feat: add geohash and h3 as built-in functions (#4656)

* feat: add built-in functions h3 and geohash

* tests: add sqlness tests for geo functions

* doc: correct h3 comment

* fix: lint error

* fix: toml format

* refactor: address review comments

* test: add more sqlness cases

* Apply suggestions from code review

Co-authored-by: Ruihang Xia <[email protected]>

---------

Co-authored-by: Ruihang Xia <[email protected]>

src/common/function/Cargo.toml

@@ -7,6 +7,10 @@ license.workspace = true
 [lints]
 workspace = true
 
+[features]
+default = ["geo"]
+geo = ["geohash", "h3o"]
+
 [dependencies]
 api.workspace = true
 arc-swap = "1.0"
@@ -23,6 +27,8 @@ common-time.workspace = true
 common-version.workspace = true
 datafusion.workspace = true
 datatypes.workspace = true
+geohash = { version = "0.13", optional = true }
+h3o = { version = "0.6", optional = true }
 num = "0.4"
 num-traits = "0.2"
 once_cell.workspace = true

src/common/function/src/function_registry.rs

@@ -116,6 +116,10 @@ pub static FUNCTION_REGISTRY: Lazy<Arc<FunctionRegistry>> = Lazy::new(|| {
     SystemFunction::register(&function_registry);
     TableFunction::register(&function_registry);
 
+    // Geo functions
+    #[cfg(feature = "geo")]
+    crate::scalars::geo::GeoFunctions::register(&function_registry);
+
     Arc::new(function_registry)
 });
 

src/common/function/src/scalars.rs

@@ -15,6 +15,8 @@
 pub mod aggregate;
 pub(crate) mod date;
 pub mod expression;
+#[cfg(feature = "geo")]
+pub mod geo;
 pub mod matches;
 pub mod math;
 pub mod numpy;

src/common/function/src/scalars/geo.rs

@@ -0,0 +1,31 @@
+// 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::sync::Arc;
+mod geohash;
+mod h3;
+
+use geohash::GeohashFunction;
+use h3::H3Function;
+
+use crate::function_registry::FunctionRegistry;
+
+pub(crate) struct GeoFunctions;
+
+impl GeoFunctions {
+    pub fn register(registry: &FunctionRegistry) {
+        registry.register(Arc::new(GeohashFunction));
+        registry.register(Arc::new(H3Function));
+    }
+}

src/common/function/src/scalars/geo/geohash.rs

@@ -0,0 +1,135 @@
+// 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;
+
+use common_error::ext::{BoxedError, PlainError};
+use common_error::status_code::StatusCode;
+use common_query::error::{self, InvalidFuncArgsSnafu, Result};
+use common_query::prelude::{Signature, TypeSignature};
+use datafusion::logical_expr::Volatility;
+use datatypes::prelude::ConcreteDataType;
+use datatypes::scalars::ScalarVectorBuilder;
+use datatypes::value::Value;
+use datatypes::vectors::{MutableVector, StringVectorBuilder, VectorRef};
+use geohash::Coord;
+use snafu::{ensure, ResultExt};
+
+use crate::function::{Function, FunctionContext};
+
+/// Function that return geohash string for a given geospatial coordinate.
+#[derive(Clone, Debug, Default)]
+pub struct GeohashFunction;
+
+const NAME: &str = "geohash";
+
+impl Function for GeohashFunction {
+    fn name(&self) -> &str {
+        NAME
+    }
+
+    fn return_type(&self, _input_types: &[ConcreteDataType]) -> Result<ConcreteDataType> {
+        Ok(ConcreteDataType::string_datatype())
+    }
+
+    fn signature(&self) -> Signature {
+        let mut signatures = Vec::new();
+        for coord_type in &[
+            ConcreteDataType::float32_datatype(),
+            ConcreteDataType::float64_datatype(),
+        ] {
+            for resolution_type in &[
+                ConcreteDataType::int8_datatype(),
+                ConcreteDataType::int16_datatype(),
+                ConcreteDataType::int32_datatype(),
+                ConcreteDataType::int64_datatype(),
+                ConcreteDataType::uint8_datatype(),
+                ConcreteDataType::uint16_datatype(),
+                ConcreteDataType::uint32_datatype(),
+                ConcreteDataType::uint64_datatype(),
+            ] {
+                signatures.push(TypeSignature::Exact(vec![
+                    // latitude
+                    coord_type.clone(),
+                    // longitude
+                    coord_type.clone(),
+                    // resolution
+                    resolution_type.clone(),
+                ]));
+            }
+        }
+        Signature::one_of(signatures, Volatility::Stable)
+    }
+
+    fn eval(&self, _func_ctx: FunctionContext, columns: &[VectorRef]) -> Result<VectorRef> {
+        ensure!(
+            columns.len() == 3,
+            InvalidFuncArgsSnafu {
+                err_msg: format!(
+                    "The length of the args is not correct, expect 3, provided : {}",
+                    columns.len()
+                ),
+            }
+        );
+
+        let lat_vec = &columns[0];
+        let lon_vec = &columns[1];
+        let resolution_vec = &columns[2];
+
+        let size = lat_vec.len();
+        let mut results = StringVectorBuilder::with_capacity(size);
+
+        for i in 0..size {
+            let lat = lat_vec.get(i).as_f64_lossy();
+            let lon = lon_vec.get(i).as_f64_lossy();
+            let r = match resolution_vec.get(i) {
+                Value::Int8(v) => v as usize,
+                Value::Int16(v) => v as usize,
+                Value::Int32(v) => v as usize,
+                Value::Int64(v) => v as usize,
+                Value::UInt8(v) => v as usize,
+                Value::UInt16(v) => v as usize,
+                Value::UInt32(v) => v as usize,
+                Value::UInt64(v) => v as usize,
+                _ => unreachable!(),
+            };
+
+            let result = match (lat, lon) {
+                (Some(lat), Some(lon)) => {
+                    let coord = Coord { x: lon, y: lat };
+                    let encoded = geohash::encode(coord, r)
+                        .map_err(|e| {
+                            BoxedError::new(PlainError::new(
+                                format!("Geohash error: {}", e),
+                                StatusCode::EngineExecuteQuery,
+                            ))
+                        })
+                        .context(error::ExecuteSnafu)?;
+                    Some(encoded)
+                }
+                _ => None,
+            };
+
+            results.push(result.as_deref());
+        }
+
+        Ok(results.to_vector())
+    }
+}
+
+impl fmt::Display for GeohashFunction {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", NAME)
+    }
+}