WL#4903 Plugin Service API part I

(mysql-next-mr backport)

9 files changed, 197 insertions, 95 deletions

diff --git a/sql/CMakeLists.txt b/sql/CMakeLists.txt
index 3e350144f74..15c2d950ff9 100755
--- a/sql/CMakeLists.txt
+++ b/sql/CMakeLists.txt
@@ -45,7 +45,7 @@ SET (SQL_SOURCE
                discover.cc ../libmysql/errmsg.c field.cc  field_conv.cc 
                filesort.cc gstream.cc
                ha_partition.cc
-               handler.cc hash_filo.cc hash_filo.h 
+               handler.cc hash_filo.cc hash_filo.h sql_plugin_services.h
                hostname.cc init.cc item.cc item_buff.cc item_cmpfunc.cc 
                item_create.cc item_func.cc item_geofunc.cc item_row.cc 
                item_strfunc.cc item_subselect.cc item_sum.cc item_timefunc.cc 
diff --git a/sql/Makefile.am b/sql/Makefile.am
index 569bb70965e..5c3a1d3a8fe 100644
--- a/sql/Makefile.am
+++ b/sql/Makefile.am
@@ -82,7 +82,7 @@ mysqld_LDADD =		libndb.la \
 
 noinst_HEADERS =	item.h item_func.h item_sum.h item_cmpfunc.h \
 			item_strfunc.h item_timefunc.h \
-			item_xmlfunc.h \
+			item_xmlfunc.h sql_plugin_services.h \
 			item_create.h item_subselect.h item_row.h \
 			mysql_priv.h item_geofunc.h sql_bitmap.h \
 			procedure.h sql_class.h sql_lex.h sql_list.h \
diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 05a79957963..c9909298b63 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -28,6 +28,16 @@
 
 #ifndef MYSQL_CLIENT
 
+/*
+  the following #define adds server-only members to enum_mysql_show_type,
+  that is defined in mysql/plugin.h
+  it has to be before mysql/plugin.h is included.
+*/
+#define SHOW_always_last SHOW_KEY_CACHE_LONG, \
+            SHOW_KEY_CACHE_LONGLONG, SHOW_LONG_STATUS, SHOW_DOUBLE_STATUS, \
+            SHOW_HAVE, SHOW_MY_BOOL, SHOW_HA_ROWS, SHOW_SYS, \
+            SHOW_LONG_NOFLUSH, SHOW_LONGLONG_STATUS
+
 #include <my_global.h>
 #include <mysql_version.h>
 #include <mysql_embed.h>
diff --git a/sql/replication.h b/sql/replication.h
index 6b7be58a5b1..eea77ef9f8e 100644
--- a/sql/replication.h
+++ b/sql/replication.h
@@ -16,6 +16,8 @@
 #ifndef REPLICATION_H
 #define REPLICATION_H
 
+typedef struct st_mysql MYSQL;
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -483,6 +485,64 @@ const char* thd_enter_cond(MYSQL_THD thd, pthread_cond_t *cond,
 */
 void thd_exit_cond(MYSQL_THD thd, const char *old_msg);
 
+/**
+   Get the value of user variable as an integer.
+
+   This function will return the value of variable @a name as an
+   integer. If the original value of the variable is not an integer,
+   the value will be converted into an integer.
+
+   @param name     user variable name
+   @param value    pointer to return the value
+   @param null_value if not NULL, the function will set it to true if
+   the value of variable is null, set to false if not
+
+   @retval 0 Success
+   @retval 1 Variable not found
+*/
+int get_user_var_int(const char *name,
+                     long long int *value, int *null_value);
+
+/**
+   Get the value of user variable as a double precision float number.
+
+   This function will return the value of variable @a name as real
+   number. If the original value of the variable is not a real number,
+   the value will be converted into a real number.
+
+   @param name     user variable name
+   @param value    pointer to return the value
+   @param null_value if not NULL, the function will set it to true if
+   the value of variable is null, set to false if not
+
+   @retval 0 Success
+   @retval 1 Variable not found
+*/
+int get_user_var_real(const char *name,
+                      double *value, int *null_value);
+
+/**
+   Get the value of user variable as a string.
+
+   This function will return the value of variable @a name as
+   string. If the original value of the variable is not a string,
+   the value will be converted into a string.
+
+   @param name     user variable name
+   @param value    pointer to the value buffer
+   @param len      length of the value buffer
+   @param precision precision of the value if it is a float number
+   @param null_value if not NULL, the function will set it to true if
+   the value of variable is null, set to false if not
+
+   @retval 0 Success
+   @retval 1 Variable not found
+*/
+int get_user_var_str(const char *name,
+                     char *value, unsigned long len,
+                     unsigned int precision, int *null_value);
+
+  
 
 #ifdef __cplusplus
 }
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 757f6abb00b..1958bbe271c 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -272,12 +272,7 @@ const char* thd_enter_cond(MYSQL_THD thd, pthread_cond_t *cond,
   if (!thd)
     thd= current_thd;
 
-  const char* old_msg = thd->proc_info;
-  safe_mutex_assert_owner(mutex);
-  thd->mysys_var->current_mutex = mutex;
-  thd->mysys_var->current_cond = cond;
-  thd->proc_info = msg;
-  return old_msg;
+  return thd->enter_cond(cond, mutex, msg);
 }
 
 extern "C"
@@ -286,18 +281,7 @@ void thd_exit_cond(MYSQL_THD thd, const char *old_msg)
   if (!thd)
     thd= current_thd;
 
-  /*
-    Putting the mutex unlock in thd_exit_cond() ensures that
-    mysys_var->current_mutex is always unlocked _before_ mysys_var->mutex is
-    locked (if that would not be the case, you'll get a deadlock if someone
-    does a THD::awake() on you).
-  */
-  pthread_mutex_unlock(thd->mysys_var->current_mutex);
-  pthread_mutex_lock(&thd->mysys_var->mutex);
-  thd->mysys_var->current_mutex = 0;
-  thd->mysys_var->current_cond = 0;
-  thd->proc_info = old_msg;
-  pthread_mutex_unlock(&thd->mysys_var->mutex);
+  thd->exit_cond(old_msg);
   return;
 }
 
diff --git a/sql/sql_class.h b/sql/sql_class.h
index aaa959feae9..3f40195ba5b 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -25,7 +25,6 @@
 
 #include "log.h"
 #include "rpl_tblmap.h"
-#include "replication.h"
 
 /**
   An interface that is used to take an action when
@@ -1886,11 +1885,28 @@ public:
   inline const char* enter_cond(pthread_cond_t *cond, pthread_mutex_t* mutex,
 			  const char* msg)
   {
-    return thd_enter_cond(this, cond, mutex, msg);
+    const char* old_msg = proc_info;
+    safe_mutex_assert_owner(mutex);
+    mysys_var->current_mutex = mutex;
+    mysys_var->current_cond = cond;
+    proc_info = msg;
+    return old_msg;
   }
   inline void exit_cond(const char* old_msg)
   {
-    thd_exit_cond(this, old_msg);
+    /*
+      Putting the mutex unlock in thd->exit_cond() ensures that
+      mysys_var->current_mutex is always unlocked _before_ mysys_var->mutex is
+      locked (if that would not be the case, you'll get a deadlock if someone
+      does a THD::awake() on you).
+    */
+    pthread_mutex_unlock(mysys_var->current_mutex);
+    pthread_mutex_lock(&mysys_var->mutex);
+    mysys_var->current_mutex = 0;
+    mysys_var->current_cond = 0;
+    proc_info = old_msg;
+    pthread_mutex_unlock(&mysys_var->mutex);
+    return;
   }
   inline time_t query_start() { query_start_used=1; return start_time; }
   inline void set_time()
diff --git a/sql/sql_plugin.cc b/sql/sql_plugin.cc
index 1278eafce92..fb1da901f1b 100644
--- a/sql/sql_plugin.cc
+++ b/sql/sql_plugin.cc
@@ -1,4 +1,4 @@
-/* Copyright (C) 2005 MySQL AB
+/* Copyright (C) 2005 MySQL AB, 2009 Sun Microsystems, Inc.
 
    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
@@ -99,7 +99,9 @@ static int cur_plugin_info_interface_version[MYSQL_MAX_PLUGIN_TYPE_NUM]=
   MYSQL_REPLICATION_INTERFACE_VERSION,
 };
 
-static bool initialized= 0;
+/* support for Services */
+
+#include "sql_plugin_services.h"
 
 /*
   A mutex LOCK_plugin must be acquired before accessing the
@@ -113,6 +115,8 @@ static HASH plugin_hash[MYSQL_MAX_PLUGIN_TYPE_NUM];
 static bool reap_needed= false;
 static int plugin_array_version=0;
 
+static bool initialized= 0;
+
 /*
   write-lock on LOCK_system_variables_hash is required before modifying
   the following variables/structures
@@ -225,6 +229,22 @@ extern bool throw_bounds_warning(THD *thd, bool fixed, bool unsignd,
 extern bool check_if_table_exists(THD *thd, TABLE_LIST *table, bool *exists);
 #endif /* EMBEDDED_LIBRARY */
 
+static void report_error(int where_to, uint error, ...)
+{
+  va_list args;
+  if (where_to & REPORT_TO_USER)
+  {
+    va_start(args, error);
+    my_printv_error(error, ER(error), MYF(0), args);
+    va_end(args);
+  }
+  if (where_to & REPORT_TO_LOG)
+  {
+    va_start(args, error);
+    error_log_print(ERROR_LEVEL, ER(error), args);
+    va_end(args);
+  }
+}
 
 /****************************************************************************
   Value type thunks, allows the C world to play in the C++ world
@@ -345,7 +365,7 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
 {
 #ifdef HAVE_DLOPEN
   char dlpath[FN_REFLEN];
-  uint plugin_dir_len, dummy_errors, dlpathlen;
+  uint plugin_dir_len, dummy_errors, dlpathlen, i;
   struct st_plugin_dl *tmp, plugin_dl;
   void *sym;
   DBUG_ENTER("plugin_dl_add");
@@ -360,10 +380,7 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
                                system_charset_info, 1) ||
       plugin_dir_len + dl->length + 1 >= FN_REFLEN)
   {
-    if (report & REPORT_TO_USER)
-      my_error(ER_UDF_NO_PATHS, MYF(0));
-    if (report & REPORT_TO_LOG)
-      sql_print_error("%s", ER_DEFAULT(ER_UDF_NO_PATHS));
+    report_error(report, ER_UDF_NO_PATHS);
     DBUG_RETURN(0);
   }
   /* If this dll is already loaded just increase ref_count. */
@@ -388,21 +405,14 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
       if (*errmsg == ':') errmsg++;
       if (*errmsg == ' ') errmsg++;
     }
-    if (report & REPORT_TO_USER)
-      my_error(ER_CANT_OPEN_LIBRARY, MYF(0), dlpath, errno, errmsg);
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_CANT_OPEN_LIBRARY), dlpath, errno, errmsg);
+    report_error(report, ER_CANT_OPEN_LIBRARY, dlpath, errno, errmsg);
     DBUG_RETURN(0);
   }
   /* Determine interface version */
   if (!(sym= dlsym(plugin_dl.handle, plugin_interface_version_sym)))
   {
     free_plugin_mem(&plugin_dl);
-    if (report & REPORT_TO_USER)
-      my_error(ER_CANT_FIND_DL_ENTRY, MYF(0), plugin_interface_version_sym);
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_CANT_FIND_DL_ENTRY),
-                      plugin_interface_version_sym);
+    report_error(report, ER_CANT_FIND_DL_ENTRY, plugin_interface_version_sym);
     DBUG_RETURN(0);
   }
   plugin_dl.version= *(int *)sym;
@@ -411,29 +421,42 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
       (plugin_dl.version >> 8) > (MYSQL_PLUGIN_INTERFACE_VERSION >> 8))
   {
     free_plugin_mem(&plugin_dl);
-    if (report & REPORT_TO_USER)
-      my_error(ER_CANT_OPEN_LIBRARY, MYF(0), dlpath, 0,
-               "plugin interface version mismatch");
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_CANT_OPEN_LIBRARY), dlpath, 0,
-                      "plugin interface version mismatch");
+    report_error(report, ER_CANT_OPEN_LIBRARY, MYF(0), dlpath, 0,
+                 "plugin interface version mismatch");
     DBUG_RETURN(0);
   }
+
+  /* link the services in */
+  for (i= 0; i < array_elements(list_of_services); i++)
+  {
+    if ((sym= dlsym(plugin_dl.handle, list_of_services[i].name)))
+    {
+      uint ver= (uint)(intptr)*(void**)sym;
+      if (ver > list_of_services[i].version ||
+        (ver >> 8) < (list_of_services[i].version >> 8))
+      {
+        char buf[MYSQL_ERRMSG_SIZE];
+        my_snprintf(buf, sizeof(buf),
+                    "service '%s' interface version mismatch",
+                    list_of_services[i].name);
+        report_error(report, ER_CANT_OPEN_LIBRARY, dlpath, 0, buf);
+        DBUG_RETURN(0);
+      }
+      *(void**)sym= list_of_services[i].service;
+    }
+  }
+
   /* Find plugin declarations */
   if (!(sym= dlsym(plugin_dl.handle, plugin_declarations_sym)))
   {
     free_plugin_mem(&plugin_dl);
-    if (report & REPORT_TO_USER)
-      my_error(ER_CANT_FIND_DL_ENTRY, MYF(0), plugin_declarations_sym);
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_CANT_FIND_DL_ENTRY),
-                      plugin_declarations_sym);
+    report_error(report, ER_CANT_FIND_DL_ENTRY, MYF(0),
+                 plugin_declarations_sym);
     DBUG_RETURN(0);
   }
 
   if (plugin_dl.version != MYSQL_PLUGIN_INTERFACE_VERSION)
   {
-    int i;
     uint sizeof_st_plugin;
     struct st_mysql_plugin *old, *cur;
     char *ptr= (char *)sym;
@@ -443,11 +466,7 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
     else
     {
 #ifdef ERROR_ON_NO_SIZEOF_PLUGIN_SYMBOL
-      free_plugin_mem(&plugin_dl);
-      if (report & REPORT_TO_USER)
-        my_error(ER_CANT_FIND_DL_ENTRY, MYF(0), sizeof_st_plugin_sym);
-      if (report & REPORT_TO_LOG)
-        sql_print_error(ER_DEFAULT(ER_CANT_FIND_DL_ENTRY), sizeof_st_plugin_sym);
+      report_error(report, ER_CANT_FIND_DL_ENTRY, sizeof_st_plugin_sym);
       DBUG_RETURN(0);
 #else
       /*
@@ -469,10 +488,7 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
     if (!cur)
     {
       free_plugin_mem(&plugin_dl);
-      if (report & REPORT_TO_USER)
-        my_error(ER_OUTOFMEMORY, MYF(0), plugin_dl.dl.length);
-      if (report & REPORT_TO_LOG)
-        sql_print_error(ER_DEFAULT(ER_OUTOFMEMORY), plugin_dl.dl.length);
+      report_error(report, ER_OUTOFMEMORY, plugin_dl.dl.length);
       DBUG_RETURN(0);
     }
     /*
@@ -494,10 +510,7 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
   if (! (plugin_dl.dl.str= (char*) my_malloc(plugin_dl.dl.length, MYF(0))))
   {
     free_plugin_mem(&plugin_dl);
-    if (report & REPORT_TO_USER)
-      my_error(ER_OUTOFMEMORY, MYF(0), plugin_dl.dl.length);
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_OUTOFMEMORY), plugin_dl.dl.length);
+    report_error(report, ER_OUTOFMEMORY, plugin_dl.dl.length);
     DBUG_RETURN(0);
   }
   plugin_dl.dl.length= copy_and_convert(plugin_dl.dl.str, plugin_dl.dl.length,
@@ -508,19 +521,13 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
   if (! (tmp= plugin_dl_insert_or_reuse(&plugin_dl)))
   {
     free_plugin_mem(&plugin_dl);
-    if (report & REPORT_TO_USER)
-      my_error(ER_OUTOFMEMORY, MYF(0), sizeof(struct st_plugin_dl));
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_OUTOFMEMORY), sizeof(struct st_plugin_dl));
+    report_error(report, ER_OUTOFMEMORY, sizeof(struct st_plugin_dl));
     DBUG_RETURN(0);
   }
   DBUG_RETURN(tmp);
 #else
   DBUG_ENTER("plugin_dl_add");
-  if (report & REPORT_TO_USER)
-    my_error(ER_FEATURE_DISABLED, MYF(0), "plugin", "HAVE_DLOPEN");
-  if (report & REPORT_TO_LOG)
-    sql_print_error(ER_DEFAULT(ER_FEATURE_DISABLED), "plugin", "HAVE_DLOPEN");
+  report_error(report, ER_FEATURE_DISABLED, "plugin", "HAVE_DLOPEN");
   DBUG_RETURN(0);
 #endif
 }
@@ -636,7 +643,7 @@ static plugin_ref intern_plugin_lock(LEX *lex, plugin_ref rc CALLER_INFO_PROTO)
     /*
       For debugging, we do an additional malloc which allows the
       memory manager and/or valgrind to track locked references and
-      double unlocks to aid resolving reference counting.problems.
+      double unlocks to aid resolving reference counting problems.
     */
     if (!(plugin= (plugin_ref) my_malloc_ci(sizeof(pi), MYF(MY_WME))))
       DBUG_RETURN(NULL);
@@ -719,10 +726,7 @@ static bool plugin_add(MEM_ROOT *tmp_root,
   DBUG_ENTER("plugin_add");
   if (plugin_find_internal(name, MYSQL_ANY_PLUGIN))
   {
-    if (report & REPORT_TO_USER)
-      my_error(ER_UDF_EXISTS, MYF(0), name->str);
-    if (report & REPORT_TO_LOG)
-      sql_print_error(ER_DEFAULT(ER_UDF_EXISTS), name->str);
+    report_error(report, ER_UDF_EXISTS, name->str);
     DBUG_RETURN(TRUE);
   }
   /* Clear the whole struct to catch future extensions. */
@@ -749,10 +753,7 @@ static bool plugin_add(MEM_ROOT *tmp_root,
         strxnmov(buf, sizeof(buf) - 1, "API version for ",
                  plugin_type_names[plugin->type].str,
                  " plugin is too different", NullS);
-        if (report & REPORT_TO_USER)
-          my_error(ER_CANT_OPEN_LIBRARY, MYF(0), dl->str, 0, buf);
-        if (report & REPORT_TO_LOG)
-          sql_print_error(ER_DEFAULT(ER_CANT_OPEN_LIBRARY), dl->str, 0, buf);
+        report_error(report, ER_CANT_OPEN_LIBRARY, dl->str, 0, buf);
         goto err;
       }
       tmp.plugin= plugin;
@@ -781,10 +782,7 @@ static bool plugin_add(MEM_ROOT *tmp_root,
       DBUG_RETURN(FALSE);
     }
   }
-  if (report & REPORT_TO_USER)
-    my_error(ER_CANT_FIND_DL_ENTRY, MYF(0), name->str);
-  if (report & REPORT_TO_LOG)
-    sql_print_error(ER_DEFAULT(ER_CANT_FIND_DL_ENTRY), name->str);
+  report_error(report, ER_CANT_FIND_DL_ENTRY, name->str);
 err:
   plugin_dl_del(dl);
   DBUG_RETURN(TRUE);
diff --git a/sql/sql_plugin.h b/sql/sql_plugin.h
index c6ad846943c..23ce85c994b 100644
--- a/sql/sql_plugin.h
+++ b/sql/sql_plugin.h
@@ -35,16 +35,6 @@ class sys_var;
 
 #define INITIAL_LEX_PLUGIN_LIST_SIZE    16
 
-/*
-  the following #define adds server-only members to enum_mysql_show_type,
-  that is defined in plugin.h
-*/
-#define SHOW_FUNC    SHOW_FUNC, SHOW_KEY_CACHE_LONG, SHOW_KEY_CACHE_LONGLONG, \
-                     SHOW_LONG_STATUS, SHOW_DOUBLE_STATUS, SHOW_HAVE,   \
-                     SHOW_MY_BOOL, SHOW_HA_ROWS, SHOW_SYS, SHOW_LONG_NOFLUSH, \
-                     SHOW_LONGLONG_STATUS
-#include <mysql/plugin.h>
-#undef SHOW_FUNC
 typedef enum enum_mysql_show_type SHOW_TYPE;
 typedef struct st_mysql_show_var SHOW_VAR;
 
diff --git a/sql/sql_plugin_services.h b/sql/sql_plugin_services.h
new file mode 100644
index 00000000000..7491ddab79d
--- /dev/null
+++ b/sql/sql_plugin_services.h
@@ -0,0 +1,44 @@
+/* Copyright (C) 2009 Sun Microsystems, Inc.
+
+   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 */
+
+/* support for Services */
+#include <service_versions.h>
+
+struct st_service_ref {
+  const char *name;
+  uint version;
+  void *service;
+};
+
+static struct my_snprintf_service_st my_snprintf_handler = {
+  my_snprintf,
+  my_vsnprintf
+};
+
+static struct thd_alloc_service_st thd_alloc_handler= {
+  thd_alloc,
+  thd_calloc,
+  thd_strdup,
+  thd_strmake,
+  thd_memdup,
+  thd_make_lex_string
+};
+
+static struct st_service_ref list_of_services[]=
+{
+  { "my_snprintf_service", VERSION_my_snprintf, &my_snprintf_handler },
+  { "thd_alloc_service",   VERSION_thd_alloc,   &thd_alloc_handler }
+};
+