Add back in serde 0.3 support for back compat

This is a bit of a dubious hack since anyone that tries to turn on both
serde and serde_json are screwed.

Cargo.toml

@@ -32,6 +32,7 @@ rustc-serialize = "0.3"
 net2 = { version = "0.2", features = ["nightly"] }
 chrono = { version = "0.2.14", optional = true }
 openssl = { version = "0.6.4", optional = true }
+serde = { version = "0.3", optional = true } # Delete for 0.11
 serde_json = { version = "0.6", optional = true }
 time = { version = "0.1.14", optional = true }
 unix_socket = { version = ">= 0.3, < 0.5", optional = true, features = ["socket_timeout"] }

src/types/mod.rs

@@ -51,6 +51,8 @@ mod slice;
 mod rustc_serialize;
 #[cfg(feature = "serde_json")]
 mod serde_json;
+#[cfg(feature = "serde")]
+mod serde;
 #[cfg(feature = "chrono")]
 mod chrono;
 

src/types/serde.rs

@@ -0,0 +1,41 @@
+extern crate serde;
+
+use std::error;
+use std::io::prelude::*;
+use byteorder::{ReadBytesExt, WriteBytesExt};
+use self::serde::json::{self, Value};
+
+use Result;
+use error::Error;
+use types::{FromSql, ToSql, IsNull, Type, SessionInfo};
+
+impl FromSql for Value {
+    fn from_sql<R: Read>(ty: &Type, raw: &mut R, _: &SessionInfo) -> Result<Value> {
+        if let Type::Jsonb = *ty {
+            // We only support version 1 of the jsonb binary format
+            if try!(raw.read_u8()) != 1 {
+                let err: Box<error::Error+Sync+Send> = "unsupported JSONB encoding version".into();
+                return Err(Error::Conversion(err));
+            }
+        }
+        json::de::from_reader(raw).map_err(|err| Error::Conversion(Box::new(err)))
+    }
+
+    accepts!(Type::Json, Type::Jsonb);
+}
+
+impl ToSql for Value {
+    fn to_sql<W: Write+?Sized>(&self, ty: &Type, mut out: &mut W, _: &SessionInfo)
+                               -> Result<IsNull> {
+        if let Type::Jsonb = *ty {
+            try!(out.write_u8(1));
+        }
+
+        try!(write!(out, "{:?}", self));
+
+        Ok(IsNull::No)
+    }
+
+    accepts!(Type::Json, Type::Jsonb);
+    to_sql_checked!();
+}