Clean up directory structure (#426)

* Remove unused circular-buffer crate
* Move transports into subdirectory
* Move misc into subdirectory
* Move stores into subdirectory
* Move multiplexers
* Move protocols
* Move libp2p top layer
* Fix Test: skip doctest if secio isn't enabled

misc/multihash/src/hashes.rs

@@ -0,0 +1,93 @@
+
+/// List of types currently supported in the multihash spec.
+///
+/// Not all hash types are supported by this library.
+#[derive(PartialEq, Eq, Clone, Debug, Copy, Hash)]
+pub enum Hash {
+    /// SHA-1 (20-byte hash size)
+    SHA1,
+    /// SHA-256 (32-byte hash size)
+    SHA2256,
+    /// SHA-512 (64-byte hash size)
+    SHA2512,
+    /// SHA3-512 (64-byte hash size)
+    SHA3512,
+    /// SHA3-384 (48-byte hash size)
+    SHA3384,
+    /// SHA3-256 (32-byte hash size)
+    SHA3256,
+    /// SHA3-224 (28-byte hash size)
+    SHA3224,
+    /// Keccak-224 (28-byte hash size)
+    Keccak224,
+    /// Keccak-256 (32-byte hash size)
+    Keccak256,
+    /// Keccak-384 (48-byte hash size)
+    Keccak384,
+    /// Keccak-512 (64-byte hash size)
+    Keccak512,
+    /// Encoding unsupported
+    Blake2b,
+    /// Encoding unsupported
+    Blake2s,
+}
+
+impl Hash {
+    /// Get the corresponding hash code.
+    pub fn code(&self) -> u8 {
+        match *self {
+            Hash::SHA1 => 0x11,
+            Hash::SHA2256 => 0x12,
+            Hash::SHA2512 => 0x13,
+            Hash::SHA3224 => 0x17,
+            Hash::SHA3256 => 0x16,
+            Hash::SHA3384 => 0x15,
+            Hash::SHA3512 => 0x14,
+            Hash::Keccak224 => 0x1A,
+            Hash::Keccak256 => 0x1B,
+            Hash::Keccak384 => 0x1C,
+            Hash::Keccak512 => 0x1D,
+            Hash::Blake2b => 0x40,
+            Hash::Blake2s => 0x41,
+        }
+    }
+
+    /// Get the hash length in bytes.
+    pub fn size(&self) -> u8 {
+        match *self {
+            Hash::SHA1 => 20,
+            Hash::SHA2256 => 32,
+            Hash::SHA2512 => 64,
+            Hash::SHA3224 => 28,
+            Hash::SHA3256 => 32,
+            Hash::SHA3384 => 48,
+            Hash::SHA3512 => 64,
+            Hash::Keccak224 => 28,
+            Hash::Keccak256 => 32,
+            Hash::Keccak384 => 48,
+            Hash::Keccak512 => 64,
+            Hash::Blake2b => 64,
+            Hash::Blake2s => 32,
+        }
+    }
+
+    /// Returns the algorithm corresponding to a code, or `None` if no algorith is matching.
+    pub fn from_code(code: u8) -> Option<Hash> {
+        Some(match code {
+            0x11 => Hash::SHA1,
+            0x12 => Hash::SHA2256,
+            0x13 => Hash::SHA2512,
+            0x14 => Hash::SHA3512,
+            0x15 => Hash::SHA3384,
+            0x16 => Hash::SHA3256,
+            0x17 => Hash::SHA3224,
+            0x1A => Hash::Keccak224,
+            0x1B => Hash::Keccak256,
+            0x1C => Hash::Keccak384,
+            0x1D => Hash::Keccak512,
+            0x40 => Hash::Blake2b,
+            0x41 => Hash::Blake2s,
+            _ => return None,
+        })
+    }
+}