From 3fa1bbe33e947a5f2bf8c79349df3d3311d3b118 Mon Sep 17 00:00:00 2001
From: akwizgran <akwizgran@users.sourceforge.net>
Date: Mon, 8 Feb 2016 15:18:05 +0000
Subject: [PATCH] Expose transactions through DatabaseComponent interface.
---
.../api/db/DatabaseComponent.java | 15 +++++++++++++++
.../org/briarproject/api/db/Transaction.java | 15 +++++++++++++++
.../db/DatabaseComponentImpl.java | 19 +++++++++++++++++--
.../org/briarproject/db/DatabaseModule.java | 3 ++-
.../db/DatabaseComponentImplTest.java | 5 +++--
5 files changed, 52 insertions(+), 5 deletions(-)
create mode 100644 briar-api/src/org/briarproject/api/db/Transaction.java
diff --git a/briar-api/src/org/briarproject/api/db/DatabaseComponent.java b/briar-api/src/org/briarproject/api/db/DatabaseComponent.java
index 5609844f42..06800e1c4c 100644
--- a/briar-api/src/org/briarproject/api/db/DatabaseComponent.java
+++ b/briar-api/src/org/briarproject/api/db/DatabaseComponent.java
@@ -39,6 +39,21 @@ public interface DatabaseComponent {
/** Waits for any open transactions to finish and closes the database. */
void close() throws DbException, IOException;
+ /** Starts a new transaction and returns an object representing it. */
+ Transaction startTransaction() throws DbException;
+
+ /**
+ * Aborts the given transaction - no changes made during the transaction
+ * will be applied to the database.
+ */
+ void abortTransaction(Transaction txn);
+
+ /**
+ * Commits the given transaction - all changes made during the transaction
+ * will be applied to the database.
+ */
+ void commitTransaction(Transaction txn) throws DbException;
+
/**
* Stores a contact associated with the given local and remote pseudonyms,
* and returns an ID for the contact.
diff --git a/briar-api/src/org/briarproject/api/db/Transaction.java b/briar-api/src/org/briarproject/api/db/Transaction.java
new file mode 100644
index 0000000000..2ea803b05e
--- /dev/null
+++ b/briar-api/src/org/briarproject/api/db/Transaction.java
@@ -0,0 +1,15 @@
+package org.briarproject.api.db;
+
+/** A wrapper around a database transaction. */
+public class Transaction {
+
+ private final Object txn;
+
+ public Transaction(Object txn) {
+ this.txn = txn;
+ }
+
+ public Object unbox() {
+ return txn;
+ }
+}
diff --git a/briar-core/src/org/briarproject/db/DatabaseComponentImpl.java b/briar-core/src/org/briarproject/db/DatabaseComponentImpl.java
index dcf88660af..b62f180902 100644
--- a/briar-core/src/org/briarproject/db/DatabaseComponentImpl.java
+++ b/briar-core/src/org/briarproject/db/DatabaseComponentImpl.java
@@ -14,6 +14,7 @@ import org.briarproject.api.db.NoSuchLocalAuthorException;
import org.briarproject.api.db.NoSuchMessageException;
import org.briarproject.api.db.NoSuchTransportException;
import org.briarproject.api.db.StorageStatus;
+import org.briarproject.api.db.Transaction;
import org.briarproject.api.event.EventBus;
import org.briarproject.api.event.GroupAddedEvent;
import org.briarproject.api.event.GroupRemovedEvent;
@@ -77,6 +78,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
Logger.getLogger(DatabaseComponentImpl.class.getName());
private final Database<T> db;
+ private final Class<T> txnClass;
private final EventBus eventBus;
private final ShutdownManager shutdown;
private final AtomicBoolean closed = new AtomicBoolean(false);
@@ -84,9 +86,10 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
private volatile int shutdownHandle = -1;
@Inject
- DatabaseComponentImpl(Database<T> db, EventBus eventBus,
+ DatabaseComponentImpl(Database<T> db, Class<T> txnClass, EventBus eventBus,
ShutdownManager shutdown) {
this.db = db;
+ this.txnClass = txnClass;
this.eventBus = eventBus;
this.shutdown = shutdown;
}
@@ -116,6 +119,18 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
db.close();
}
+ public Transaction startTransaction() throws DbException {
+ return new Transaction(db.startTransaction());
+ }
+
+ public void abortTransaction(Transaction txn) {
+ db.abortTransaction(txnClass.cast(txn.unbox()));
+ }
+
+ public void commitTransaction(Transaction txn) throws DbException {
+ db.commitTransaction(txnClass.cast(txn.unbox()));
+ }
+
public ContactId addContact(Author remote, AuthorId local)
throws DbException {
T txn = db.startTransaction();
@@ -975,7 +990,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
public void setVisibleToContact(ContactId c, GroupId g, boolean visible)
throws DbException {
- boolean wasVisible = false;
+ boolean wasVisible;
T txn = db.startTransaction();
try {
if (!db.containsContact(txn, c))
diff --git a/briar-core/src/org/briarproject/db/DatabaseModule.java b/briar-core/src/org/briarproject/db/DatabaseModule.java
index 9ac531c077..6a050ed44b 100644
--- a/briar-core/src/org/briarproject/db/DatabaseModule.java
+++ b/briar-core/src/org/briarproject/db/DatabaseModule.java
@@ -51,7 +51,8 @@ public class DatabaseModule extends AbstractModule {
@Provides @Singleton
DatabaseComponent getDatabaseComponent(Database<Connection> db,
EventBus eventBus, ShutdownManager shutdown) {
- return new DatabaseComponentImpl<Connection>(db, eventBus, shutdown);
+ return new DatabaseComponentImpl<Connection>(db, Connection.class,
+ eventBus, shutdown);
}
@Provides @Singleton @DatabaseExecutor
diff --git a/briar-tests/src/org/briarproject/db/DatabaseComponentImplTest.java b/briar-tests/src/org/briarproject/db/DatabaseComponentImplTest.java
index 70a9113f23..178dee5b6a 100644
--- a/briar-tests/src/org/briarproject/db/DatabaseComponentImplTest.java
+++ b/briar-tests/src/org/briarproject/db/DatabaseComponentImplTest.java
@@ -106,9 +106,10 @@ public class DatabaseComponentImplTest extends BriarTestCase {
StorageStatus.ACTIVE);
}
- private <T> DatabaseComponent createDatabaseComponent(Database<T> database,
+ private DatabaseComponent createDatabaseComponent(Database<Object> database,
EventBus eventBus, ShutdownManager shutdown) {
- return new DatabaseComponentImpl<T>(database, eventBus, shutdown);
+ return new DatabaseComponentImpl<Object>(database, Object.class,
+ eventBus, shutdown);
}
@Test
--
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