X-Git-Url: https://git.llucax.com/z.facultad/75.52/treemulator.git/blobdiff_plain/6fcd86dce909f05de818fdd78d76e70aabc3ad22..44c4c40e48cc4a72e81e0af80842738c45d6116f:/src/btree.cpp?ds=sidebyside

diff --git a/src/btree.cpp b/src/btree.cpp
index 1ad006d..1bbb755 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 +36,461 @@ 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)
+{
+	uint left, right;
+	Clave *kout = AddKeyR (&k, 0, left, right);
+
+	if (kout) {
+		unsigned short level;
+		/* Debo dejar la raiz en el nodo 0, por lo que paso el nodo
+		 * que esta usando el hijo izquierdo a un nuevo nodo */
+		std::list<BTreeData *> node_keys;
+		BTreeNodeHeader node_header;
+		uchar *node = ReadBlock (left);
+		ReadNodoHeader (node, &node_header);
+		node_keys = ReadKeys (node, node_header);
+		level = node_header.level + 1;
+
+		uchar *new_node = NewBlock (left);
+		delete [] new_node; /* No me interesa, voy a usar lo leio antes */
+		
+		WriteKeys (node, node_header, node_keys);
+		WriteNodoHeader (node, &node_header);
+		WriteBlock (node, left);
+		delete [] node;
+
+		/* Leo y actualizo la Raiz */
+		node = ReadBlock (0);
+		ReadNodoHeader (node, &node_header);
+		node_keys = std::list<BTreeData *>();
+
+		node_keys.push_back (new BTreeChildData (left));
+		node_keys.push_back (new BTreeData (kout, right));
+
+		node_header.level = level;
+		node_header.item_count = 1;
+
+		WriteKeys (node, node_header, node_keys);
+		WriteNodoHeader (node, &node_header);
+		WriteBlock (node, 0);
+		PrintNode (0);
+	}
+}
+
+Clave* BTree::AddKeyR (const Clave *k, uint node_num, uint &left_child, uint &right_child)
+{
+	uchar *node = ReadBlock (node_num);
+	BTreeNodeHeader node_header;
+	ReadNodoHeader (node, &node_header);
+	delete [] node;
+
+	if (node_header.level == 0)
+		return AddKeyLeafR (k, node_num, left_child, right_child);
+
+	return AddKeyOtherR (k, node_num, left_child, right_child);
+}
+
+Clave* BTree::AddKeyLeafR (const Clave *k, uint node_num, uint &left_child, uint &right_child)
+{
+	Clave *kout = NULL;
+	std::list<BTreeData *> node_keys;
+
+	BTreeData *data = new BTreeLeafData (k->Clone ());
+
+	/* Leo el nodo raiz para empezar a agregar */
+	uchar *node = ReadBlock (node_num);
+	BTreeNodeHeader node_header;
+	ReadNodoHeader (node, &node_header);
+
+	if (node_header.free_space > data->Size ()) {
+		BTreeData *datait;
+		node_keys = ReadKeys (node, node_header);
+		std::list<BTreeData *>::iterator it = node_keys.begin ();
+
+		while (it != node_keys.end ()) {
+			datait = (*it);
+			if ((*data) < (*datait))
+				/* Me pase, lo agrego aca! */
+				break;
+			it++;
+		}
+		node_keys.insert (it, data);
+		WriteKeys (node, node_header, node_keys);
+		WriteNodoHeader (node, &node_header);
+		WriteBlock (node, node_num);
+
+		PrintNode (node_num);
+	} else {
+		/* Split : Creo e inicializo el nuevo nodo */
+		std::list<BTreeData *> new_node_keys;
+		std::list<BTreeData *> old_node_keys;
+		BTreeNodeHeader new_node_header;
+		uint new_node_num;
+		uchar *new_node = NewBlock (new_node_num);
+		ReadNodoHeader (new_node, &new_node_header);
+		new_node_header.level = node_header.level;
+
+		node_keys = ReadKeys (node, node_header);
+		new_node_keys = ReadKeys (new_node, new_node_header);
+
+		/* Agrego la clave en la lista que ya tengo de manera ordenada */
+		std::list<BTreeData *>::iterator it = node_keys.begin ();
+		std::list<BTreeData *>::iterator previt = node_keys.begin ();
+
+		while (it != node_keys.end ()) {
+			BTreeData *datait;
+			datait = (*it);
+			if ((*data) < (*datait))
+				/* Me pase, lo agrego aca! */
+				break;
+			previt = it;
+			it++;
+		}
+		if (it != node_keys.end ())
+			node_keys.insert (it, data);
+		else
+			node_keys.push_back (data);
+
+		/* Tengo que guardar claves hasta ocupar nodo size/2 en cada nodo
+		 * y subir la clave del medio */
+		node_header.item_count = 0;
+		node_header.free_space = header.block_size - sizeof (BTreeNodeHeader);
+
+		uint total_size = 0;
+		it = node_keys.begin ();
+		while (it != node_keys.end ()) {
+			BTreeData *datait;
+			datait = (*it);
+			total_size += datait->Size ();
+			it++;
+			/* Hack : Si me quedo con todas las claves, en el caso de ser
+			 * del mismo tama#o se desbalancea. Hay que ver que efecto 
+			 * puede tener en el caso de claves de long. variable
+			 */
+			if (it == node_keys.end ())
+				total_size -= datait->Size ();
+		}
+
+		it = node_keys.begin ();
+		uint used = 0;
+		while (used < total_size/2) {
+			BTreeData *d = (*it);
+			old_node_keys.push_back (d);
+			used += d->Size ();
+			it++;
+		}
+		kout = (*it++)->getClave (); // Esta se retorna al "padre" para que se la agregue
+
+		while (it != node_keys.end ()) {
+			BTreeData *d = (*it);
+			new_node_keys.push_back (d);
+			it++;
+		}
+	
+		/* Guardo */
+		WriteKeys (node, node_header, old_node_keys);
+		WriteNodoHeader (node, &node_header);
+		WriteBlock (node, node_num);
+		WriteKeys (new_node, new_node_header, new_node_keys);
+		WriteNodoHeader (new_node, &new_node_header);
+		WriteBlock (new_node, new_node_num);
+
+		PrintNode (node_num);
+		PrintNode (new_node_num);
+
+		/* Paso los hijos */
+		left_child = node_num;
+		right_child = new_node_num;
+		delete [] new_node;
+		delete [] node;
+	}
+
+	return kout;
+}
+
+Clave* BTree::AddKeyOtherR (const Clave *k, uint node_num, uint &left_child, uint &right_child)
+{
+	Clave *kout = NULL;
+	std::list<BTreeData *> node_keys;
+
+	BTreeData *data = new BTreeLeafData (k->Clone ());
+
+	/* 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);
+
+	std::list<BTreeData *>::iterator it = node_keys.begin ();
+	std::list<BTreeData *>::iterator posterior;
+	std::list<BTreeData *>::iterator ultima;
+	
+	/* Se supone que la primera es un hijo :) */
+	BTreeData *lchild = (*it++);
+	posterior = it;
+
+	while (it != node_keys.end ()) {
+		if ((*data) < (*(*it)))
+			break;
+		ultima = it;
+		it++;
+	}
+
+	if (it == posterior) {
+		k = AddKeyR (k, lchild->getChild (), left_child, right_child);
+	} else {
+		k = AddKeyR (k, (*ultima)->getChild (), left_child, right_child);
+	}
+
+	/* Nada que hacer */
+	if (!k) return NULL;
+
+	data = new BTreeData (k->Clone (), right_child);
+
+	if (node_header.free_space > data->Size ()) {
+		BTreeData *datait;
+		node_keys = ReadKeys (node, node_header);
+		std::list<BTreeData *>::iterator it = node_keys.begin ();
+
+		while (it != node_keys.end ()) {
+			datait = (*it);
+			if ((*data) < (*datait))
+				/* Me pase, lo agrego aca! */
+				break;
+			it++;
+		}
+		node_keys.insert (it, data);
+		WriteKeys (node, node_header, node_keys);
+		WriteNodoHeader (node, &node_header);
+		WriteBlock (node, node_num);
+
+		PrintNode (node_num);
+	} else {
+		/* Split : Creo e inicializo el nuevo nodo */
+		std::list<BTreeData *> new_node_keys;
+		std::list<BTreeData *> old_node_keys;
+		BTreeNodeHeader new_node_header;
+		uint new_node_num;
+		uchar *new_node = NewBlock (new_node_num);
+		ReadNodoHeader (new_node, &new_node_header);
+		new_node_header.level = node_header.level;
+
+		node_keys = ReadKeys (node, node_header);
+		new_node_keys = ReadKeys (new_node, new_node_header);
+
+		/* Agrego la clave en la lista que ya tengo de manera ordenada */
+		std::list<BTreeData *>::iterator it = node_keys.begin ();
+		std::list<BTreeData *>::iterator previt = node_keys.begin ();
+
+		previt = ++it;
+	
+		while (it != node_keys.end ()) {
+			BTreeData *datait;
+			datait = (*it);
+			if ((*data) < (*datait))
+				/* Me pase, lo agrego aca! */
+				break;
+			previt = it;
+			it++;
+		}
+		if (it != node_keys.end ())
+			node_keys.insert (it, data);
+		else
+			node_keys.push_back (data);
+
+		/* Tengo que guardar claves hasta ocupar nodo size/2 en cada nodo
+		 * y subir la clave del medio */
+		node_header.item_count = 0;
+		node_header.free_space = header.block_size - sizeof (BTreeNodeHeader);
+
+		uint total_size = 0;
+		it = node_keys.begin ();
+		while (it != node_keys.end ()) {
+			BTreeData *datait;
+			datait = (*it);
+			total_size += datait->Size ();
+			it++;
+			/* Hack : Si me quedo con todas las claves, en el caso de ser
+			 * del mismo tama#o se desbalancea. Hay que ver que efecto 
+			 * puede tener en el caso de claves de long. variable
+			 */
+			if (it == node_keys.end ())
+				total_size -= datait->Size ();
+		}
+
+		it = node_keys.begin ();
+		uint used = 0;
+		while (used < total_size/2) {
+			BTreeData *d = (*it);
+			old_node_keys.push_back (d);
+			used += d->Size ();
+			it++;
+		}
+		kout = (*it)->getClave (); // Esta se retorna al "padre" para que se la agregue
+
+		new_node_keys.push_back ( new BTreeChildData ((*it)->getChild ()));
+		it++;
+		while (it != node_keys.end ()) {
+			BTreeData *d = (*it);
+			new_node_keys.push_back (d);
+			it++;
+		}
+	
+		/* Guardo */
+		WriteKeys (node, node_header, old_node_keys);
+		WriteNodoHeader (node, &node_header);
+		WriteBlock (node, node_num);
+		WriteKeys (new_node, new_node_header, new_node_keys);
+		WriteNodoHeader (new_node, &new_node_header);
+		WriteBlock (new_node, new_node_num);
+
+		PrintNode (node_num);
+		PrintNode (new_node_num);
+
+		/* Paso los hijos */
+		left_child = node_num;
+		right_child = new_node_num;
+		delete [] new_node;
+		delete [] node;
+	}
+
+	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);
+	uint count = node_header.item_count;
+
+	if (node_header.item_count == 0) return keys;
+
+	if (node_header.level != 0) {
+		/* Si no es una hoja, lo primero que tengo es un BTreeChildData */
+		BTreeChildData *d = new BTreeChildData (node);
+		node += d->Size ();
+		keys.push_back (d);
+		count--;
+	}
+
+	for (uint i=0; i<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;
+		if (node_header.level == 0) {
+			data = new BTreeLeafData (node);
+		} else {
+			data = new BTreeData (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? */
+}
+		
+void BTree::PrintNode (uint num)
+{
+	uchar *node = ReadBlock (num);
+	BTreeNodeHeader node_header;
+	ReadNodoHeader (node, &node_header);
+		
+	std::list<BTreeData *> node_keys = ReadKeys (node, node_header);
+	std::list<BTreeData *>::iterator it = node_keys.begin ();
+
+	std::cout << "Nodo  : " << num << std::endl;
+	std::cout << "Level : " << node_header.level << std::endl;
+	std::cout << "Items : " << node_header.item_count << std::endl;
+	std::cout << "Free  : " << node_header.free_space << " (" << (header.block_size - sizeof (BTreeNodeHeader)) << ")" << std::endl;
+	while (it != node_keys.end ()) {
+		std::string s = *(*it);
+		std::cout << s << " "; 
+		it++;
+	}
+	std::cout << std::endl;
+
+	delete [] node;
+}
+
+uchar *BTree::NewBlock (uint &num)
+{
+	long filelen;
+	uchar *node;
+	BTreeNodeHeader nh;
+
+	fseek (fp, 0, SEEK_END);
+	filelen = ftell (fp);
+
+	num = (filelen - sizeof (BTreeFileHeader))/header.block_size;
+
+	node = new uchar[header.block_size];
+	ReadNodoHeader (node, &nh);
+	nh.level = 0;
+	nh.free_space = header.block_size - sizeof (BTreeNodeHeader);
+	nh.item_count = 0;
+	WriteNodoHeader (node, &nh);
+	WriteBlock (node, num);
+
+	return node;
+}