From f3936c21a31e7e8e4a595904b8af8fbcce27bedc Mon Sep 17 00:00:00 2001
From: Greg Fitzgerald <greg@solana.com>
Date: Sun, 24 Mar 2019 20:55:32 -0600
Subject: [PATCH] Add message

---
 sdk/src/instruction_compiler.rs | 18 +++++++++---------
 sdk/src/lib.rs                  |  1 +
 sdk/src/message.rs              | 13 +++++++++++++
 sdk/src/transaction.rs          | 15 ++++++++++++++-
 4 files changed, 37 insertions(+), 10 deletions(-)
 create mode 100644 sdk/src/message.rs

diff --git a/sdk/src/instruction_compiler.rs b/sdk/src/instruction_compiler.rs
index 87a6843313..b2779abb18 100644
--- a/sdk/src/instruction_compiler.rs
+++ b/sdk/src/instruction_compiler.rs
@@ -2,8 +2,8 @@
 
 use crate::hash::Hash;
 use crate::instruction::{CompiledInstruction, Instruction};
+use crate::message::Message;
 use crate::pubkey::Pubkey;
-use crate::transaction::Transaction;
 use itertools::Itertools;
 
 fn position(keys: &[Pubkey], key: &Pubkey) -> u8 {
@@ -81,14 +81,14 @@ impl InstructionCompiler {
     }
 
     /// Return an unsigned transaction with space for requires signatures.
-    pub fn compile(&self) -> Transaction {
+    pub fn compile(&self) -> Message {
         let program_ids = self.program_ids();
         let (mut signed_keys, unsigned_keys) = self.keys();
-        let signed_len = signed_keys.len();
+        let num_signatures = signed_keys.len() as u8;
         signed_keys.extend(&unsigned_keys);
         let instructions = compile_instructions(&self.instructions, &signed_keys, &program_ids);
-        Transaction {
-            signatures: Vec::with_capacity(signed_len),
+        Message {
+            num_signatures,
             account_keys: signed_keys,
             recent_blockhash: Hash::default(),
             fee: 0,
@@ -211,12 +211,12 @@ mod tests {
         let program_id = Pubkey::default();
         let id0 = Pubkey::default();
         let ix = Instruction::new(program_id, &0, vec![AccountMeta::new(id0, false)]);
-        let tx = InstructionCompiler::new(vec![ix]).compile();
-        assert_eq!(tx.signatures.capacity(), 0);
+        let message = InstructionCompiler::new(vec![ix]).compile();
+        assert_eq!(message.num_signatures, 0);
 
         let ix = Instruction::new(program_id, &0, vec![AccountMeta::new(id0, true)]);
-        let tx = InstructionCompiler::new(vec![ix]).compile();
-        assert_eq!(tx.signatures.capacity(), 1);
+        let message = InstructionCompiler::new(vec![ix]).compile();
+        assert_eq!(message.num_signatures, 1);
     }
 
     #[test]
diff --git a/sdk/src/lib.rs b/sdk/src/lib.rs
index af5242de21..436c30e62f 100644
--- a/sdk/src/lib.rs
+++ b/sdk/src/lib.rs
@@ -5,6 +5,7 @@ pub mod hash;
 pub mod instruction;
 mod instruction_compiler;
 pub mod loader_instruction;
+mod message;
 pub mod native_loader;
 pub mod native_program;
 pub mod packet;
diff --git a/sdk/src/message.rs b/sdk/src/message.rs
new file mode 100644
index 0000000000..8ce9f76f16
--- /dev/null
+++ b/sdk/src/message.rs
@@ -0,0 +1,13 @@
+use crate::hash::Hash;
+use crate::instruction::CompiledInstruction;
+use crate::pubkey::Pubkey;
+
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub struct Message {
+    pub num_signatures: u8,
+    pub account_keys: Vec<Pubkey>,
+    pub recent_blockhash: Hash,
+    pub fee: u64,
+    pub program_ids: Vec<Pubkey>,
+    pub instructions: Vec<CompiledInstruction>,
+}
diff --git a/sdk/src/transaction.rs b/sdk/src/transaction.rs
index 35f77d73e5..b8e6ce3aed 100644
--- a/sdk/src/transaction.rs
+++ b/sdk/src/transaction.rs
@@ -3,6 +3,7 @@
 use crate::hash::{Hash, Hasher};
 use crate::instruction::{AccountMeta, CompiledInstruction, Instruction, InstructionError};
 use crate::instruction_compiler::InstructionCompiler;
+use crate::message::Message;
 use crate::packet::PACKET_DATA_SIZE;
 use crate::pubkey::Pubkey;
 use crate::shortvec::{deserialize_vec_with, encode_len, serialize_vec_with};
@@ -72,8 +73,20 @@ pub struct Transaction {
 }
 
 impl Transaction {
+    pub fn new_message(message: Message) -> Self {
+        Self {
+            signatures: Vec::with_capacity(message.num_signatures as usize),
+            account_keys: message.account_keys,
+            recent_blockhash: message.recent_blockhash,
+            fee: message.fee,
+            program_ids: message.program_ids,
+            instructions: message.instructions,
+        }
+    }
+
     pub fn new(instructions: Vec<Instruction>) -> Self {
-        InstructionCompiler::new(instructions).compile()
+        let message = InstructionCompiler::new(instructions).compile();
+        Self::new_message(message)
     }
 
     pub fn new_signed_instructions<T: KeypairUtil>(