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From elecha...@apache.org
Subject svn commit: r1593558 - /directory/site/trunk/content/mavibot/user-guide/4-btree-operations.mdtext
Date Fri, 09 May 2014 15:10:01 GMT
Author: elecharny
Date: Fri May  9 15:10:00 2014
New Revision: 1593558

URL: http://svn.apache.org/r1593558
Log:
Added some place holders for the operations, and completed some of the existing documentation

Modified:
    directory/site/trunk/content/mavibot/user-guide/4-btree-operations.mdtext

Modified: directory/site/trunk/content/mavibot/user-guide/4-btree-operations.mdtext
URL: http://svn.apache.org/viewvc/directory/site/trunk/content/mavibot/user-guide/4-btree-operations.mdtext?rev=1593558&r1=1593557&r2=1593558&view=diff
==============================================================================
--- directory/site/trunk/content/mavibot/user-guide/4-btree-operations.mdtext (original)
+++ directory/site/trunk/content/mavibot/user-guide/4-btree-operations.mdtext Fri May  9 15:10:00
2014
@@ -73,7 +73,9 @@ Tells if there is a next available tuple
 
 #### 4.1.2.2 hasPrev
 
-Returns true if there is a tuple available before the current tuple.
+Returns true if there is a tuple available before the current tuple. The following picture
shows the returned value for calls in various cases :
+
+![Has Next](images/ug-btree-has-next.png)
 
 #### 4.1.2.3 next
 
@@ -83,27 +85,127 @@ Moves to the next value of the current k
 
 Moves to the previous value of the current key or to the previous key if all the values of
the current key have been processed, and return the associated tuple.
 
-#### 4.1.2.5 hasNextKey
+## 4.1 Browse Operations
+
+Now that we know what a _Cursor_ is about, we can describe the various _browse_ operations
that can be applied on a _BTree_.
 
-Tells if there is a key after the current key.
+### 4.1.1 BTree.browse()
 
-#### 4.1.2.6 hasPrevKey
+This method returns a cursor with the position set before the first element of the **B-tree**,
for the current revision. It returns a _TupleCursor_ that contain the tuples <key,value>
present in the _Btree_.
 
-Tells if there is a previous key before the current key.
+Assuming you have an existing _BTree_, using this method is quite straigthforward. Here is
an example with a persisted _BTree_  :
 
-#### 4.1.2.7 nextKey
+        // Create a RecordManager that will contain the BTree
+        RecordManager recordManager = new RecordManager( "Test.db" );
 
-Moves(jumps) to the next key, even if not all values of the current key are navigated.
+        // Create a BTree to play with
+        BTree<Long, String> btree = recordManager.addBTree( "test", LongSerializer.INSTANCE,
StringSerializer.INSTANCE, true );
 
-#### 4.1.2.8 prevKey
+        // Inject some data
+        btree.insert( 1L, "1" );
+        btree.insert( 4L, "4" );
+        btree.insert( 2L, "2" );
+        btree.insert( 3L, "3" );
+        btree.insert( 5L, "5" );
 
-Moves(jumps) to the previous key, even if not all values of the current key are navigated.
+        // Create the cursor
+        TupleCursor<Long, String> cursor = btree.browse();
 
-## 4.1 Browse Operations
+        // Set the cursor at the beginning of the BTree
+        cursor.beforeFirst();
+
+        // Get the tuples
+        // Create the cursor
+        TupleCursor<Long, String> cursor = btree.browse();
+
+        // Move forward
+        while ( cursor.hasNext() )
+        {
+            Tuple<Long, String> tuple = cursor.next();
+            System.out.println( tuple );
+        }
+
+        ...
+
+will produce this output :
+
+    <1,1>
+    <2,2>
+    <3,3>
+    <4,4>
+    <5,5>
+
+### 4.1.2 BTree.browse( long )
+
+This method returns a cursor with the position set before the first element of the **B-tree**,
for the given revision. 
+
+Here, the big difference is that you can fetch some data from an older revision - assuming
this revision is still present, of course -.
+
+It returns a _TupleCursor_ that contain the tuples <key,value> present in the _Btree_.
+
+You can use the exact same code than for the _browse()_ method, except that you have to pass
the version you want to browse.
+
+### 4.1.3 BTree.browseFrom( K key )
+
+This method returns a cursor with the position set before the given key of the **B-tree**.
If the key does not exist, the cursor will be set to the closest lower value (or upper value
if it's lower than the lowest value)
+
+It returns a _TupleCursor_ that contain the tuples <key,value> present in the _Btree_.
+
+You can use the exact same code than for the _browse()_ method. Here is an example, where
we start after the latest present key :
+
+        // Inject some data
+        for ( long i = 0; i <= 1000L; i += 2 )
+        {
+            btree.insert( i, Long.toString( i ) );
+        }
+
+        // Create the cursor
+        TupleCursor<Long, String> cursor = btree.browseFrom( 1500L );
+        
+        assertFalse( cursor.hasNext() );
+        assertTrue( cursor.hasPrev() );
+        assertEquals( 1000L, cursor.prev().getKey().longValue() );
+
+### 4.1.4 BTree.browseFrom( long revision, K key )
+TODO
+
+### 4.1.5 BTree.close()
+TODO
+
+### 4.1.6 BTree.contains( K key, V value )
+TODO
+
+### 4.1.7 BTree.contains( long revision, K key, V value )
+TODO
+
+### 4.1.8 BTree.delete( K key )
+TODO
+
+### 4.1.9 BTree.delete( K key, V value )
+TODO
+
+### 4.1.10 BTree.flush()
+TODO
+
+### 4.1.11 BTree.get( K key )
+TODO
+
+### 4.1.12 BTree.get( long revision, K key )
+TODO
+
+### 4.1.13 BTree.getRevision()
+TODO
+
+### 4.1.14 BTree.getValues( K key )
+TODO
+
+### 4.1.15 BTree.hasKey( K key )
+TODO
 
-Now that we know what a _Cursor_ is about, we can describe the various _browse_ operations.
+### 4.1.16 BTree.hasKey( long revision, K key )
+TODO
 
-### 4.1.1 browse()
+### 4.1.17 BTree.insert( K key, V value )
+TODO
 
-This method returns a cursor with the position set before the first key of the **B-tree**.

 



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