X-Git-Url: https://git.llucax.com/z.facultad/75.52/treemulator.git/blobdiff_plain/6fcd86dce909f05de818fdd78d76e70aabc3ad22..7fbdb57d39dea2e7545271be5d706c2df5b5b095:/src/btree.cpp?ds=inline

diff --git a/src/btree.cpp b/src/btree.cpp
index 1ad006d..5df88a2 100644
--- a/src/btree.cpp
+++ b/src/btree.cpp
@@ -1,12 +1,12 @@
 
 #include "btree.h"
 
-BTree::BTree (const char *name, unsigned int block_size, bool create_new_file)
+BTree::BTree (const std::string &name, unsigned int block_size, bool create_new_file)
 {
 	uchar *node;
+	BTreeNodeHeader nh;
 
-
-	fp = fopen (name, "wb");
+	fp = fopen (name.c_str(), "wb");
 	if (!fp) {
 		/* TODO : mandar una exception ? */
 		return;
@@ -17,11 +17,17 @@ BTree::BTree (const char *name, unsigned int block_size, bool create_new_file)
 	
 	/* Inicializo el header */
 	header.block_size = block_size;
-	write_tree_header ();
+	WriteFileHeader ();
 
 	/* Creo el primer bloque vacio */
 	node = new uchar[block_size];
-	write_block (node, 0);
+	ReadNodoHeader (node, &nh);
+	nh.level = 0;
+	nh.free_space = block_size - sizeof (BTreeNodeHeader);
+	nh.item_count = 0;
+	WriteNodoHeader (node, &nh);
+	WriteBlock (node, 0);
+
 	delete [] node;
 }
 
@@ -30,18 +36,115 @@ BTree::~BTree ()
 	fclose (fp);
 }
 
-void BTree::write_tree_header ()
+void BTree::WriteFileHeader ()
 {
 	fseek (fp, 0L, SEEK_SET);
-	fwrite (&header, 1, sizeof (BTreeHeader), fp);
+	fwrite (&header, 1, sizeof (BTreeFileHeader), fp);
 }
 
-void BTree::write_block (uchar *block, uint num)
+void BTree::WriteBlock (uchar *block, uint num)
 {
-	fseek (fp, num*header.block_size + sizeof (BTreeHeader), SEEK_SET);
+	fseek (fp, num*header.block_size + sizeof (BTreeFileHeader), SEEK_SET);
 	fwrite (block, 1, header.block_size, fp);
 }
 
-void BTree::AddKey () {}
-void BTree::DelKey () {}
+void BTree::AddKey (const Clave &k)
+{
+	AddKeyR (&k, 0);
+}
+
+Clave* BTree::AddKeyR (const Clave *k, uint node_num)
+{
+	Clave *kout = NULL;
+	std::list<BTreeData> node_keys;
+
+	/* Leo el nodo raiz para empezar a agregar */
+	uchar *node = ReadBlock (node_num);
+	BTreeNodeHeader node_header;
+	ReadNodoHeader (node, &node_header);
+
+	node_keys = ReadKeys (node, node_header);
+	
+	if (node_header.free_space >= k->Size ()) {
+		/* TODO : Insertar ordenado */
+		/* Siempre se agrega en una hoja */
+		node_keys.push_back (BTreeLeafData (k->Clone ()));
+
+		WriteKeys (node, node_header, node_keys);
+		WriteNodoHeader (node, &node_header);
+		WriteBlock (node, node_num);
+		delete [] node;
+	} else {
+		/* Split */
+		/* Lo que debe pasar :
+		 *  1) Separar N/2 claves en "nodo"
+		 *  2) Separar N/2-1 claves en un nuevo nodo
+		 *  3) kout = clave del medio y mandarla al padre
+		 */
+		std::cout << "SPLIT" << std::endl;
+	}
+
+	return kout;
+}
+
+void BTree::DelKey (const Clave &k) {}
+
+void BTree::ReadNodoHeader (uchar *node, BTreeNodeHeader *header)
+{
+	memcpy (header, node, sizeof (BTreeNodeHeader));
+}
+
+void BTree::WriteNodoHeader (uchar *node, BTreeNodeHeader *header)
+{
+	memcpy (node, header, sizeof (BTreeNodeHeader));
+}
+
+uchar *BTree::ReadBlock (uint num)
+{
+	uchar *out = new uchar[header.block_size];
+
+	fseek (fp, num*header.block_size + sizeof (BTreeFileHeader), SEEK_SET);	
+	fread (out, 1, header.block_size, fp);
+
+	return out;
+}
+
+std::list<BTreeData> BTree::ReadKeys (uchar *node, BTreeNodeHeader &node_header)
+{
+	std::list<BTreeData> 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
+		 */
+		/* TODO : Detectar si estoy en una hoja */
+		BTreeData data(node);
+		node += data.Size ();
+		keys.push_back (data);
+	}
 
+	return keys;
+}
+
+void BTree::WriteKeys (uchar *node, BTreeNodeHeader &node_header, std::list<BTreeData> &keys)
+{
+	std::list<BTreeData>::iterator it = keys.begin ();
+
+	node += sizeof (BTreeNodeHeader);
+
+	node_header.item_count = 0;
+	node_header.free_space = header.block_size - sizeof (BTreeNodeHeader);
+
+	while (it != keys.end ()) {
+		BTreeData d = (*it);
+		memcpy (node, d.ToArray(), d.Size ());
+		node += d.Size ();
+		node_header.free_space -= d.Size ();
+		node_header.item_count++;
+		it++;
+	}
+
+	/* TODO : incrementar node_header.item_count aca o fuera de este metodo? */
+}