thread: Add maximum instruction size for thread space calculation (#83)

Author: Aursen

programs/thread/src/constants.rs

@@ -14,3 +14,7 @@ pub const POOL_ID: u64 = 0;
 /// The number of lamports to reimburse the worker with after they've submitted a transaction's worth of exec instructions.
 #[constant]
 pub const TRANSACTION_BASE_FEE_REIMBURSEMENT: u64 = 5_000;
+
+/// Static space for next_instruction field.
+#[constant]
+pub const NEXT_INSTRUCTION_SIZE: usize = 1232;

programs/thread/src/state/thread.rs

@@ -5,7 +5,7 @@ use sablier_utils::{
     MinSpace, Space,
 };
 
-use crate::constants::SEED_THREAD;
+use crate::constants::{NEXT_INSTRUCTION_SIZE, SEED_THREAD};
 
 /// Tracks the current state of a transaction thread on Solana.
 #[account]
@@ -72,11 +72,6 @@ pub trait ThreadAccount {
 impl Thread {
     pub fn min_space(instructions: &[SerializableInstruction]) -> Result<usize> {
         let ins_space = instructions.try_to_vec()?.len();
-        let max_ins_size = instructions
-            .iter()
-            .map(|ins| ins.try_to_vec().map(|v| v.len()).unwrap_or(0))
-            .max()
-            .unwrap_or(0);
 
         Ok(
             8
@@ -88,7 +83,7 @@ impl Thread {
             + u64::MIN_SPACE // fee
             + (4 + 32) // id
             + (4 + ins_space) // instructions
-            + (1 + max_ins_size) // next_instruction
+            + (1 + NEXT_INSTRUCTION_SIZE) // next_instruction
             + bool::MIN_SPACE // paused
             + u64::MIN_SPACE // rate_limit
             + Trigger::MIN_SPACE, // trigger