refactoring /deposit towards new transaction style (#5010)

1 files changed, 52 insertions, 9 deletions

diff --git a/src/exchange/taler-exchange-httpd_db.h b/src/exchange/taler-exchange-httpd_db.h
index 55faafa06..6d0b7e35a 100644
--- a/src/exchange/taler-exchange-httpd_db.h
+++ b/src/exchange/taler-exchange-httpd_db.h
@@ -24,20 +24,63 @@
 #include <microhttpd.h>
 #include "taler_exchangedb_plugin.h"
 
+/**
+ * Function implementing a database transaction.  Runs the transaction
+ * logic; IF it returns a non-error code, the transaction logic MUST
+ * NOT queue a MHD response.  IF it returns an hard error, the
+ * transaction logic MUST queue a MHD response and set @a mhd_ret.  IF
+ * it returns the soft error code, the function MAY be called again to
+ * retry and MUST not queue a MHD response.
+ *
+ * @param cls closure
+ * @param connection MHD request which triggered the transaction
+ * @param session database session to use
+ * @param[out] mhd_ret set to MHD response status for @a connection,
+ *             if transaction failed (!)
+ * @return transaction status
+ */
+typedef enum GNUNET_DB_QueryStatus
+(*TEH_DB_TransactionCallback)(void *cls,
+			      struct MHD_Connection *connection,
+			      struct TALER_EXCHANGEDB_Session *session,
+			      int *mhd_ret);
+
 
 /**
- * Execute a "/deposit".  The validity of the coin and signature
- * have already been checked.  The database must now check that
- * the coin is not (double or over) spent, and execute the
- * transaction (record details, generate success or failure response).
+ * Run a database transaction for @a connection.
+ * Starts a transaction and calls @a cb.  Upon success,
+ * attempts to commit the transaction.  Upon soft failures,
+ * retries @a cb a few times.  Upon hard or persistent soft
+ * errors, generates an error message for @a connection.
+ * 
+ * @param connection MHD connection to run @a cb for
+ * @param[out] set to MHD response code, if transaction failed
+ * @param cb callback implementing transaction logic
+ * @param cb_cls closure for @a cb, must be read-only!
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
+ */
+int
+TEH_DB_run_transaction (struct MHD_Connection *connection,
+			int *mhd_ret,
+			TEH_DB_TransactionCallback cb,
+			void *cb_cls);
+
+
+/**
+ * Calculate the total value of all transactions performed.
+ * Stores @a off plus the cost of all transactions in @a tl
+ * in @a ret.
  *
- * @param connection the MHD connection to handle
- * @param deposit information about the deposit
- * @return MHD result code
+ * @param tl transaction list to process
+ * @param off offset to use as the starting value
+ * @param[out] ret where the resulting total is to be stored
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on errors
  */
+// FIXME: maybe move to another module?
 int
-TEH_DB_execute_deposit (struct MHD_Connection *connection,
-                        const struct TALER_EXCHANGEDB_Deposit *deposit);
+TEH_DB_calculate_transaction_list_totals (struct TALER_EXCHANGEDB_TransactionList *tl,
+					  const struct TALER_Amount *off,
+					  struct TALER_Amount *ret);
 
 
 /**