Reduce memory used by maria_open

- Allocate only enough memory that we need for key status
  - Saves ~100K temp usage on maria_open

storage/maria/ma_open.c

@@ -274,7 +274,7 @@ MARIA_HA *maria_open(const char *name, int mode, uint open_flags)
 {
   int kfile,open_mode,save_errno;
   uint i,j,len,errpos,head_length,base_pos,keys, realpath_err,
-    key_parts,unique_key_parts,fulltext_keys,uniques;
+    key_parts,base_key_parts,unique_key_parts,fulltext_keys,uniques;
   uint internal_table= MY_TEST(open_flags & HA_OPEN_INTERNAL_TABLE);
   uint file_version;
   size_t info_length;
@@ -404,21 +404,11 @@ MARIA_HA *maria_open(const char *name, int mode, uint open_flags)
       Allocate space for header information and for data that is too
       big to keep on stack
     */
-    if (!my_multi_malloc(MY_WME,
-                         &disk_cache, info_length+128,
-                         &rec_per_key_part,
-                         (sizeof(*rec_per_key_part) * HA_MAX_POSSIBLE_KEY *
-                          HA_MAX_KEY_SEG),
-                         &nulls_per_key_part,
-                         (sizeof(*nulls_per_key_part) * HA_MAX_POSSIBLE_KEY *
-                          HA_MAX_KEY_SEG),
-                         NullS))
+    if (!(disk_cache= my_malloc(info_length+128, MYF(MY_WME))))
     {
       my_errno=ENOMEM;
       goto err;
     }
-    share_buff.state.rec_per_key_part=   rec_per_key_part;
-    share_buff.state.nulls_per_key_part= nulls_per_key_part;
 
     end_pos=disk_cache+info_length;
     errpos= 3;
@@ -431,7 +421,7 @@ MARIA_HA *maria_open(const char *name, int mode, uint open_flags)
     keys=    (uint) share->state.header.keys;
     uniques= (uint) share->state.header.uniques;
     fulltext_keys= (uint) share->state.header.fulltext_keys;
-    key_parts= mi_uint2korr(share->state.header.key_parts);
+    base_key_parts= key_parts= mi_uint2korr(share->state.header.key_parts);
     unique_key_parts= mi_uint2korr(share->state.header.unique_key_parts);
     if (len != MARIA_STATE_INFO_SIZE)
     {
@@ -441,7 +431,8 @@ MARIA_HA *maria_open(const char *name, int mode, uint open_flags)
     }
     share->state_diff_length=len-MARIA_STATE_INFO_SIZE;
 
-    _ma_state_info_read(disk_cache, &share->state);
+    if (!_ma_state_info_read(disk_cache, &share->state))
+      goto err;
     len= mi_uint2korr(share->state.header.base_info_length);
     if (len != MARIA_BASE_INFO_SIZE)
     {
@@ -582,9 +573,9 @@ MARIA_HA *maria_open(const char *name, int mode, uint open_flags)
     share->open_file_name.length=   strlen(name);
     if (!my_multi_malloc(MY_WME,
 			 &share,sizeof(*share),
-			 &share->state.rec_per_key_part,
+			 &rec_per_key_part,
                          sizeof(double) * key_parts,
-                         &share->state.nulls_per_key_part,
+                         &nulls_per_key_part,
                          sizeof(long)* key_parts,
 			 &share->keyinfo,keys*sizeof(MARIA_KEYDEF),
 			 &share->uniqueinfo,uniques*sizeof(MARIA_UNIQUEDEF),
@@ -609,11 +600,16 @@ MARIA_HA *maria_open(const char *name, int mode, uint open_flags)
       goto err;
     errpos= 4;
 
-    *share=share_buff;
-    memcpy((char*) share->state.rec_per_key_part,
-	   (char*) rec_per_key_part, sizeof(double)*key_parts);
-    memcpy((char*) share->state.nulls_per_key_part,
-	   (char*) nulls_per_key_part, sizeof(long)*key_parts);
+    *share= share_buff;
+    share->state.rec_per_key_part=   rec_per_key_part;
+    share->state.nulls_per_key_part= nulls_per_key_part;
+
+    memcpy((char*) rec_per_key_part,
+	   (char*) share_buff.state.rec_per_key_part,
+           sizeof(double)*base_key_parts);
+    memcpy((char*) nulls_per_key_part,
+	   (char*) share_buff.state.nulls_per_key_part,
+           sizeof(long)*base_key_parts);
     memcpy((char*) share->state.key_root,
 	   (char*) key_root, sizeof(my_off_t)*keys);
     strmov(share->unique_file_name.str, name_buff);
@@ -911,6 +907,10 @@ MARIA_HA *maria_open(const char *name, int mode, uint open_flags)
 					(keys ? MARIA_INDEX_BLOCK_MARGIN *
 					 share->block_size * keys : 0));
     my_free(disk_cache);
+    my_free(share_buff.state.rec_per_key_part);
+    disk_cache= 0;
+    share_buff.state.rec_per_key_part= 0;
+
     _ma_setup_functions(share);
     max_data_file_length= share->base.max_data_file_length;
     if ((*share->once_init)(share, info.dfile.file))
@@ -1092,6 +1092,7 @@ MARIA_HA *maria_open(const char *name, int mode, uint open_flags)
     /* fall through */
   case 3:
     my_free(disk_cache);
+    my_free(share_buff.state.rec_per_key_part);
     /* fall through */
   case 1:
     mysql_file_close(kfile,MYF(0));
@@ -1507,6 +1508,16 @@ static uchar *_ma_state_info_read(uchar *ptr, MARIA_STATE_INFO *state)
   keys= (uint) state->header.keys;
   key_parts= mi_uint2korr(state->header.key_parts);
 
+  /* Allocate memory for key parts if not already done */
+  if (!state->rec_per_key_part &&
+      !my_multi_malloc(MY_WME,
+                       &state->rec_per_key_part,
+                       sizeof(*state->rec_per_key_part) * key_parts,
+                       &state->nulls_per_key_part,
+                       sizeof(*state->nulls_per_key_part) * key_parts,
+                       NullS))
+    DBUG_RETURN(0);
+
   state->open_count = mi_uint2korr(ptr);		ptr+= 2;
   state->changed= mi_uint2korr(ptr);			ptr+= 2;
   state->create_rename_lsn= lsn_korr(ptr);		ptr+= LSN_STORE_SIZE;