Cambio constructor por metodo estatico.

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

diff --git a/src/btree.cpp b/src/btree.cpp
index 77967bf45ce1471d2a90793753067547f96f7a47..2701b3a270aa3864346edf05525ef9c035471573 100644 (file)
--- a/src/btree.cpp
+++ b/src/btree.cpp
@@ -19,6 +19,9 @@ BTree::BTree (const std::string &name, unsigned int block_size, int tt, int kt,
        header.block_size = block_size;
        header.tree_type = tt;
        header.key_type = kt;
+       header.block_data_counter = 0;
+       strcpy (header.magic, "DILUMA");
+       header.magic[6] = '\0';
        WriteFileHeader ();
 
        /* Creo el primer bloque vacio */
@@ -33,28 +36,54 @@ BTree::BTree (const std::string &name, unsigned int block_size, int tt, int kt,
        delete [] node;
 }
 
-BTree::BTree (const std::string &name)
+BTree* BTree::Open (const std::string &name)
 {
        /* Leo los bloques recuperables */
-       std::string del = filename + ".del";
+       FILE *fp;
+       BTree *tree = new BTree ();
+
+       std::string del = name + ".del";
 
        fp = fopen (del.c_str (), "wb");
        if (fp != NULL) {
                uint i;
 
                while (fread (&i, 1, sizeof (uint), fp)) {
-                       deleted_nodes.push_back (i);
+                       tree->deleted_nodes.push_back (i);
                }
 
                fclose (fp);
        }
 
-       fp = fopen (name.c_str(), "rb+");
+       del = name + ".blockdel";
+
+       fp = fopen (del.c_str (), "wb");
+       if (fp != NULL) {
+               uint i;
+
+               while (fread (&i, 1, sizeof (uint), fp)) {
+                       tree->deleted_block_data.push_back (i);
+               }
+
+               fclose (fp);
+       }
+
+       tree->filename = name;
+       tree->fp = fopen (name.c_str(), "rb+");
        if (!fp) {
                /* TODO : mandar una exception ? */
-               return;
+               delete tree;
+               return NULL;
        }
-       ReadFileHeader ();
+       tree->ReadFileHeader ();
+
+       if (strcmp ("DILUMA", tree->header.magic)) {
+               /* Arbol no tiene magic!! */
+               delete tree;
+               return NULL;
+       }
+
+       return tree;
 }
 
 BTree::~BTree ()
@@ -72,6 +101,16 @@ BTree::~BTree ()
                it++;
        }
 
+       del = filename + ".del";
+
+       fp = fopen (del.c_str (), "wb");
+       it = deleted_block_data.begin ();
+
+       while (it != deleted_block_data.end ()) {
+               uint i = *it;
+               fwrite (&i, 1, sizeof (uint), fp);
+               it++;
+       }
        fclose (fp);
 }
 
@@ -100,8 +139,7 @@ void BTree::AddKey (const Clave &k)
        Clave *kout, *in;
 
        in = k.Clone ();
-       /* TODO : Hacer un contador con recuperacion */
-       in->SetBlockData (0);
+       in->SetBlockData ( GetNextBlockData () );
 
        try {
                kout = AddKeyR (in->Clone (), 0, left, right);
@@ -582,6 +620,7 @@ void BTree::DelKeyFromLeaf (Clave *k, uint node_num, uint padre)
                if ((*data) == (*(*it))) {
                        BTreeData *aborrar = (*it);
                        node_keys.erase (it);
+                       deleted_block_data.push_back (aborrar->GetKey ()->GetBlockData ());
                        delete aborrar;
                        break;
                }
@@ -1298,3 +1337,18 @@ int BTree::type () const
 {
        return header.key_type;
 }
+
+uint BTree::GetNextBlockData ()
+{
+       uint n;
+       if (deleted_block_data.size ()) {
+               std::list<uint>::iterator it = deleted_block_data.begin ();
+               n = *it;
+               deleted_block_data.erase (it);
+       } else {
+               n = header.block_data_counter++;
+       }
+
+       return n;
+}
+