[move stdlib] minimize calls to length in vector functions

Calling length in a loop is less gas and wall time efficient than calling it once and using a simple loop.

crates/sui-adapter-transactional-tests/tests/programmable/split_coins.exp

@@ -7,7 +7,7 @@ task 1, lines 9-22:
 //# publish
 created: object(1,0)
 mutated: object(0,2)
-gas summary: computation_cost: 1000000, storage_cost: 5563200,  storage_rebate: 0, non_refundable_storage_fee: 0
+gas summary: computation_cost: 1000000, storage_cost: 5791200,  storage_rebate: 0, non_refundable_storage_fee: 0
 
 task 2, lines 24-28:
 //# programmable --sender A --inputs 100000 @A

crates/sui-framework/docs/move-stdlib/vector.md

@@ -312,10 +312,8 @@ Pushes all of the elements of the <code>other</code> vector into the <code>lhs</
 <summary>Implementation</summary>
 
 
-<pre><code><b>public</b> <b>fun</b> <a href="../move-stdlib/vector.md#0x1_vector_append">append</a>&lt;Element&gt;(lhs: &<b>mut</b> <a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;Element&gt;, <b>mut</b> other: <a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;Element&gt;) {
-    other.<a href="../move-stdlib/vector.md#0x1_vector_reverse">reverse</a>();
-    <b>while</b> (other.<a href="../move-stdlib/vector.md#0x1_vector_length">length</a>() != 0) lhs.<a href="../move-stdlib/vector.md#0x1_vector_push_back">push_back</a>(other.<a href="../move-stdlib/vector.md#0x1_vector_pop_back">pop_back</a>());
-    other.<a href="../move-stdlib/vector.md#0x1_vector_destroy_empty">destroy_empty</a>();
+<pre><code><b>public</b> <b>fun</b> <a href="../move-stdlib/vector.md#0x1_vector_append">append</a>&lt;Element&gt;(lhs: &<b>mut</b> <a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;Element&gt;, other: <a href="../move-stdlib/vector.md#0x1_vector">vector</a>&lt;Element&gt;) {
+    other.do!(|e| lhs.<a href="../move-stdlib/vector.md#0x1_vector_push_back">push_back</a>(e));
 }
 </code></pre>
 

crates/sui-framework/packages/move-stdlib/sources/vector.move

@@ -84,10 +84,8 @@ public fun reverse<Element>(v: &mut vector<Element>) {
 }
 
 /// Pushes all of the elements of the `other` vector into the `lhs` vector.
-public fun append<Element>(lhs: &mut vector<Element>, mut other: vector<Element>) {
-    other.reverse();
-    while (other.length() != 0) lhs.push_back(other.pop_back());
-    other.destroy_empty();
+public fun append<Element>(lhs: &mut vector<Element>, other: vector<Element>) {
+    other.do!(|e| lhs.push_back(e));
 }
 
 /// Return `true` if the vector `v` has no elements and `false` otherwise.
@@ -185,7 +183,7 @@ public macro fun destroy<$T>($v: vector<$T>, $f: |$T|) {
 public macro fun do<$T>($v: vector<$T>, $f: |$T|) {
     let mut v = $v;
     v.reverse();
-    while (v.length() != 0) $f(v.pop_back());
+    v.length().do!(|_| $f(v.pop_back()));
     v.destroy_empty();
 }
 

crates/sui-framework/packages/move-stdlib/tests/vector_tests.move

@@ -37,6 +37,16 @@ fun append_empties_is_empty() {
     assert!(v1.is_empty());
 }
 
+#[test]
+fun append_singletons() {
+    let mut v1 = vector[0];
+    let v2 = vector[1];
+    v1.append(v2);
+    assert!(v1.length() == 2);
+    assert!(v1[0] == 0);
+    assert!(v1[1] == 1);
+}
+
 #[test]
 fun append_respects_order_empty_lhs() {
     let mut v1 = vector[];

crates/sui-protocol-config/src/lib.rs

@@ -202,6 +202,7 @@ const MAX_PROTOCOL_VERSION: u64 = 70;
 //             Enable probing for accepted rounds in round prober in testnet
 //             Add new gas model version to update charging of native functions.
 //             Add std::uq64_64 module to Move stdlib.
+//             Improve gas/wall time efficiency of some Move stdlib vector functions
 
 #[derive(Copy, Clone, Debug, Hash, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
 pub struct ProtocolVersion(u64);

crates/sui-swarm-config/tests/snapshots/snapshot_tests__populated_genesis_snapshot_matches-2.snap

@@ -240,56 +240,56 @@ validators:
         next_epoch_worker_address: ~
         extra_fields:
           id:
-            id: "0xcebe975bb1b8e53e6af39513515419a9a7c689693f249740e43689f6aeda32ba"
+            id: "0xd336ec43763c7e6cb1a58af9e463220f7f28afb4bf5ac683e53c87ffe1df0a4c"
           size: 0
       voting_power: 10000
-      operation_cap_id: "0x2e4b656205b19fc58169a879f3ac919d5299a471693c23c70a93e36f9ae5d4a0"
+      operation_cap_id: "0x8dab96e36a4870498181e5f793537a9430944acddf495603c6afa93cc37f3889"
       gas_price: 1000
       staking_pool:
-        id: "0x9c8b960db18d273e85a80401ca97c09253b3fd82f413d9e355afe9eab0e82858"
+        id: "0x131722dffbbebd704bf861887766f9b11b8ff4ae88e014b1d343eee977d3b4bc"
         activation_epoch: 0
         deactivation_epoch: ~
         sui_balance: 20000000000000000
         rewards_pool:
           value: 0
         pool_token_balance: 20000000000000000
         exchange_rates:
-          id: "0x705442e06a6805513bbde51a9030bd4725274e8843bd4ad603afcc48fedda000"
+          id: "0x87e0379fe286c022d350f16878363aa19706f483aabf4d5b28cbe64b737bfbb9"
           size: 1
         pending_stake: 0
         pending_total_sui_withdraw: 0
         pending_pool_token_withdraw: 0
         extra_fields:
           id:
-            id: "0x4ad2829c103ec2f25d4a2d8138fba5111ad6b5289a3ecddedf5ac4e030aae877"
+            id: "0x4391b75bfd492755194154168d934d80fce1c2b661b08de7eee4c353ab2c2302"
           size: 0
       commission_rate: 200
       next_epoch_stake: 20000000000000000
       next_epoch_gas_price: 1000
       next_epoch_commission_rate: 200
       extra_fields:
         id:
-          id: "0xbfb962637c22ef853d4acb95ebfb811996d6ec8a27546e3d3f9e52c5c2713e82"
+          id: "0x152af272a7a45cc3216bc6355b7dcfd0e4ed47271b4821d4af3566fb87e957fd"
         size: 0
   pending_active_validators:
     contents:
-      id: "0xb33ed5bbf74e91ab4d04031ec1ab518e780a7c3f3a366cd192d1cd853bfbc8be"
+      id: "0xa0aa2ed79148441eba1d8cf0c080a6136a55376c58e9451b4c5a2507d49e2f80"
       size: 0
   pending_removals: []
   staking_pool_mappings:
-    id: "0xedbabcc635a1f34d5739154e11f258cea3e8bf15115f89508c5939b4ef577291"
+    id: "0xb31a46b712d3bce7378b42f74d5514b46d2d5532a267dad65d6627b638acd908"
     size: 1
   inactive_validators:
-    id: "0xb8d534ef50875b43804861d8e5dbf4a06a5f4c963cc0ae8c659c87dfdda4c43f"
+    id: "0x10b278cfadb57996d8c63c0c15c1aa9656d3ff2e0c6384fdc006b6a9b5a37597"
     size: 0
   validator_candidates:
-    id: "0xa112fa6e91b7ce533851360d8368830407cdc9bf3599fa243d5204d97fe42711"
+    id: "0x4f013d2a81f8c361a9411df03397dc5cdae04023c68fe2b15a1334cc7fab78c4"
     size: 0
   at_risk_validators:
     contents: []
   extra_fields:
     id:
-      id: "0x410bd3fc4e5000f94e8b70851d0aa23cb611154e3046cb06a4d8023c39fbb70b"
+      id: "0xd8d77e98c2913975291b41b79954b1f679f0193ddecde2158b6fd899ebecf93d"
     size: 0
 storage_fund:
   total_object_storage_rebates:
@@ -306,7 +306,7 @@ parameters:
   validator_low_stake_grace_period: 7
   extra_fields:
     id:
-      id: "0x5e42d5798306b3e67b20ead164d54956558be121660350ca2447a08422bed768"
+      id: "0x6dd6b96ea34c02dc9ca19574bd3689c7680b7910a34ace35b5960d62b2f89f24"
     size: 0
 reference_gas_price: 1000
 validator_report_records:
@@ -320,7 +320,7 @@ stake_subsidy:
   stake_subsidy_decrease_rate: 1000
   extra_fields:
     id:
-      id: "0xb001553979b3d2613e00064f5c8a03c94879530f7faf9e3641c86ef5d02df396"
+      id: "0xf6c77f67f7f190260b807bbcaef13dc3a4054fb7f85927c969d5b0d50c162c23"
     size: 0
 safe_mode: false
 safe_mode_storage_rewards:
@@ -332,5 +332,6 @@ safe_mode_non_refundable_storage_fee: 0
 epoch_start_timestamp_ms: 10
 extra_fields:
   id:
-    id: "0x91168b5f93153d5b24b67b76d4e0dd4553a4bca86ce596e948c0bdefe7c56715"
+    id: "0xa2545fec3666cb6bbd9099d52f2e461d4d679511ed481f8a95f4c99bfbaaf6dd"
   size: 0
+