feat: add vec_dim function (#5587)

* feat:add `vec_dim` function

* delete unused imports

* Modified to be implemented correctly

* fix comment

* add order for sqlness test

src/common/function/src/scalars/vector.rs

@@ -22,6 +22,7 @@ mod scalar_add;
 mod scalar_mul;
 pub(crate) mod sum;
 mod vector_add;
+mod vector_dim;
 mod vector_div;
 mod vector_mul;
 mod vector_norm;
@@ -54,6 +55,7 @@ impl VectorFunction {
         registry.register(Arc::new(vector_mul::VectorMulFunction));
         registry.register(Arc::new(vector_div::VectorDivFunction));
         registry.register(Arc::new(vector_norm::VectorNormFunction));
+        registry.register(Arc::new(vector_dim::VectorDimFunction));
         registry.register(Arc::new(elem_sum::ElemSumFunction));
         registry.register(Arc::new(elem_product::ElemProductFunction));
     }

src/common/function/src/scalars/vector/vector_dim.rs

@@ -0,0 +1,172 @@
+// 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::borrow::Cow;
+use std::fmt::Display;
+
+use common_query::error::InvalidFuncArgsSnafu;
+use common_query::prelude::{Signature, TypeSignature, Volatility};
+use datatypes::prelude::ConcreteDataType;
+use datatypes::scalars::ScalarVectorBuilder;
+use datatypes::vectors::{MutableVector, UInt64VectorBuilder, VectorRef};
+use snafu::ensure;
+
+use crate::function::{Function, FunctionContext};
+use crate::scalars::vector::impl_conv::{as_veclit, as_veclit_if_const};
+
+const NAME: &str = "vec_dim";
+
+/// Returns the dimension of the vector.
+///
+/// # Example
+///
+/// ```sql
+/// SELECT vec_dim('[7.0, 8.0, 9.0, 10.0]');
+///
+/// +---------------------------------------------------------------+
+/// | vec_dim(Utf8("[7.0, 8.0, 9.0, 10.0]"))                        |
+/// +---------------------------------------------------------------+
+/// | 4                                                             |
+/// +---------------------------------------------------------------+
+///
+#[derive(Debug, Clone, Default)]
+pub struct VectorDimFunction;
+
+impl Function for VectorDimFunction {
+    fn name(&self) -> &str {
+        NAME
+    }
+
+    fn return_type(
+        &self,
+        _input_types: &[ConcreteDataType],
+    ) -> common_query::error::Result<ConcreteDataType> {
+        Ok(ConcreteDataType::uint64_datatype())
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::one_of(
+            vec![
+                TypeSignature::Exact(vec![ConcreteDataType::string_datatype()]),
+                TypeSignature::Exact(vec![ConcreteDataType::binary_datatype()]),
+            ],
+            Volatility::Immutable,
+        )
+    }
+
+    fn eval(
+        &self,
+        _func_ctx: FunctionContext,
+        columns: &[VectorRef],
+    ) -> common_query::error::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 arg0 = &columns[0];
+
+        let len = arg0.len();
+        let mut result = UInt64VectorBuilder::with_capacity(len);
+        if len == 0 {
+            return Ok(result.to_vector());
+        }
+
+        let arg0_const = as_veclit_if_const(arg0)?;
+
+        for i in 0..len {
+            let arg0 = match arg0_const.as_ref() {
+                Some(arg0) => Some(Cow::Borrowed(arg0.as_ref())),
+                None => as_veclit(arg0.get_ref(i))?,
+            };
+            let Some(arg0) = arg0 else {
+                result.push_null();
+                continue;
+            };
+            result.push(Some(arg0.len() as u64));
+        }
+
+        Ok(result.to_vector())
+    }
+}
+
+impl Display for VectorDimFunction {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", NAME.to_ascii_uppercase())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+
+    use common_query::error::Error;
+    use datatypes::vectors::StringVector;
+
+    use super::*;
+
+    #[test]
+    fn test_vec_dim() {
+        let func = VectorDimFunction;
+
+        let input0 = Arc::new(StringVector::from(vec![
+            Some("[0.0,2.0,3.0]".to_string()),
+            Some("[1.0,2.0,3.0,4.0]".to_string()),
+            None,
+            Some("[5.0]".to_string()),
+        ]));
+
+        let result = func.eval(FunctionContext::default(), &[input0]).unwrap();
+
+        let result = result.as_ref();
+        assert_eq!(result.len(), 4);
+        assert_eq!(result.get_ref(0).as_u64().unwrap(), Some(3));
+        assert_eq!(result.get_ref(1).as_u64().unwrap(), Some(4));
+        assert!(result.get_ref(2).is_null());
+        assert_eq!(result.get_ref(3).as_u64().unwrap(), Some(1));
+    }
+
+    #[test]
+    fn test_dim_error() {
+        let func = VectorDimFunction;
+
+        let input0 = Arc::new(StringVector::from(vec![
+            Some("[1.0,2.0,3.0]".to_string()),
+            Some("[4.0,5.0,6.0]".to_string()),
+            None,
+            Some("[2.0,3.0,3.0]".to_string()),
+        ]));
+        let input1 = Arc::new(StringVector::from(vec![
+            Some("[1.0,1.0,1.0]".to_string()),
+            Some("[6.0,5.0,4.0]".to_string()),
+            Some("[3.0,2.0,2.0]".to_string()),
+        ]));
+
+        let result = func.eval(FunctionContext::default(), &[input0, input1]);
+
+        match result {
+            Err(Error::InvalidFuncArgs { err_msg, .. }) => {
+                assert_eq!(
+                    err_msg,
+                    "The length of the args is not correct, expect exactly one, have: 2"
+                )
+            }
+            _ => unreachable!(),
+        }
+    }
+}