Poniendole forma al Agregar.

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

diff --git a/src/btree.cpp b/src/btree.cpp
index 9591ec890afacc4fb2689910acc3cc84695253a9..fc0a5e926f27973bb60c2c82619d4f4d8551e0a4 100644 (file)
--- a/src/btree.cpp
+++ b/src/btree.cpp
@@ -6,7 +6,7 @@ BTree::BTree (const std::string &name, unsigned int block_size, bool create_new_
        uchar *node;
        BTreeNodeHeader nh;
 
-       fp = fopen (name.c_str(), "wb");
+       fp = fopen (name.c_str(), "wb+");
        if (!fp) {
                /* TODO : mandar una exception ? */
                return;
@@ -17,7 +17,7 @@ BTree::BTree (const std::string &name, unsigned int block_size, bool create_new_
        
        /* Inicializo el header */
        header.block_size = block_size;
-       write_tree_header ();
+       WriteFileHeader ();
 
        /* Creo el primer bloque vacio */
        node = new uchar[block_size];
@@ -26,7 +26,7 @@ BTree::BTree (const std::string &name, unsigned int block_size, bool create_new_
        nh.free_space = block_size - sizeof (BTreeNodeHeader);
        nh.item_count = 0;
        WriteNodoHeader (node, &nh);
-       write_block (node, 0);
+       WriteBlock (node, 0);
 
        delete [] node;
 }
@@ -36,13 +36,13 @@ BTree::~BTree ()
        fclose (fp);
 }
 
-void BTree::write_tree_header ()
+void BTree::WriteFileHeader ()
 {
        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);
        fwrite (block, 1, header.block_size, fp);
@@ -50,23 +50,61 @@ void BTree::write_block (uchar *block, uint num)
 
 void BTree::AddKey (const Clave &k)
 {
-       std::list<Clave *> node_keys;
+       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 *root = ReadBlock (0);
-       BTreeNodeHeader root_header;
-       ReadNodoHeader (root, &root_header);
+       uchar *node = ReadBlock (node_num);
+       BTreeNodeHeader node_header;
+       ReadNodoHeader (node, &node_header);
 
-       node_keys = ReadKeys (root, root_header);
-       std::cout << node_keys.size () << std::endl;
-       
-       if (root_header.free_space >= k.Size ()) {
-               std::cout << "Hay lugar para meter la clave" << std::endl;
+       if (node_header.level != 0) {
+               /* No estoy en una hoja, asi que tengo que buscar
+                * para donde moverme para agregar la clave
+                */
+               /* TODO :) */
+       }
+
+
+       /* Estoy en una hoja, veo si lo puedo agregar */
+       BTreeLeafData data (k->Clone ());
+
+       if (node_header.free_space > data.Size ()) {
+               /* TODO : Insertar ordenado */
+               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;
+               }
+               node_keys.insert (it, data);
+               WriteKeys (node, node_header, node_keys);
+               WriteNodoHeader (node, &node_header);
+               WriteBlock (node, node_num);
+
+               PrintNode (node_num);
        } else {
-               std::cout << "__NO__ hay lugar para meter la clave" << std::endl;
+               /* 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;
+               delete [] node;
        }
 
-       delete [] root;
+       return kout;
 }
 
 void BTree::DelKey (const Clave &k) {}
@@ -91,9 +129,9 @@ uchar *BTree::ReadBlock (uint num)
        return out;
 }
 
-std::list<Clave *> BTree::ReadKeys (uchar *node, BTreeNodeHeader &node_header)
+std::list<BTreeData> BTree::ReadKeys (uchar *node, BTreeNodeHeader &node_header)
 {
-       std::list<Clave *> keys;
+       std::list<BTreeData> keys;
        node += sizeof (BTreeNodeHeader);
 
        for (uint i=0; i<node_header.item_count; i++) {
@@ -101,26 +139,56 @@ std::list<Clave *> BTree::ReadKeys (uchar *node, BTreeNodeHeader &node_header)
                 * dependiendo de algun dato en el header del
                 * arbol
                 */
-               ClaveFija *k = new ClaveFija (node);
-               node += k->Size ();
-               keys.push_back (k);
+               /* TODO : Detectar si estoy en una hoja */
+               BTreeData data;
+               if (node_header.level == 0)
+                       data = BTreeLeafData (node);
+               else
+                       data = BTreeData (node);
+               node += data.Size ();
+               keys.push_back (data);
        }
 
        return keys;
 }
 
-void BTree::WriteKeys (uchar *node, BTreeNodeHeader &node_header, std::list<Clave *> &keys)
+void BTree::WriteKeys (uchar *node, BTreeNodeHeader &node_header, std::list<BTreeData> &keys)
 {
-       std::list<Clave *>::iterator it = keys.begin ();
+       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 ()) {
-               Clave *c = (*it);
-               memcpy (node, c->ToArray(), c->Size ());
-               node += c->Size ();
+               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 << "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 << ") "; 
+       }
+       std::cout << std::endl;
+}
+