bzr commit into mysql-5.1-bugteam branch (joro:3237) Bug#49141

[Georgi Kodinov]

#At file:///home/kgeorge/mysql/work/B49141-5.1-bugteam/ based on revid:satya.bn@stripped

 3237 Georgi Kodinov	2009-12-02
      Bug #49141: Encode function is significantly slower in 5.1 compared to 5.0
      
      The fix for bug 22684 moved all the calculations to run time.
      For some special cases (e.g. a constant password) it's greatly beneficial
      to initialize the random structures at compile time and only calculate
      the outcome of the operation at run time.
      Implemented such caching of the random structures initialization.
      Fixed both ENCODE() and DECODE() functions.

    modified:
      sql/item_strfunc.cc
      sql/item_strfunc.h
      sql/sql_crypt.cc
      sql/sql_crypt.h
=== modified file 'sql/item_strfunc.cc'
--- a/sql/item_strfunc.cc	2009-11-18 14:50:31 +0000
+++ b/sql/item_strfunc.cc	2009-12-02 15:08:44 +0000
@@ -1722,16 +1722,27 @@ String *Item_func_encrypt::val_str(Strin
 
 void Item_func_encode::fix_length_and_dec()
 {
+  Item *password_item= args[1];
+
   max_length=args[0]->max_length;
   maybe_null=args[0]->maybe_null || args[1]->maybe_null;
   collation.set(&my_charset_bin);
+
+  if (password_item->const_item() && password_item->result_type() == STRING_RESULT)
+  {
+    char pw_buff[80];
+    String tmp_pw_value(pw_buff, sizeof(pw_buff), system_charset_info);
+    String *str, *res;
+
+    if (!(str= password_item->val_str(&tmp_pw_value)))
+      return;
+    sql_crypt.crypt_password_hash (str->ptr(), str->length());
+  }
 }
 
 String *Item_func_encode::val_str(String *str)
 {
   String *res;
-  char pw_buff[80];
-  String tmp_pw_value(pw_buff, sizeof(pw_buff), system_charset_info);
   String *password;
   DBUG_ASSERT(fixed == 1);
 
@@ -1741,45 +1752,33 @@ String *Item_func_encode::val_str(String
     return 0; /* purecov: inspected */
   }
 
-  if (!(password=args[1]->val_str(& tmp_pw_value)))
+  if (!sql_crypt.is_initialized())
   {
-    null_value=1;
-    return 0;
+    char pw_buff[80];
+    String tmp_pw_value(pw_buff, sizeof(pw_buff), system_charset_info);
+    if (!(password=args[1]->val_str(& tmp_pw_value)))
+    {
+      null_value=1;
+      return 0;
+    }
+    sql_crypt.crypt_password_hash (password->ptr(), password->length());
   }
 
   null_value=0;
   res=copy_if_not_alloced(str,res,res->length());
-  SQL_CRYPT sql_crypt(password->ptr(), password->length());
   sql_crypt.init();
+  return calculate(res);
+}
+
+String *Item_func_encode::calculate(String *res)
+{
   sql_crypt.encode((char*) res->ptr(),res->length());
   res->set_charset(&my_charset_bin);
   return res;
 }
 
-String *Item_func_decode::val_str(String *str)
+String *Item_func_decode::calculate(String *res)
 {
-  String *res;
-  char pw_buff[80];
-  String tmp_pw_value(pw_buff, sizeof(pw_buff), system_charset_info);
-  String *password;
-  DBUG_ASSERT(fixed == 1);
-
-  if (!(res=args[0]->val_str(str)))
-  {
-    null_value=1; /* purecov: inspected */
-    return 0; /* purecov: inspected */
-  }
-
-  if (!(password=args[1]->val_str(& tmp_pw_value)))
-  {
-    null_value=1;
-    return 0;
-  }
-
-  null_value=0;
-  res=copy_if_not_alloced(str,res,res->length());
-  SQL_CRYPT sql_crypt(password->ptr(), password->length());
-  sql_crypt.init();
   sql_crypt.decode((char*) res->ptr(),res->length());
   return res;
 }

=== modified file 'sql/item_strfunc.h'
--- a/sql/item_strfunc.h	2009-06-01 12:00:38 +0000
+++ b/sql/item_strfunc.h	2009-12-02 15:08:44 +0000
@@ -351,12 +351,16 @@ public:
 
 class Item_func_encode :public Item_str_func
 {
+protected:  
+  SQL_CRYPT sql_crypt;
 public:
   Item_func_encode(Item *a, Item *seed):
-    Item_str_func(a, seed) {}
+    Item_str_func(a, seed), sql_crypt() {}
   String *val_str(String *);
   void fix_length_and_dec();
   const char *func_name() const { return "encode"; }
+protected:
+  virtual String *calculate (String *argument);
 };
 
 
@@ -364,8 +368,9 @@ class Item_func_decode :public Item_func
 {
 public:
   Item_func_decode(Item *a, Item *seed): Item_func_encode(a, seed) {}
-  String *val_str(String *);
   const char *func_name() const { return "decode"; }
+protected:
+  String *calculate (String *argument);
 };
 
 

=== modified file 'sql/sql_crypt.cc'
--- a/sql/sql_crypt.cc	2009-04-23 07:43:42 +0000
+++ b/sql/sql_crypt.cc	2009-12-02 15:08:44 +0000
@@ -28,7 +28,7 @@
 
 #include "mysql_priv.h"
 
-SQL_CRYPT::SQL_CRYPT(const char *password, uint length)
+void SQL_CRYPT::crypt_password_hash(const char *password, uint length)
 {
   ulong rand_nr[2];
   hash_password(rand_nr,password, length);
@@ -54,6 +54,7 @@ void SQL_CRYPT::crypt_init(ulong *rand_n
    encode_buff[(uchar) decode_buff[i]]=i;
   org_rand=rand;
   shift=0;
+  initialized= TRUE;
 }
 
 

=== modified file 'sql/sql_crypt.h'
--- a/sql/sql_crypt.h	2009-04-23 07:43:42 +0000
+++ b/sql/sql_crypt.h	2009-12-02 15:08:44 +0000
@@ -24,9 +24,14 @@ class SQL_CRYPT :public Sql_alloc
   char decode_buff[256],encode_buff[256];
   uint shift;
   void crypt_init(ulong *seed);
+  bool initialized;
  public:
-  SQL_CRYPT(const char *seed, uint length);
-  SQL_CRYPT(ulong *seed)
+  SQL_CRYPT() : initialized (FALSE) {}
+  SQL_CRYPT(const char *seed, uint length) : initialized(FALSE)
+  {
+    crypt_password_hash(seed, length);
+  }
+  SQL_CRYPT(ulong *seed) : initialized(FALSE)
   {
     crypt_init(seed);
   }
@@ -34,4 +39,6 @@ class SQL_CRYPT :public Sql_alloc
   void init() { shift=0; rand=org_rand; }
   void encode(char *str, uint length);
   void decode(char *str, uint length);
+  void crypt_password_hash (const char *password, uint length);
+  bool is_initialized() { return initialized; }; 
 };


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