svn commit: r1234497 - /directory/sandbox/elecharny/shared-mvbt/src/main/java/org/apache/directory/btree/BTree.java

[el...@apache.org]

Author: elecharny
Date: Sun Jan 22 12:02:13 2012
New Revision: 1234497

URL: http://svn.apache.org/viewvc?rev=1234497&view=rev
Log:
Added some Javadoc

Modified:
    directory/sandbox/elecharny/shared-mvbt/src/main/java/org/apache/directory/btree/BTree.java

Modified: directory/sandbox/elecharny/shared-mvbt/src/main/java/org/apache/directory/btree/BTree.java
URL: http://svn.apache.org/viewvc/directory/sandbox/elecharny/shared-mvbt/src/main/java/org/apache/directory/btree/BTree.java?rev=1234497&r1=1234496&r2=1234497&view=diff
==============================================================================
--- directory/sandbox/elecharny/shared-mvbt/src/main/java/org/apache/directory/btree/BTree.java (original)
+++ directory/sandbox/elecharny/shared-mvbt/src/main/java/org/apache/directory/btree/BTree.java Sun Jan 22 12:02:13 2012
@@ -43,13 +43,19 @@ public class BTree<K, V>
     /** This BTree's record ID in the PageManager. */
     private transient long recordId;
     
+    /** A field used to generate new revisions in a thread safe way */
+    private AtomicLong revision = new AtomicLong(0);
+
+    /** A field used to generate new recordId in a thread safe way */
     private transient AtomicLong pageRecordIdGenerator;
 
     /** Comparator used to index entries. */
     Comparator<K> comparator;
 
+    /** The current rootPage */
     protected Page<K, V> rootPage;
     
+    /** A map containing all the existing revisions */
     private Map<Long, Page<K, V>> roots = new HashMap<Long, Page<K, V>>();
 
     /**
@@ -58,15 +64,14 @@ public class BTree<K, V>
      */
     int bTreeHeight;
 
-    /** Revision  */
-    private AtomicLong revision = new AtomicLong(0);
-
     /** Number of entries in each Page. */
     protected int pageSize;
 
 
     /**
+     * Creates a new BTree with a default page size and a comparator.
      * 
+     * @param comparator The comparator to use
      */
     public BTree( Comparator<K> comparator ) throws IOException
     {
@@ -75,7 +80,10 @@ public class BTree<K, V>
     
     
     /**
+     * Creates a new BTree with a specific page size and a comparator.
      * 
+     * @param comparator The comparator to use
+     * @param pageSize The number of elements we can store in a page
      */
     public BTree( Comparator<K> comparator, int pageSize ) throws IOException
     {
@@ -93,14 +101,25 @@ public class BTree<K, V>
     }
     
     
-    public void setPageSize( int pageSize )
+    /**
+     * Find the value associated with the given key.
+     *
+     * @param key Lookup key.
+     * @return Value associated with the key, or null if not found.
+     */
+    public V find( K key ) throws IOException
     {
-        this.pageSize = pageSize;
+        if ( key == null )
+        {
+            throw new IllegalArgumentException( "Key must not be null" );
+        }
 
-        if ( pageSize <= 0 )
+        if ( rootPage == null )
         {
-            this.pageSize = DEFAULT_PAGE_SIZE;
+            return null;
         }
+        
+        return rootPage.find( key );
     }
 
 
@@ -169,29 +188,33 @@ public class BTree<K, V>
     
     
     /**
-     * Find the value associated with the given key.
-     *
-     * @param key Lookup key.
-     * @return Value associated with the key, or null if not found.
+     * @return The number of element we can stoe in a page
      */
-    public V find( K key ) throws IOException
+    public int getPageSize()
     {
-        if ( key == null )
-        {
-            throw new IllegalArgumentException( "Key must not be null" );
-        }
+        return pageSize;
+    }
+    
+    
+    /**
+     * Set the maximum number of elements we can store in a page. This must be a
+     * number greater than 1. The default page size is 16.
+     * 
+     * @param pageSize The requested page size
+     */
+    public void setPageSize( int pageSize )
+    {
+        this.pageSize = pageSize;
 
-        if ( rootPage == null )
+        if ( pageSize <= 2 )
         {
-            return null;
+            this.pageSize = DEFAULT_PAGE_SIZE;
         }
-        
-        return rootPage.find( key );
     }
 
 
     /**
-     * Return the persistent record identifier of the BTree.
+     * @return the persistent record identifier of the BTree.
      */
     public long getRecordId()
     {
@@ -208,18 +231,31 @@ public class BTree<K, V>
     }
 
     
+    /**
+     * Generates a new RecordId.
+     * 
+     * @return a new incremental recordId
+     */
     /** No qualifier */ long generateRecordId()
     {
         return pageRecordIdGenerator.getAndIncrement();
     }
     
     
+    /**
+     * Generates a new revision number.
+     * 
+     * @return a new incremental revision number
+     */
     /** No qualifier */ long generateRevision()
     {
         return revision.getAndIncrement();
     }
     
     
+    /**
+     * @see Object#toString()
+     */
     public String toString()
     {
         StringBuilder sb = new StringBuilder();