fixing #3816: adding 'id' field to uniquely identify each deposit

src/include/taler_mintdb_plugin.h

@@ -516,6 +516,31 @@ struct TALER_MINTDB_MeltCommitment
 struct TALER_MINTDB_Session;
 
 
+/**
+ * Function called with details about deposits that
+ * have been made, with the goal of executing the
+ * corresponding wire transaction.
+ *
+ * @param cls closure
+ * @param id transaction ID (used as future `min_id` to avoid
+ *           iterating over transactions more than once)
+ * @param amount_with_fee amount that was deposited including fee
+ * @param deposit_fee amount the mint gets to keep as transaction fees
+ * @param transaction_id unique transaction ID chosen by the merchant
+ * @param h_contract hash of the contract between merchant and customer
+ * @param wire wire details for the merchant
+ * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
+ */
+typedef int
+(*TALER_MINTDB_DepositIterator)(void *cls,
+                                uint64_t id,
+                                const struct TALER_Amount *amount_with_fee,
+                                const struct TALER_Amount *deposit_fee,
+                                uint64_t transaction_id,
+                                const struct GNUNET_HashCode *h_contract,
+                                const char *wire);
+
+
 /**
  * Function called with the session hashes and transfer secret
  * information for a given coin.
@@ -780,8 +805,7 @@ struct TALER_MINTDB_Plugin
 
 
   /**
-   * Insert information about deposited coin into the
+   * Insert information about deposited coin into the database.
-   * database.
    *
    * @param cls the @e cls of this struct with the plugin-specific state
    * @param sesssion connection to the database
@@ -794,6 +818,30 @@ struct TALER_MINTDB_Plugin
                      const struct TALER_MINTDB_Deposit *deposit);
 
 
+  /**
+   * Obtain information about deposits.  Iterates over all deposits
+   * above a certain ID.  Use a @a min_id of 0 to start at the beginning.
+   * This operation is executed in its own transaction in transaction
+   * mode "READ COMMITTED", i.e. we should only see valid deposits.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param sesssion connection to the database
+   * @param min_id deposit to start at
+   * @param limit maximum number of transactions to fetch
+   * @param deposit_cb function to call for each deposit
+   * @param deposit_cb_cls closure for @a deposit_cb
+   * @return number of rows processed, 0 if none exist,
+   *         #GNUNET_SYSERR on error
+   */
+  int
+  (*iterate_deposits) (void *cls,
+                       struct TALER_MINTDB_Session *sesssion,
+                       uint64_t min_id,
+                       unsigned int limit,
+                       TALER_MINTDB_DepositIterator deposit_cb,
+                       void *deposit_cb_cls);
+
+
   /**
    * Lookup refresh session data under the given @a session_hash.
    *

src/mintdb/plugin_mintdb_postgres.c

@@ -424,15 +424,10 @@ postgres_create_tables (void *cls,
           ",ev_sig BYTEA NOT NULL"
           ")");
   /* This table contains the wire transfers the mint is supposed to
-     execute to transmit funds to the merchants (and manage refunds).
+     execute to transmit funds to the merchants (and manage refunds). */
-     TODO: we might want to generate some other primary key
-     to internally identify outgoing transactions, as "coin_pub"
-     may not be unique if a wallet chooses not to refresh.  The
-     resulting transaction ID should then be returned to the merchant
-     and could be used by the mearchant for further inquriries about
-     the deposit's execution. (#3816); */
   SQLEXEC("CREATE TABLE IF NOT EXISTS deposits "
-          "(coin_pub BYTEA NOT NULL CHECK (LENGTH(coin_pub)=32)"
+          "(id BIGSERIAL"
+          ",coin_pub BYTEA NOT NULL CHECK (LENGTH(coin_pub)=32)"
           ",denom_pub BYTEA NOT NULL REFERENCES denominations (pub)"
           ",denom_sig BYTEA NOT NULL"
           ",transaction_id INT8 NOT NULL"
@@ -853,6 +848,24 @@ postgres_prepare (PGconn *db_conn)
            "  (merchant_pub=$3)"
            " )",
            3, NULL);
+
+  /* Used in #postgres_iterate_deposits() */
+  PREPARE ("deposits_iterate",
+           "SELECT"
+           " id"
+           " amount_with_fee_val"
+           ",amount_with_fee_frac"
+           ",amount_with_fee_curr"
+           ",deposit_fee_val"
+           ",deposit_fee_frac"
+           ",deposit_fee_curr"
+           ",transaction_id"
+           ",h_contract"
+           ",wire"
+           " FROM deposits"
+           " WHERE id>=$1"
+           " LIMIT $2;",
+           2, NULL);
   /* Used in #postgres_get_coin_transactions() to obtain information
      about how a coin has been spend with /deposit requests. */
   PREPARE ("get_deposit_with_coin_pub",