updating btree delete

Author: xtaci

include/btree.h

@@ -240,27 +240,20 @@ namespace alg {
 WRITE(x);
 return;
 } else { // in non-leaf node
-node y, z;
-if (i-1 >= 0) {// case 2a
-y = READ(x, i-1);
-std::auto_ptr<node_t> _y(y);
-if (y->n >= T) {
-x->key[i] = y->key[y->n-1];
-WRITE(x);
-delete_op(y, x->key[i]);
-return;
-}
+std::auto_ptr<node_t> y(READ(x, i));
+if (y->n >= T) {// case 2a.
+x->key[i] = y->key[y->n-1];
+WRITE(x);
+delete_op(y.get(), x->key[i]);
+return;
 }
 
-if (i+1 < x->n) { // case 2b
-z = READ(x, i+1);
-std::auto_ptr<node_t> _z(z);
-if (z->n >= T) {
-x->key[i] = z->key[0];
-WRITE(x);
-delete_op(z, x->key[i]);
-return;
-}
+std::auto_ptr<node_t> z(READ(x, i+1));
+if (z->n >= T) {// case 2b.
+x->key[i] = z->key[0];
+WRITE(x);
+delete_op(z.get(), x->key[i]);
+return;
 }
 
 if (y->n == T-1 && z->n == T-1) { // case 2c
@@ -277,8 +270,8 @@ namespace alg {
 // mark free this node
 z->flag |= MARKFREE;
 y->n = y->n + z->n + 1; // size after merge
-WRITE(z);
-WRITE(y);
+WRITE(z.get());
+WRITE(y.get());
 
 // shift x
 for (j=i;j<x->n-1;j++) {
@@ -288,7 +281,7 @@ namespace alg {
 WRITE(x);
 
 // recursive delete k
-delete_op(y, k);
+delete_op(y.get(), k);
 return;
 }