From 0b4a059f9406a00b760f4762b10bcdc7f8954183 Mon Sep 17 00:00:00 2001
From: Dadepo Aderemi <dadepo@gmail.com>
Date: Sat, 20 Apr 2024 17:51:23 +0400
Subject: [PATCH] switch implementation of hostmask to use ScalarUDFImpl

---
 src/postgres/mod.rs          | 17 ++-------
 src/postgres/network_udfs.rs | 70 +++++++++++++++++++++++++++---------
 2 files changed, 55 insertions(+), 32 deletions(-)

diff --git a/src/postgres/mod.rs b/src/postgres/mod.rs
index cce6455..231709c 100644
--- a/src/postgres/mod.rs
+++ b/src/postgres/mod.rs
@@ -13,7 +13,7 @@ use crate::postgres::math_udfs::{
     Acosd, Asind, Atand, Ceiling, Cosd, Cotd, Div, Erf, Erfc, RandomNormal, Sind, Tand,
 };
 use crate::postgres::network_udfs::{
-    broadcast, family, host, hostmask, InetMerge, InetSameFamily, MaskLen, Netmask, Network,
+    broadcast, family, host, HostMask, InetMerge, InetSameFamily, MaskLen, Netmask, Network,
     SetMaskLen,
 };
 
@@ -46,7 +46,7 @@ fn register_network_udfs(ctx: &SessionContext) -> Result<()> {
     register_broadcast(ctx);
     register_family(ctx);
     register_host(ctx);
-    register_hostmask(ctx);
+    ctx.register_udf(ScalarUDF::from(HostMask::new()));
     ctx.register_udf(ScalarUDF::from(InetSameFamily::new()));
     ctx.register_udf(ScalarUDF::from(InetMerge::new()));
     ctx.register_udf(ScalarUDF::from(MaskLen::new()));
@@ -94,16 +94,3 @@ fn register_host(ctx: &SessionContext) {
 
     ctx.register_udf(host_udf);
 }
-
-fn register_hostmask(ctx: &SessionContext) {
-    let hostmask_udf = make_scalar_function(hostmask);
-    let return_type: ReturnTypeFunction = Arc::new(move |_| Ok(Arc::new(Utf8)));
-    let hostmask_udf = ScalarUDF::new(
-        "hostmask",
-        &Signature::uniform(1, vec![Utf8], Volatility::Immutable),
-        &return_type,
-        &hostmask_udf,
-    );
-
-    ctx.register_udf(hostmask_udf);
-}
diff --git a/src/postgres/network_udfs.rs b/src/postgres/network_udfs.rs
index 0697274..1e8b2f9 100644
--- a/src/postgres/network_udfs.rs
+++ b/src/postgres/network_udfs.rs
@@ -85,25 +85,61 @@ pub fn family(args: &[ArrayRef]) -> Result<ArrayRef> {
 
 /// Constructs host mask for network.
 /// Returns NULL for columns with NULL values.
-pub fn hostmask(args: &[ArrayRef]) -> Result<ArrayRef> {
-    let mut string_builder = StringBuilder::with_capacity(args[0].len(), u8::MAX as usize);
-    let ip_string = datafusion::common::cast::as_string_array(&args[0])?;
-    ip_string.iter().try_for_each(|ip_string| {
-        if let Some(ip_string) = ip_string {
-            let hostmask = IpNet::from_str(ip_string)
-                .map_err(|e| {
-                    DataFusionError::Internal(format!("Parsing {ip_string} failed with error {e}"))
-                })?
-                .hostmask();
-            string_builder.append_value(hostmask.to_string());
-            Ok::<(), DataFusionError>(())
-        } else {
-            string_builder.append_null();
-            Ok::<(), DataFusionError>(())
+#[derive(Debug)]
+pub struct HostMask {
+    signature: Signature,
+}
+
+impl HostMask {
+    pub fn new() -> Self {
+        Self {
+            signature: Signature::uniform(1, vec![Utf8], Volatility::Immutable),
         }
-    })?;
+    }
+}
 
-    Ok(Arc::new(string_builder.finish()) as ArrayRef)
+impl ScalarUDFImpl for HostMask {
+    fn as_any(&self) -> &dyn std::any::Any {
+        self
+    }
+
+    fn name(&self) -> &str {
+        "hostmask"
+    }
+
+    fn signature(&self) -> &Signature {
+        &self.signature
+    }
+
+    fn return_type(&self, _arg_types: &[DataType]) -> Result<DataType> {
+        Ok(Utf8)
+    }
+
+    fn invoke(&self, args: &[ColumnarValue]) -> Result<ColumnarValue> {
+        let args = ColumnarValue::values_to_arrays(args)?;
+        let mut string_builder = StringBuilder::with_capacity(args[0].len(), u8::MAX as usize);
+        let ip_string = datafusion::common::cast::as_string_array(&args[0])?;
+        ip_string.iter().try_for_each(|ip_string| {
+            if let Some(ip_string) = ip_string {
+                let hostmask = IpNet::from_str(ip_string)
+                    .map_err(|e| {
+                        DataFusionError::Internal(format!(
+                            "Parsing {ip_string} failed with error {e}"
+                        ))
+                    })?
+                    .hostmask();
+                string_builder.append_value(hostmask.to_string());
+                Ok::<(), DataFusionError>(())
+            } else {
+                string_builder.append_null();
+                Ok::<(), DataFusionError>(())
+            }
+        })?;
+
+        Ok(ColumnarValue::Array(
+            Arc::new(string_builder.finish()) as ArrayRef
+        ))
+    }
 }
 
 /// Checks if IP address is from the same family.