Support BIT/VARBIT to BitVec

Closes #148

Cargo.toml

@@ -38,6 +38,7 @@ time = { version = "0.1.14", optional = true }
 unix_socket = { version = "0.4.1", optional = true, features = ["socket_timeout"] }
 uuid = { version = "0.1", optional = true }
 security-framework = { version = "0.1.1", optional = true }
+bit-vec = { version = "0.4", optional = true }
 
 [dev-dependencies]
 url = "0.2"

src/types/bit_vec.rs

@@ -0,0 +1,41 @@
+extern crate bit_vec;
+
+use std::io::prelude::*;
+use byteorder::{ReadBytesExt, WriteBytesExt, BigEndian};
+use self::bit_vec::BitVec;
+
+use Result;
+use types::{FromSql, ToSql, IsNull, Type, SessionInfo, downcast};
+
+impl FromSql for BitVec {
+    fn from_sql<R: Read>(_: &Type, raw: &mut R, _: &SessionInfo) -> Result<BitVec> {
+        let len = try!(raw.read_i32::<BigEndian>()) as usize;
+        let mut bytes = vec![];
+        try!(raw.take(((len + 7) / 8) as u64).read_to_end(&mut bytes));
+
+        let mut bitvec = BitVec::from_bytes(&bytes);
+        while bitvec.len() > len {
+            bitvec.pop();
+        }
+
+        Ok(bitvec)
+    }
+
+    accepts!(Type::Bit, Type::Varbit);
+}
+
+impl ToSql for BitVec {
+    fn to_sql<W: Write + ?Sized>(&self,
+                                 _: &Type,
+                                 mut out: &mut W,
+                                 _: &SessionInfo)
+                                 -> Result<IsNull> {
+        try!(out.write_i32::<BigEndian>(try!(downcast(self.len()))));
+        try!(out.write_all(&self.to_bytes()));
+
+        Ok(IsNull::No)
+    }
+
+    accepts!(Type::Bit, Type::Varbit);
+    to_sql_checked!();
+}

src/types/mod.rs

@@ -42,6 +42,8 @@ macro_rules! to_sql_checked {
     }
 }
 
+#[cfg(feature = "bit-vec")]
+mod bit_vec;
 #[cfg(feature = "uuid")]
 mod uuid;
 #[cfg(feature = "time")]
@@ -586,6 +588,7 @@ impl error::Error for WasNull {
 /// | chrono::NaiveDate                   | DATE                                |
 /// | chrono::NaiveTime                   | TIME                                |
 /// | uuid::Uuid                          | UUID                                |
+/// | bit_vec::BitVec                     | BIT, VARBIT                         |
 ///
 /// # Nullability
 ///
@@ -796,6 +799,7 @@ pub enum IsNull {
 /// | chrono::NaiveDate                   | DATE                                |
 /// | chrono::NaiveTime                   | TIME                                |
 /// | uuid::Uuid                          | UUID                                |
+/// | bit_vec::BitVec                     | BIT, VARBIT                         |
 ///
 /// # Nullability
 ///

tests/types/bit_vec.rs

@@ -0,0 +1,26 @@
+extern crate bit_vec;
+
+use self::bit_vec::BitVec;
+use types::test_type;
+
+#[test]
+fn test_bit_params() {
+    let mut bv = BitVec::from_bytes(&[0b0110_1001, 0b0000_0111]);
+    bv.pop();
+    bv.pop();
+    test_type("BIT(14)", &[(Some(bv),
+                            "B'01101001000001'"),
+                           (None, "NULL")])
+}
+
+#[test]
+fn test_varbit_params() {
+    let mut bv = BitVec::from_bytes(&[0b0110_1001, 0b0000_0111]);
+    bv.pop();
+    bv.pop();
+    test_type("VARBIT", &[(Some(bv),
+                           "B'01101001000001'"),
+                          (Some(BitVec::from_bytes(&[])),
+                           "B''"),
+                          (None, "NULL")])
+}

tests/types/mod.rs

@@ -7,6 +7,8 @@ use postgres::{Connection, SslMode};
 use postgres::error::Error;
 use postgres::types::{ToSql, FromSql, Slice};
 
+#[cfg(feature = "bit-vec")]
+mod bit_vec;
 #[cfg(feature = "uuid")]
 mod uuid;
 #[cfg(feature = "time")]