Safe upgrade (#29)

* splay tree

* upgrade

* test

* check init arg during upgrade

* fix

* use vessel

.github/workflows/backend.yml

@@ -11,6 +11,7 @@ jobs:
     env:
       DFX_VERSION: 0.7.2
       IC_REPL_VERSION: 2021-06-17
+      VESSEL_VERSION: v0.6.2
     steps:
     - uses: actions/checkout@v2
     - name: Install
@@ -20,6 +21,9 @@ jobs:
         wget https://github.com/chenyan2002/ic-repl/releases/download/$IC_REPL_VERSION/ic-repl-linux64
         cp ./ic-repl-linux64 /home/runner/bin/ic-repl
         chmod a+x /home/runner/bin/ic-repl
+        wget https://github.com/dfinity/vessel/releases/download/$VESSEL_VERSION/vessel-linux64
+        cp ./vessel-linux64 /home/runner/bin/vessel
+        chmod a+x /home/runner/bin/vessel
     - name: Build
       run: |
         dfx cache install

.gitignore

@@ -25,8 +25,9 @@ yarn-debug.log*
 yarn-error.log*
 
 .eslintcache
+.vessel
 
 # IDEs
 /.idea
 /.vscode
-/.history
+/.history

backend/Main.mo

@@ -1,18 +1,34 @@
-import Iter "mo:base/Iter";
 import Cycles "mo:base/ExperimentalCycles";
 import Time "mo:base/Time";
 import Error "mo:base/Error";
-import RBTree "mo:base/RBTree";
 import Option "mo:base/Option";
 import Types "./Types";
 import ICType "./IC";
 
 actor class Self(opt_params : ?Types.InitParams) {
     let IC : ICType.Self = actor "aaaaa-aa";
     let params = Option.get(opt_params, Types.defaultParams);
-
     var pool = Types.CanisterPool(params.max_num_canisters, params.TTL);
 
+    stable var stablePool : [Types.CanisterInfo] = [];
+    stable var previousParam : ?Types.InitParams = null;
+    system func preupgrade() {
+        stablePool := pool.share();
+        previousParam := ?params;
+    };
+    system func postupgrade() {
+        switch previousParam {
+        case (?old) {
+                 if (old.max_num_canisters > params.max_num_canisters) {
+                     //throw Error.reject("Cannot reduce canisterPool for upgrade");
+                     assert false;
+                 };
+             };
+        case null {};
+        };
+        pool.unshare(stablePool);
+    };
+
     // TODO: only playground frontend can call these functions
     public func getCanisterId() : async Types.CanisterInfo {
         switch (pool.getExpiredCanisterId()) {
@@ -26,8 +42,10 @@ actor class Self(opt_params : ?Types.InitParams) {
         case (#reuse(info)) {
                  let cid = { canister_id = info.id };
                  let status = await IC.canister_status(cid);
-                 let top_up_cycles : Nat = params.cycles_per_canister - status.cycles;
-                 Cycles.add(top_up_cycles);
+                 if (status.cycles < params.cycles_per_canister) {
+                     let top_up_cycles : Nat = params.cycles_per_canister - status.cycles;
+                     Cycles.add(top_up_cycles);
+                 };
                  await IC.uninstall_code(cid);
                  info
              };
@@ -53,8 +71,7 @@ actor class Self(opt_params : ?Types.InitParams) {
         };
     };
 
-    public query func dump() : async RBTree.Tree<Types.CanisterInfo, ()> {
-        //Iter.toArray(state.project.entries());
+    public query func dump() : async [Types.CanisterInfo] {
         pool.share()
     };
 }

backend/Types.mo

@@ -1,8 +1,8 @@
 import Principal "mo:base/Principal";
-import RBTree "mo:base/RBTree";
+import Splay "mo:splay";
 import Time "mo:base/Time";
 import Buffer "mo:base/Buffer";
-import Option "mo:base/Option";
+import Iter "mo:base/Iter";
 
 module {
     public type InitParams = {
@@ -33,21 +33,21 @@ module {
     };
     public class CanisterPool(size: Nat, TTL: Nat) {
         var len = 0;
-        var tree = RBTree.RBTree<CanisterInfo, ()>(canisterInfoCompare);
+        var tree = Splay.Splay<CanisterInfo>(canisterInfoCompare);
         public type NewId = { #newId; #reuse:CanisterInfo; #outOfCapacity:Int };
         public func getExpiredCanisterId() : NewId {
             if (len < size) {
                 #newId
             } else {
                 switch (tree.entries().next()) {
                 case null #outOfCapacity(-1);
-                case (?(info,_)) {
+                case (?info) {
                          let now = Time.now();
                          let elapsed = now - info.timestamp;
                          if (elapsed >= TTL) {
-                             Option.assertSome(tree.remove(info));
+                             tree.remove(info);
                              let new_info = { timestamp = now; id = info.id };
-                             tree.put(new_info, ());
+                             tree.insert(new_info);
                              #reuse(new_info)
                          } else {
                              #outOfCapacity(TTL - elapsed)
@@ -61,22 +61,22 @@ module {
                 assert false;
             };
             len += 1;
-            tree.put(info, ());
+            tree.insert(info);
         };
         public func refresh(info: CanisterInfo) : CanisterInfo {
-            Option.assertSome(tree.remove(info));
+            tree.remove(info);
             let new_info = { timestamp = Time.now(); id = info.id };
-            tree.put(new_info, ());
+            tree.insert(new_info);
             new_info
         };
         public func retire(info: CanisterInfo) {
-            Option.assertSome(tree.remove(info));
-            tree.put({ timestamp = 0; id = info.id }, ());
+            tree.remove(info);
+            tree.insert({ timestamp = 0; id = info.id });
         };
         public func gcList() : Buffer.Buffer<Principal> {
             let now = Time.now();
             let result = Buffer.Buffer<Principal>(len);
-            for ((info, _) in tree.entries()) {
+            for (info in tree.entries()) {
                 if (info.timestamp > 0) {
                     // assumes when timestamp == 0, uninstall_code is already done
                     if (info.timestamp > now - TTL) { return result };
@@ -86,8 +86,12 @@ module {
             };
             result
         };
-        public func share() : RBTree.Tree<CanisterInfo, ()> {
-            tree.share()
+        public func share() : [CanisterInfo] {
+            Iter.toArray(tree.entries())
+        };
+        public func unshare(list: [CanisterInfo]) {
+            len := list.size();
+            tree.fromArray(list);
         };
     };
 }

backend/tests/canisterPool.test.sh

@@ -25,14 +25,15 @@ let c3 = call S.getCanisterId();
 c3;
 let c4 = call S.getCanisterId();
 c4;
+assert c1.id != c2.id;
 assert c1.id == c3.id;
 assert c2.id == c4.id;
 
 // Out of capacity
 let init = opt record {
   cycles_per_canister = 105_000_000_000 : nat;
   max_num_canisters = 2 : nat;
-  TTL = 60_000_000_000 : nat;
+  TTL = 3600_000_000_000 : nat;
 };
 call ic.install_code(
   record {
@@ -42,10 +43,16 @@ call ic.install_code(
     canister_id = S;
   },
 );
-call S.getCanisterId();
-call S.getCanisterId();
+let c3 = call S.getCanisterId();
+c3;
+let c4 = call S.getCanisterId();
+c4;
 fail call S.getCanisterId();
 assert _ ~= "No available canister id";
+call S.removeCode(c4);
+call S.getCanisterId();
+assert _.id == c4.id;
+assert _.timestamp != c4.timestamp;
 
 // Out of cycle
 let id = call ic.provisional_create_canister_with_cycles(record { settings = null; amount = opt 10_000_000 });

backend/tests/upgrade.test.sh

@@ -0,0 +1,78 @@
+#!ic-repl
+
+let id = call ic.provisional_create_canister_with_cycles(record { settings = null; amount = null });
+let S = id.canister_id;
+
+let init = opt record {
+  cycles_per_canister = 105_000_000_000 : nat;
+  max_num_canisters = 2 : nat;
+  TTL = 1 : nat;
+};
+call ic.install_code(
+  record {
+    arg = encode (init);
+    wasm_module = file "../../.dfx/local/canisters/backend/backend.wasm";
+    mode = variant { install };
+    canister_id = S;
+  },
+);
+let c1 = call S.getCanisterId();
+c1;
+let c2 = call S.getCanisterId();
+c2;
+
+call ic.install_code(
+  record {
+    arg = encode (init);
+    wasm_module = file "../../.dfx/local/canisters/backend/backend.wasm";
+    mode = variant { upgrade };
+    canister_id = S;
+  },
+);
+let c3 = call S.getCanisterId();
+c3;
+let c4 = call S.getCanisterId();
+c4;
+assert c1.id != c2.id;
+assert c1.id == c3.id;
+assert c2.id == c4.id;
+
+// Okay to increase pool and TTL
+let init = opt record {
+  cycles_per_canister = 105_000_000_000 : nat;
+  max_num_canisters = 3 : nat;
+  TTL = 3600_000_000_000 : nat;
+};
+call ic.install_code(
+  record {
+    arg = encode (init);
+    wasm_module = file "../../.dfx/local/canisters/backend/backend.wasm";
+    mode = variant { upgrade };
+    canister_id = S;
+  },
+);
+let c5 = call S.getCanisterId();
+c5;
+assert c5.id != c1.id;
+assert c5.id != c2.id;
+fail call S.getCanisterId();
+assert _ ~= "No available canister id";
+
+// Cannot reduce pool
+let init = opt record {
+  cycles_per_canister = 105_000_000_000 : nat;
+  max_num_canisters = 1 : nat;
+  TTL = 1 : nat;
+};
+fail call ic.install_code(
+  record {
+    arg = encode (init);
+    wasm_module = file "../../.dfx/local/canisters/backend/backend.wasm";
+    mode = variant { upgrade };
+    canister_id = S;
+  },
+);
+assert _ ~= "assertion failed";
+// still old canister, new TTL does not apply
+fail call S.getCanisterId();
+assert _ ~= "No available canister id";

dfx.json

@@ -16,7 +16,7 @@
   "defaults": {
     "build": {
       "output": "build",
-      "packtool": ""
+      "packtool": "vessel sources"
     }
   },
   "networks": {

package-set.dhall

@@ -0,0 +1,29 @@
+let upstream = https://github.com/kritzcreek/vessel-package-set/releases/download/mo-0.6.4-20210624/package-set.dhall sha256:3f4cffd315d8ee5d2b4b5b00dc03b2e02732345b565340b7cb9cc0001444f525
+let Package =
+    { name : Text, version : Text, repo : Text, dependencies : List Text }
+
+let
+  -- This is where you can add your own packages to the package-set
+  additions =
+      [{ name = "base"
+      , repo = "https://github.com/dfinity/motoko-base"
+      , version = "dfx-0.7.0"
+      , dependencies = [] : List Text
+      }] : List Package
+
+let
+  {- This is where you can override existing packages in the package-set
+
+     For example, if you wanted to use version `v2.0.0` of the foo library:
+     let overrides = [
+         { name = "foo"
+         , version = "v2.0.0"
+         , repo = "https://github.com/bar/foo"
+         , dependencies = [] : List Text
+         }
+     ]
+  -}
+  overrides =
+    [] : List Package
+
+in  upstream # additions # overrides

vessel.dhall

@@ -0,0 +1,4 @@
+{
+  dependencies = [ "base", "splay" ],
+  compiler = None Text
+}