init transaction

transaction.h

@@ -0,0 +1,65 @@
+#include "list.h"
+#ifndef TRANSACTION_H
+#define TRANSACTION_H
+typedef struct
+{
+    statement_t statement;
+    list_node_t entry;
+} transaction_t;
+typedef transaction_t trans_t;
+
+// a dummy list node
+static trans_t *trans = NULL;
+
+// this function will run before main
+static inline void __attribute__((constructor)) init_transaction()
+{
+    trans = (trans_t *)malloc(sizeof(trans_t));
+    init_list_head(&(trans->entry));
+}
+
+static inline void __attribute__((destructor)) free_transaction()
+{
+    list_node_t *pos, *next;
+    list_for_each_safe(pos, next, &(trans->entry))
+    {
+        if (pos != NULL)
+            free(pos);
+    }
+    if (trans != NULL)
+        free(trans);
+}
+
+static inline void transaction_push(statement_t *statement)
+{
+    trans_t *node = (trans_t *)malloc(sizeof(trans_t));
+    memcpy(&(node->statement), statement, sizeof(statement_t));
+    list_add_tail(&(node->entry), &(trans->entry));
+}
+
+static inline trans_t *transaction_pop()
+{
+    list_node_t *last = (trans->entry).prev;
+    list_del(last);
+    return list_entry(last, trans_t, entry);
+}
+
+static inline void transaction_commit()
+{
+    list_node_t *pos, *next;
+    trans_t *node;
+    list_for_each_safe(pos, next, &(trans->entry))
+    {
+        node = list_entry(pos, trans_t, entry);
+        // TODO: commit, write page to disk: memory -> disk
+    }
+}
+
+// rollback only one step
+static inline void transaction_rollback()
+{
+    trans_t *last = transaction_pop();
+    // TODO: rollback, read page from disk: memory <- disk
+}
+
+#endif