_path_function() {
-        let to_json = ToJsonFunction;
+        let parse_json = ParseJsonFunction;
 
-        assert_eq!("to_json", to_json.name());
+        assert_eq!("parse_json", parse_json.name());
         assert_eq!(
             ConcreteDataType::json_datatype(),
-            to_json
+            parse_json
                 .return_type(&[ConcreteDataType::json_datatype()])
                 .unwrap()
         );
 
-        assert!(matches!(to_json.signature(),
+        assert!(matches!(parse_json.signature(),
                          Signature {
                              type_signature: TypeSignature::Exact(valid_types),
                              volatility: Volatility::Immutable
@@ -152,13 +152,12 @@ mod tests {
 
         let json_string_vector = StringVector::from_vec(json_strings.to_vec());
         let args: Vec<VectorRef> = vec![Arc::new(json_string_vector)];
-        let vector = to_json.eval(FunctionContext::default(), &args).unwrap();
+        let vector = parse_json.eval(FunctionContext::default(), &args).unwrap();
 
         assert_eq!(3, vector.len());
         for (i, gt) in jsonbs.iter().enumerate() {
             let result = vector.get_ref(i);
             let result = result.as_binary().unwrap().unwrap();
-            // remove whitespaces
             assert_eq!(gt, result);
         }
     }