feat(vector): add conversion between vector and string (#5029)

* feat(vector): add conversion between vector and string

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

* fix sqlness

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

* address comments

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

---------

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

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

@@ -12,20 +12,24 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+mod convert;
 mod distance;
 
 use std::sync::Arc;
 
-use distance::{CosDistanceFunction, DotProductFunction, L2SqDistanceFunction};
-
 use crate::function_registry::FunctionRegistry;
 
 pub(crate) struct VectorFunction;
 
 impl VectorFunction {
     pub fn register(registry: &FunctionRegistry) {
-        registry.register(Arc::new(CosDistanceFunction));
-        registry.register(Arc::new(DotProductFunction));
-        registry.register(Arc::new(L2SqDistanceFunction));
+        // conversion
+        registry.register(Arc::new(convert::ParseVectorFunction));
+        registry.register(Arc::new(convert::VectorToStringFunction));
+
+        // distance
+        registry.register(Arc::new(distance::CosDistanceFunction));
+        registry.register(Arc::new(distance::DotProductFunction));
+        registry.register(Arc::new(distance::L2SqDistanceFunction));
     }
 }

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

@@ -0,0 +1,19 @@
+// 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.
+
+mod parse_vector;
+mod vector_to_string;
+
+pub use parse_vector::ParseVectorFunction;
+pub use vector_to_string::VectorToStringFunction;

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

@@ -0,0 +1,160 @@
+// 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::Display;
+
+use common_query::error::{InvalidFuncArgsSnafu, InvalidVectorStringSnafu, Result};
+use common_query::prelude::{Signature, Volatility};
+use datatypes::prelude::ConcreteDataType;
+use datatypes::scalars::ScalarVectorBuilder;
+use datatypes::types::parse_string_to_vector_type_value;
+use datatypes::vectors::{BinaryVectorBuilder, MutableVector, VectorRef};
+use snafu::{ensure, ResultExt};
+
+use crate::function::{Function, FunctionContext};
+
+const NAME: &str = "parse_vec";
+
+#[derive(Debug, Clone, Default)]
+pub struct ParseVectorFunction;
+
+impl Function for ParseVectorFunction {
+    fn name(&self) -> &str {
+        NAME
+    }
+
+    fn return_type(&self, _input_types: &[ConcreteDataType]) -> Result<ConcreteDataType> {
+        Ok(ConcreteDataType::binary_datatype())
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::exact(
+            vec![ConcreteDataType::string_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 column = &columns[0];
+        let size = column.len();
+
+        let mut result = BinaryVectorBuilder::with_capacity(size);
+        for i in 0..size {
+            let value = column.get(i).as_string();
+            if let Some(value) = value {
+                let res = parse_string_to_vector_type_value(&value, None)
+                    .context(InvalidVectorStringSnafu { vec_str: &value })?;
+                result.push(Some(&res));
+            } else {
+                result.push_null();
+            }
+        }
+
+        Ok(result.to_vector())
+    }
+}
+
+impl Display for ParseVectorFunction {
+    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_base::bytes::Bytes;
+    use datatypes::value::Value;
+    use datatypes::vectors::StringVector;
+
+    use super::*;
+
+    #[test]
+    fn test_parse_vector() {
+        let func = ParseVectorFunction;
+
+        let input = Arc::new(StringVector::from(vec![
+            Some("[1.0,2.0,3.0]".to_string()),
+            Some("[4.0,5.0,6.0]".to_string()),
+            None,
+        ]));
+
+        let result = func.eval(FunctionContext::default(), &[input]).unwrap();
+
+        let result = result.as_ref();
+        assert_eq!(result.len(), 3);
+        assert_eq!(
+            result.get(0),
+            Value::Binary(Bytes::from(
+                [1.0f32, 2.0, 3.0]
+                    .iter()
+                    .flat_map(|e| e.to_le_bytes())
+                    .collect::<Vec<u8>>()
+            ))
+        );
+        assert_eq!(
+            result.get(1),
+            Value::Binary(Bytes::from(
+                [4.0f32, 5.0, 6.0]
+                    .iter()
+                    .flat_map(|e| e.to_le_bytes())
+                    .collect::<Vec<u8>>()
+            ))
+        );
+        assert!(result.get(2).is_null());
+    }
+
+    #[test]
+    fn test_parse_vector_error() {
+        let func = ParseVectorFunction;
+
+        let input = Arc::new(StringVector::from(vec![
+            Some("[1.0,2.0,3.0]".to_string()),
+            Some("[4.0,5.0,6.0]".to_string()),
+            Some("[7.0,8.0,9.0".to_string()),
+        ]));
+
+        let result = func.eval(FunctionContext::default(), &[input]);
+        assert!(result.is_err());
+
+        let input = Arc::new(StringVector::from(vec![
+            Some("[1.0,2.0,3.0]".to_string()),
+            Some("[4.0,5.0,6.0]".to_string()),
+            Some("7.0,8.0,9.0]".to_string()),
+        ]));
+
+        let result = func.eval(FunctionContext::default(), &[input]);
+        assert!(result.is_err());
+
+        let input = Arc::new(StringVector::from(vec![
+            Some("[1.0,2.0,3.0]".to_string()),
+            Some("[4.0,5.0,6.0]".to_string()),
+            Some("[7.0,hello,9.0]".to_string()),
+        ]));
+
+        let result = func.eval(FunctionContext::default(), &[input]);
+        assert!(result.is_err());
+    }
+}

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

@@ -0,0 +1,139 @@
+// 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::Display;
+
+use common_query::error::{InvalidFuncArgsSnafu, Result};
+use common_query::prelude::{Signature, Volatility};
+use datatypes::prelude::ConcreteDataType;
+use datatypes::scalars::ScalarVectorBuilder;
+use datatypes::types::vector_type_value_to_string;
+use datatypes::value::Value;
+use datatypes::vectors::{MutableVector, StringVectorBuilder, VectorRef};
+use snafu::ensure;
+
+use crate::function::{Function, FunctionContext};
+
+const NAME: &str = "vec_to_string";
+
+#[derive(Debug, Clone, Default)]
+pub struct VectorToStringFunction;
+
+impl Function for VectorToStringFunction {
+    fn name(&self) -> &str {
+        NAME
+    }
+
+    fn return_type(&self, _input_types: &[ConcreteDataType]) -> Result<ConcreteDataType> {
+        Ok(ConcreteDataType::string_datatype())
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::exact(
+            vec![ConcreteDataType::binary_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 column = &columns[0];
+        let size = column.len();
+
+        let mut result = StringVectorBuilder::with_capacity(size);
+        for i in 0..size {
+            let value = column.get(i);
+            match value {
+                Value::Binary(bytes) => {
+                    let len = bytes.len();
+                    if len % std::mem::size_of::<f32>() != 0 {
+                        return InvalidFuncArgsSnafu {
+                            err_msg: format!("Invalid binary length of vector: {}", len),
+                        }
+                        .fail();
+                    }
+
+                    let dim = len / std::mem::size_of::<f32>();
+                    // Safety: `dim` is calculated from the length of `bytes` and is guaranteed to be valid
+                    let res = vector_type_value_to_string(&bytes, dim as _).unwrap();
+                    result.push(Some(&res));
+                }
+                Value::Null => {
+                    result.push_null();
+                }
+                _ => {
+                    return InvalidFuncArgsSnafu {
+                        err_msg: format!("Invalid value type: {:?}", value.data_type()),
+                    }
+                    .fail();
+                }
+            }
+        }
+
+        Ok(result.to_vector())
+    }
+}
+
+impl Display for VectorToStringFunction {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", NAME.to_ascii_uppercase())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use datatypes::value::Value;
+    use datatypes::vectors::BinaryVectorBuilder;
+
+    use super::*;
+
+    #[test]
+    fn test_vector_to_string() {
+        let func = VectorToStringFunction;
+
+        let mut builder = BinaryVectorBuilder::with_capacity(3);
+        builder.push(Some(
+            [1.0f32, 2.0, 3.0]
+                .iter()
+                .flat_map(|e| e.to_le_bytes())
+                .collect::<Vec<_>>()
+                .as_slice(),
+        ));
+        builder.push(Some(
+            [4.0f32, 5.0, 6.0]
+                .iter()
+                .flat_map(|e| e.to_le_bytes())
+                .collect::<Vec<_>>()
+                .as_slice(),
+        ));
+        builder.push_null();
+        let vector = builder.to_vector();
+
+        let result = func.eval(FunctionContext::default(), &[vector]).unwrap();
+
+        assert_eq!(result.len(), 3);
+        assert_eq!(result.get(0), Value::String("[1,2,3]".to_string().into()));
+        assert_eq!(result.get(1), Value::String("[4,5,6]".to_string().into()));
+        assert_eq!(result.get(2), Value::Null);
+    }
+}

src/common/query/src/error.rs

@@ -245,6 +245,14 @@ pub enum Error {
         #[snafu(implicit)]
         location: Location,
     },
+
+    #[snafu(display("Invalid vector string: {}", vec_str))]
+    InvalidVectorString {
+        vec_str: String,
+        source: DataTypeError,
+        #[snafu(implicit)]
+        location: Location,
+    },
 }
 
 pub type Result<T> = std::result::Result<T, Error>;
@@ -273,7 +281,8 @@ impl ErrorExt for Error {
             | Error::IntoVector { source, .. }
             | Error::FromScalarValue { source, .. }
             | Error::ConvertArrowSchema { source, .. }
-            | Error::FromArrowArray { source, .. } => source.status_code(),
+            | Error::FromArrowArray { source, .. }
+            | Error::InvalidVectorString { source, .. } => source.status_code(),
 
             Error::MissingTableMutationHandler { .. }
             | Error::MissingProcedureServiceHandler { .. }