Merge rust-bitcoin/rust-bitcoin#580: Add Bloom filter network messages

894f0f09b6 Add Bloom filter network messages (Ben Carman)

Pull request description:

  Adds initial support for parsing the `merkleblock`, `filterload`, `filteradd` and `filterclear` network messages.

  https://developer.bitcoin.org/reference/p2p_networking.html#filteradd

  https://developer.bitcoin.org/reference/p2p_networking.html#filterclear

ACKs for top commit:
  dr-orlovsky:
    ACK 894f0f09b6
  apoelstra:
    ACK 894f0f09b6

Tree-SHA512: 6483457faf4e63fad0c9ac52b473c37fb04ad28ec60c92e5c3b5be7472d02fd873cbccfe387799002d1862b88bcdc2ded3a7b03349f3ac8fd591942dae005e6d

src/network/message_bloom.rs

@@ -0,0 +1,64 @@
+//!
+//! BIP37 Connection Bloom filtering network messages
+//!
+
+use consensus::encode;
+use consensus::{Decodable, Encodable, ReadExt};
+use std::io;
+
+/// `filterload` message sets the current bloom filter
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct FilterLoad {
+    /// The filter itself
+    pub filter: Vec<u8>,
+    /// The number of hash functions to use
+    pub hash_funcs: u32,
+    /// A random value
+    pub tweak: u32,
+    /// Controls how matched items are added to the filter
+    pub flags: BloomFlags,
+}
+
+impl_consensus_encoding!(FilterLoad, filter, hash_funcs, tweak, flags);
+
+/// Bloom filter update flags
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub enum BloomFlags {
+    /// Never update the filter with outpoints.
+    None,
+    /// Always update the filter with outpoints.
+    All,
+    /// Only update the filter with outpoints if it is P2PK or P2MS
+    PubkeyOnly,
+}
+
+impl Encodable for BloomFlags {
+    fn consensus_encode<W: io::Write>(&self, mut e: W) -> Result<usize, io::Error> {
+        e.write_all(&[match self {
+            BloomFlags::None => 0,
+            BloomFlags::All => 1,
+            BloomFlags::PubkeyOnly => 2,
+        }])?;
+        Ok(1)
+    }
+}
+
+impl Decodable for BloomFlags {
+    fn consensus_decode<D: io::Read>(mut d: D) -> Result<Self, encode::Error> {
+        Ok(match d.read_u8()? {
+            0 => BloomFlags::None,
+            1 => BloomFlags::All,
+            2 => BloomFlags::PubkeyOnly,
+            _ => return Err(encode::Error::ParseFailed("unknown bloom flag")),
+        })
+    }
+}
+
+/// `filteradd` message updates the current filter with new data
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct FilterAdd {
+    /// The data element to add to the current filter.
+    pub data: Vec<u8>,
+}
+
+impl_consensus_encoding!(FilterAdd, data);

src/network/mod.rs

@@ -28,6 +28,7 @@ pub mod constants;
 #[cfg(feature = "std")] pub use self::address::Address;
 #[cfg(feature = "std")] pub mod message;
 #[cfg(feature = "std")] pub mod message_blockdata;
+#[cfg(feature = "std")] pub mod message_bloom;
 #[cfg(feature = "std")] pub mod message_network;
 #[cfg(feature = "std")] pub mod message_filter;
 #[cfg(feature = "std")] pub mod stream_reader;