Restore index as the guardian set naming convention

Change-Id: I531413d961a3fb0068bc278f72073497746f5eee

solana/anchor-bridge/programs/anchor-bridge/src/account.rs

@@ -1,6 +1,6 @@
 use anchor_lang::{prelude::*, solana_program};
 
-use crate::{types::Version, MAX_LEN_GUARDIAN_KEYS};
+use crate::{types::Index, MAX_LEN_GUARDIAN_KEYS};
 
 #[account]
 pub struct BridgeInfo {}
@@ -8,7 +8,7 @@ pub struct BridgeInfo {}
 #[account]
 pub struct GuardianSetInfo {
     /// Version number of this guardian set.
-    pub version: Version,
+    pub index: Index,
     /// Number of keys stored
     pub len_keys: u8,
     /// public key hashes of the guardian set

solana/anchor-bridge/programs/anchor-bridge/src/api/initialize.rs

@@ -3,7 +3,7 @@ use anchor_lang::{prelude::*, solana_program};
 use crate::{
     accounts,
     anchor_bridge::Bridge,
-    types::{BridgeConfig, Version},
+    types::{BridgeConfig, Index},
     Initialize, InitializeData, MAX_LEN_GUARDIAN_KEYS,
 };
 
@@ -13,17 +13,17 @@ pub fn initialize(
     initial_guardian_key: [[u8; 20]; MAX_LEN_GUARDIAN_KEYS],
     config: BridgeConfig,
 ) -> Result<Bridge, ProgramError> {
-    let version = Version(0);
+    let index = Index(0);
 
     // Initialize the Guardian Set for the first time.
-    ctx.accounts.guardian_set.version = version;
+    ctx.accounts.guardian_set.index = index;
     ctx.accounts.guardian_set.creation_time = ctx.accounts.clock.unix_timestamp as u32;
     ctx.accounts.guardian_set.keys = initial_guardian_key;
     ctx.accounts.guardian_set.len_keys = len_guardians;
 
-    // Generate a Version 0 state for the bridges genesis.
+    // Create an initial bridge state, labeled index 0.
     Ok(Bridge {
-        guardian_set_version: version,
+        guardian_set_index: index,
         config,
     })
 }

solana/anchor-bridge/programs/anchor-bridge/src/api/publish_message.rs

@@ -3,7 +3,7 @@ use anchor_lang::{prelude::*, solana_program};
 use crate::{
     accounts,
     anchor_bridge::Bridge,
-    types::{BridgeConfig, Version},
+    types::{BridgeConfig, Index},
     PublishMessage,
 };
 

solana/anchor-bridge/programs/anchor-bridge/src/lib.rs

@@ -106,7 +106,7 @@ pub mod anchor_bridge {
 
     #[state]
     pub struct Bridge {
-        pub guardian_set_version: types::Version,
+        pub guardian_set_index: types::Index,
         pub config: types::BridgeConfig,
     }
 

solana/anchor-bridge/programs/anchor-bridge/src/types.rs

@@ -1,8 +1,8 @@
 use anchor_lang::prelude::*;
 
-// Distinguishes a Version number from a standard u32.
+// Enforces a single bumping index number.
 #[derive(AnchorSerialize, AnchorDeserialize, Clone, Copy, Debug)]
-pub struct Version(pub u32);
+pub struct Index(pub u32);
 
 #[repr(C)]
 #[derive(AnchorSerialize, AnchorDeserialize, Clone, Copy, Debug)]