Bugfix : Condición base para cortar la recursividad.

[z.facultad/75.52/treemulator.git] / src / btree.cpp

diff --git a/src/btree.cpp b/src/btree.cpp
index 50a78016fa05554a203184c8bfa9be486ed1729b..a063befcafc4d49cfb9b2c5f8fc59e8711a122d5 100644 (file)
--- a/src/btree.cpp
+++ b/src/btree.cpp
@@ -1,12 +1,13 @@
 
 #include "btree.h"
 
 
 #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, int kt, bool create_new_file)

 {
 {

+       key_type = kt;

        uchar *node;
        BTreeNodeHeader nh;
 
        uchar *node;
        BTreeNodeHeader nh;
 

-       fp = fopen (name, "wb");
+       fp = fopen (name.c_str(), "wb+");

        if (!fp) {
                /* TODO : mandar una exception ? */
                return;
        if (!fp) {
                /* TODO : mandar una exception ? */
                return;


@@ -17,7 +18,7 @@ BTree::BTree (const char *name, unsigned int block_size, bool create_new_file)
        
        /* Inicializo el header */
        header.block_size = block_size;
        
        /* Inicializo el header */
        header.block_size = block_size;

-       write_tree_header ();
+       WriteFileHeader ();

 
        /* Creo el primer bloque vacio */
        node = new uchar[block_size];
 
        /* Creo el primer bloque vacio */
        node = new uchar[block_size];


@@ -26,7 +27,7 @@ BTree::BTree (const char *name, unsigned int block_size, bool create_new_file)
        nh.free_space = block_size - sizeof (BTreeNodeHeader);
        nh.item_count = 0;
        WriteNodoHeader (node, &nh);
        nh.free_space = block_size - sizeof (BTreeNodeHeader);
        nh.item_count = 0;
        WriteNodoHeader (node, &nh);

-       write_block (node, 0);
+       WriteBlock (node, 0);

 
        delete [] node;
 }
 
        delete [] node;
 }


@@ -36,20 +37,359 @@ BTree::~BTree ()
        fclose (fp);
 }
 
        fclose (fp);
 }
 

-void BTree::write_tree_header ()
+void BTree::WriteFileHeader ()

 {
        fseek (fp, 0L, SEEK_SET);
        fwrite (&header, 1, sizeof (BTreeFileHeader), fp);
 }
 
 {
        fseek (fp, 0L, SEEK_SET);
        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 (BTreeFileHeader), SEEK_SET);
+       num++;
+       fseek (fp, num*header.block_size, SEEK_SET);

        fwrite (block, 1, header.block_size, fp);
 }
 
        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.Clone (), 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);
+               DeleteKeys (node_keys);
+               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);
+               delete [] node;
+               DeleteKeys (node_keys);
+               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);
+               DeleteKeys (node_keys);
+               delete [] node;
+
+               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);
+               DeleteKeys (old_node_keys);
+               DeleteKeys (new_node_keys);
+
+               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);
+       }
+       DeleteKeys (node_keys);
+
+       /* Nada que hacer */
+       if (data) delete data;
+       if (!k) {
+               delete [] node;
+               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);
+               DeleteKeys (node_keys);
+               delete [] node;
+
+               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);
+               DeleteKeys (old_node_keys);
+               DeleteKeys (new_node_keys);
+
+               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)
 {
 
 void BTree::ReadNodoHeader (uchar *node, BTreeNodeHeader *header)
 {


@@ -61,3 +401,186 @@ void BTree::WriteNodoHeader (uchar *node, BTreeNodeHeader *header)
        memcpy (node, header, sizeof (BTreeNodeHeader));
 }
 
        memcpy (node, header, sizeof (BTreeNodeHeader));
 }
 

+uchar *BTree::ReadBlock (uint num)
+{
+       /* Como el bloque 0 se usa para el header, el Nodo "num"
+        * está en el bloque "num+1"
+        */
+       num++;
+
+       uchar *out = new uchar[header.block_size];
+
+       fseek (fp, num*header.block_size, 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, key_type);
+               } else {
+                       data = new BTreeData (node, key_type);
+               }
+               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);
+               uchar *n = d->ToArray ();
+               memcpy (node, n, d->Size ());
+               delete [] n;
+               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;
+       DeleteKeys (node_keys);
+}
+
+uchar *BTree::NewBlock (uint &num)
+{
+       long filelen;
+       uchar *node;
+       BTreeNodeHeader nh;
+
+       fseek (fp, 0, SEEK_END);
+       filelen = ftell (fp);
+
+       num = filelen/header.block_size - 1;
+
+       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;
+}
+
+bool BTree::FindKey (const Clave &k)
+{
+       return FindKeyR (&k, 0);
+}
+
+bool BTree::FindKeyR (const Clave *k, uint node_num)
+{
+       std::list<BTreeData *> node_keys;
+       BTreeNodeHeader node_header;
+
+       /* Leo el nodo raiz para empezar a agregar */
+       uchar *node = ReadBlock (node_num);
+       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;
+       if (node_header.level != 0) {
+               lchild = (*it++);
+       }
+       posterior = it;
+
+       BTreeData *data;
+       if (node_header.level == 0)
+               data = new BTreeLeafData ((Clave *)k);
+       else
+               data = new BTreeData ((Clave *)k, 0);
+
+       while (it != node_keys.end ()) {
+               if ((*data) == (*(*it))) {
+                       /* La encontre!, retorno */
+                       delete [] node;
+                       DeleteKeys (node_keys);
+                       return true;
+               }
+
+               if ((*data) < (*(*it)))
+                       break;
+               ultima = it;
+               it++;
+       }
+
+       /* TODO: Aca faltaria liberar memoria */
+       if (it == posterior)
+               return FindKeyR (k, lchild->getChild ());
+               
+       return FindKeyR (k, (*ultima)->getChild ());
+}
+
+void BTree::DeleteKeys (std::list<BTreeData *> &keys)
+{
+       std::list<BTreeData *>::iterator it = keys.begin ();
+
+       while (it != keys.end ()) {
+               BTreeData *d = (*it);
+               delete d;
+               it++;
+       }
+}
+