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

diff --git a/src/btree.cpp b/src/btree.cpp
index 3f6fba6e3c2a7f39ca0a33d7d3e1cc3a45e1ea79..e78a91e406688633f1818fad4464e9776f9b8c03 100644 (file)
--- a/src/btree.cpp
+++ b/src/btree.cpp
@@ -3,8 +3,6 @@
 
 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;
 
@@ -19,6 +17,8 @@ BTree::BTree (const std::string &name, unsigned int block_size, int tt, int kt,
        
        /* Inicializo el header */
        header.block_size = block_size;
+       header.tree_type = tt;
+       header.key_type = kt;
        WriteFileHeader ();
 
        /* Creo el primer bloque vacio */
@@ -33,9 +33,52 @@ BTree::BTree (const std::string &name, unsigned int block_size, int tt, int kt,
        delete [] node;
 }
 
+BTree::BTree (const std::string &name)
+{
+       /* Leo los bloques recuperables */
+       std::string del = filename + ".del";
+
+       fp = fopen (del.c_str (), "wb");
+       if (fp != NULL) {
+               uint i;
+
+               while (fread (&i, 1, sizeof (uint), fp)) {
+                       deleted_nodes.push_back (i);
+               }
+
+               fclose (fp);
+       }
+
+       fp = fopen (name.c_str(), "rb+");
+       if (!fp) {
+               /* TODO : mandar una exception ? */
+               return;
+       }
+       ReadFileHeader ();
+}
+
 BTree::~BTree ()
 {
        fclose (fp);
+
+       std::string del = filename + ".del";
+
+       fp = fopen (del.c_str (), "wb");
+       std::list<uint>::iterator it = deleted_nodes.begin ();
+
+       while (it != deleted_nodes.end ()) {
+               uint i = *it;
+               fwrite (&i, 1, sizeof (uint), fp);
+               it++;
+       }
+
+       fclose (fp);
+}
+
+void BTree::ReadFileHeader ()
+{
+       fseek (fp, 0L, SEEK_SET);
+       fread (&header, 1, sizeof (BTreeFileHeader), fp);
 }
 
 void BTree::WriteFileHeader ()
@@ -143,7 +186,7 @@ Clave* BTree::AddKeyLeafR (const Clave *k, uint node_num, uint &left_child, uint
 
                while (it != node_keys.end ()) {
                        datait = (*it);
-                       if (tree_type == TYPE_IDENTIFICACION) {
+                       if (header.tree_type == TYPE_IDENTIFICACION) {
                                /* Verifico que la clave no existea ya en el arbol */
                                if ((*data) == (*datait)) {
                                        throw new AddException ();
@@ -184,7 +227,7 @@ Clave* BTree::AddKeyLeafR (const Clave *k, uint node_num, uint &left_child, uint
                while (it != node_keys.end ()) {
                        BTreeData *datait;
                        datait = (*it);
-                       if (tree_type == TYPE_IDENTIFICACION) {
+                       if (header.tree_type == TYPE_IDENTIFICACION) {
                                /* Verifico que la clave no existea ya en el arbol */
                                if ((*data) == (*datait)) {
                                        throw new AddException ();
@@ -284,7 +327,7 @@ Clave* BTree::AddKeyOtherR (const Clave *k, uint node_num, uint &left_child, uin
        posterior = it;
 
        while (it != node_keys.end ()) {
-               if (tree_type == TYPE_IDENTIFICACION) {
+               if (header.tree_type == TYPE_IDENTIFICACION) {
                        /* Verifico que la clave no existea ya en el arbol */
                        if ((*data) == (*(*it))) {
                                throw new AddException ();
@@ -320,7 +363,7 @@ Clave* BTree::AddKeyOtherR (const Clave *k, uint node_num, uint &left_child, uin
 
                while (it != node_keys.end ()) {
                        datait = (*it);
-                       if (tree_type == TYPE_IDENTIFICACION) {
+                       if (header.tree_type == TYPE_IDENTIFICACION) {
                                /* Verifico que la clave no existea ya en el arbol */
                                if ((*data) == (*datait)) {
                                        throw new AddException ();
@@ -362,7 +405,7 @@ Clave* BTree::AddKeyOtherR (const Clave *k, uint node_num, uint &left_child, uin
                while (it != node_keys.end ()) {
                        BTreeData *datait;
                        datait = (*it);
-                       if (tree_type == TYPE_IDENTIFICACION) {
+                       if (header.tree_type == TYPE_IDENTIFICACION) {
                                /* Verifico que la clave no existea ya en el arbol */
                                if ((*data) == (*datait)) {
                                        throw new AddException ();
@@ -714,13 +757,15 @@ void BTree::JoinNodes (uint node1, uint node2, uint padre, int tipohermano)
                WriteNodoHeader (npadre, &nhp);
                WriteBlock (npadre, padre);
 
-        /* TODO: Recuperar nodo1 y nodo2 */
+               deleted_nodes.push_back (node1);
+               deleted_nodes.push_back (node2);
        } else {
                WriteKeys (n1, nh1, newkeys);
                WriteNodoHeader (n1, &nh1);
                WriteBlock (n1, node1);
 
-               /* TODO : Recuperar node2 */
+               deleted_nodes.push_back (node2);
+
                /* Actualizo punero al padre */
                (*anterior)->SetChild (node1);
        
@@ -1035,9 +1080,9 @@ std::list<BTreeData *> BTree::ReadKeys (uchar *node, BTreeNodeHeader &node_heade
        for (uint i=0; i<count; i++) {
                BTreeData *data;
                if (node_header.level == 0) {
-                       data = new BTreeLeafData (node, key_type);
+                       data = new BTreeLeafData (node, header.key_type);
                } else {
-                       data = new BTreeData (node, key_type);
+                       data = new BTreeData (node, header.key_type);
                }
                node += data->Size ();
                keys.push_back (data);
@@ -1050,7 +1095,7 @@ std::list<BTreeData *> BTree::ReadKeys (uchar *node, BTreeNodeHeader &node_heade
 void BTree::AbrevKey (std::list<BTreeData *> &lst)
 {
        /* Claves Fijas No se abrevian */
-       if (key_type == KEY_FIXED) return;
+       if (header.key_type == KEY_FIXED) return;
 
        BTreeData *primera = NULL;
        std::list<BTreeData *>::iterator it = lst.begin ();
@@ -1065,7 +1110,7 @@ void BTree::AbrevKey (std::list<BTreeData *> &lst)
 void BTree::DeAbrevKey (std::list<BTreeData *> &lst)
 {
        /* Claves Fijas No se abrevian */
-       if (key_type == KEY_FIXED) return;
+       if (header.key_type == KEY_FIXED) return;
 
        BTreeData *primera = NULL;
        std::list<BTreeData *>::iterator it = lst.begin ();
@@ -1135,11 +1180,18 @@ uchar *BTree::NewBlock (uint &num)
        uchar *node;
        BTreeNodeHeader nh;
 
-       fseek (fp, 0, SEEK_END);
-       filelen = ftell (fp);
+       std::list<uint>::iterator it;
 
-       num = filelen/header.block_size - 1;
+       if (deleted_nodes.size ()) {
+               it = deleted_nodes.begin ();
+               num = *it;
+               deleted_nodes.erase (it);
+       } else {
+               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;
@@ -1238,5 +1290,5 @@ void BTree::DeleteKeys (std::list<BTreeData *> &keys)
 
 int BTree::type () const
 {
-       return key_type;
+       return header.key_type;
 }