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Posted to commits@directory.apache.org by el...@apache.org on 2014/05/09 17:10:01 UTC
svn commit: r1593558 -
/directory/site/trunk/content/mavibot/user-guide/4-btree-operations.mdtext
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 :
+
+
#### 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**.