--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/dbfs/trans.h	Fri Oct 17 18:53:05 2008 +0300
@@ -0,0 +1,69 @@
+#ifndef DBFS_TRANS_H
+#define DBFS_TRANS_H
+
+/*
+ * Support for single-fuse_req transactions.
+ */
+
+#include "dbfs.h"
+
+// forward-declaration
+struct dbfs_trans;
+
+// generic callback
+typedef void (*dbfs_trans_cb) (struct dbfs_trans *ctx);
+
+/*
+ * Request/transaction state.
+ */
+struct dbfs_trans {
+    struct fuse_req *req;
+    struct evsql_trans *trans;
+    
+    // called when the dbfs_trans is being free'd
+    dbfs_trans_cb free_fn;
+
+    // called once the transaction is ready
+    dbfs_trans_cb begin_fn;
+
+    // called once the transaction has been commited
+    dbfs_trans_cb commit_fn;
+
+    // set by trans_error to EIO if !NULL
+    int *err_ptr;
+};
+
+/*
+ * Call from commit_fn once you've set req to NULL. Also called from trans_fail.
+ *
+ * Will call free_fn if present.
+ */
+void dbfs_trans_free (struct dbfs_trans *ctx);
+
+/*
+ * Fail the dbfs_trans, aborting any trans, erroring out any req and freeing the ctx.
+ */
+void dbfs_trans_fail (struct dbfs_trans *ctx, int err);
+
+/*
+ * Initialize the ctx with the given req (stays the same during the lifetime), and opens the transaction.
+ *
+ * You should set the callback functions after/before calling this.
+ *
+ * begin_fn will be called once the transaction is open, if that fails, the req will be errored for you.
+ *
+ * If opening the transaction fails, this will return nonzero and not touch req, otherwise zero.
+ */
+int dbfs_trans_init (struct dbfs_trans *ctx, struct fuse_req *req);
+
+/*
+ * Same as init, but allocates/frees-on-error the dbfs_trans for you.
+ */
+struct dbfs_trans *dbfs_trans_new (struct fuse_req *req);
+
+/*
+ * Commit the dbfs_trans. After calling this, the ctx may or may not be valid, and commit_fn may or may not be called.
+ */
+void dbfs_trans_commit (struct dbfs_trans *ctx);
+
+#endif /* DBFS_TRANS_H */