Server side parameters via with_param

Fixes #142

Author: serprex

src/lib.rs

@@ -5,7 +5,8 @@
 #[macro_use]
 extern crate static_assertions;
 
-use self::{error::Result, http_client::HttpClient};
+use self::{error::Result, http_client::HttpClient, sql::ser};
+use ::serde::Serialize;
 use std::{collections::HashMap, fmt::Display, sync::Arc};
 
 pub use self::{compression::Compression, row::Row};
@@ -160,6 +161,12 @@ impl Client {
         self
     }
 
+    pub fn with_param(self, name: &str, value: impl Serialize) -> Result<Self, String> {
+        let mut param = String::from("");
+        ser::write_param(&mut param, &value)?;
+        Ok(self.with_option(format!("param_{name}"), param))
+    }
+
     /// Used to specify a header that will be passed to all queries.
     ///
     /// # Example

src/query.rs

@@ -1,5 +1,5 @@
 use hyper::{header::CONTENT_LENGTH, Method, Request};
-use serde::Deserialize;
+use serde::{Deserialize, Serialize};
 use std::fmt::Display;
 use url::Url;
 
@@ -10,7 +10,7 @@ use crate::{
     request_body::RequestBody,
     response::Response,
     row::Row,
-    sql::{Bind, SqlBuilder},
+    sql::{ser, Bind, SqlBuilder},
     Client,
 };
 
@@ -195,6 +195,12 @@ impl Query {
         self.client.add_option(name, value);
         self
     }
+
+    pub fn with_param(self, name: &str, value: impl Serialize) -> Result<Self, String> {
+        let mut param = String::from("");
+        ser::write_param(&mut param, &value)?;
+        Ok(self.with_option(format!("param_{name}"), param))
+    }
 }
 
 /// A cursor that emits rows.

src/sql/mod.rs

@@ -9,7 +9,7 @@ pub use bind::{Bind, Identifier};
 
 mod bind;
 pub(crate) mod escape;
-mod ser;
+pub(crate) mod ser;
 
 #[derive(Debug, Clone)]
 pub(crate) enum SqlBuilder {

src/sql/ser.rs

@@ -8,32 +8,32 @@ use thiserror::Error;
 
 use super::escape;
 
-// === SqlSerializerError ===
+// === SerializerError ===
 
 #[derive(Debug, Error)]
-enum SqlSerializerError {
+enum SerializerError {
     #[error("{0} is unsupported")]
     Unsupported(&'static str),
     #[error("{0}")]
     Custom(String),
 }
 
-impl ser::Error for SqlSerializerError {
+impl ser::Error for SerializerError {
     fn custom<T: fmt::Display>(msg: T) -> Self {
         Self::Custom(msg.to_string())
     }
 }
 
-impl From<fmt::Error> for SqlSerializerError {
+impl From<fmt::Error> for SerializerError {
     fn from(err: fmt::Error) -> Self {
         Self::Custom(err.to_string())
     }
 }
 
 // === SqlSerializer ===
 
-type Result<T = (), E = SqlSerializerError> = std::result::Result<T, E>;
-type Impossible = ser::Impossible<(), SqlSerializerError>;
+type Result<T = (), E = SerializerError> = std::result::Result<T, E>;
+type Impossible = ser::Impossible<(), SerializerError>;
 
 struct SqlSerializer<'a, W> {
     writer: &'a mut W,
@@ -43,7 +43,7 @@ macro_rules! unsupported {
     ($ser_method:ident($ty:ty) -> $ret:ty, $($other:tt)*) => {
         #[inline]
         fn $ser_method(self, _v: $ty) -> $ret {
-            Err(SqlSerializerError::Unsupported(stringify!($ser_method)))
+            Err(SerializerError::Unsupported(stringify!($ser_method)))
         }
         unsupported!($($other)*);
     };
@@ -53,7 +53,7 @@ macro_rules! unsupported {
     ($ser_method:ident, $($other:tt)*) => {
         #[inline]
         fn $ser_method(self) -> Result {
-            Err(SqlSerializerError::Unsupported(stringify!($ser_method)))
+            Err(SerializerError::Unsupported(stringify!($ser_method)))
         }
         unsupported!($($other)*);
     };
@@ -73,7 +73,7 @@ macro_rules! forward_to_display {
 }
 
 impl<'a, W: Write> Serializer for SqlSerializer<'a, W> {
-    type Error = SqlSerializerError;
+    type Error = SerializerError;
     type Ok = ();
     type SerializeMap = Impossible;
     type SerializeSeq = SqlListSerializer<'a, W>;
@@ -177,12 +177,12 @@ impl<'a, W: Write> Serializer for SqlSerializer<'a, W> {
         _variant: &'static str,
         _value: &T,
     ) -> Result {
-        Err(SqlSerializerError::Unsupported("serialize_newtype_variant"))
+        Err(SerializerError::Unsupported("serialize_newtype_variant"))
     }
 
     #[inline]
     fn serialize_tuple_struct(self, _name: &'static str, _len: usize) -> Result<Impossible> {
-        Err(SqlSerializerError::Unsupported("serialize_tuple_struct"))
+        Err(SerializerError::Unsupported("serialize_tuple_struct"))
     }
 
     #[inline]
@@ -193,12 +193,12 @@ impl<'a, W: Write> Serializer for SqlSerializer<'a, W> {
         _variant: &'static str,
         _len: usize,
     ) -> Result<Impossible> {
-        Err(SqlSerializerError::Unsupported("serialize_tuple_variant"))
+        Err(SerializerError::Unsupported("serialize_tuple_variant"))
     }
 
     #[inline]
     fn serialize_struct(self, _name: &'static str, _len: usize) -> Result<Self::SerializeStruct> {
-        Err(SqlSerializerError::Unsupported("serialize_struct"))
+        Err(SerializerError::Unsupported("serialize_struct"))
     }
 
     #[inline]
@@ -209,7 +209,7 @@ impl<'a, W: Write> Serializer for SqlSerializer<'a, W> {
         _variant: &'static str,
         _len: usize,
     ) -> Result<Self::SerializeStructVariant> {
-        Err(SqlSerializerError::Unsupported("serialize_struct_variant"))
+        Err(SerializerError::Unsupported("serialize_struct_variant"))
     }
 
     #[inline]
@@ -227,7 +227,7 @@ struct SqlListSerializer<'a, W> {
 }
 
 impl<'a, W: Write> SerializeSeq for SqlListSerializer<'a, W> {
-    type Error = SqlSerializerError;
+    type Error = SerializerError;
     type Ok = ();
 
     #[inline]
@@ -254,7 +254,7 @@ impl<'a, W: Write> SerializeSeq for SqlListSerializer<'a, W> {
 }
 
 impl<'a, W: Write> SerializeTuple for SqlListSerializer<'a, W> {
-    type Error = SqlSerializerError;
+    type Error = SerializerError;
     type Ok = ();
 
     #[inline]
@@ -271,6 +271,167 @@ impl<'a, W: Write> SerializeTuple for SqlListSerializer<'a, W> {
     }
 }
 
+// === ParamSerializer ===
+
+struct ParamSerializer<'a, W> {
+    writer: &'a mut W,
+}
+
+impl<'a, W: Write> Serializer for ParamSerializer<'a, W> {
+    type Error = SerializerError;
+    type Ok = ();
+    type SerializeMap = Impossible;
+    type SerializeSeq = SqlListSerializer<'a, W>;
+    type SerializeStruct = Impossible;
+    type SerializeStructVariant = Impossible;
+    type SerializeTuple = SqlListSerializer<'a, W>;
+    type SerializeTupleStruct = Impossible;
+    type SerializeTupleVariant = Impossible;
+
+    unsupported!(
+        serialize_map(Option<usize>) -> Result<Impossible>,
+        serialize_bytes(&[u8]),
+        serialize_unit,
+        serialize_unit_struct(&'static str),
+    );
+
+    forward_to_display!(
+        serialize_i8(i8),
+        serialize_i16(i16),
+        serialize_i32(i32),
+        serialize_i64(i64),
+        serialize_i128(i128),
+        serialize_u8(u8),
+        serialize_u16(u16),
+        serialize_u32(u32),
+        serialize_u64(u64),
+        serialize_u128(u128),
+        serialize_f32(f32),
+        serialize_f64(f64),
+        serialize_bool(bool),
+    );
+
+    #[inline]
+    fn serialize_char(self, value: char) -> Result {
+        let mut tmp = [0u8; 4];
+        self.serialize_str(value.encode_utf8(&mut tmp))
+    }
+
+    #[inline]
+    fn serialize_str(self, value: &str) -> Result {
+        // ClickHouse expects strings in params to be unquoted until inside a nested type
+        // nested types go through serialize_seq which'll quote strings
+        let mut rest = value;
+        while let Some(nextidx) = rest.find('\\') {
+            let (before, after) = rest.split_at(nextidx + 1);
+            rest = after;
+            self.writer.write_str(before)?;
+            self.writer.write_char('\\')?;
+        }
+        self.writer.write_str(rest)?;
+        Ok(())
+    }
+
+    #[inline]
+    fn serialize_seq(self, _len: Option<usize>) -> Result<SqlListSerializer<'a, W>> {
+        self.writer.write_char('[')?;
+        Ok(SqlListSerializer {
+            writer: self.writer,
+            has_items: false,
+            closing_char: ']',
+        })
+    }
+
+    #[inline]
+    fn serialize_tuple(self, _len: usize) -> Result<SqlListSerializer<'a, W>> {
+        self.writer.write_char('(')?;
+        Ok(SqlListSerializer {
+            writer: self.writer,
+            has_items: false,
+            closing_char: ')',
+        })
+    }
+
+    #[inline]
+    fn serialize_some<T: Serialize + ?Sized>(self, _value: &T) -> Result {
+        _value.serialize(self)
+    }
+
+    #[inline]
+    fn serialize_none(self) -> std::result::Result<Self::Ok, Self::Error> {
+        self.writer.write_str("NULL")?;
+        Ok(())
+    }
+
+    #[inline]
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        variant: &'static str,
+    ) -> Result {
+        escape::string(variant, self.writer)?;
+        Ok(())
+    }
+
+    #[inline]
+    fn serialize_newtype_struct<T: Serialize + ?Sized>(
+        self,
+        _name: &'static str,
+        value: &T,
+    ) -> Result {
+        value.serialize(self)
+    }
+
+    #[inline]
+    fn serialize_newtype_variant<T: Serialize + ?Sized>(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _value: &T,
+    ) -> Result {
+        Err(SerializerError::Unsupported("serialize_newtype_variant"))
+    }
+
+    #[inline]
+    fn serialize_tuple_struct(self, _name: &'static str, _len: usize) -> Result<Impossible> {
+        Err(SerializerError::Unsupported("serialize_tuple_struct"))
+    }
+
+    #[inline]
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Impossible> {
+        Err(SerializerError::Unsupported("serialize_tuple_variant"))
+    }
+
+    #[inline]
+    fn serialize_struct(self, _name: &'static str, _len: usize) -> Result<Self::SerializeStruct> {
+        Err(SerializerError::Unsupported("serialize_struct"))
+    }
+
+    #[inline]
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStructVariant> {
+        Err(SerializerError::Unsupported("serialize_struct_variant"))
+    }
+
+    #[inline]
+    fn is_human_readable(&self) -> bool {
+        true
+    }
+}
+
 // === Public API ===
 
 pub(crate) fn write_arg(writer: &mut impl Write, value: &impl Serialize) -> Result<(), String> {
@@ -279,6 +440,12 @@ pub(crate) fn write_arg(writer: &mut impl Write, value: &impl Serialize) -> Resu
         .map_err(|err| err.to_string())
 }
 
+pub(crate) fn write_param(writer: &mut impl Write, value: &impl Serialize) -> Result<(), String> {
+    value
+        .serialize(ParamSerializer { writer })
+        .map_err(|err| err.to_string())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;