From bc55152b0a60b9fa68e00971d07ee91bc7a63856 Mon Sep 17 00:00:00 2001
From: Sree Harsha Totakura <sreeharsha@totakura.in>
Date: Thu, 5 Mar 2015 16:05:06 +0100
Subject: [PATCH] Move table creation logic to DB layer.  Also support
 temporary schema creation for the sake of testing

---
 src/mint/mint_db.c             | 211 ++++++++++++++++++++++++++++++++-
 src/mint/mint_db.h             |  22 +++-
 src/mint/taler-mint-dbinit.c   | 187 +----------------------------
 src/mint/taler-mint-httpd_db.c |  14 +--
 4 files changed, 239 insertions(+), 195 deletions(-)

diff --git a/src/mint/mint_db.c b/src/mint/mint_db.c
index 786d04ac7..91d6705c3 100644
--- a/src/mint/mint_db.c
+++ b/src/mint/mint_db.c
@@ -13,11 +13,13 @@
   You should have received a copy of the GNU General Public License along with
   TALER; see the file COPYING.  If not, If not, see <http://www.gnu.org/licenses/>
 */
+
 /**
  * @file mint_db.c
  * @brief Low-level (statement-level) database access for the mint
  * @author Florian Dold
  * @author Christian Grothoff
+ * @author Sree Harsha Totakura
  *
  * TODO:
  * - The mint_db.h-API should ideally be what we need to port
@@ -32,6 +34,7 @@
 #include "mint_db.h"
 #include <pthread.h>
 
+
 /**
  * Thread-local database connection.
  * Contains a pointer to PGconn or NULL.
@@ -45,7 +48,6 @@ static pthread_key_t db_conn_threadlocal;
  */
 static char *TALER_MINT_db_connection_cfg_str;
 
-
 #define break_db_err(result) do { \
     GNUNET_break(0); \
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Database failure: %s\n", PQresultErrorMessage (result)); \
@@ -60,6 +62,213 @@ static char *TALER_MINT_db_connection_cfg_str;
   } while (0)
 
 
+#define SQLEXEC_(conn, sql, result)                                     \
+  do {                                                                  \
+    result = PQexec (conn, sql);                                        \
+    if (PGRES_COMMAND_OK != PQresultStatus (result))                    \
+    {                                                                   \
+      break_db_err (result);                                            \
+      PQclear (result); result = NULL;                                  \
+      goto SQLEXEC_fail;                                                \
+    }                                                                   \
+    PQclear (result); result = NULL;                                    \
+  } while (0)
+
+
+/**
+ * Set the given connection to use a temporary schema
+ *
+ * @param db the database connection
+ * @return #GNUNET_OK upon success; #GNUNET_SYSERR upon error
+ */
+static int
+set_temporary_schema (PGconn *db)
+{
+  PGresult *result;
+
+  SQLEXEC_(db,
+           "CREATE SCHEMA IF NOT EXISTS " TALER_TEMP_SCHEMA_NAME ";"
+           "SET search_path to " TALER_TEMP_SCHEMA_NAME ";",
+           result);
+  return GNUNET_OK;
+ SQLEXEC_fail:
+  return GNUNET_SYSERR;
+}
+
+
+/**
+ * Drop the temporary taler schema.  This is only useful for testcases
+ *
+ * @return #GNUNET_OK upon success; #GNUNET_SYSERR upon failure
+ */
+int
+TALER_MINT_DB_drop_temporary (PGconn *db)
+{
+  PGresult *result;
+
+  SQLEXEC_ (db,
+            "DROP SCHEMA " TALER_TEMP_SCHEMA_NAME " CASCADE;",
+            result);
+  return GNUNET_OK;
+ SQLEXEC_fail:
+  return GNUNET_SYSERR;
+}
+
+
+/**
+ * Create the necessary tables if they are not present
+ *
+ * @param temporary should we use a temporary schema
+ * @return #GNUNET_OK upon success; #GNUNET_SYSERR upon failure
+ */
+int
+TALER_MINT_DB_create_tables (int temporary)
+{
+  PGresult *result;
+  PGconn *conn;
+
+  result = NULL;
+  conn = PQconnectdb (TALER_MINT_db_connection_cfg_str);
+  if (CONNECTION_OK != PQstatus (conn))
+  {
+    LOG_ERROR ("Database connection failed: %s\n",
+               PQerrorMessage (conn));
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  if ((GNUNET_YES == temporary)
+      && (GNUNET_SYSERR == set_temporary_schema (conn)))
+  {
+    PQfinish (conn);
+    return GNUNET_SYSERR;
+  }
+#define SQLEXEC(sql) SQLEXEC_(conn, sql, result);
+  /* reserves table is for summarization of a reserve.  It is updated when new
+     funds are added and existing funds are withdrawn */
+  SQLEXEC ("CREATE TABLE IF NOT EXISTS reserves"
+           "("
+           " reserve_pub BYTEA PRIMARY KEY"
+           ",current_balance_value INT4 NOT NULL"
+           ",current_balance_fraction INT4 NOT NULL"
+           ",balance_currency VARCHAR(4) NOT NULL"
+           ",expiration_date INT8 NOT NULL"
+           ")");
+  /* reserves_in table collects the transactions which transfer funds into the
+     reserve.  The amount and expiration date for the corresponding reserve are
+     updated when new transfer funds are added.  The rows of this table
+     correspond to each incoming transaction. */
+  SQLEXEC("CREATE TABLE IF NOT EXISTS reserves_in"
+          "("
+          " reserve_pub BYTEA REFERENCES reserves (reserve_pub) ON DELETE CASCADE"
+          ",balance_value INT4 NOT NULL"
+          ",balance_fraction INT4 NOT NULL"
+          ",expiration_date INT8 NOT NULL"
+          ");");
+  result = PQexec (conn,
+                   "CREATE INDEX reserves_in_index ON reserves_in (reserve_pub);");
+  if (PGRES_COMMAND_OK != PQresultStatus (result))
+  {
+    ExecStatusType status = PQresultStatus (result);
+    PQclear (result);
+    result = NULL;
+    goto SQLEXEC_fail;
+  }
+  PQclear (result);
+  SQLEXEC ("CREATE TABLE IF NOT EXISTS collectable_blindcoins"
+           "("
+           "blind_ev BYTEA PRIMARY KEY"
+           ",blind_ev_sig BYTEA NOT NULL"
+           ",denom_pub BYTEA NOT NULL"
+           ",reserve_sig BYTEA NOT NULL"
+           ",reserve_pub BYTEA REFERENCES reserves (reserve_pub) ON DELETE CASCADE"
+           ");"
+           "CREATE INDEX collectable_blindcoins_index ON"
+           " collectable_blindcoins(reserve_pub)");
+  SQLEXEC("CREATE TABLE IF NOT EXISTS known_coins "
+          "("
+          " coin_pub BYTEA NOT NULL PRIMARY KEY"
+          ",denom_pub BYTEA NOT NULL"
+          ",denom_sig BYTEA NOT NULL"
+          ",expended_value INT4 NOT NULL"
+          ",expended_fraction INT4 NOT NULL"
+          ",expended_currency VARCHAR(4) NOT NULL"
+          ",refresh_session_pub BYTEA"
+          ")");
+  SQLEXEC("CREATE TABLE IF NOT EXISTS refresh_sessions "
+          "("
+          " session_pub BYTEA PRIMARY KEY CHECK (length(session_pub) = 32)"
+          ",session_melt_sig BYTEA"
+          ",session_commit_sig BYTEA"
+          ",noreveal_index INT2 NOT NULL"
+          // non-zero if all reveals were ok
+          // and the new coin signatures are ready
+          ",reveal_ok BOOLEAN NOT NULL DEFAULT false"
+          ") ");
+  SQLEXEC("CREATE TABLE IF NOT EXISTS refresh_order "
+          "( "
+          " session_pub BYTEA NOT NULL REFERENCES refresh_sessions (session_pub)"
+          ",newcoin_index INT2 NOT NULL "
+          ",denom_pub BYTEA NOT NULL "
+          ",PRIMARY KEY (session_pub, newcoin_index)"
+          ") ");
+  SQLEXEC("CREATE TABLE IF NOT EXISTS refresh_commit_link"
+          "("
+          " session_pub BYTEA NOT NULL REFERENCES refresh_sessions (session_pub)"
+          ",transfer_pub BYTEA NOT NULL"
+          ",link_secret_enc BYTEA NOT NULL"
+          // index of the old coin in the customer's request
+          ",oldcoin_index INT2 NOT NULL"
+          // index for cut and choose,
+          // ranges from 0 to kappa-1
+          ",cnc_index INT2 NOT NULL"
+          ")");
+  SQLEXEC("CREATE TABLE IF NOT EXISTS refresh_commit_coin"
+          "("
+          " session_pub BYTEA NOT NULL REFERENCES refresh_sessions (session_pub) "
+          ",link_vector_enc BYTEA NOT NULL"
+          // index of the new coin in the customer's request
+          ",newcoin_index INT2 NOT NULL"
+          // index for cut and choose,
+          ",cnc_index INT2 NOT NULL"
+          ",coin_ev BYTEA NOT NULL"
+          ")");
+  SQLEXEC("CREATE TABLE IF NOT EXISTS refresh_melt"
+          "("
+          " session_pub BYTEA NOT NULL REFERENCES refresh_sessions (session_pub) "
+          ",coin_pub BYTEA NOT NULL REFERENCES known_coins (coin_pub) "
+          ",denom_pub BYTEA NOT NULL "
+          ",oldcoin_index INT2 NOT NULL"
+          ")");
+  SQLEXEC("CREATE TABLE IF NOT EXISTS refresh_collectable"
+          "("
+          " session_pub BYTEA NOT NULL REFERENCES refresh_sessions (session_pub) "
+          ",ev_sig BYTEA NOT NULL"
+          ",newcoin_index INT2 NOT NULL"
+          ")");
+  SQLEXEC("CREATE TABLE IF NOT EXISTS deposits "
+          "( "
+          " coin_pub BYTEA NOT NULL PRIMARY KEY CHECK (length(coin_pub)=32)"
+          ",denom_pub BYTEA NOT NULL CHECK (length(denom_pub)=32)"
+          ",transaction_id INT8 NOT NULL"
+          ",amount_currency VARCHAR(4) NOT NULL"
+          ",amount_value INT4 NOT NULL"
+          ",amount_fraction INT4 NOT NULL"
+          ",merchant_pub BYTEA NOT NULL"
+          ",h_contract BYTEA NOT NULL CHECK (length(h_contract)=64)"
+          ",h_wire BYTEA NOT NULL CHECK (length(h_wire)=64)"
+          ",coin_sig BYTEA NOT NULL CHECK (length(coin_sig)=64)"
+          ",wire TEXT NOT NULL"
+          ")");
+#undef SQLEXEC
+  PQfinish (conn);
+  return GNUNET_OK;
+
+ SQLEXEC_fail:
+  PQfinish (conn);
+  return GNUNET_SYSERR;
+}
+
+
 /**
  * Setup prepared statements.
  *
diff --git a/src/mint/mint_db.h b/src/mint/mint_db.h
index a32cbd773..b6bc46e3e 100644
--- a/src/mint/mint_db.h
+++ b/src/mint/mint_db.h
@@ -42,12 +42,32 @@ TALER_MINT_DB_init (const char *connection_cfg);
  * Get the thread-local database-handle.
  * Connect to the db if the connection does not exist yet.
  *
+ * @param temporary #GNUNET_YES to use a temporary schema; #GNUNET_NO to use the
+ *        database default one
  * @param the database connection, or NULL on error
  */
 PGconn *
-TALER_MINT_DB_get_connection (void);
+TALER_MINT_DB_get_connection (int temporary);
 
 
+/**
+ * Drop the temporary taler schema.  This is only useful for testcases
+ *
+ * @return #GNUNET_OK upon success; #GNUNET_SYSERR upon failure
+ */
+int
+TALER_MINT_DB_drop_temporary (PGconn *db);
+
+
+/**
+ * Create the necessary tables if they are not present
+ *
+ * @param temporary should we use a temporary schema
+ * @return #GNUNET_OK upon success; #GNUNET_SYSERR upon failure
+ */
+int
+TALER_MINT_DB_create_tables (int temporary);
+
 /**
  * Setup prepared statements.  FIXME: should this be part of the API,
  * or just internal to "TALER_MINT_DB_get_connection()"?
diff --git a/src/mint/taler-mint-dbinit.c b/src/mint/taler-mint-dbinit.c
index 7611802ea..c5b0ae4c3 100644
--- a/src/mint/taler-mint-dbinit.c
+++ b/src/mint/taler-mint-dbinit.c
@@ -36,192 +36,7 @@ static PGconn *db_conn;
 static char *TALER_MINT_db_connection_cfg_str;
 
 
-static int
-TALER_MINT_init_withdraw_tables (PGconn *conn)
-{
-  PGresult *result;
-  result = PQexec (conn,
-                   "CREATE TABLE IF NOT EXISTS reserves"
-                   "("
-                   " reserve_pub BYTEA PRIMARY KEY"
-                   ",balance_value INT4 NOT NULL"
-                   ",balance_fraction INT4 NOT NULL"
-                   ",balance_currency VARCHAR(4) NOT NULL"
-                   ",status_sig BYTEA"
-                   ",status_sign_pub BYTEA"
-                   ",expiration_date INT8 NOT NULL"
-                   ")");
-  if (PGRES_COMMAND_OK != PQresultStatus(result))
-  {
-    break_db_err (result);
-    return GNUNET_SYSERR;
-  }
-  PQclear (result);
 
-  result = PQexec (conn,
-                   "CREATE TABLE IF NOT EXISTS collectable_blindcoins"
-                   "("
-                   "blind_ev BYTEA PRIMARY KEY"
-                   ",blind_ev_sig BYTEA NOT NULL"
-                   ",denom_pub BYTEA NOT NULL"
-                   ",reserve_sig BYTEA NOT NULL"
-                   ",reserve_pub BYTEA NOT NULL REFERENCES reserves (reserve_pub)"
-                   ")");
-  if (PGRES_COMMAND_OK != PQresultStatus(result))
-  {
-    break_db_err (result);
-    return GNUNET_SYSERR;
-  }
-  PQclear (result);
-
-  result = PQexec (conn,
-                   "CREATE TABLE IF NOT EXISTS known_coins "
-                   "("
-                   " coin_pub BYTEA NOT NULL PRIMARY KEY"
-                   ",denom_pub BYTEA NOT NULL"
-                   ",denom_sig BYTEA NOT NULL"
-                   ",expended_value INT4 NOT NULL"
-                   ",expended_fraction INT4 NOT NULL"
-                   ",expended_currency VARCHAR(4) NOT NULL"
-                   ",refresh_session_pub BYTEA"
-                   ")");
-  if (PGRES_COMMAND_OK != PQresultStatus(result))
-  {
-    break_db_err (result);
-    return GNUNET_SYSERR;
-  }
-  PQclear (result);
-
-  result = PQexec (conn,
-                   "CREATE TABLE IF NOT EXISTS refresh_sessions "
-                   "("
-                   " session_pub BYTEA PRIMARY KEY CHECK (length(session_pub) = 32)"
-                   ",session_melt_sig BYTEA"
-                   ",session_commit_sig BYTEA"
-                   ",noreveal_index INT2 NOT NULL"
-                   // non-zero if all reveals were ok
-                   // and the new coin signatures are ready
-                   ",reveal_ok BOOLEAN NOT NULL DEFAULT false"
-                   ") ");
-  if (PGRES_COMMAND_OK != PQresultStatus(result))
-  {
-    break_db_err (result);
-    return GNUNET_SYSERR;
-  }
-  PQclear (result);
-
-  result = PQexec (conn,
-                   "CREATE TABLE IF NOT EXISTS refresh_order "
-                   "( "
-                   " session_pub BYTEA NOT NULL REFERENCES refresh_sessions (session_pub)"
-                   ",newcoin_index INT2 NOT NULL "
-                   ",denom_pub BYTEA NOT NULL "
-                   ",PRIMARY KEY (session_pub, newcoin_index)"
-                   ") ");
-
-  if (PGRES_COMMAND_OK != PQresultStatus(result))
-  {
-    break_db_err (result);
-    return GNUNET_SYSERR;
-  }
-  PQclear (result);
-
-
-  result = PQexec (conn,
-                   "CREATE TABLE IF NOT EXISTS refresh_commit_link"
-                   "("
-                   " session_pub BYTEA NOT NULL REFERENCES refresh_sessions (session_pub)"
-                   ",transfer_pub BYTEA NOT NULL"
-                   ",link_secret_enc BYTEA NOT NULL"
-                   // index of the old coin in the customer's request
-                   ",oldcoin_index INT2 NOT NULL"
-                   // index for cut and choose,
-                   // ranges from 0 to kappa-1
-                   ",cnc_index INT2 NOT NULL"
-                   ")");
-
-  if (PGRES_COMMAND_OK != PQresultStatus(result))
-  {
-    break_db_err (result);
-    return GNUNET_SYSERR;
-  }
-  PQclear (result);
-
-  result = PQexec (conn,
-                   "CREATE TABLE IF NOT EXISTS refresh_commit_coin"
-                   "("
-                   " session_pub BYTEA NOT NULL REFERENCES refresh_sessions (session_pub) "
-                   ",link_vector_enc BYTEA NOT NULL"
-                   // index of the new coin in the customer's request
-                   ",newcoin_index INT2 NOT NULL"
-                   // index for cut and choose,
-                   ",cnc_index INT2 NOT NULL"
-                   ",coin_ev BYTEA NOT NULL"
-                   ")");
-
-  if (PGRES_COMMAND_OK != PQresultStatus(result))
-  {
-    break_db_err (result);
-    return GNUNET_SYSERR;
-  }
-  PQclear (result);
-
-  result = PQexec (conn,
-                   "CREATE TABLE IF NOT EXISTS refresh_melt"
-                   "("
-                   " session_pub BYTEA NOT NULL REFERENCES refresh_sessions (session_pub) "
-                   ",coin_pub BYTEA NOT NULL REFERENCES known_coins (coin_pub) "
-                   ",denom_pub BYTEA NOT NULL "
-                   ",oldcoin_index INT2 NOT NULL"
-                   ")");
-
-  if (PGRES_COMMAND_OK != PQresultStatus(result))
-  {
-    break_db_err (result);
-    return GNUNET_SYSERR;
-  }
-  PQclear (result);
-
-  result = PQexec (conn,
-                   "CREATE TABLE IF NOT EXISTS refresh_collectable"
-                   "("
-                   " session_pub BYTEA NOT NULL REFERENCES refresh_sessions (session_pub) "
-                   ",ev_sig BYTEA NOT NULL"
-                   ",newcoin_index INT2 NOT NULL"
-                   ")");
-
-  if (PGRES_COMMAND_OK != PQresultStatus(result))
-  {
-    break_db_err (result);
-    return GNUNET_SYSERR;
-  }
-  PQclear (result);
-
-  result = PQexec (conn,
-                   "CREATE TABLE IF NOT EXISTS deposits "
-                   "( "
-                   " coin_pub BYTEA NOT NULL PRIMARY KEY CHECK (length(coin_pub)=32)"
-                   ",denom_pub BYTEA NOT NULL CHECK (length(denom_pub)=32)"
-                   ",transaction_id INT8 NOT NULL"
-                   ",amount_currency VARCHAR(4) NOT NULL"
-                   ",amount_value INT4 NOT NULL"
-                   ",amount_fraction INT4 NOT NULL"
-                   ",merchant_pub BYTEA NOT NULL"
-                   ",h_contract BYTEA NOT NULL CHECK (length(h_contract)=64)"
-                   ",h_wire BYTEA NOT NULL CHECK (length(h_wire)=64)"
-                   ",coin_sig BYTEA NOT NULL CHECK (length(coin_sig)=64)"
-                   ",wire TEXT NOT NULL"
-                   ")");
-
-  if (PGRES_COMMAND_OK != PQresultStatus(result))
-  {
-    break_db_err (result);
-    return GNUNET_SYSERR;
-  }
-  PQclear (result);
-
-  return GNUNET_OK;
-}
 
 
 /**
@@ -271,7 +86,7 @@ main (int argc, char *const *argv)
     return 1;
   }
 
-  if (GNUNET_OK != TALER_MINT_init_withdraw_tables (db_conn))
+  if (GNUNET_OK != TALER_MINT_DB_create_tables (db_conn))
   {
     fprintf (stderr, "Failed to initialize database.\n");
     return 1;
diff --git a/src/mint/taler-mint-httpd_db.c b/src/mint/taler-mint-httpd_db.c
index 19fcb1c12..d5613c0dc 100644
--- a/src/mint/taler-mint-httpd_db.c
+++ b/src/mint/taler-mint-httpd_db.c
@@ -85,7 +85,7 @@ TALER_MINT_db_execute_deposit (struct MHD_Connection *connection,
   struct TALER_MINT_DenomKeyIssuePriv *dki;
   int ret;
 
-  if (NULL == (db_conn = TALER_MINT_DB_get_connection ()))
+  if (NULL == (db_conn = TALER_MINT_DB_get_connection (GNUNET_NO)))
   {
     GNUNET_break (0);
     return TALER_MINT_reply_internal_db_error (connection);
@@ -203,7 +203,7 @@ TALER_MINT_db_execute_withdraw_status (struct MHD_Connection *connection,
   struct ReserveHistory *rh;
   int res;
 
-  if (NULL == (db_conn = TALER_MINT_DB_get_connection ()))
+  if (NULL == (db_conn = TALER_MINT_DB_get_connection (GNUNET_NO)))
   {
     GNUNET_break (0);
     return TALER_MINT_reply_internal_db_error (connection);
@@ -264,7 +264,7 @@ TALER_MINT_db_execute_withdraw_sign (struct MHD_Connection *connection,
                       blinded_msg_len,
                       &h_blind);
 
-  if (NULL == (db_conn = TALER_MINT_DB_get_connection ()))
+  if (NULL == (db_conn = TALER_MINT_DB_get_connection (GNUNET_NO)))
   {
     GNUNET_break (0);
     return TALER_MINT_reply_internal_db_error (connection);
@@ -521,7 +521,7 @@ TALER_MINT_db_execute_refresh_melt (struct MHD_Connection *connection,
   int res;
   unsigned int i;
 
-  if (NULL == (db_conn = TALER_MINT_DB_get_connection ()))
+  if (NULL == (db_conn = TALER_MINT_DB_get_connection (GNUNET_NO)))
   {
     GNUNET_break (0);
     return TALER_MINT_reply_internal_db_error (connection);
@@ -650,7 +650,7 @@ TALER_MINT_db_execute_refresh_commit (struct MHD_Connection *connection,
   unsigned int j;
   int res;
 
-  if (NULL == (db_conn = TALER_MINT_DB_get_connection ()))
+  if (NULL == (db_conn = TALER_MINT_DB_get_connection (GNUNET_NO)))
   {
     GNUNET_break (0);
     return TALER_MINT_reply_internal_db_error (connection);
@@ -1034,7 +1034,7 @@ TALER_MINT_db_execute_refresh_reveal (struct MHD_Connection *connection,
   unsigned int j;
   unsigned int off;
 
-  if (NULL == (db_conn = TALER_MINT_DB_get_connection ()))
+  if (NULL == (db_conn = TALER_MINT_DB_get_connection (GNUNET_NO)))
   {
     GNUNET_break (0);
     return TALER_MINT_reply_internal_db_error (connection);
@@ -1202,7 +1202,7 @@ TALER_MINT_db_execute_refresh_link (struct MHD_Connection *connection,
   struct TALER_EncryptedLinkSecret shared_secret_enc;
   struct LinkDataList *ldl;
 
-  if (NULL == (db_conn = TALER_MINT_DB_get_connection ()))
+  if (NULL == (db_conn = TALER_MINT_DB_get_connection (GNUNET_NO)))
   {
     GNUNET_break (0);
     return TALER_MINT_reply_internal_db_error (connection);