Use `io::sink` rather than our custom `EmptyWrite` utility

bitcoin/src/blockdata/block.rs

@@ -637,7 +637,7 @@ mod benches {
 
     use super::Block;
     use crate::consensus::{deserialize, Decodable, Encodable};
-    use crate::EmptyWrite;
+    use crate::io::sink;
 
     #[bench]
     pub fn bench_stream_reader(bh: &mut Bencher) {
@@ -674,7 +674,7 @@ mod benches {
         let block: Block = deserialize(&raw_block[..]).unwrap();
 
         bh.iter(|| {
-            let size = block.consensus_encode(&mut EmptyWrite);
+            let size = block.consensus_encode(&mut sink());
             black_box(&size);
         });
     }

bitcoin/src/blockdata/transaction.rs

@@ -2112,7 +2112,7 @@ mod benches {
 
     use super::Transaction;
     use crate::consensus::{deserialize, Encodable};
-    use crate::EmptyWrite;
+    use crate::io::sink;
 
     const SOME_TX: &str = "0100000001a15d57094aa7a21a28cb20b59aab8fc7d1149a3bdbcddba9c622e4f5f6a99ece010000006c493046022100f93bb0e7d8db7bd46e40132d1f8242026e045f03a0efe71bbb8e3f475e970d790221009337cd7f1f929f00cc6ff01f03729b069a7c21b59b1736ddfee5db5946c5da8c0121033b9b137ee87d5a812d6f506efdd37f0affa7ffc310711c06c7f3e097c9447c52ffffffff0100e1f505000000001976a9140389035a9225b3839e2bbf32d826a1e222031fd888ac00000000";
 
@@ -2147,7 +2147,7 @@ mod benches {
         let tx: Transaction = deserialize(&raw_tx).unwrap();
 
         bh.iter(|| {
-            let size = tx.consensus_encode(&mut EmptyWrite);
+            let size = tx.consensus_encode(&mut sink());
             black_box(&size);
         });
     }

bitcoin/src/lib.rs

@@ -196,27 +196,3 @@ mod prelude {
 
     pub use hex::DisplayHex;
 }
-
-#[cfg(bench)]
-use bench::EmptyWrite;
-
-#[cfg(bench)]
-mod bench {
-    use core::fmt::Arguments;
-
-    use crate::io::{IoSlice, Result, Write};
-
-    #[derive(Default, Clone, Debug, PartialEq, Eq)]
-    pub struct EmptyWrite;
-
-    impl Write for EmptyWrite {
-        fn write(&mut self, buf: &[u8]) -> Result<usize> { Ok(buf.len()) }
-        fn write_vectored(&mut self, bufs: &[IoSlice]) -> Result<usize> {
-            Ok(bufs.iter().map(|s| s.len()).sum())
-        }
-        fn flush(&mut self) -> Result<()> { Ok(()) }
-
-        fn write_all(&mut self, _: &[u8]) -> Result<()> { Ok(()) }
-        fn write_fmt(&mut self, _: Arguments) -> Result<()> { Ok(()) }
-    }
-}

bitcoin/src/p2p/message_bloom.rs

@@ -5,10 +5,9 @@
 //! This module describes BIP37 Connection Bloom filtering network messages.
 //!
 
-use std::io;
-
 use crate::consensus::{encode, Decodable, Encodable, ReadExt};
 use crate::internal_macros::impl_consensus_encoding;
+use crate::io;
 
 /// `filterload` message sets the current bloom filter
 #[derive(Clone, PartialEq, Eq, Debug)]

io/src/lib.rs

@@ -36,7 +36,7 @@ pub mod io {
     compile_error!("At least one of std or core2 must be enabled");
 
     #[cfg(feature = "std")]
-    pub use std::io::{Read, Write, Cursor, Take, IoSlice, Error, ErrorKind, Result};
+    pub use std::io::{Read, Write, sink, Cursor, Take, Error, ErrorKind, Result};
 
     #[cfg(not(feature = "std"))]
     pub use core2::io::{Read, Write, Cursor, Take, Error, ErrorKind, Result};