Add comment to explain that doPut() does not overwrite existing block.

JoshRosen · JoshRosen · commit 0aafba29bf99 · 2016-03-01T20:57:30.000-08:00
diff --git a/core/src/main/scala/org/apache/spark/storage/BlockManager.scala b/core/src/main/scala/org/apache/spark/storage/BlockManager.scala
@@ -726,6 +726,8 @@ private[spark] class BlockManager(
    * Put the given block according to the given level in one of the block stores, replicating
    * the values if necessary.
    *
+   * If the block already exists, this method will not overwrite it.
+   *
    * @param effectiveStorageLevel the level according to which the block will actually be handled.
    *                              This allows the caller to specify an alternate behavior of doPut
    *                              while preserving the original level specified by the user.

Original file line number	Diff line number	Diff line change
`@@ -726,6 +726,8 @@ private[spark] class BlockManager(`
`726`	`726`	`* Put the given block according to the given level in one of the block stores, replicating`
`727`	`727`	`* the values if necessary.`
`728`	`728`	`*`
	`729`	`+ * If the block already exists, this method will not overwrite it.`
	`730`	`+ *`
`729`	`731`	`* @param effectiveStorageLevel the level according to which the block will actually be handled.`
`730`	`732`	`* This allows the caller to specify an alternate behavior of doPut`
`731`	`733`	`* while preserving the original level specified by the user.`