Manejo de headers de nodos del arbol

diff --git a/src/btree.cpp b/src/btree.cpp
index 1ad006de4d029cfa203e2a47b522ad6193460a39..50a78016fa05554a203184c8bfa9be486ed1729b 100644 (file)
--- a/src/btree.cpp
+++ b/src/btree.cpp
@@ -4,7 +4,7 @@
 BTree::BTree (const char *name, unsigned int block_size, bool create_new_file)
 {
        uchar *node;
-
+       BTreeNodeHeader nh;
 
        fp = fopen (name, "wb");
        if (!fp) {
@@ -21,7 +21,13 @@ BTree::BTree (const char *name, unsigned int block_size, bool create_new_file)
 
        /* Creo el primer bloque vacio */
        node = new uchar[block_size];
+       ReadNodoHeader (node, &nh);
+       nh.level = 0;
+       nh.free_space = block_size - sizeof (BTreeNodeHeader);
+       nh.item_count = 0;
+       WriteNodoHeader (node, &nh);
        write_block (node, 0);
+
        delete [] node;
 }
 
@@ -33,15 +39,25 @@ BTree::~BTree ()
 void BTree::write_tree_header ()
 {
        fseek (fp, 0L, SEEK_SET);
-       fwrite (&header, 1, sizeof (BTreeHeader), fp);
+       fwrite (&header, 1, sizeof (BTreeFileHeader), fp);
 }
 
 void BTree::write_block (uchar *block, uint num)
 {
-       fseek (fp, num*header.block_size + sizeof (BTreeHeader), SEEK_SET);
+       fseek (fp, num*header.block_size + sizeof (BTreeFileHeader), SEEK_SET);
        fwrite (block, 1, header.block_size, fp);
 }
 
 void BTree::AddKey () {}
 void BTree::DelKey () {}
 
+void BTree::ReadNodoHeader (uchar *node, BTreeNodeHeader *header)
+{
+       memcpy (header, node, sizeof (BTreeNodeHeader));
+}
+
+void BTree::WriteNodoHeader (uchar *node, BTreeNodeHeader *header)
+{
+       memcpy (node, header, sizeof (BTreeNodeHeader));
+}
+

diff --git a/src/btree.h b/src/btree.h
index cacd29b9c6463a2309d373865233b5026decae68..0ed4fbdcadae9625011998d3b37ac5e9dd50d900 100644 (file)
--- a/src/btree.h
+++ b/src/btree.h
@@ -51,7 +51,7 @@ typedef unsigned char uchar;
 
 /** Encabezado del archivo BTree */
 typedef struct _btree_file_ {
-       unsigned int block_size;
+       uint block_size;
 } BTreeFileHeader;
 
 /** Encabezado de un bloque */
@@ -71,7 +71,7 @@ typedef struct _btree_header_ {
 
        /** Cantidad de elementos en el nodo */
        unsigned int item_count;
-} BTreeHeader;
+} BTreeNodeHeader;
 
 /** Crea un nuevo arbol B
  *
@@ -90,6 +90,8 @@ class BTree {
        private:
                void write_tree_header ();
                void write_block (uchar *block, uint num);
+               void ReadNodoHeader (uchar *node, BTreeNodeHeader *header);
+               void WriteNodoHeader (uchar *node, BTreeNodeHeader *header);
 
                std::string filename;
                BTreeFileHeader header;