Redesign ToSql and remove RawToSql

Author: sfackler

src/lib.rs

@@ -76,6 +76,7 @@ use url::Url;
 pub use error::{Error, ConnectError, SqlState, DbError, ErrorPosition};
 #[doc(inline)]
 pub use types::{Oid, Type, Kind, ToSql, FromSql};
+use types::IsNull;
 #[doc(inline)]
 pub use types::Slice;
 use io::{InternalStream, Timeout};
@@ -727,12 +728,17 @@ impl InnerConnection {
         }
 
         // Ew @ doing this manually :(
+        let mut buf = vec![];
+        let value = match try!(oid.to_sql_checked(&Type::Oid, &mut buf)) {
+            IsNull::Yes => None,
+            IsNull::No => Some(buf),
+        };
         try!(self.write_messages(&[
             Bind {
                 portal: "",
                 statement: TYPEINFO_QUERY,
                 formats: &[1],
-                values: &[try!(oid.to_sql(&Type::Oid))],
+                values: &[value],
                 result_formats: &[1]
             },
             Execute {
@@ -1319,7 +1325,11 @@ impl<'conn> Statement<'conn> {
                 params.len());
         let mut values = vec![];
         for (param, ty) in params.iter().zip(self.param_types.iter()) {
-            values.push(try!(param.to_sql(ty)));
+            let mut buf = vec![];
+            match try!(param.to_sql_checked(ty, &mut buf)) {
+                IsNull::Yes => values.push(None),
+                IsNull::No => values.push(Some(buf)),
+            }
         };
 
         try!(conn.write_messages(&[
@@ -2054,13 +2064,14 @@ impl<'a> CopyInStatement<'a> {
             loop {
                 match (row.next(), types.next()) {
                     (Some(val), Some(ty)) => {
-                        match val.to_sql(ty) {
-                            Ok(None) => {
+                        let mut inner_buf = vec![];
+                        match val.to_sql_checked(ty, &mut inner_buf) {
+                            Ok(IsNull::Yes) => {
                                 let _ = buf.write_be_i32(-1);
                             }
-                            Ok(Some(val)) => {
-                                let _ = buf.write_be_i32(val.len() as i32);
-                                let _ = buf.write_all(&val);
+                            Ok(IsNull::No) => {
+                                let _ = buf.write_be_i32(inner_buf.len() as i32);
+                                let _ = buf.write_all(&inner_buf);
                             }
                             Err(err) => {
                                 // FIXME this is not the right way to handle this

src/types/json.rs

@@ -1,7 +1,7 @@
 use serialize::json;
 
 use {Result, Error};
-use types::{FromSql, RawToSql, Type};
+use types::{FromSql, ToSql, IsNull, Type};
 
 impl FromSql for json::Json {
     fn from_sql<R: Reader>(ty: &Type, raw: &mut R) -> Result<json::Json> {
@@ -17,14 +17,17 @@ impl FromSql for json::Json {
     accepts!(Type::Json, Type::Jsonb);
 }
 
-impl RawToSql for json::Json {
-    fn raw_to_sql<W: Writer>(&self, ty: &Type, raw: &mut W) -> Result<()> {
+impl ToSql for json::Json {
+    fn to_sql<W: Writer+?Sized>(&self, ty: &Type, out: &mut W) -> Result<IsNull> {
         if let Type::Jsonb = *ty {
-            try!(raw.write_u8(1));
+            try!(out.write_u8(1));
         }
 
-        Ok(try!(write!(raw, "{}", self)))
+        try!(write!(out, "{}", self));
+
+        Ok(IsNull::No)
     }
-}
 
-to_raw_to_impl!(Type::Json, Type::Jsonb; json::Json);
+    accepts!(Type::Json, Type::Jsonb);
+    to_sql_checked!();
+}