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 6771746f1971b7b7aa8aa61ece6f580c01c52b01..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 */
@@ -33,9 +36,88 @@ BTree::BTree (const std::string &name, unsigned int block_size, int tt, int kt,
        delete [] node;
 }
 
+BTree* BTree::Open (const std::string &name)
+{
+       /* Leo los bloques recuperables */
+       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)) {
+                       tree->deleted_nodes.push_back (i);
+               }
+
+               fclose (fp);
+       }
+
+       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 ? */
+               delete tree;
+               return NULL;
+       }
+       tree->ReadFileHeader ();
+
+       if (strcmp ("DILUMA", tree->header.magic)) {
+               /* Arbol no tiene magic!! */
+               delete tree;
+               return NULL;
+       }
+
+       return tree;
+}
+
 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++;
+       }
+
+       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);
+}
+
+void BTree::ReadFileHeader ()
+{
+       fseek (fp, 0L, SEEK_SET);
+       fread (&header, 1, sizeof (BTreeFileHeader), fp);
 }
 
 void BTree::WriteFileHeader ()
@@ -54,14 +136,19 @@ void BTree::WriteBlock (uchar *block, uint num)
 void BTree::AddKey (const Clave &k)
 {
        uint left, right;
-       Clave *kout;
+       Clave *kout, *in;
+
+       in = k.Clone ();
+       in->SetBlockData ( GetNextBlockData () );
 
        try {
-               kout = AddKeyR (k.Clone (), 0, left, right);
+               kout = AddKeyR (in->Clone (), 0, left, right);
        } catch (Exception *e) {
                throw e;
        }
 
+       delete in;
+
        if (kout) {
                unsigned short level;
                /* Debo dejar la raiz en el nodo 0, por lo que paso el nodo
@@ -533,6 +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;
                }
@@ -1138,9 +1226,9 @@ uchar *BTree::NewBlock (uint &num)
        BTreeNodeHeader nh;
 
        std::list<uint>::iterator it;
-       it = deleted_nodes.begin ();
 
-       if (it != deleted_nodes.end ()) {
+       if (deleted_nodes.size ()) {
+               it = deleted_nodes.begin ();
                num = *it;
                deleted_nodes.erase (it);
        } else {
@@ -1249,3 +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;
+}
+