HBASE-1215 migration part 7; javadoc and extra setVersion utility

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@796731 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/hadoop/hbase/util/FSUtils.java

@@ -192,12 +192,25 @@ public class FSUtils {
    * @throws IOException
    */
   public static void setVersion(FileSystem fs, Path rootdir) 
+  throws IOException {
+    setVersion(fs, rootdir, HConstants.FILE_SYSTEM_VERSION);
+  }
+
+  /**
+   * Sets version of file system
+   * 
+   * @param fs
+   * @param rootdir
+   * @param version
+   * @throws IOException
+   */
+  public static void setVersion(FileSystem fs, Path rootdir, String version) 
   throws IOException {
     FSDataOutputStream s =
       fs.create(new Path(rootdir, HConstants.VERSION_FILE_NAME));
-    s.writeUTF(HConstants.FILE_SYSTEM_VERSION);
+    s.writeUTF(version);
     s.close();
-    LOG.debug("Created version file to: " + rootdir.toString());
+    LOG.debug("Created version file at " + rootdir.toString() + " set its version at:" + version);
   }
 
   /**

src/java/org/apache/hadoop/hbase/util/MetaUtils.java

@@ -42,8 +42,6 @@ import org.apache.hadoop.hbase.client.HTable;
 import org.apache.hadoop.hbase.client.Put;
 import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.client.Scan;
-import org.apache.hadoop.hbase.io.BatchUpdate;
-import org.apache.hadoop.hbase.io.Cell;
 import org.apache.hadoop.hbase.regionserver.HLog;
 import org.apache.hadoop.hbase.regionserver.HRegion;
 import org.apache.hadoop.hbase.regionserver.InternalScanner;
@@ -124,7 +122,7 @@ public class MetaUtils {
     HRegion meta = metaRegions.get(metaInfo.getRegionName());
     if (meta == null) {
       meta = openMetaRegion(metaInfo);
-          LOG.info("META OPEN " + meta.toString());
+      LOG.info("OPENING META " + meta.toString());
       this.metaRegions.put(metaInfo.getRegionName(), meta);
     }
     return meta;
@@ -147,7 +145,7 @@ public class MetaUtils {
     }
     try {
       for (HRegion r: metaRegions.values()) {
-          LOG.info("META CLOSE " + r.toString());
+        LOG.info("CLOSING META " + r.toString());
         r.close();
       }
     } catch (IOException e) {
@@ -230,6 +228,9 @@ public class MetaUtils {
    * TODO: Use Visitor rather than Listener pattern.  Allow multiple Visitors.
    * Use this everywhere we scan meta regions: e.g. in metascanners, in close
    * handling, etc.  Have it pass in the whole row, not just HRegionInfo.
+   * <p>Use for reading meta only.  Does not close region when done.
+   * Use {@link #getMetaRegion(HRegionInfo)} instead if writing.  Adds
+   * meta region to list that will get a close on {@link #shutdown()}.
    * 
    * @param metaRegionInfo HRegionInfo for meta region
    * @param listener method to be called for each meta region found
@@ -255,8 +256,7 @@ public class MetaUtils {
     
     Scan scan = new Scan();
     scan.addColumn(HConstants.CATALOG_FAMILY, HConstants.REGIONINFO_QUALIFIER);
-    InternalScanner metaScanner = 
+    InternalScanner metaScanner = m.getScanner(scan);
-      m.getScanner(scan);
     
     try {
       List<KeyValue> results = new ArrayList<KeyValue>();

src/java/org/apache/hadoop/hbase/util/Migrate.java

@@ -244,7 +244,6 @@ public class Migrate extends Configured implements Tool {
         throw new IOException(msg);
       }
     }
-    // TOOD: Verify all has been brought over from old to new layout.
     final MetaUtils utils = new MetaUtils(this.conf);
     final List<HRegionInfo> metas = new ArrayList<HRegionInfo>();
     try {
@@ -264,14 +263,14 @@ public class Migrate extends Configured implements Tool {
       });
       // Scan meta.
       for (HRegionInfo hri: metas) {
-        final HRegionInfo metahri = hri;
+        final HRegion h = utils.getMetaRegion(hri);
-        utils.scanMetaRegion(hri, new MetaUtils.ScannerListener() {
+        utils.scanMetaRegion(h, new MetaUtils.ScannerListener() {
           public boolean processRow(HRegionInfo info) throws IOException {
             if (check && !migrationNeeded) {
               migrationNeeded = true;
               return false;
             }
-            rewriteHRegionInfo(utils.getMetaRegion(metahri), info);
+            rewriteHRegionInfo(h, info);
             return true;
           }
         });
@@ -341,7 +340,7 @@ public class Migrate extends Configured implements Tool {
   }
   
   /**
-   * Rewrite the passed mapfile
+   * Rewrite the passed 0.19 mapfile as a 0.20 file.
    * @param fs
    * @param mf
    * @throws IOExcepion