Added SYSTEM FORGETALL.

docs/_docs/types/system.md

@@ -20,3 +20,13 @@ The system log is kept trimmed to a fixed maximum length to avoid unbounded memo
 Returns an array where each element is a two-element array containing the value and timestamp of that entry.
 
 The values will be returned as string, and the timestamps as integers.
+
+### `FORGETALL`
+
+Clear all data from the local in-memory database for this node. This is intended for use in application testing environments.
+
+If in a cluster, data will remain in the other nodes, meaning that all of the cleared data will be restored locally over time using the normal anti-entropy repair mechanisms - the local node will still be eventually consistent with the rest of the cluster.
+
+This command is not meant to be used in conjunction with disk persistence, but if used when disk persistence is enabled, there are no guarantees about how much of the data will remain present on the local disk in the immediate or short term. However, if in a cluster, eventual consistency guarantees with the other nodes in the cluster will still hold as described in the paragraph above.
+
+Returns a simple string reply of `OK` immediately, while the database is being cleared asynchronously.

jylis/database.pony

@@ -41,6 +41,12 @@ class val Database
         """)
     end
 
+  fun forget_all() =>
+    _system.log.info() and _system.log.i("database forgetting all data")
+    for repo in _map.values() do
+      repo.forget_all()
+    end
+
   fun flush_deltas(fn: _NameTokensFn) =>
     for repo in _map.values() do
       repo.flush_deltas(fn)

jylis/main.pony

@@ -8,5 +8,5 @@ actor Main
       let disk     = DiskSetup(system) .> replay(database)
       let server   = Server(auth, system, database)
       let cluster  = Cluster(auth, system, database, disk)
-      system.dispose.setup(database, disk, server, cluster)
+      system.setup(database, disk, server, cluster)
     end

jylis/repo_manager.pony

@@ -15,6 +15,7 @@ interface RepoAny
 
 interface tag RepoManagerAny
   be apply(resp: Respond, cmd: Array[String] val)
+  be forget_all()
   be flush_deltas(fn: _NameTokensFn)
   be converge_deltas(deltas: crdt.TokensIterator iso)
   be send_data(send_fn: _NameTokensFn)
@@ -34,6 +35,9 @@ actor RepoManager[R: RepoAny ref, H: HelpLeaf val] is RepoManagerAny
   be apply(resp: Respond, cmd: Array[String] val) =>
     _core(resp, cmd)
 
+  be forget_all() =>
+    _core.forget_all()
+
   be flush_deltas(fn: _NameTokensFn) =>
     _core.flush_deltas(fn)
 
@@ -58,13 +62,18 @@ actor RepoManager[R: RepoAny ref, H: HelpLeaf val] is RepoManagerAny
 
 class RepoManagerCore[R: RepoAny ref, H: HelpLeaf val]
   let _name: String
-  let _repo: R
+  let _identity: U64
+  var _repo: R
   var _deltas_fn: (_NameTokensFn | None) = None
   var _last_proactive: U64 = 0
   var _shutdown: Bool = false
 
   new create(name': String, identity': U64) =>
-    (_name, _repo) = (name', R(identity'))
+    (_name, _identity) = (name', identity')
+    _repo = R(_identity)
+
+  fun ref forget_all() =>
+    _repo = R(_identity)
 
   fun name(): String => _name
   fun repo(): this->R => _repo

jylis/repo_system.pony

@@ -9,15 +9,18 @@ primitive RepoSYSTEMHelp is HelpLeaf
     """
     The following are valid SYSTEM commands:
       SYSTEM GETLOG [count]
+      SYSTEM FORGETALL
     """
 
 class RepoSYSTEM
   let _identity: U64
+  var _database: (Database | None) = None
 
   let _log:       TLog[String] = TLog[String]
   var _log_delta: TLog[String] = TLog[String]
 
   new create(identity': U64) => _identity = identity'
+  fun ref setup(database': Database) => _database = database'
 
   fun ref delta_empty(): Bool => _log_delta.is_empty()
   fun ref flush_deltas(): Tokens =>
@@ -39,7 +42,8 @@ class RepoSYSTEM
 
   fun ref apply(r: Respond, cmd: Iterator[String]): Bool? =>
     match cmd.next()?
-    | "GETLOG" => getlog(r, _optcount(cmd))
+    | "GETLOG"    => getlog(r, _optcount(cmd))
+    | "FORGETALL" => forgetall(r)
     else error
     end
 
@@ -61,6 +65,11 @@ class RepoSYSTEM
     end
     false
 
+  fun forgetall(resp: Respond): Bool =>
+    try (_database as Database).forget_all() end
+    resp.ok()
+    false
+
   ///
   // System private methods, meant for use only within the jylis server.
   // Generally, the purpose is to fill data that is read-only to the user.

jylis/system.pony

@@ -13,22 +13,26 @@ class val System
     dispose = SystemDispose
     repo    = SystemRepoManager(config)
     log     = config.log .> set_sys(repo)
-
-actor SystemDispose
-  var _dispose: (Dispose | None) = None
-  var _dispose_when_ready: Bool = false
 
-  be setup(
+  fun val setup(
     database: Database,
     disk: DiskAny,
     server: Server,
     cluster: Cluster)
   =>
-    _dispose = Dispose(database, disk, server, cluster) .> on_signal()
-    if _dispose_when_ready then apply() end
+    dispose.setup(Dispose(database, disk, server, cluster) .> on_signal())
+    repo.setup(database)
+
+actor SystemDispose
+  var _dispose: (Dispose | None) = None
+  var _pending: Bool = false
+
+  be setup(dispose': Dispose) =>
+    _dispose = dispose'
+    if _pending then apply() end
 
   be apply() =>
-    try (_dispose as Dispose).dispose() else _dispose_when_ready = true end
+    try (_dispose as Dispose).dispose() else _pending = true end
 
 actor SystemRepoManager is RepoManagerAny
   let _config: Config
@@ -38,9 +42,15 @@ actor SystemRepoManager is RepoManagerAny
     _config = config'
     _core   = _core.create("SYSTEM", _config.addr.hash64())
 
+  be setup(database': Database) =>
+    _core.repo().setup(database')
+
   be apply(resp: Respond, cmd: Array[String] val) =>
     _core(resp, cmd)
 
+  be forget_all() =>
+    None // don't forget any SYSTEM data.
+
   be flush_deltas(fn: _NameTokensFn) =>
     _core.flush_deltas(fn)
 

spec/system_spec.rb

@@ -0,0 +1,29 @@
+require_relative "spec_helper"
+
+require "securerandom"
+require "fileutils"
+
+describe "System functions" do
+  subject { Jylis.new }
+
+  describe "FORGETALL" do
+    it "saves to and loads from an append-only file with a predictable format" do
+      subject.run do
+        subject.call(%w[TREG SET key1 foo 7]).should eq "OK"
+        subject.call(%w[TREG GET key1]).should eq ["foo", 7]
+
+        subject.call(%w[SYSTEM FORGETALL]).should eq "OK"
+        subject.call(%w[TREG GET key1]).should eq ["", 0]
+
+        subject.call(%w[TREG SET key1 bar 8]).should eq "OK"
+        subject.call(%w[TREG GET key1]).should eq ["bar", 8]
+
+        subject.call(%w[SYSTEM FORGETALL]).should eq "OK"
+        subject.call(%w[TREG GET key1]).should eq ["", 0]
+
+        subject.call(%w[TREG SET key1 baz 9]).should eq "OK"
+        subject.call(%w[TREG GET key1]).should eq ["baz", 9]
+      end
+    end
+  end
+end