From 8cf437b34942a99798d13357859079032c371e89 Mon Sep 17 00:00:00 2001
From: debris <marek.kotewicz@gmail.com>
Date: Mon, 7 Dec 2015 11:27:12 +0100
Subject: [PATCH] rlp uses elastic array

---
 Cargo.toml |  1 +
 src/lib.rs |  1 +
 src/rlp.rs | 29 +++++++++++++++--------------
 3 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 65ea8508f..13295f766 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,6 +19,7 @@ rocksdb = "0.2.1"
 lazy_static = "0.1.*"
 secp256k1 = "0.5.1"
 rust-crypto = "0.2.34"
+elastic-array = "0.4"
 
 [dev-dependencies]
 json-tests = { path = "json-tests" }
diff --git a/src/lib.rs b/src/lib.rs
index 6366d682e..883cac2f2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -42,6 +42,7 @@ extern crate time;
 extern crate crypto as rcrypto;
 extern crate secp256k1;
 extern crate arrayvec;
+extern crate elastic_array;
 
 pub mod macros;
 pub mod error;
diff --git a/src/rlp.rs b/src/rlp.rs
index 624254fc6..d0dece3ba 100644
--- a/src/rlp.rs
+++ b/src/rlp.rs
@@ -33,6 +33,7 @@
 use std::fmt;
 use std::cell::Cell;
 use std::error::Error as StdError;
+use elastic_array::*;
 use bytes::{ToBytes, FromBytes, FromBytesError};
 use vector::InsertSlice;
 
@@ -758,7 +759,7 @@ impl Decoder for BasicDecoder {
 	}
 }
 
-#[derive(Debug)]
+#[derive(Debug, Copy, Clone)]
 struct ListInfo {
 	position: usize,
 	current: usize,
@@ -777,7 +778,7 @@ impl ListInfo {
 
 /// Appendable rlp encoder.
 pub struct RlpStream {
-	unfinished_lists: Vec<ListInfo>,
+	unfinished_lists: ElasticArray16<ListInfo>,
 	encoder: BasicEncoder,
 }
 
@@ -785,7 +786,7 @@ impl RlpStream {
 	/// Initializes instance of empty `RlpStream`.
 	pub fn new() -> RlpStream {
 		RlpStream {
-			unfinished_lists: vec![],
+			unfinished_lists: ElasticArray16::new(),
 			encoder: BasicEncoder::new(),
 		}
 	}
@@ -846,7 +847,7 @@ impl RlpStream {
 			},
 			_ => { 
 				// reserve at least double size of the len
-				self.encoder.bytes.reserve(len * 2);
+				//self.encoder.bytes.reserve(len * 2);
 				self.unfinished_lists.push(ListInfo::new(position, len));
 			},
 		}
@@ -882,7 +883,7 @@ impl RlpStream {
 	/// Appends raw (pre-serialised) RLP data. Use with caution. Chainable.
 	pub fn append_raw<'a>(&'a mut self, bytes: &[u8], item_count: usize) -> &'a mut RlpStream {
 		// push raw items
-		self.encoder.bytes.extend(bytes);	
+		self.encoder.bytes.append_slice(bytes);	
 
 		// try to finish and prepend the length
 		self.note_appended(item_count);
@@ -937,7 +938,7 @@ impl RlpStream {
 	/// panic! if stream is not finished.
 	pub fn out(self) -> Vec<u8> {
 		match self.is_finished() {
-			true => self.encoder.out(),
+			true => self.encoder.out().to_vec(),
 			false => panic!()
 		}
 	}
@@ -985,7 +986,7 @@ pub fn encode<E>(object: &E) -> Vec<u8> where E: Encodable
 {
 	let mut encoder = BasicEncoder::new();
 	object.encode(&mut encoder);
-	encoder.out()
+	encoder.out().to_vec()
 }
 
 pub trait Encodable {
@@ -1038,12 +1039,12 @@ impl Encodable for Vec<u8> {
 }
 
 struct BasicEncoder {
-	bytes: Vec<u8>,
+	bytes: ElasticArray1024<u8>,
 }
 
 impl BasicEncoder {
 	fn new() -> BasicEncoder {
-		BasicEncoder { bytes: vec![] }
+		BasicEncoder { bytes: ElasticArray1024::new() }
 	}
 
 	/// inserts list prefix at given position
@@ -1062,7 +1063,7 @@ impl BasicEncoder {
 	}
 
 	/// get encoded value
-	fn out(self) -> Vec<u8> {
+	fn out(self) -> ElasticArray1024<u8> {
 		self.bytes
 	}
 }
@@ -1073,17 +1074,17 @@ impl Encoder for BasicEncoder {
 			// just 0
 			0 => self.bytes.push(0x80u8),
 			// byte is its own encoding
-			1 if bytes[0] < 0x80 => self.bytes.extend(bytes),
+			1 if bytes[0] < 0x80 => self.bytes.append_slice(bytes),
 			// (prefix + length), followed by the string
 			len @ 1 ... 55 => {
 				self.bytes.push(0x80u8 + len as u8);
-				self.bytes.extend(bytes);
+				self.bytes.append_slice(bytes);
 			}
 			// (prefix + length of length), followed by the length, followd by the string
 			len => {
 				self.bytes.push(0xb7 + len.to_bytes_len() as u8);
-				self.bytes.extend(len.to_bytes());
-				self.bytes.extend(bytes);
+				self.bytes.append_slice(&len.to_bytes());
+				self.bytes.append_slice(bytes);
 			}
 		}
 	}