X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;ds=sidebyside;f=opendaylight%2Fmd-sal%2Fsal-common-api%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fmd%2Fsal%2Fcommon%2Fapi%2Fdata%2FAsyncReadTransaction.java;h=3396b61f28412f20b041a51b32c182780c8dffc9;hb=21775f1de8552c3be584735ea179ce87e0929986;hp=7744f71888fe0ac6017bea1513962e00915da57e;hpb=48814d6a264b8f13e5db1422336d9ef25cb05fa9;p=controller.git diff --git a/opendaylight/md-sal/sal-common-api/src/main/java/org/opendaylight/controller/md/sal/common/api/data/AsyncReadTransaction.java b/opendaylight/md-sal/sal-common-api/src/main/java/org/opendaylight/controller/md/sal/common/api/data/AsyncReadTransaction.java index 7744f71888..3396b61f28 100644 --- a/opendaylight/md-sal/sal-common-api/src/main/java/org/opendaylight/controller/md/sal/common/api/data/AsyncReadTransaction.java +++ b/opendaylight/md-sal/sal-common-api/src/main/java/org/opendaylight/controller/md/sal/common/api/data/AsyncReadTransaction.java @@ -9,29 +9,53 @@ package org.opendaylight.controller.md.sal.common.api.data; import org.opendaylight.yangtools.concepts.Path; -import com.google.common.base.Optional; -import com.google.common.util.concurrent.ListenableFuture; - +/** + * Marker interface for stateful read view of the data tree. + * + *
+ * View of the data tree is a stable point-in-time snapshot of the current data tree state when + * the transaction was created. It's state and underlying data tree + * is not affected by other concurrently running transactions. + * + *
+ * Implementation Note: This interface is not intended to be implemented + * by users of MD-SAL, but only to be consumed by them. + * + *
PATH
is A
.
+ *
+ * + * txRead = broker.newReadOnlyTransaction(); // read Transaction is snapshot of data + * txWrite = broker.newReadWriteTransactoin(); // concurrent write transaction + * + * txRead.read(OPERATIONAL,PATH).get(); // will return Optional containing A + * txWrite = broker.put(OPERATIONAL,PATH,B); // writes B to PATH + * + * txRead.read(OPERATIONAL,PATH).get(); // still returns Optional containing A + * + * txWrite.commit().get(); // data tree is updated, PATH contains B + * txRead.read(OPERATIONAL,PATH).get(); // still returns Optional containing A + * + * txAfterCommit = broker.newReadOnlyTransaction(); // read Transaction is snapshot of new state + * txAfterCommit.read(OPERATIONAL,PATH).get(); // returns Optional containing B; + *+ * + *
+ * Note: example contains blocking calls on future only to illustrate + * that action happened after other asynchronous action. Use of blocking call + * {@link com.google.common.util.concurrent.ListenableFuture#get()} is discouraged for most + * uses and you should use + * {@link com.google.common.util.concurrent.Futures#addCallback(com.google.common.util.concurrent.ListenableFuture, + * com.google.common.util.concurrent.FutureCallback, java.util.concurrent.Executor)} + * or other functions from {@link com.google.common.util.concurrent.Futures} to + * register more specific listeners. + * + * @param
+ * Type of path (subtree identifier), which represents location in
+ * tree
+ * @param , D> extends AsyncTransaction {
- /**
- *
- * Reads data from provided logical data store located at provided path
- *
- *
- * @param store
- * Logical data store from which read should occur.
- * @param path
- * Path which uniquely identifies subtree which client want to
- * read
- * @return Listenable Future which contains read result
- *
- *
- */
- ListenableFuture