#include "btree.h"
-BTree::BTree (const std::string &name, unsigned int block_size, int kt, bool create_new_file)
+BTree::BTree (const std::string &name, unsigned int block_size, int tt, int kt, bool create_new_file)
{
key_type = kt;
+ tree_type = tt;
uchar *node;
BTreeNodeHeader nh;
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);
}
void BTree::AddKey (const Clave &k)
{
uint left, right;
- Clave *kout = AddKeyR (&k, 0, left, right);
+ Clave *kout = AddKeyR (k.Clone (), 0, left, right);
if (kout) {
unsigned short level;
WriteKeys (node, node_header, node_keys);
WriteNodoHeader (node, &node_header);
WriteBlock (node, left);
+ DeleteKeys (node_keys);
delete [] node;
/* Leo y actualizo la Raiz */
WriteKeys (node, node_header, node_keys);
WriteNodoHeader (node, &node_header);
WriteBlock (node, 0);
+ delete [] node;
+ DeleteKeys (node_keys);
PrintNode (0);
}
}
ReadNodoHeader (node, &node_header);
delete [] node;
- if (node_header.level == 0)
- return AddKeyLeafR (k, node_num, left_child, right_child);
+ if (node_header.level == 0) {
+ try {
+ return AddKeyLeafR (k, node_num, left_child, right_child);
+ } catch (Exception *e) {
+ throw e;
+ }
+ }
- return AddKeyOtherR (k, node_num, left_child, right_child);
+ try {
+ return AddKeyOtherR (k, node_num, left_child, right_child);
+ } catch (Exception *e) {
+ throw e;
+ }
}
Clave* BTree::AddKeyLeafR (const Clave *k, uint node_num, uint &left_child, uint &right_child)
while (it != node_keys.end ()) {
datait = (*it);
+ if (tree_type == TYPE_UNIQUE) {
+ /* Verifico que la clave no existea ya en el arbol */
+ if ((*data) == (*datait)) {
+ throw new AddException ();
+ return NULL;
+ }
+ }
+
if ((*data) < (*datait))
/* Me pase, lo agrego aca! */
break;
WriteKeys (node, node_header, node_keys);
WriteNodoHeader (node, &node_header);
WriteBlock (node, node_num);
+ DeleteKeys (node_keys);
+ delete [] node;
PrintNode (node_num);
} else {
while (it != node_keys.end ()) {
BTreeData *datait;
datait = (*it);
+ if (tree_type == TYPE_UNIQUE) {
+ /* Verifico que la clave no existea ya en el arbol */
+ if ((*data) == (*datait)) {
+ throw new AddException ();
+ return NULL;
+ }
+ }
if ((*data) < (*datait))
/* Me pase, lo agrego aca! */
break;
used += d->Size ();
it++;
}
- kout = (*it++)->getClave (); // Esta se retorna al "padre" para que se la agregue
+ kout = (*it++)->GetKey (); // Esta se retorna al "padre" para que se la agregue
while (it != node_keys.end ()) {
BTreeData *d = (*it);
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);
posterior = it;
while (it != node_keys.end ()) {
+ if (tree_type == TYPE_UNIQUE) {
+ /* Verifico que la clave no existea ya en el arbol */
+ if ((*data) == (*(*it))) {
+ throw new AddException ();
+ return NULL;
+ }
+ }
if ((*data) < (*(*it)))
break;
ultima = it;
}
if (it == posterior) {
- k = AddKeyR (k, lchild->getChild (), left_child, right_child);
+ k = AddKeyR (k, lchild->GetChild (), left_child, right_child);
} else {
- k = AddKeyR (k, (*ultima)->getChild (), left_child, right_child);
+ k = AddKeyR (k, (*ultima)->GetChild (), left_child, right_child);
}
+ DeleteKeys (node_keys);
/* Nada que hacer */
- if (!k) return NULL;
+ if (data) delete data;
+ if (!k) {
+ delete [] node;
+ return NULL;
+ }
data = new BTreeData (k->Clone (), right_child);
while (it != node_keys.end ()) {
datait = (*it);
+ if (tree_type == TYPE_UNIQUE) {
+ /* Verifico que la clave no existea ya en el arbol */
+ if ((*data) == (*datait)) {
+ throw new AddException ();
+ return NULL;
+ }
+ }
if ((*data) < (*datait))
/* Me pase, lo agrego aca! */
break;
WriteKeys (node, node_header, node_keys);
WriteNodoHeader (node, &node_header);
WriteBlock (node, node_num);
+ DeleteKeys (node_keys);
+ delete [] node;
PrintNode (node_num);
} else {
while (it != node_keys.end ()) {
BTreeData *datait;
datait = (*it);
+ if (tree_type == TYPE_UNIQUE) {
+ /* Verifico que la clave no existea ya en el arbol */
+ if ((*data) == (*datait)) {
+ throw new AddException ();
+ return NULL;
+ }
+ }
if ((*data) < (*datait))
/* Me pase, lo agrego aca! */
break;
used += d->Size ();
it++;
}
- kout = (*it)->getClave (); // Esta se retorna al "padre" para que se la agregue
+ kout = (*it)->GetKey (); // Esta se retorna al "padre" para que se la agregue
- new_node_keys.push_back ( new BTreeChildData ((*it)->getChild ()));
+ new_node_keys.push_back ( new BTreeChildData ((*it)->GetChild ()));
it++;
while (it != node_keys.end ()) {
BTreeData *d = (*it);
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);
return kout;
}
-void BTree::DelKey (const Clave &k) {}
+void BTree::DelKey (const Clave &k)
+{
+ std::string s = k;
+ std::cout << "========= Borrando " << s << " =================\n";
+ BTreeData *b = new BTreeLeafData (k.Clone ());
+ DelKeyR (b, 0, 0);
+ delete b;
+}
+
+void BTree::DelKeyR (BTreeData *k, uint node_num, uint padre)
+{
+ std::list<BTreeData *> node_keys;
+ BTreeNodeHeader node_header;
+ uchar *node;
+
+ 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 ultima;
+ std::list<BTreeData *>::iterator posterior;
+
+ BTreeData *lchild;
+ if (node_header.level != 0) {
+ lchild = (*it++);
+ }
+ posterior = it;
+
+ while (it != node_keys.end ()) {
+ if ((*k) == (*(*it))) {
+ /* La encontre!, retorno */
+ if (node_header.level == 0) {
+ DelKeyFromLeaf (k->GetKey (), node_num, padre);
+ } else {
+ uint left, right;
+ if (it == posterior) {
+ left = lchild->GetChild ();
+ right = (*it)->GetChild ();
+ } else {
+ left = (*ultima)->GetChild ();
+ right = (*it)->GetChild ();
+ }
+ std::cout << "Eliminar de Nodo con hijos : " << left << " y " << right << std::endl;
+ DelKeyFromNode (k->GetKey (), node_num, padre, left, right);
+ }
+ DeleteKeys (node_keys);
+ delete [] node;
+ return;
+ }
+
+ if ((*k) < (*(*it)))
+ break;
+ ultima = it;
+ it++;
+ }
+
+ /* Si llego aca y estoy en nivel 0 (una hoja) quiere
+ * decir que no lo encontre
+ */
+ if (node_header.level == 0) {
+ std::cout << "*** Clave no encontrada ***\n";
+ return;
+ }
+
+ /* TODO: Aca faltaria liberar memoria */
+ if (it == posterior) {
+ DelKeyR (k, lchild->GetChild (), node_num);
+ } else {
+ DelKeyR (k, (*ultima)->GetChild (), node_num);
+ }
+}
+
+void BTree::DelKeyFromLeaf (Clave *k, uint node_num, uint padre)
+{
+ BTreeData *data;
+ uchar *node;
+ BTreeNodeHeader node_header;
+ std::list<BTreeData *> node_keys;
+
+ node = ReadBlock (node_num);
+ ReadNodoHeader (node, &node_header);
+ node_keys = ReadKeys (node, node_header);
+
+ data = new BTreeLeafData (k->Clone ());
+
+ std::list<BTreeData *>::iterator it;
+ it = node_keys.begin ();
+ while (it != node_keys.end ()) {
+ if ((*data) == (*(*it))) {
+ BTreeData *aborrar = (*it);
+ node_keys.erase (it);
+ delete aborrar;
+ break;
+ }
+ it++;
+ }
+
+ delete data;
+
+ WriteKeys (node, node_header, node_keys);
+ WriteNodoHeader (node, &node_header);
+ WriteBlock (node, node_num);
+
+ /* Veo si se cumple la condición de minimalidad */
+ uint min_free = (header.block_size-sizeof(BTreeNodeHeader))/2;
+ if ((node_header.free_space > min_free) && (node_num != 0)) {
+ /* Oops! Debo pedir prestada clave */
+ uint hi, hd;
+ Clave *pedida;
+
+ FindBrothers (node_num, padre, hi, hd);
+
+ if ((pedida = GetKey (hi, 1)) != NULL) {
+ std::string s = *pedida;
+ std::cout << "Clave Pedida : " << s << std::endl;
+
+ pedida = ReplaceKeyInFather (node_num, padre, pedida);
+
+ node_keys.insert (node_keys.begin (), new BTreeLeafData (pedida));
+ } else if ((pedida = GetKey (hd, 0)) != NULL) {
+ std::string s = *pedida;
+ std::cout << "Clave Pedida : " << s << std::endl;
+
+ pedida = ReplaceKeyInFather (node_num, padre, pedida);
+
+ node_keys.push_back (new BTreeLeafData (pedida));
+ } else {
+ std::cout << "NADIE ME PUEDE PRESTAR, FUNDIR NODOS\n";
+ uint join1, join2;
+ int tipoh;
+ if (hi != 0) {
+ std::cout << "Join con Hermano Izquierdo\n";
+ join1 = hi;
+ join2 = node_num;
+ tipoh = 0;
+ } else {
+ std::cout << "Join con Hermano Derecho\n";
+ join1 = node_num;
+ join2 = hd;
+ tipoh = 1;
+ }
+
+ JoinNodes (join1, join2, padre, tipoh);
+
+ DeleteKeys (node_keys);
+ delete [] node;
+ return;
+ }
+
+ WriteKeys (node, node_header, node_keys);
+ WriteNodoHeader (node, &node_header);
+ WriteBlock (node, node_num);
+ }
+
+ DeleteKeys (node_keys);
+ delete [] node;
+ std::cout << "Borrado de una hoja listo\n";
+}
+
+void BTree::JoinNodes (uint node1, uint node2, uint padre, int tipohermano)
+{
+ uchar *n1, *n2, *npadre;
+ BTreeNodeHeader nh1, nh2, nhp;
+ std::list<BTreeData *> nk1, nk2, nkpadre;
+
+ if (node1 == node2) {
+ std::cout << "PANIC : No puedo juntar el mismo nodo con si mismo!!\n";
+ exit (1);
+ }
+ if (node1 == padre) {
+ std::cout << "PANIC : No puedo juntar el mismo nodo con si mismo!!\n";
+ exit (1);
+ }
+ if (node2 == padre) {
+ std::cout << "PANIC : No puedo juntar el mismo nodo con si mismo!!\n";
+ exit (1);
+ }
+
+ PrintNode (padre);
+ PrintNode (node1);
+ PrintNode (node2);
+
+ /* Leo los nodos */
+ n1 = ReadBlock (node1);
+ n2 = ReadBlock (node2);
+ npadre = ReadBlock (padre);
+
+ ReadNodoHeader (n1, &nh1);
+ ReadNodoHeader (n2, &nh2);
+ ReadNodoHeader (npadre, &nhp);
+
+ /* Apunto de Unir */
+ uint tmp = header.block_size - sizeof (BTreeNodeHeader);
+ uint l = tmp - nh1.free_space;
+ l += tmp - nh1.free_space;
+ l += 4;
+
+ std::cout << "Espacio ocupado despues de unir : " << l << " de " << tmp << std::endl;
+
+ nk1 = ReadKeys (n1, nh1);
+ nk2 = ReadKeys (n2, nh2);
+ nkpadre = ReadKeys (npadre, nhp);
+
+ /* Busco la clave del padre a juntar con los nodos */
+ std::list<BTreeData *>::iterator it = nkpadre.begin ();
+ std::list<BTreeData *>::iterator borrar_padre;
+ std::list<BTreeData *>::iterator sig;
+ std::list<BTreeData *>::iterator anterior = it;
+
+ Clave *cpadre;
+ BTreeData *lchild = (*it++);
+
+ if (lchild->GetChild () == node1) {
+ cpadre = (*it)->GetKey ();
+ borrar_padre = it;
+ } else {
+ while (it != nkpadre.end ()) {
+ if (tipohermano == 0) {
+ if ((*it)->GetChild () == node2)
+ break;
+ } else {
+ if ((*it)->GetChild () == node1)
+ break;
+ }
+ anterior = it;
+ it++;
+ }
+ cpadre = (*it)->GetKey ();
+ borrar_padre = it;
+ }
+ if (it == nkpadre.end ()) {
+ std::cout << "PANIC : Me pase sin encontrar la clave!!\n";
+ exit(1);
+ }
+ it++;
+ sig = it;
+
+ std::list<BTreeData *> newkeys;
+ std::list<BTreeData *>::iterator i;
+
+ i = nk1.begin ();
+ while (i != nk1.end ()) {
+ newkeys.push_back ( new BTreeLeafData ((*i)->GetKey ()->Clone ()));
+ i++;
+ }
+ //if (tipohermano == 0)
+ newkeys.push_back ( new BTreeLeafData (cpadre->Clone ()));
+ i = nk2.begin ();
+ while (i != nk2.end ()) {
+ newkeys.push_back ( new BTreeLeafData ((*i)->GetKey ()->Clone ()));
+ i++;
+ }
+
+ std::cout << "Espacio ocupado por las nuevas claves : " << (newkeys.size()*4) << std::endl;
+ if ((newkeys.size()*4) > tmp) {
+ std::cout << "PANIC : El nodo fundido no entra !!!\n";
+ exit (1);
+ }
+
+ /* Para el padre, tener 2 items significa tener solo 1 clave, ya que
+ * el otro item es el LeftChild!
+ */
+ if ((padre == 0) && (nhp.item_count == 2)) {
+ /* Si junte 2 nodos, cuyo padre era la raiz, y esta tenia
+ * solo una clave, quiere decir que lo que me queda
+ * es de nuevo solo una raiz con todas las claves
+ */
+ nhp.level = 0;
+ WriteKeys (npadre, nhp, newkeys);
+ WriteNodoHeader (npadre, &nhp);
+ WriteBlock (npadre, padre);
+
+ /* TODO: Recuperar nodo1 y nodo2 */
+ } else {
+ WriteKeys (n1, nh1, newkeys);
+ WriteNodoHeader (n1, &nh1);
+ WriteBlock (n1, node1);
+
+ /* TODO : Recuperar node2 */
+ /* Actualizo punero al padre */
+ (*anterior)->SetChild (node1);
+
+ nkpadre.erase (borrar_padre);
+ WriteKeys (npadre, nhp, nkpadre);
+ WriteNodoHeader (npadre, &nhp);
+ WriteBlock (npadre, padre);
+ }
+
+ std::cout << " ----- Luego de Fundir -----\n";
+ PrintNode (node1);
+ PrintNode (padre);
+ std::cout << " ---------------------------\n";
+
+ DeleteKeys (nk1);
+ DeleteKeys (nk2);
+ DeleteKeys (nkpadre);
+ DeleteKeys (newkeys);
+
+ delete [] n1;
+ delete [] n2;
+ delete [] npadre;
+}
+
+Clave *BTree::GetKey (uint node_num, char maxmin)
+{
+ if (node_num == 0) {
+ std::cout << "Nodo no me puede prestar ... es NULL\n";
+ return NULL;
+ }
+
+ uchar *node;
+ BTreeNodeHeader node_header;
+ std::list<BTreeData *> node_keys;
+
+ node = ReadBlock (node_num);
+ ReadNodoHeader (node, &node_header);
+ node_keys = ReadKeys (node, node_header);
+
+ std::list<BTreeData *>::iterator it = node_keys.begin ();
+
+ if (node_header.level != 0) it++;
+
+ Clave *k;
+ uint free = node_header.free_space; // + (*it)->Size ();
+ uint min_free = (header.block_size - sizeof (BTreeNodeHeader))/2;
+ if (free > min_free) {
+ std::cout << "No puedo prestar : Free = " << free << " Minimo = " << min_free << std::endl;
+ PrintNode (node_num);
+ WriteKeys (node, node_header, node_keys);
+ WriteNodoHeader (node, &node_header);
+ WriteBlock (node, node_num);
+ DeleteKeys (node_keys);
+
+ delete [] node;
+
+ return NULL;
+ }
+
+ if (maxmin == 0) {
+ k = (*it)->GetKey ()->Clone ();
+ node_keys.erase (it);
+ } else {
+ it = node_keys.end ();
+ it--;
+ k = (*it)->GetKey ()->Clone ();
+ node_keys.erase (it);
+ }
+
+ WriteKeys (node, node_header, node_keys);
+ WriteNodoHeader (node, &node_header);
+ WriteBlock (node, node_num);
+ DeleteKeys (node_keys);
+
+ delete [] node;
+
+ return k;
+}
+
+void BTree::FindBrothers (uint node_num, uint padre, uint &left, uint &right)
+{
+ uchar *node;
+ BTreeNodeHeader node_header;
+ std::list<BTreeData *> node_keys;
+
+ node = ReadBlock (padre);
+ ReadNodoHeader (node, &node_header);
+ node_keys = ReadKeys (node, node_header);
+
+ std::list<BTreeData *>::iterator it = node_keys.begin ();
+ std::list<BTreeData *>::iterator anterior = node_keys.begin ();
+ std::list<BTreeData *>::iterator siguiente;
+
+ BTreeData *lchild = (*it++);
+
+ if (lchild->GetChild () == node_num) {
+ /* Solo tengo hermano derecho */
+ std::cout << "Hermano Izquierdo : NO TENGO" << std::endl;
+ left = 0;
+ std::cout << "Hermano Derecho : " << (*it)->GetChild () << std::endl;
+ right = (*it)->GetChild ();
+ return;
+ }
+
+ while (it != node_keys.end ()) {
+ if ((*it)->GetChild () == node_num)
+ break;
+ anterior = it;
+ it++;
+ }
+ siguiente = it++;
+
+ std::cout << "Hermano Izquierdo : " << (*anterior)->GetChild () << std::endl;
+ left = (*anterior)->GetChild ();
+ if (siguiente != node_keys.end ()) {
+ right = (*siguiente)->GetChild ();
+ std::cout << "Hermano Derecho : " << (*siguiente)->GetChild () << std::endl;
+ } else {
+ right = 0;
+ std::cout << "Hermano Derecho : NO TENGO" << std::endl;
+ }
+}
+
+Clave *BTree::ReplaceKeyInFather (uint node_num, uint padre, Clave *k)
+{
+ uchar *node;
+ BTreeNodeHeader node_header;
+ std::list<BTreeData *> node_keys;
+
+ node = ReadBlock (padre);
+ ReadNodoHeader (node, &node_header);
+ node_keys = ReadKeys (node, node_header);
+
+ std::list<BTreeData *>::iterator it = node_keys.begin ();
+ std::list<BTreeData *>::iterator anterior = node_keys.begin ();
+ std::list<BTreeData *>::iterator siguiente;
+
+ BTreeData *lchild = (*it++);
+
+ if (lchild->GetChild () == node_num) {
+ Clave *ret = (*it)->GetKey ();
+ (*it)->SetKey (k);
+
+ WriteKeys (node, node_header, node_keys);
+ WriteNodoHeader (node, &node_header);
+ WriteBlock (node, padre);
+ DeleteKeys (node_keys);
+
+ delete [] node;
+ return ret;
+ }
+
+ while (it != node_keys.end ()) {
+ if ((*it)->GetChild () == node_num)
+ break;
+ anterior = it;
+ it++;
+ }
+
+ Clave *ret = (*it)->GetKey ();
+ (*it)->SetKey (k);
+
+ WriteKeys (node, node_header, node_keys);
+ WriteNodoHeader (node, &node_header);
+ WriteBlock (node, padre);
+ DeleteKeys (node_keys);
+
+ delete [] node;
+ return ret;
+}
+
+void BTree::DelKeyFromNode (Clave *k, uint node_num, uint padre, uint left, uint right)
+{
+ uint padre_hijo;
+ uchar *node;
+ BTreeNodeHeader node_header;
+ std::list<BTreeData *> node_keys;
+
+ node = ReadBlock (node_num);
+ ReadNodoHeader (node, &node_header);
+ node_keys = ReadKeys (node, node_header);
+
+ if (right != 0) {
+ std::cout << "Busco para la derecha y luego todo a la izquierda\n";
+ uchar *node_r;
+ BTreeNodeHeader node_hr;
+ std::list<BTreeData *> node_keyr;
+
+ /* Busco la clave inmediatamente superior en el arbol */
+ padre_hijo = node_num;
+ do {
+ node_r = ReadBlock (right);
+ ReadNodoHeader (node_r, &node_hr);
+ if (node_hr.level != 0) {
+ BTreeData *data_r;
+ node_keyr = ReadKeys (node_r, node_hr);
+ data_r = *(node_keyr.begin ());
+ padre_hijo = right;
+ right = data_r->GetChild ();
+
+ DeleteKeys (node_keyr);
+ delete [] node_r;
+ }
+ } while (node_hr.level != 0);
+
+ std::cout << "Voy a reemplazar en el nodo " << right << std::endl;
+
+ /* Reemplazo la clave a borrar por la de la hoja */
+ node_keyr = ReadKeys (node_r, node_hr);
+ BTreeData *reemplazar = *(node_keyr.begin ());
+
+ std::string ss = *reemplazar;
+ std::cout << "Voy a reemplazar por : " << ss << std::endl;
+
+ BTreeData *data = new BTreeLeafData (k->Clone());
+
+ std::list<BTreeData *>::iterator it = node_keys.begin ();
+ while (it != node_keys.end ()) {
+ std::string ss1, ss2;
+ ss1 = *data;
+ ss2 = *(*it);
+ std::cout << ss1 << " == " << ss2 << std::endl;
+ if ((*data) == (*(*it))) {
+ break;
+ }
+ it++;
+ }
+ if (it == node_keys.end ()) {
+ std::cout << "PANIC : No encontre la clave en el nodo!!!!\n";
+ std::string s = *data;
+ std::cout << s << std::endl;
+ PrintNode (node_num);
+ exit (1);
+ }
+ (*it)->SetKey (reemplazar->GetKey ());
+ reemplazar->SetKey (k->Clone ());
+
+ std::cout << "Tengo todo reemplazado ...\n";
+
+ /* Grabo los nodos */
+ WriteKeys (node, node_header, node_keys);
+ WriteNodoHeader (node, &node_header);
+ WriteBlock (node, node_num);
+ DeleteKeys (node_keys);
+ delete [] node;
+
+ WriteKeys (node_r, node_hr, node_keyr);
+ WriteNodoHeader (node_r, &node_hr);
+ WriteBlock (node_r, right);
+ DeleteKeys (node_keyr);
+ delete [] node_r;
+
+ std::cout << "Grabe todo en disco ...\n";
+ PrintNode (node_num);
+ PrintNode (right);
+ /* Ahora debo eliminar la clave que puse en el nodo hoja */
+ std::cout << "Borro la clave desde la hoja!\n";
+
+ DelKeyFromLeaf (k, right, padre_hijo);
+
+ std::cout << "Listo, Listo!\n";
+ } else if (left != 0) {
+ std::cout << "PANIC : Deberia poder reemplazar en la derecha!!!!!\n";
+ exit (1);
+ } else {
+ std::cout << "PANIC : No tengo hijos para reemplazar!!!!\n";
+ exit (1);
+ }
+}
void BTree::ReadNodoHeader (uchar *node, BTreeNodeHeader *header)
{
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 + sizeof (BTreeFileHeader), SEEK_SET);
+ fseek (fp, num*header.block_size, SEEK_SET);
fread (out, 1, header.block_size, fp);
return out;
}
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);
keys.push_back (data);
}
+ DeAbrevKey (keys);
return keys;
}
+void BTree::AbrevKey (std::list<BTreeData *> &lst)
+{
+ /* Claves Fijas No se abrevian */
+ if (key_type == KEY_FIXED) return;
+
+ BTreeData *primera = NULL;
+ std::list<BTreeData *>::iterator it = lst.begin ();
+
+ while (it != lst.end ()) {
+ if ((*it)->Abrev (primera) == false)
+ primera = (*it);
+ it++;
+ }
+}
+
+void BTree::DeAbrevKey (std::list<BTreeData *> &lst)
+{
+ /* Claves Fijas No se abrevian */
+ if (key_type == KEY_FIXED) return;
+
+ BTreeData *primera = NULL;
+ std::list<BTreeData *>::iterator it = lst.begin ();
+
+ while (it != lst.end ()) {
+ if ((*it)->DesAbrev (primera) == false)
+ primera = (*it);
+ it++;
+ }
+}
+
void BTree::WriteKeys (uchar *node, BTreeNodeHeader &node_header, std::list<BTreeData *> &keys)
{
+ AbrevKey (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);
+ uint acumulado = 0;
while (it != keys.end ()) {
BTreeData *d = (*it);
- memcpy (node, d->ToArray(), d->Size ());
+ uchar *n = d->ToArray ();
+ acumulado += d->Size ();
+ //std::cout << "WriteKeys :: Acumulado = " << acumulado << std::endl;
+ 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? */
+ DeAbrevKey (keys);
}
void BTree::PrintNode (uint num)
std::cout << std::endl;
delete [] node;
+ DeleteKeys (node_keys);
}
uchar *BTree::NewBlock (uint &num)
fseek (fp, 0, SEEK_END);
filelen = ftell (fp);
- num = (filelen - sizeof (BTreeFileHeader))/header.block_size;
+ num = filelen/header.block_size - 1;
node = new uchar[header.block_size];
ReadNodoHeader (node, &nh);
return node;
}
+BTreeFindResult *BTree::FindKey (const Clave &k)
+{
+ return FindKeyR (&k, 0);
+}
+
+BTreeFindResult *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 (k->Clone ());
+ else
+ data = new BTreeData (k->Clone (), 0);
+
+ while (it != node_keys.end ()) {
+ if ((*data) == (*(*it))) {
+ /* La encontre!, retorno */
+ delete data;
+ delete [] node;
+ DeleteKeys (node_keys);
+ BTreeFindResult *result = new BTreeFindResult ();
+ result->node = node_num;
+ result->header = node_header;
+
+ return result;
+ }
+
+ if ((*data) < (*(*it)))
+ break;
+ ultima = it;
+ it++;
+ }
+
+ delete data;
+
+ /* Si llego aca y estoy en nivel 0 (una hoja) quiere
+ * decir que no lo encontré
+ */
+ if (node_header.level == 0) {
+ DeleteKeys (node_keys);
+ delete [] node;
+ return NULL;
+ }
+
+ /* TODO: Aca faltaria liberar memoria */
+ BTreeFindResult *ret;
+ if (it == posterior)
+ ret = FindKeyR (k, lchild->GetChild ());
+ else
+ ret = FindKeyR (k, (*ultima)->GetChild ());
+
+ DeleteKeys (node_keys);
+ delete [] node;
+ return ret;
+}
+
+void BTree::DeleteKeys (std::list<BTreeData *> &keys)
+{
+ std::list<BTreeData *>::iterator it = keys.begin ();
+
+ while (it != keys.end ()) {
+ BTreeData *d = (*it);
+ delete d;
+ it++;
+ }
+}
projects / z.facultad / 75.52 / treemulator.git / blobdiff