From 113597e3c369b18fa4e73a0b9744398a0e9e0a79 Mon Sep 17 00:00:00 2001
From: Ricardo Markiewicz <rmarkie@fi.uba.ar>
Date: Mon, 12 Sep 2005 18:45:52 +0000
Subject: [PATCH] Lectura de claves desde un nodo a memoria. La idea es que
 luego de cargar un bloque feo y molesto de trabajar se carga una std::list
 con todas las claves. Para agregar o borrar se lo hace en la lista y luego se
 llama a WriteKeys (todavia no se implemento) para volver a poner las claves
 en el bloque en modo "binario".

---
 src/btree.cpp | 27 +++++++++++++++++++++++++--
 src/btree.h   |  8 ++++++--
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/src/btree.cpp b/src/btree.cpp
index a285392..d1fbab3 100644
--- a/src/btree.cpp
+++ b/src/btree.cpp
@@ -48,13 +48,18 @@ void BTree::write_block (uchar *block, uint num)
 	fwrite (block, 1, header.block_size, fp);
 }
 
-void BTree::AddKey (Clave &k)
+void BTree::AddKey (const Clave &k)
 {
+	std::list<Clave *> node_keys;
+
 	/* Leo el nodo raiz para empezar a agregar */
 	uchar *root = ReadBlock (0);
 	BTreeNodeHeader root_header;
 	ReadNodoHeader (root, &root_header);
 
+	node_keys = ReadKeys (root, root_header);
+	std::cout << node_keys.size () << std::endl;
+	
 	if (root_header.free_space >= k.Size ()) {
 		std::cout << "Hay lugar para meter la clave" << std::endl;
 	} else {
@@ -64,7 +69,7 @@ void BTree::AddKey (Clave &k)
 	delete [] root;
 }
 
-void BTree::DelKey (Clave &k) {}
+void BTree::DelKey (const Clave &k) {}
 
 void BTree::ReadNodoHeader (uchar *node, BTreeNodeHeader *header)
 {
@@ -86,3 +91,21 @@ uchar *BTree::ReadBlock (uint num)
 	return out;
 }
 
+std::list<Clave *> BTree::ReadKeys (uchar *node, BTreeNodeHeader &node_header)
+{
+	std::list<Clave *> keys;
+	node += sizeof (BTreeNodeHeader);
+
+	for (uint i=0; i<node_header.item_count; i++) {
+		/* TODO : El tipo de clave deberia ser usado 
+		 * dependiendo de algun dato en el header del
+		 * arbol
+		 */
+		ClaveFija *k = new ClaveFija (node);
+		node += k->Size ();
+		keys.push_back (k);
+	}
+
+	return keys;
+}
+
diff --git a/src/btree.h b/src/btree.h
index 081c436..95180b0 100644
--- a/src/btree.h
+++ b/src/btree.h
@@ -46,8 +46,10 @@
 
 #include <iostream>
 #include <string>
+#include <list>
 #include "common.h"
 #include "clave.h"
+#include "clave_fija.h"
 
 /* alias para codear menos :) */
 
@@ -86,8 +88,8 @@ class BTree {
 		BTree (const std::string &filename, unsigned int block_size, bool create_new_file = false);
 		~BTree ();
 
-		void AddKey (Clave &k);
-		void DelKey (Clave &k);
+		void AddKey (const Clave &k);
+		void DelKey (const Clave &k);
 
 	private:
 		void write_tree_header ();
@@ -98,6 +100,8 @@ class BTree {
 		void ReadNodoHeader (uchar *node, BTreeNodeHeader *header);
 		void WriteNodoHeader (uchar *node, BTreeNodeHeader *header);
 
+		std::list<Clave *> ReadKeys (uchar *node, BTreeNodeHeader &node_header);
+
 		std::string filename;
 		BTreeFileHeader header;
 
-- 
2.43.0