[5/5] drill git commit: DRILL-3724: Improve javadoc of the plugin component

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DRILL-3724: Improve javadoc of the plugin component

Improve the javadoc of the key methods and classes for custom plugin development.

this closes #139


Project: http://git-wip-us.apache.org/repos/asf/drill/repo
Commit: http://git-wip-us.apache.org/repos/asf/drill/commit/0c1b293d
Tree: http://git-wip-us.apache.org/repos/asf/drill/tree/0c1b293d
Diff: http://git-wip-us.apache.org/repos/asf/drill/diff/0c1b293d

Branch: refs/heads/master
Commit: 0c1b293d92ca8db88d4c3c43a7029e53a6890430
Parents: d6adf5c
Author: Edmon Begoli <eb...@gmail.com>
Authored: Sun Aug 30 10:56:22 2015 -0400
Committer: adeneche <ad...@gmail.com>
Committed: Mon Sep 14 08:00:13 2015 -0700

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 .../drill/exec/store/AbstractStoragePlugin.java   |  3 +++
 .../apache/drill/exec/store/StoragePlugin.java    | 18 +++++++++++++++++-
 .../exec/store/dfs/easy/EasyFormatPlugin.java     |  3 +++
 3 files changed, 23 insertions(+), 1 deletion(-)
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http://git-wip-us.apache.org/repos/asf/drill/blob/0c1b293d/exec/java-exec/src/main/java/org/apache/drill/exec/store/AbstractStoragePlugin.java
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diff --git a/exec/java-exec/src/main/java/org/apache/drill/exec/store/AbstractStoragePlugin.java b/exec/java-exec/src/main/java/org/apache/drill/exec/store/AbstractStoragePlugin.java
index 33870aa..5e49bb0 100644
--- a/exec/java-exec/src/main/java/org/apache/drill/exec/store/AbstractStoragePlugin.java
+++ b/exec/java-exec/src/main/java/org/apache/drill/exec/store/AbstractStoragePlugin.java
@@ -29,6 +29,9 @@ import org.apache.drill.exec.physical.base.AbstractGroupScan;
 
 import com.google.common.collect.ImmutableSet;
 
+/** Abstract class for StorePlugin implementations.
+ * See StoragePlugin for description of the interface intent and its methods.
+ */
 public abstract class AbstractStoragePlugin implements StoragePlugin{
   static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(AbstractStoragePlugin.class);
 

http://git-wip-us.apache.org/repos/asf/drill/blob/0c1b293d/exec/java-exec/src/main/java/org/apache/drill/exec/store/StoragePlugin.java
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diff --git a/exec/java-exec/src/main/java/org/apache/drill/exec/store/StoragePlugin.java b/exec/java-exec/src/main/java/org/apache/drill/exec/store/StoragePlugin.java
index 375116d..3bb5ef5 100644
--- a/exec/java-exec/src/main/java/org/apache/drill/exec/store/StoragePlugin.java
+++ b/exec/java-exec/src/main/java/org/apache/drill/exec/store/StoragePlugin.java
@@ -28,11 +28,24 @@ import org.apache.drill.common.logical.StoragePluginConfig;
 import org.apache.drill.exec.ops.OptimizerRulesContext;
 import org.apache.drill.exec.physical.base.AbstractGroupScan;
 
+/** Interface for all implementations of the storage plugins. Different implementations of the storage
+ * formats will implement methods that indicate if Drill can write or read its tables from that format,
+ * if there are optimizer rules specific for the format, getting a storage config. etc.
+ */
 public interface StoragePlugin extends SchemaFactory {
+
+  /** Indicates if Drill can read the table from this format.
+  */
   public boolean supportsRead();
 
+  /** Indicates if Drill can write a table to this format (e.g. as JSON, csv, etc.).
+   */
   public boolean supportsWrite();
 
+  /** An implementation of this method will return one or more specialized rules that Drill query
+   *  optimizer can leverage. Otherwise, it should return an empty set.
+   * @return an empty set or a set of plugin specific optimizer rules.
+   */
   public Set<? extends RelOptRule> getOptimizerRules(OptimizerRulesContext optimizerContext);
 
   /**
@@ -53,10 +66,13 @@ public interface StoragePlugin extends SchemaFactory {
    * @param columns (optional) The list of column names to scan from the data source.
    * @return
    * @throws IOException
-   */
+  */
   public AbstractGroupScan getPhysicalScan(String userName, JSONOptions selection, List<SchemaPath> columns)
       throws IOException;
 
+  /** Method returns a jackson serializable object that extends a StoragePluginConfig
+  * @return an extension of StoragePluginConfig
+  */
   public StoragePluginConfig getConfig();
 
 }

http://git-wip-us.apache.org/repos/asf/drill/blob/0c1b293d/exec/java-exec/src/main/java/org/apache/drill/exec/store/dfs/easy/EasyFormatPlugin.java
----------------------------------------------------------------------
diff --git a/exec/java-exec/src/main/java/org/apache/drill/exec/store/dfs/easy/EasyFormatPlugin.java b/exec/java-exec/src/main/java/org/apache/drill/exec/store/dfs/easy/EasyFormatPlugin.java
index 3c2b806..a59b7f1 100644
--- a/exec/java-exec/src/main/java/org/apache/drill/exec/store/dfs/easy/EasyFormatPlugin.java
+++ b/exec/java-exec/src/main/java/org/apache/drill/exec/store/dfs/easy/EasyFormatPlugin.java
@@ -115,6 +115,9 @@ public abstract class EasyFormatPlugin<T extends FormatPluginConfig> implements
     return blockSplittable;
   }
 
+  /** Method indicates whether or not this format could also be in a compression container (for example: csv.gz versus csv).
+   * If this format uses its own internal compression scheme, such as Parquet does, then this should return false.
+   */
   public boolean isCompressible() {
     return compressible;
   }