commit c8e6304463e1771200c1fb336d9b4aeea7cb7d81
parent c867eebda512962382b827a0afed27fa6f6ca3b6
Author: Marcello Stanisci <stanisci.m@gmail.com>
Date: Tue, 6 Mar 2018 10:55:53 +0100
comments
Diffstat:
2 files changed, 52 insertions(+), 21 deletions(-)
diff --git a/src/backend/taler-merchant-httpd_track-transaction.c b/src/backend/taler-merchant-httpd_track-transaction.c
@@ -571,11 +571,11 @@ proof_cb (void *cls,
/**
- * Function called with detailed wire transfer data.
- * We were trying to find out in which wire transfer one of the
- * coins was involved in. Now we know. What we do now is first
- * obtain the inverse: all other coins of that wire transfer,
- * which is what we prefer to store.
+ * This function takes the wtid from the coin being tracked
+ * and _track_ it against the exchange. This way, we know
+ * all the other coins which were aggregated together with
+ * this one. This way we save further HTTP requests to track
+ * the other coins.
*
* @param cls closure with a `struct TrackCoinContext`
* @param http_status HTTP status code we got, 0 on exchange protocol violation
@@ -624,8 +624,10 @@ wtid_cb (void *cls,
}
tctx->current_wtid = *wtid;
tctx->current_execution_time = execution_time;
+
pcc.p_ret = NULL;
- /* FIXME: change to avoid using callback! */
+ /* attempt to find this wtid's track from our database,
+ Will make pcc.p_ret point to a "proof", if one exists. */
qs = db->find_proof_by_wtid (db->cls,
tctx->current_exchange,
wtid,
@@ -644,11 +646,13 @@ wtid_cb (void *cls,
"Fail to query database about proofs"));
return;
}
- /* WARNING: if two transactions got aggregated under the same
- WTID, then this branch is always taken (when attempting to
- track the second transaction). */
+
if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT == qs)
{
+ /* How come this wtid was already stored into the
+ database and _not all_ of its coins were already
+ tracked? Unconsistent state (! At least regarding
+ what the exchange tells us) */
GNUNET_break_op (0);
resume_track_transaction_with_response
(tcc->tctx,
@@ -792,9 +796,9 @@ find_exchange (struct TrackTransactionContext *tctx);
/**
- * This function is called to trace the wire transfers for
- * all of the coins of the transaction of the @a tctx. Once
- * we have traced all coins, we build the response.
+ * This function is called to 'trace the wire transfers'
+ * (true?) for all of the coins of the transaction of the @a tctx.
+ * Once we have traced all coins, we build the response.
*
* @param tctx track context with established connection to exchange
*/
@@ -803,10 +807,15 @@ trace_coins (struct TrackTransactionContext *tctx)
{
struct TrackCoinContext *tcc;
+ /* Make sure we are connected to the exchange. */
GNUNET_assert (NULL != tctx->eh);
+
for (tcc = tctx->tcc_head; NULL != tcc; tcc = tcc->next)
+
+ /* How come one does't have wtid? */
if (GNUNET_YES != tcc->have_wtid)
break;
+
if (NULL != tcc)
{
if (0 != strcmp (tcc->exchange_url,
@@ -837,6 +846,8 @@ trace_coins (struct TrackTransactionContext *tctx)
/**
* Function called with the result of our exchange lookup.
+ * Merely provide the execution context to the routine actually
+ * tracking the coin.
*
* @param cls the `struct TrackTransactionContext`
* @param eh NULL if exchange was not found to be acceptable
@@ -921,7 +932,7 @@ transfer_cb (void *cls,
/**
- * Function called with information about a coin that was deposited.
+ * Responsible to get the current coin wtid and store it into its state.
*
* @param cls closure
* @param transaction_id of the contract
@@ -957,6 +968,11 @@ coin_cb (void *cls,
GNUNET_CONTAINER_DLL_insert (tctx->tcc_head,
tctx->tcc_tail,
tcc);
+
+ /* find all those <coin, wtid> pairs associated to
+ this contract term's hash code. The callback
+ will then set the wtid for the "current coin"
+ context. */
qs = db->find_transfers_by_hash (db->cls,
h_contract_terms,
&transfer_cb,
@@ -1094,7 +1110,10 @@ MH_handler_track_transaction (struct TMH_RequestHandler *rh,
return TMH_RESPONSE_reply_not_found (connection,
TALER_EC_TRACK_TRANSACTION_INSTANCE_UNKNOWN,
"unknown instance");
-
+
+ /* Map order id to contract terms; the objective is to get
+ the contract term's hashcode so as to retrieve all the
+ coins which have been deposited for it. */
qs = db->find_contract_terms (db->cls,
&contract_terms,
&last_session_id,
@@ -1154,6 +1173,9 @@ MH_handler_track_transaction (struct TMH_RequestHandler *rh,
tctx->qs = GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
db->preflight (db->cls);
+
+ /* Find coins which have been deposited for this contract,
+ and retrieve the wtid for each one. */
qs = db->find_payments (db->cls,
&tctx->h_contract_terms,
&tctx->mi->pubkey,
diff --git a/src/backend/taler-merchant-httpd_track-transfer.c b/src/backend/taler-merchant-httpd_track-transfer.c
@@ -426,9 +426,9 @@ track_transfer_cleanup (struct TM_HandlerContext *hc)
/**
- * Function called with information about a coin that was transfered.
- * Verify that it matches the information claimed by the exchange.
- * Update the `check_transfer_result` field accordingly.
+ * This function checks that the information about the coin which
+ * was paid back by _this_ wire transfer matches what _we_ (the merchant)
+ * knew about this coin.
*
* @param cls closure with our `struct TrackTransferContext *`
* @param transaction_id of the contract
@@ -651,10 +651,19 @@ wire_transfer_cb (void *cls,
wire_fee))
return;
+ /* Now we want to double-check that any (Taler coin) deposit
+ * which is accounted into _this_ wire transfer, does exist
+ * into _our_ database. This is the rationale: if the
+ * exchange paid us for it, we must have received it _beforehands_!
+ *
+ * details_length is how many (Taler coin) deposits have been
+ * aggregated into _this_ wire transfer.
+ */
for (unsigned int i=0;i<details_length;i++)
{
rctx->current_offset = i;
rctx->current_detail = &details[i];
+ /* Set the coin as "never seen" before. */
rctx->check_transfer_result = GNUNET_NO;
qs = db->find_payments_by_hash_and_coin (db->cls,
&details[i].h_contract_terms,
@@ -680,8 +689,8 @@ wire_transfer_cb (void *cls,
if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
{
/* The exchange says we made this deposit, but WE do not
- recall making it! Well, let's say thanks and accept the
- money! */
+ recall making it (corrupted / unreliable database?)!
+ Well, let's say thanks and accept the money! */
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Failed to find payment data in DB\n");
rctx->check_transfer_result = GNUNET_OK;
@@ -713,8 +722,8 @@ wire_transfer_cb (void *cls,
rctx->response = NULL;
return;
}
- /* Response is consistent with the /deposit we made, remember
- it for future reference */
+ /* Response is consistent with the /deposit we made,
+ remember it for future reference */
for (unsigned int i=0;i<MAX_RETRIES;i++)
{
qs = db->store_coin_to_transfer (db->cls,
