Implement customer error hooks.

If a Lua script defines the sysbench.hooks.sql_error_ignorable function,
sysbench calls it whenever an SQL error occurs and passes information
about connection, failed query, SQL error number, state and message as
arguments. If the function returns true, the error is ignored and the
entire event is restarted. Otherwise sysbench aborts scripts execution.

tests/include/api_sql_common.sh

@@ -109,10 +109,9 @@ function event()
   print('--')
 end
 EOF
-
+sysbench $SB_ARGS run
 
 # Failed connection handling
-sysbench $SB_ARGS run
 
 SB_ARGS="--verbosity=1 --test=$CRAMTMP/api_sql.lua --max-requests=1 --num-threads=1 $DB_DRIVER_ARGS"
 cat >$CRAMTMP/api_sql.lua <<EOF
@@ -122,9 +121,39 @@ function event()
   print(m)
 end
 EOF
-
 sysbench $SB_ARGS --mysql-host="non-existing" --pgsql-host="non-existing" run
 
+# Error hooks
+SB_ARGS="--verbosity=1 --test=$CRAMTMP/api_sql.lua --max-requests=1 --num-threads=1 $DB_DRIVER_ARGS"
+cat >$CRAMTMP/api_sql.lua <<EOF
+function sysbench.hooks.sql_error_ignorable(e)
+  print("Got an error descriptor:")
+  for k,v in pairs(e) do print("  " .. k .. " = ", v) end
+end
+
+function event()
+  local drv = sysbench.sql.driver()
+  local con = drv:connect()
+  local queries = {
+    "CREATE TABLE t(a CHAR(1) NOT NULL)",
+    "INSERT INTO t VALUES (1)",
+    "INSERT INTO t VALUES (NULL)",
+    [[INSERT INTO t VALUES ("test")]],
+    "DROP TABLE t",
+    "DROP TABLE t"
+  }
+  print('--')
+  con:query("DROP TABLE IF EXISTS t")
+  for i = 1, #queries do
+    local e, m = pcall(function () con:query(queries[i]) end)
+    if not e then print(m) end
+  end
+  print('--')
+end
+EOF
+sysbench $SB_ARGS run
+
+
 ########################################################################
 # Multiple connections test
 ########################################################################