MDEV-6247: Merge 10.0-galera to 10.1.

Merged lp:maria/maria-10.0-galera up to revision 3879.

Added a new functions to handler API to forcefully abort_transaction,
producing fake_trx_id, get_checkpoint and set_checkpoint for XA. These
were added for future possiblity to add more storage engines that
could use galera replication.

1 files changed, 602 insertions, 0 deletions

diff --git a/sql/wsrep_var.cc b/sql/wsrep_var.cc
new file mode 100644
index 00000000000..2272945535d
--- /dev/null
+++ b/sql/wsrep_var.cc
@@ -0,0 +1,602 @@
+/* Copyright 2008 Codership Oy <http://www.codership.com>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#include "wsrep_var.h"
+
+#include <mysqld.h>
+#include <sql_class.h>
+#include <sql_plugin.h>
+#include <set_var.h>
+#include <sql_acl.h>
+#include "wsrep_priv.h"
+#include "wsrep_thd.h"
+#include <my_dir.h>
+#include <cstdio>
+#include <cstdlib>
+
+const  char* wsrep_provider         = 0;
+const  char* wsrep_provider_options = 0;
+const  char* wsrep_cluster_address  = 0;
+const  char* wsrep_cluster_name     = 0;
+const  char* wsrep_node_name        = 0;
+const  char* wsrep_node_address     = 0;
+const  char* wsrep_node_incoming_address = 0;
+const  char* wsrep_start_position   = 0;
+ulong  wsrep_OSU_method_options;
+
+int wsrep_init_vars()
+{
+  wsrep_provider        = my_strdup(WSREP_NONE, MYF(MY_WME));
+  wsrep_provider_options= my_strdup("", MYF(MY_WME));
+  wsrep_cluster_address = my_strdup("", MYF(MY_WME));
+  wsrep_cluster_name    = my_strdup(WSREP_CLUSTER_NAME, MYF(MY_WME));
+  wsrep_node_name       = my_strdup("", MYF(MY_WME));
+  wsrep_node_address    = my_strdup("", MYF(MY_WME));
+  wsrep_node_incoming_address= my_strdup(WSREP_NODE_INCOMING_AUTO, MYF(MY_WME));
+  wsrep_start_position  = my_strdup(WSREP_START_POSITION_ZERO, MYF(MY_WME));
+
+  global_system_variables.binlog_format=BINLOG_FORMAT_ROW;
+  return 0;
+}
+
+bool wsrep_on_update (sys_var *self, THD* thd, enum_var_type var_type)
+{
+  if (var_type == OPT_GLOBAL) {
+    // FIXME: this variable probably should be changed only per session
+    thd->variables.wsrep_on = global_system_variables.wsrep_on;
+  }
+  return false;
+}
+
+bool wsrep_causal_reads_update (sys_var *self, THD* thd, enum_var_type var_type)
+{
+  // global setting should not affect session setting.
+  // if (var_type == OPT_GLOBAL) {
+  //   thd->variables.wsrep_causal_reads = global_system_variables.wsrep_causal_reads;
+  // }
+  if (thd->variables.wsrep_causal_reads) {
+    thd->variables.wsrep_sync_wait |= WSREP_SYNC_WAIT_BEFORE_READ;
+  } else {
+    thd->variables.wsrep_sync_wait &= ~WSREP_SYNC_WAIT_BEFORE_READ;
+  }
+  return false;
+}
+
+bool wsrep_sync_wait_update (sys_var* self, THD* thd, enum_var_type var_type)
+{
+  // global setting should not affect session setting.
+  // if (var_type == OPT_GLOBAL) {
+  //   thd->variables.wsrep_sync_wait = global_system_variables.wsrep_sync_wait;
+  // }
+  thd->variables.wsrep_causal_reads = thd->variables.wsrep_sync_wait &
+          WSREP_SYNC_WAIT_BEFORE_READ;
+  return false;
+}
+
+static int wsrep_start_position_verify (const char* start_str)
+{
+  size_t        start_len;
+  wsrep_uuid_t  uuid;
+  ssize_t       uuid_len;
+
+  start_len = strlen (start_str);
+  if (start_len < 34)
+    return 1;
+
+  uuid_len = wsrep_uuid_scan (start_str, start_len, &uuid);
+  if (uuid_len < 0 || (start_len - uuid_len) < 2)
+    return 1;
+
+  if (start_str[uuid_len] != ':') // separator should follow UUID
+    return 1;
+
+  char* endptr;
+  wsrep_seqno_t const seqno __attribute__((unused)) // to avoid GCC warnings
+    (strtoll(&start_str[uuid_len + 1], &endptr, 10));
+
+  if (*endptr == '\0') return 0; // remaining string was seqno
+
+  return 1;
+}
+
+bool wsrep_start_position_check (sys_var *self, THD* thd, set_var* var)
+{
+  char start_pos_buf[FN_REFLEN];
+
+  if ((! var->save_result.string_value.str) ||
+      (var->save_result.string_value.length > (FN_REFLEN - 1))) // safety
+    goto err;
+
+  memcpy(start_pos_buf, var->save_result.string_value.str,
+         var->save_result.string_value.length);
+  start_pos_buf[var->save_result.string_value.length]= 0;
+
+  if (!wsrep_start_position_verify(start_pos_buf)) return 0;
+
+err:
+  my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), var->var->name.str,
+           var->save_result.string_value.str ?
+           var->save_result.string_value.str : "NULL");
+  return 1;
+}
+
+void wsrep_set_local_position (const char* value)
+{
+  size_t value_len  = strlen (value);
+  size_t uuid_len   = wsrep_uuid_scan (value, value_len, &local_uuid);
+
+  local_seqno = strtoll (value + uuid_len + 1, NULL, 10);
+
+  XID xid;
+  wsrep_xid_init(&xid, &local_uuid, local_seqno);
+  wsrep_set_SE_checkpoint(&xid);
+  WSREP_INFO ("wsrep_start_position var submitted: '%s'", wsrep_start_position);
+}
+
+bool wsrep_start_position_update (sys_var *self, THD* thd, enum_var_type type)
+{
+  // since this value passed wsrep_start_position_check, don't check anything
+  // here
+  wsrep_set_local_position (wsrep_start_position);
+
+  if (wsrep) {
+    wsrep_sst_received (wsrep, &local_uuid, local_seqno, NULL, 0);
+  }
+
+  return 0;
+}
+
+void wsrep_start_position_init (const char* val)
+{
+  if (NULL == val || wsrep_start_position_verify (val))
+  {
+    WSREP_ERROR("Bad initial value for wsrep_start_position: %s", 
+                (val ? val : ""));
+    return;
+  }
+
+  wsrep_set_local_position (val);
+}
+
+static bool refresh_provider_options()
+{
+  WSREP_DEBUG("refresh_provider_options: %s", 
+              (wsrep_provider_options) ? wsrep_provider_options : "null");
+  char* opts= wsrep->options_get(wsrep);
+  if (opts)
+  {
+    if (wsrep_provider_options) my_free((void *)wsrep_provider_options);
+    wsrep_provider_options = (char*)my_memdup(opts, strlen(opts) + 1, 
+                                              MYF(MY_WME));
+  }
+  else
+  {
+    WSREP_ERROR("Failed to get provider options");
+    return true;
+  }
+  return false;
+}
+
+static int wsrep_provider_verify (const char* provider_str)
+{
+  MY_STAT   f_stat;
+  char path[FN_REFLEN];
+
+  if (!provider_str || strlen(provider_str)== 0)
+    return 1;
+
+  if (!strcmp(provider_str, WSREP_NONE))
+    return 0;
+
+  if (!unpack_filename(path, provider_str))
+    return 1;
+
+  /* check that provider file exists */
+  bzero(&f_stat, sizeof(MY_STAT));
+  if (!my_stat(path, &f_stat, MYF(0)))
+  {
+    return 1;
+  }
+  return 0;
+}
+
+bool wsrep_provider_check (sys_var *self, THD* thd, set_var* var)
+{
+  char wsrep_provider_buf[FN_REFLEN];
+
+  if ((! var->save_result.string_value.str) ||
+      (var->save_result.string_value.length > (FN_REFLEN - 1))) // safety
+    goto err;
+
+  memcpy(wsrep_provider_buf, var->save_result.string_value.str,
+         var->save_result.string_value.length);
+  wsrep_provider_buf[var->save_result.string_value.length]= 0;
+
+  if (!wsrep_provider_verify(wsrep_provider_buf)) return 0;
+
+err:
+  my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), var->var->name.str,
+           var->save_result.string_value.str ?
+           var->save_result.string_value.str : "NULL");
+  return 1;
+}
+
+bool wsrep_provider_update (sys_var *self, THD* thd, enum_var_type type)
+{
+  bool rcode= false;
+
+  bool wsrep_on_saved= thd->variables.wsrep_on;
+  thd->variables.wsrep_on= false;
+
+  WSREP_DEBUG("wsrep_provider_update: %s", wsrep_provider);
+
+  /* stop replication is heavy operation, and includes closing all client 
+     connections. Closing clients may need to get LOCK_global_system_variables
+     at least in MariaDB.
+
+     Note: releasing LOCK_global_system_variables may cause race condition, if 
+     there can be several concurrent clients changing wsrep_provider
+  */
+  mysql_mutex_unlock(&LOCK_global_system_variables);
+  wsrep_stop_replication(thd);
+  mysql_mutex_lock(&LOCK_global_system_variables);
+
+  if (wsrep_inited == 1)
+    wsrep_deinit(false);
+
+  char* tmp= strdup(wsrep_provider); // wsrep_init() rewrites provider 
+                                     //when fails
+  if (wsrep_init())
+  {
+    my_error(ER_CANT_OPEN_LIBRARY, MYF(0), tmp);
+    rcode = true;
+  }
+  free(tmp);
+
+  // we sure don't want to use old address with new provider
+  wsrep_cluster_address_init(NULL);
+  wsrep_provider_options_init(NULL);
+
+  thd->variables.wsrep_on= wsrep_on_saved;
+
+  refresh_provider_options();
+
+  return rcode;
+}
+
+void wsrep_provider_init (const char* value)
+{
+  WSREP_DEBUG("wsrep_provider_init: %s -> %s", 
+              (wsrep_provider) ? wsrep_provider : "null", 
+              (value) ? value : "null");
+  if (NULL == value || wsrep_provider_verify (value))
+  {
+    WSREP_ERROR("Bad initial value for wsrep_provider: %s",
+                (value ? value : ""));
+    return;
+  }
+
+  if (wsrep_provider) my_free((void *)wsrep_provider);
+  wsrep_provider = my_strdup(value, MYF(0));
+}
+
+bool wsrep_provider_options_check(sys_var *self, THD* thd, set_var* var)
+{
+  return 0;
+}
+
+bool wsrep_provider_options_update(sys_var *self, THD* thd, enum_var_type type)
+{
+  wsrep_status_t ret= wsrep->options_set(wsrep, wsrep_provider_options);
+  if (ret != WSREP_OK)
+  {
+    WSREP_ERROR("Set options returned %d", ret);
+    refresh_provider_options();
+    return true;
+  }
+  return refresh_provider_options();
+}
+
+void wsrep_provider_options_init(const char* value)
+{
+  if (wsrep_provider_options && wsrep_provider_options != value) 
+    my_free((void *)wsrep_provider_options);
+  wsrep_provider_options = (value) ? my_strdup(value, MYF(0)) : NULL;
+}
+
+static int wsrep_cluster_address_verify (const char* cluster_address_str)
+{
+  /* There is no predefined address format, it depends on provider. */
+  return 0;
+}
+
+bool wsrep_cluster_address_check (sys_var *self, THD* thd, set_var* var)
+{
+  char addr_buf[FN_REFLEN];
+
+  if ((! var->save_result.string_value.str) ||
+      (var->save_result.string_value.length > (FN_REFLEN - 1))) // safety
+    goto err;
+
+  memcpy(addr_buf, var->save_result.string_value.str,
+         var->save_result.string_value.length);
+  addr_buf[var->save_result.string_value.length]= 0;
+
+  if (!wsrep_cluster_address_verify(addr_buf)) return 0;
+
+ err:
+  my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), var->var->name.str,
+           var->save_result.string_value.str ?
+           var->save_result.string_value.str : "NULL");
+  return 1;
+}
+
+bool wsrep_cluster_address_update (sys_var *self, THD* thd, enum_var_type type)
+{
+  bool wsrep_on_saved= thd->variables.wsrep_on;
+  thd->variables.wsrep_on= false;
+
+  /* stop replication is heavy operation, and includes closing all client 
+     connections. Closing clients may need to get LOCK_global_system_variables
+     at least in MariaDB.
+
+     Note: releasing LOCK_global_system_variables may cause race condition, if 
+     there can be several concurrent clients changing wsrep_provider
+  */
+  mysql_mutex_unlock(&LOCK_global_system_variables);
+  wsrep_stop_replication(thd);
+  mysql_mutex_lock(&LOCK_global_system_variables);
+
+  if (wsrep_start_replication())
+  {
+    wsrep_create_rollbacker();
+    wsrep_create_appliers(wsrep_slave_threads);
+  }
+
+  thd->variables.wsrep_on= wsrep_on_saved;
+
+  return false;
+}
+
+void wsrep_cluster_address_init (const char* value)
+{
+  WSREP_DEBUG("wsrep_cluster_address_init: %s -> %s", 
+              (wsrep_cluster_address) ? wsrep_cluster_address : "null", 
+              (value) ? value : "null");
+
+  if (wsrep_cluster_address) my_free ((void*)wsrep_cluster_address);
+  wsrep_cluster_address = (value) ? my_strdup(value, MYF(0)) : NULL;
+}
+
+/* wsrep_cluster_name cannot be NULL or an empty string. */
+bool wsrep_cluster_name_check (sys_var *self, THD* thd, set_var* var)
+{
+  if (!var->save_result.string_value.str ||
+      (var->save_result.string_value.length == 0))
+  {
+    my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), var->var->name.str,
+             (var->save_result.string_value.str ?
+              var->save_result.string_value.str : "NULL"));
+    return 1;
+  }
+  return 0;
+}
+
+bool wsrep_cluster_name_update (sys_var *self, THD* thd, enum_var_type type)
+{
+  return 0;
+}
+
+bool wsrep_node_name_check (sys_var *self, THD* thd, set_var* var)
+{
+  // TODO: for now 'allow' 0-length string to be valid (default)
+  if (!var->save_result.string_value.str)
+  {
+    my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), var->var->name.str,
+             (var->save_result.string_value.str ?
+              var->save_result.string_value.str : "NULL"));
+    return 1;
+  }
+  return 0;
+}
+
+bool wsrep_node_name_update (sys_var *self, THD* thd, enum_var_type type)
+{
+  return 0;
+}
+
+// TODO: do something more elaborate, like checking connectivity
+bool wsrep_node_address_check (sys_var *self, THD* thd, set_var* var)
+{
+  char addr_buf[FN_REFLEN];
+
+  if ((! var->save_result.string_value.str) ||
+      (var->save_result.string_value.length > (FN_REFLEN - 1))) // safety
+    goto err;
+
+  memcpy(addr_buf, var->save_result.string_value.str,
+         var->save_result.string_value.length);
+  addr_buf[var->save_result.string_value.length]= 0;
+
+  // TODO: for now 'allow' 0-length string to be valid (default)
+  return 0;
+
+err:
+  my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), var->var->name.str,
+           var->save_result.string_value.str ?
+           var->save_result.string_value.str : "NULL");
+  return 1;
+}
+
+bool wsrep_node_address_update (sys_var *self, THD* thd, enum_var_type type)
+{
+  return 0;
+}
+
+void wsrep_node_address_init (const char* value)
+{
+  if (wsrep_node_address && strcmp(wsrep_node_address, value))
+    my_free ((void*)wsrep_node_address);
+
+  wsrep_node_address = (value) ? my_strdup(value, MYF(0)) : NULL;
+}
+
+bool wsrep_slave_threads_check (sys_var *self, THD* thd, set_var* var)
+{
+  mysql_mutex_lock(&LOCK_wsrep_slave_threads);
+  wsrep_slave_count_change += (var->save_result.ulonglong_value -
+                               wsrep_slave_threads);
+  mysql_mutex_unlock(&LOCK_wsrep_slave_threads);
+
+  return 0;
+}
+
+bool wsrep_slave_threads_update (sys_var *self, THD* thd, enum_var_type type)
+{
+  if (wsrep_slave_count_change > 0)
+  {
+    wsrep_create_appliers(wsrep_slave_count_change);
+    wsrep_slave_count_change = 0;
+  }
+  return false;
+}
+
+bool wsrep_desync_check (sys_var *self, THD* thd, set_var* var)
+{
+  bool new_wsrep_desync= (bool) var->save_result.ulonglong_value;
+  if (wsrep_desync == new_wsrep_desync) {
+    if (new_wsrep_desync) {
+      push_warning (thd, Sql_condition::WARN_LEVEL_WARN,
+                   ER_WRONG_VALUE_FOR_VAR,
+                   "'wsrep_desync' is already ON.");
+    } else {
+      push_warning (thd, Sql_condition::WARN_LEVEL_WARN,
+                   ER_WRONG_VALUE_FOR_VAR,
+                   "'wsrep_desync' is already OFF.");
+    }
+  }
+  return 0;
+}
+
+bool wsrep_desync_update (sys_var *self, THD* thd, enum_var_type type)
+{
+  wsrep_status_t ret(WSREP_WARNING);
+  if (wsrep_desync) {
+    ret = wsrep->desync (wsrep);
+    if (ret != WSREP_OK) {
+      WSREP_WARN ("SET desync failed %d for %s", ret, thd->query());
+      my_error (ER_CANNOT_USER, MYF(0), "'desync'", thd->query());
+      return true;
+    }
+  } else {
+    ret = wsrep->resync (wsrep);
+    if (ret != WSREP_OK) {
+      WSREP_WARN ("SET resync failed %d for %s", ret, thd->query());
+      my_error (ER_CANNOT_USER, MYF(0), "'resync'", thd->query());
+      return true;
+    }
+  }
+  return false;
+}
+
+/*
+ * Status variables stuff below
+ */
+static inline void
+wsrep_assign_to_mysql (SHOW_VAR* mysql, wsrep_stats_var* wsrep)
+{
+  mysql->name = wsrep->name;
+  switch (wsrep->type) {
+  case WSREP_VAR_INT64:
+    mysql->value = (char*) &wsrep->value._int64;
+    mysql->type  = SHOW_LONGLONG;
+    break;
+  case WSREP_VAR_STRING:
+    mysql->value = (char*) &wsrep->value._string;
+    mysql->type  = SHOW_CHAR_PTR;
+    break;
+  case WSREP_VAR_DOUBLE:
+    mysql->value = (char*) &wsrep->value._double;
+    mysql->type  = SHOW_DOUBLE;
+    break;
+  }
+}
+
+#if DYNAMIC
+// somehow this mysql status thing works only with statically allocated arrays.
+static SHOW_VAR*          mysql_status_vars = NULL;
+static int                mysql_status_len  = -1;
+#else
+static SHOW_VAR           mysql_status_vars[512 + 1];
+static const int          mysql_status_len  = 512;
+#endif
+
+static void export_wsrep_status_to_mysql(THD* thd)
+{
+  int wsrep_status_len, i;
+
+  thd->wsrep_status_vars = wsrep->stats_get(wsrep);
+
+  if (!thd->wsrep_status_vars) {
+    return;
+  }
+
+  for (wsrep_status_len = 0;
+       thd->wsrep_status_vars[wsrep_status_len].name != NULL;
+       wsrep_status_len++);
+
+#if DYNAMIC
+  if (wsrep_status_len != mysql_status_len) {
+    void* tmp = realloc (mysql_status_vars,
+                         (wsrep_status_len + 1) * sizeof(SHOW_VAR));
+    if (!tmp) {
+
+      sql_print_error ("Out of memory for wsrep status variables."
+                       "Number of variables: %d", wsrep_status_len);
+      return;
+    }
+
+    mysql_status_len  = wsrep_status_len;
+    mysql_status_vars = (SHOW_VAR*)tmp;
+  }
+  /* @TODO: fix this: */
+#else
+  if (mysql_status_len < wsrep_status_len) wsrep_status_len= mysql_status_len;
+#endif
+
+  for (i = 0; i < wsrep_status_len; i++)
+    wsrep_assign_to_mysql (mysql_status_vars + i, thd->wsrep_status_vars + i);
+
+  mysql_status_vars[wsrep_status_len].name  = NullS;
+  mysql_status_vars[wsrep_status_len].value = NullS;
+  mysql_status_vars[wsrep_status_len].type  = SHOW_LONG;
+}
+
+int wsrep_show_status (THD *thd, SHOW_VAR *var, char *buff)
+{
+  export_wsrep_status_to_mysql(thd);
+  var->type= SHOW_ARRAY;
+  var->value= (char *) &mysql_status_vars;
+  return 0;
+}
+
+void wsrep_free_status (THD* thd)
+{
+  if (thd->wsrep_status_vars)
+  {
+    wsrep->stats_free (wsrep, thd->wsrep_status_vars);
+    thd->wsrep_status_vars = 0;
+  }
+}