From 5949c6f6c2bc4a0829376b89cac3d0626e7d11f6 Mon Sep 17 00:00:00 2001
From: Ludovic Le Frioux <llefriou@po461-pro.paris.inria.fr>
Date: Mon, 28 Sep 2020 15:19:22 +0200
Subject: [PATCH] Update pseudo code after discussion with @fcoriat
---
CObject | 21 ++++--
ClientId | 1 -
Collection | 27 ++++---
CollectionId | 1 -
ConsistencyLevel | 6 --
Global | 11 ---
OpId | 1 -
ServiceHandler | 2 +-
Session | 75 +++++++++++++------
Transaction | 19 ++---
TxnId | 1 -
CObjectId => utils/CObjectId | 1 +
utils/ClientId | 2 +
utils/CollectionId | 2 +
utils/ConsistencyLevel | 7 ++
utils/Global | 2 +
.../NotificationHandler | 1 +
utils/OperationId | 2 +
TransactionBody => utils/TransactionBody | 1 +
utils/TxnId | 2 +
20 files changed, 110 insertions(+), 75 deletions(-)
delete mode 100644 ClientId
delete mode 100644 CollectionId
delete mode 100644 ConsistencyLevel
delete mode 100644 Global
delete mode 100644 OpId
delete mode 100644 TxnId
rename CObjectId => utils/CObjectId (53%)
create mode 100644 utils/ClientId
create mode 100644 utils/CollectionId
create mode 100644 utils/ConsistencyLevel
create mode 100644 utils/Global
rename NotificationHandler => utils/NotificationHandler (83%)
create mode 100644 utils/OperationId
rename TransactionBody => utils/TransactionBody (76%)
create mode 100644 utils/TxnId
diff --git a/CObject b/CObject
index b76963f..6f43467 100644
--- a/CObject
+++ b/CObject
@@ -1,16 +1,21 @@
class CObject<T> {
+ // Concordant object id
private id: CObjectId
+ // Is openned in read only mode
private readOnly: Boolean
+ // The encapsulated CRDT
private crdt: DeltaCRDT<T>
+ // Backup for the necapsulated CRDT (used in case of transaction abort)
private txnBackup: DeltaCRDT<T>?
CObject(oid: CObjectId, crdt: DeltaCRDT<T>, readOnly: Boolean) {
this.id = oid
this.crdt = crdt
+ this.readOnly = readOnly
this.txnBackup = null
}
@@ -24,20 +29,26 @@ class CObject<T> {
}
fun update(args) {
- if (NOT Global.DirtyCObjects.contains(this)) {
- Global.DirtyCObjects.put(this.id, this)
+ if (Session.currentTransaction == null) throw Exception
+ if (this.readOnly) throw Exception
+ if (NOT ActiveSession.dirtyObjects.contains(this.id)) {
+ ActiveSession.dirtyObjects.put(this.id, this)
this.txnBackup = this.crdt.copy()
}
- ts = Global.TxnEnv.tick()
- crdt.update(args, ts)
+ // Should be integrrated to CRDTs
+ ts = ActiveSession.txnEnv.tick()
+ this.crdt.update(args, ts)
}
fun getter(args): val {
+ if (ActiveSession.currentTransaction == null) throw Exception
return crdt.getter(args)
}
fun close() {
- Global.Cache.remove(this.id)
+ if (NOT ActiveSession.currentTransaction == null) throw Exception
+ ActiveSession.cache.remove(this.id)
+ ActiveSession.handlers.remove(this.id)
SERVICE.unsubscribe(this.id)
}
}
diff --git a/ClientId b/ClientId
deleted file mode 100644
index d73e248..0000000
--- a/ClientId
+++ /dev/null
@@ -1 +0,0 @@
-type ClientId = UUID
diff --git a/Collection b/Collection
index 69c99fa..c6939da 100644
--- a/Collection
+++ b/Collection
@@ -9,32 +9,35 @@ class Collection {
// Static boolean used to ensure that only one collection is openned
private static otherOpenned: Boolean = false
- Collection(cid: CollectionId) {
- if (otherOpenned == true) throw Exception
+ Collection(cid: CollectionId, readOnly: Boolean) {
+ if (Collection.otherOpenned == true) throw Exception
Collection.otherOpenned = true
this.id = cid
+ this.readOnly = readOnly
}
// c_open_read|write<T>
fun open<T>(oid: String, readOnly: Boolean, handler: NotificationHandler): T {
if (this.readOnly AND NOT readOnly) throw Exception
+ if (NOT Session.currentTransaction == null) throw Exception
+
oid = CObjectId(this.id, oid, T)
- if (Global.Cache.contains(oid)) return Global.Cache.get(oid)
- crdt, _ = SERVICE.getObject(oid, TxnEnv.getState())
- SERVICE.subscribe(oid)
+ if (ActiveSession.cache.contains(oid)) return ActiveSession.cache.get(oid)
+
+ crdt, v = SERVICE.getObject(oid, ActiveSession.txnEnv.getState())
+ ActiveSession.txnEnv.updateSate(v)
obj = CObject<T>(oid, crdt, readOnly)
- Global.Cache.put(oid, obj)
- Global.Handlers.put(oid, handler)
+ ActiveSession.cache.put(oid, obj)
+ ActiveSession.handlers.put(oid, handler)
return obj
}
// c_close_collection
fun close() {
- for oid in Global.Cache {
- SERVICE.unsubscribe(oid)
- }
- Global.Cache.clear()
- Global.Handlers.clear()
+ if (NOT Session.currentTransaction == null) throw Exception
+ SERVICE.unsubscribeAll()
+ ActiveSession.cache.clear()
+ ActiveSession.handlers.clear()
Collection.otherOpenned = false
}
}
diff --git a/CollectionId b/CollectionId
deleted file mode 100644
index a332d25..0000000
--- a/CollectionId
+++ /dev/null
@@ -1 +0,0 @@
-type CollectionId = String
diff --git a/ConsistencyLevel b/ConsistencyLevel
deleted file mode 100644
index acd920f..0000000
--- a/ConsistencyLevel
+++ /dev/null
@@ -1,6 +0,0 @@
-enum ConsistencyLevel {
-
- RC,
- Snapshot,
- Strong
-}
diff --git a/Global b/Global
deleted file mode 100644
index 7d3cff3..0000000
--- a/Global
+++ /dev/null
@@ -1,11 +0,0 @@
-// Transaction environment should inherit from crdtlib.utils.Environment
-TxnEnv: TransactionEnvironment
-
-// Map for dirty objects
-DirtyCObjects: Map<CObjectId, CObject>
-
-// Map for the cache
-Cache: Map<CObjectId, CObject>
-
-// Map for c-object handlers management
-Handlers: Map<CObjectId, NotificationHandler>
diff --git a/OpId b/OpId
deleted file mode 100644
index 9d43b68..0000000
--- a/OpId
+++ /dev/null
@@ -1 +0,0 @@
-type OpId = (TxnId, Int)
diff --git a/ServiceHandler b/ServiceHandler
index 120db22..932a384 100644
--- a/ServiceHandler
+++ b/ServiceHandler
@@ -8,7 +8,7 @@ class ServiceHandler: Thread {
fun work() {
while (true) {
v, oid = readMessage()
- if (Global.Handlers.contains(oid)) {
+ if (ActiveSession.handlers.contains(oid)) {
// call the corresponding handler
Handlers.get(oid)(v, oid)
}
diff --git a/Session b/Session
index 57a8642..12a7506 100644
--- a/Session
+++ b/Session
@@ -1,64 +1,93 @@
class Session {
- // Current consistency level
- private consistency: ConsistencyLevel
-
// The client id
private cliendId: CliendId
+ // Current consistency level
+ private consistency: ConsistencyLevel?
+
// The attached service handler
private serviceHandler: ServiceHandler
- Session(cid: ClientId) {
+ // Current running transaction
+ private currentTransaction: Transaction?
+
+ // Transaction environment should inherit from crdtlib.utils.Environment
+ package txnEnv: TransactionEnvironment
+
+ // Map for dirty Concordant objects
+ package dirtyObjects: Map<CObjectId, CObject>
+
+ // Map for the cache of Concordant objects
+ package cache: Map<CObjectId, CObject>
+
+ // Map for Concordant object handlers management
+ package handlers: Map<CObjectId, NotificationHandler>
+
+ private Session(cid: ClientId) {
this.clientId = cid
+ this.txnEnv = TransactionEnvironment(this.clientId)
+ this.dirtyObjects = mutableMapOf()
+ this.cache = mutableMapOf()
+ this.handlers = mutableMapOf()
+ this.serviceHandler = ServiceHandler()
+ this.serviceHandler.run()
+ this.currentTransaction = null
}
// c_begin_session
- static fun open(dbName: String, credentials: String): Session {
+ static fun connect(dbName: String, credentials: String): Session {
+ if (NOT ActiveSession == null) throw Exception
clientId = ClientId()
- if (NOT SERVICE.open(dbName, credentials, clientId)) throw Exception
- this.serviceHandler = ServiceHandler()
- this.serviceHandler.run()
- return Session(clientId)
+ if (NOT SERVICE.connect(dbName, credentials, clientId)) throw Exception
+ ActiveSession = Session(clientId)
+ retur ActiveSession
}
// c_pull_XX_view
fun pull(type: ConsistencyLevel) {
- if (consistency != null AND consistency > type) throw Exception
+ if (NOT this.currentTransaction == null) throw Exception
+ if (this.consistency != null AND this.consistency > type) throw Exception
this.consistency = type
- for oid in Cache {
- crdt, v = SERVICE.getObject(oid)
- obj = Global.Cache.get(oid)
+ for oid in this.cache {
+ crdt, v = SERVICE.getObject(oid, this.consistency)
+ obj = this.cache.get(oid)
obj.crdt = crdt
- Global.TxnEnv.updateSate(v)
+ this.txnEnv.updateSate(v)
}
}
// c_pull_XX_view(v)
fun pull(type: ConsistencyLevel, vv: VersionVector) {
- if (view != null AND view.type > type) throw Exception
- if (vv < global.TxnEnv.getState()) throw Exception
- for oid in Cache {
- crdt, v = SERVICE.getObject(oid, vv)
- obj = Global.Cache.get(oid)
+ if (NOT this.currentTransaction == null) throw Exception
+ if (this.consistency != null AND this.consistency > type) throw Exception
+ if (vv < this.txnEnv.getState()) throw Exception
+ this.consistency = type
+ for oid in this.cache {
+ crdt, v = SERVICE.getObject(oid, vv, this.consistency)
+ obj = this.cache.get(oid)
obj.crdt = crdt
- Global.TxnEnv.updateSate(v)
+ this.txnEnv.updateSate(v)
}
}
// c_open_collection_read|write
fun openCollection(cid: CollectionId, readOnly: Boolean): Collection {
- return Collection(cid)
+ if (NOT this.currentTransaction == null) throw Exception
+ return Collection(cid, readOnly)
}
// c_XX_txn
- fun beginTransaction(body: () -> Unit) {
- Transaction(body)
+ fun transaction(body: TransactionBody) {
+ if (NOT this.currentTransaction == null) throw Exception
+ this.currentTransaction = Transaction(body)
}
// c_end_session
fun close() {
+ if (this.currentTransaction == null) this.currentTransaction.abort()
SERVICE.close(clientId)
this.serviceHandler.stop()
+ ActiveSession = null
}
}
diff --git a/Transaction b/Transaction
index a30bacf..ffe0d61 100644
--- a/Transaction
+++ b/Transaction
@@ -3,17 +3,12 @@ class Transaction {
// Transaction id
private transactionId: TxnId
- // Static boolean used to ensure that only one collection is openned
- private static otherOpenned: Boolean = false
-
// The version vector at which the transaction has started
private begin: VersionVector
Transaction(tid: TxnId, body: TransactionBody) {
- if (Transaction.otherOpenned) throw Exception
- Transaction.otherOpenned = true
- this.begin = Global.TxnEnv.getState()
- this.transactionId = Global.TxnEnv.tickTransaction()
+ this.begin = ActiveSession.txnEnv.getState()
+ this.transactionId = ActiveSession.txnEnv.tickTransaction()
try {
// call the body function
@@ -28,22 +23,20 @@ class Transaction {
// c_abort_txn
fun abort() {
- for obj in Global.DirtyCObjects {
+ for obj in ActiveSession.dirtyObjects {
obj.txnAbort()
}
- Global.DirtyCObjects.clear()
- Transaction.otherOpenned = false
+ ActiveSession.dirtyObjects.clear()
}
// c_commit_txn
fun commit() {
SERVICE.beginTransaction(this.transactionId)
- for obj in Global.DirtyCObjects {
+ for obj in ActiveSession.dirtyObjects {
SERVICE.pushObject(obj.crdt.getDelta(this.begin))
obj.txnCommit()
}
SERVICE.commitTransaction(this.transactionId)
- Global.DirtyCObjects.clear()
- Transaction.otherOpenned = false
+ ActiveSession.dirtyObjects.clear()
}
}
diff --git a/TxnId b/TxnId
deleted file mode 100644
index c64b3eb..0000000
--- a/TxnId
+++ /dev/null
@@ -1 +0,0 @@
-type TxnId = (Int, ClientId)
diff --git a/CObjectId b/utils/CObjectId
similarity index 53%
rename from CObjectId
rename to utils/CObjectId
index e75632f..8bde73e 100644
--- a/CObjectId
+++ b/utils/CObjectId
@@ -1 +1,2 @@
+// Concordant object unique identifiers
type CObjectId = (CollectionId, String, Type)
diff --git a/utils/ClientId b/utils/ClientId
new file mode 100644
index 0000000..a591f0b
--- /dev/null
+++ b/utils/ClientId
@@ -0,0 +1,2 @@
+// Client unique identifiers are UUId, they can also be hierarchic
+type ClientId = UUId
diff --git a/utils/CollectionId b/utils/CollectionId
new file mode 100644
index 0000000..330f9c2
--- /dev/null
+++ b/utils/CollectionId
@@ -0,0 +1,2 @@
+// Collection unique identifiers
+type CollectionId = String
diff --git a/utils/ConsistencyLevel b/utils/ConsistencyLevel
new file mode 100644
index 0000000..7caa60f
--- /dev/null
+++ b/utils/ConsistencyLevel
@@ -0,0 +1,7 @@
+// Different types of consistency level provided by the Concordant platform
+enum ConsistencyLevel {
+
+ RC,
+ Snapshot,
+ Strong
+}
diff --git a/utils/Global b/utils/Global
new file mode 100644
index 0000000..475f16d
--- /dev/null
+++ b/utils/Global
@@ -0,0 +1,2 @@
+// Global variable(s)
+ActiveSession: Session? = null
diff --git a/NotificationHandler b/utils/NotificationHandler
similarity index 83%
rename from NotificationHandler
rename to utils/NotificationHandler
index 3f95a44..d905e70 100644
--- a/NotificationHandler
+++ b/utils/NotificationHandler
@@ -1,2 +1,3 @@
// The notification handler (function) type accepted for c-objects
+// Unit == void in Kotlin
type NotificationHandler = (VersionVector, CObjectId) -> Unit
diff --git a/utils/OperationId b/utils/OperationId
new file mode 100644
index 0000000..6b954f5
--- /dev/null
+++ b/utils/OperationId
@@ -0,0 +1,2 @@
+// Operations unique identifiers
+type OperationId = (TxnId, Int)
diff --git a/TransactionBody b/utils/TransactionBody
similarity index 76%
rename from TransactionBody
rename to utils/TransactionBody
index cb39263..6c6e44b 100644
--- a/TransactionBody
+++ b/utils/TransactionBody
@@ -1,2 +1,3 @@
// The function type accepted for a transaction body
+// Unit == void in Kotlin
type TransactionBody = () -> Unit
diff --git a/utils/TxnId b/utils/TxnId
new file mode 100644
index 0000000..f262855
--- /dev/null
+++ b/utils/TxnId
@@ -0,0 +1,2 @@
+// Transaction unique identifiers
+type TxnId = (Int, ClientId)
--
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