MyISAM: always store alloced_rec_buff_length with the buffer itself

include/myisam.h:
  always store alloced_rec_buff_length with the buffer itself
myisam/mi_check.c:
  always store alloced_rec_buff_length with the buffer itself
myisam/mi_dynrec.c:
  always store alloced_rec_buff_length with the buffer itself
myisam/mi_extra.c:
  always store alloced_rec_buff_length with the buffer itself
myisam/mi_key.c:
  always store alloced_rec_buff_length with the buffer itself
myisam/mi_open.c:
  always store alloced_rec_buff_length with the buffer itself
myisam/mi_packrec.c:
  always store alloced_rec_buff_length with the buffer itself
myisam/myisamdef.h:
  always store alloced_rec_buff_length with the buffer itself

include/myisam.h

@@ -379,7 +379,6 @@ typedef struct st_mi_sort_param
   my_off_t pos,max_pos,filepos,start_recpos;
   uint key, key_length,real_key_length,sortbuff_size;
   uint maxbuffers, keys, find_length, sort_keys_length;
-  uint alloced_rec_buff_length;
   my_bool fix_datafile, master;
   MI_KEYDEF *keyinfo;
   SORT_INFO *sort_info;

myisam/mi_check.c

@@ -841,8 +841,7 @@ int chk_data_link(MI_CHECK *param, MI_INFO *info,int extend)
 	  if (info->s->base.blobs)
 	  {
 	    if (!(to= mi_alloc_rec_buff(info, block_info.rec_len,
-					&info->rec_buff,
-					&info->alloced_rec_buff_length)))
+					&info->rec_buff)))
 	    {
 	      mi_check_print_error(param,"Not enough memory for blob at %s",
 			  llstr(start_recpos,llbuff));
@@ -1146,7 +1145,6 @@ int mi_repair(MI_CHECK *param, register MI_INFO *info,
       goto err;
   info->opt_flag|=WRITE_CACHE_USED;
   sort_param.rec_buff=info->rec_buff;
-  sort_param.alloced_rec_buff_length=info->alloced_rec_buff_length;
   if (!(sort_param.record=(byte*) my_malloc((uint) share->base.pack_reclength,
 					   MYF(0))))
   {
@@ -1810,7 +1808,6 @@ int mi_repair_by_sort(MI_CHECK *param, register MI_INFO *info,
   info->rec_cache.file=info->dfile;		/* for sort_delete_record */
 
   sort_param.rec_buff=info->rec_buff;
-  sort_param.alloced_rec_buff_length=info->alloced_rec_buff_length;
   if (!(sort_param.record=(byte*) my_malloc((uint) share->base.pack_reclength,
 					   MYF(0))))
   {
@@ -2793,8 +2790,7 @@ static int sort_get_next_record(MI_SORT_PARAM *sort_param)
 	  if (share->base.blobs)
 	  {
 	    if (!(to=mi_alloc_rec_buff(info,block_info.rec_len,
-				       &(sort_param->rec_buff),
-				       &(sort_param->alloced_rec_buff_length))))
+				       &(sort_param->rec_buff))))
 	    {
 	      mi_check_print_error(param,"Not enough memory for blob at %s",
 			  llstr(sort_param->start_recpos,llbuff));

myisam/mi_dynrec.c

@@ -1060,8 +1060,7 @@ int _mi_read_dynamic_record(MI_INFO *info, my_off_t filepos, byte *buf)
 	if (info->s->base.blobs)
 	{
 	  if (!(to=mi_alloc_rec_buff(info, block_info.rec_len,
-				     &info->rec_buff,
-				     &info->alloced_rec_buff_length)))
+				     &info->rec_buff)))
 	    goto err;
 	}
 	else
@@ -1107,12 +1106,8 @@ int _mi_cmp_dynamic_unique(MI_INFO *info, MI_UNIQUEDEF *def,
 
   /* Don't let the compare destroy blobs that may be in use */
   rec_buff=info->rec_buff;
-  alloced_rec_buff_length=info->alloced_rec_buff_length;
   if (info->s->base.blobs)
-  {
     info->rec_buff=0;
-    info->alloced_rec_buff_length=0;
-  }
   error=_mi_read_dynamic_record(info,pos,old_record);
   if (!error)
     error=mi_unique_comp(def, record, old_record, def->null_are_equal);
@@ -1120,7 +1115,6 @@ int _mi_cmp_dynamic_unique(MI_INFO *info, MI_UNIQUEDEF *def,
   {
     my_free(mi_get_rec_buff_ptr(info, info->rec_buff), MYF(MY_ALLOW_ZERO_PTR));
     info->rec_buff=rec_buff;
-    info->alloced_rec_buff_length=alloced_rec_buff_length;
   }
   my_afree(old_record);
   DBUG_RETURN(error);
@@ -1331,8 +1325,7 @@ int _mi_read_rnd_dynamic_record(MI_INFO *info, byte *buf,
       if (share->base.blobs)
       {
 	if (!(to= mi_alloc_rec_buff(info, block_info.rec_len,
-				    &info->rec_buff,
-				    &info->alloced_rec_buff_length)))
+				    &info->rec_buff)))
 	  goto err;
       }
       else

myisam/mi_extra.c

@@ -344,8 +344,7 @@ int mi_extra(MI_INFO *info, enum ha_extra_function function, void *extra_arg)
       }
     }
     if (share->base.blobs)
-      mi_alloc_rec_buff(info, -1, &info->rec_buff,
-			&info->alloced_rec_buff_length);
+      mi_alloc_rec_buff(info, -1, &info->rec_buff);
     break;
   case HA_EXTRA_NORMAL:				/* Theese isn't in use */
     info->quick_mode=0;

myisam/mi_key.c

@@ -251,8 +251,7 @@ static int _mi_put_key_in_record(register MI_INFO *info, uint keynr,
   {
     if (!(blob_ptr=
 	  mi_alloc_rec_buff(info, info->s->keyinfo[keynr].keylength,
-			    &info->rec_buff,
-			    &info->alloced_rec_buff_length)))
+			    &info->rec_buff)))
       goto err;
   }
   key=(byte*) info->lastkey;

myisam/mi_open.c

@@ -507,10 +507,9 @@ MI_INFO *mi_open(const char *name, int mode, uint open_flags)
   /* Allocate buffer for one record */
 
   /* prerequisites: bzero(info) && info->s=share; are met. */
-  if (!mi_alloc_rec_buff(&info, -1, &info.rec_buff,
-			 &info.alloced_rec_buff_length))
+  if (!mi_alloc_rec_buff(&info, -1, &info.rec_buff))
     goto err;
-  bzero(info.rec_buff, info.alloced_rec_buff_length);
+  bzero(info.rec_buff, mi_get_rec_buff_len(&info, info.rec_buff));
 
   *m_info=info;
 #ifdef THREAD
@@ -560,21 +559,11 @@ err:
   DBUG_RETURN (NULL);
 } /* mi_open */
 
-
-gptr mi_get_rec_buff_ptr(MI_INFO *info, byte *buf)
-{
-  if (info->s->options & HA_OPTION_PACK_RECORD && buf)
-    return buf - MI_REC_BUFF_OFFSET;
-  else
-    return buf;
-}
-
-
-byte *mi_alloc_rec_buff(MI_INFO *info, ulong length, byte **buf, uint *buf_len)
+byte *mi_alloc_rec_buff(MI_INFO *info, ulong length, byte **buf)
 {
   uint extra;
 
-  if (! *buf || length > *buf_len)
+  if (! *buf || length > mi_get_rec_buff_len(info, *buf))
   {
     byte *newptr = *buf;
 
@@ -588,10 +577,10 @@ byte *mi_alloc_rec_buff(MI_INFO *info, ulong length, byte **buf, uint *buf_len)
     if (extra && newptr)
       newptr-=MI_REC_BUFF_OFFSET;
     if (!(newptr=(byte*) my_realloc((gptr)newptr, length+extra+8,
-				    MYF(MY_ALLOW_ZERO_PTR))))
-      return 0;
+                                     MYF(MY_ALLOW_ZERO_PTR))))
+      return newptr;
+    *((uint *)newptr)=length;
     *buf= newptr+(extra ?  MI_REC_BUFF_OFFSET : 0);
-    *buf_len= length;
   }
   return *buf;
 }

myisam/mi_packrec.c

@@ -1058,8 +1058,7 @@ uint _mi_pack_get_block_info(MI_INFO *myisam, MI_BLOCK_INFO *info, File file,
       head_length+=4;
     }
     if (!(mi_alloc_rec_buff(myisam,info->rec_len + info->blob_len,
-			    &myisam->rec_buff,
-			    &myisam->alloced_rec_buff_length)))
+			    &myisam->rec_buff)))
       return BLOCK_FATAL_ERROR;			/* not enough memory */
     myisam->bit_buff.blob_pos=(uchar*) myisam->rec_buff+info->rec_len;
     myisam->blob_length=info->blob_len;
@@ -1235,8 +1234,7 @@ static uchar *_mi_mempack_get_block_info(MI_INFO *myisam,MI_BLOCK_INFO *info,
     }
     /* mi_alloc_rec_buff sets my_errno on error */
     if (!(mi_alloc_rec_buff(myisam, info->blob_len,
-			    &myisam->rec_buff,
-			    &myisam->alloced_rec_buff_length)))
+			    &myisam->rec_buff)))
       return 0;				/* not enough memory */
     myisam->bit_buff.blob_pos=(uchar*) myisam->rec_buff;
   }

myisam/myisamdef.h

@@ -247,7 +247,6 @@ struct st_myisam_info {
   int  dfile;				/* The datafile */
   uint opt_flag;			/* Optim. for space/speed */
   uint update;				/* If file changed since open */
-  uint	alloced_rec_buff_length;	/* Max recordlength malloced */
   uint  int_nod_flag;			/*  -""-  */
   int	lastinx;			/* Last used index */
   uint	lastkey_length;			/* Length of key in lastkey */
@@ -359,7 +358,7 @@ struct st_myisam_info {
 #define MI_DYN_ALIGN_SIZE	4	/* Align blocks on this */
 #define MI_MAX_DYN_HEADER_BYTE	13	/* max header byte for dynamic rows */
 #define MI_MAX_BLOCK_LENGTH	((((ulong) 1 << 24)-1) & (~ (ulong) (MI_DYN_ALIGN_SIZE-1)))
-#define MI_REC_BUFF_OFFSET      ALIGN_SIZE(MI_DYN_DELETE_BLOCK_HEADER)
+#define MI_REC_BUFF_OFFSET      ALIGN_SIZE(MI_DYN_DELETE_BLOCK_HEADER+sizeof(uint))
 
 #define MEMMAP_EXTRA_MARGIN	7	/* Write this as a suffix for file */
 
@@ -523,8 +522,14 @@ extern int _mi_read_key_record(MI_INFO *info,my_off_t filepos,byte *buf);
 extern int _mi_read_cache(IO_CACHE *info,byte *buff,my_off_t pos,
 			  uint length,int re_read_if_possibly);
 extern void update_auto_increment(MI_INFO *info,const byte *record);
-extern byte *mi_alloc_rec_buff(MI_INFO *,ulong, byte**, uint*);
-extern gptr mi_get_rec_buff_ptr(MI_INFO *, byte *);
+
+extern byte *mi_alloc_rec_buff(MI_INFO *,ulong, byte**);
+#define mi_get_rec_buff_ptr(info,buf)                              \
+        ((((info)->s->options & HA_OPTION_PACK_RECORD) && (buf)) ? \
+        (buf) - MI_REC_BUFF_OFFSET : (buf))
+#define mi_get_rec_buff_len(info,buf)                              \
+        (*((uint *)(mi_get_rec_buff_ptr(info,buf))))
+
 extern ulong _mi_rec_unpack(MI_INFO *info,byte *to,byte *from,
 			    ulong reclength);
 extern my_bool _mi_rec_check(MI_INFO *info,const char *record, byte *packpos);