* frm extra2 segment.

* persistent table versions in the extra2
* ha_archive::frm_compare using TABLE_SHARE::tabledef_version
* distinguish between "important" and "optional" extra2 frm values
* write engine-defined attributes (aka "table options") to extra2, not to extra,
  but still read from the old location, if they're found there.

3 files changed, 26 insertions, 26 deletions

diff --git a/storage/archive/azio.c b/storage/archive/azio.c
index c6058af2e3d..4519d15cefc 100644
--- a/storage/archive/azio.c
+++ b/storage/archive/azio.c
@@ -364,6 +364,8 @@ void read_header(azio_stream *s, unsigned char *buffer)
 {
   if (buffer[0] == az_magic[0]  && buffer[1] == az_magic[1])
   {
+    uchar tmp[AZ_FRMVER_LEN + 2];
+
     s->version= (unsigned int)buffer[AZ_VERSION_POS];
     s->minor_version= (unsigned int)buffer[AZ_MINOR_VERSION_POS];
     s->block_size= 1024 * buffer[AZ_BLOCK_POS];
@@ -379,6 +381,22 @@ void read_header(azio_stream *s, unsigned char *buffer)
     s->comment_start_pos= (unsigned int)uint4korr(buffer + AZ_COMMENT_POS);
     s->comment_length= (unsigned int)uint4korr(buffer + AZ_COMMENT_LENGTH_POS);
     s->dirty= (unsigned int)buffer[AZ_DIRTY_POS];
+
+    /*
+      we'll hard-code the current frm format for now, to avoid
+      changing archive table versions.
+    */
+    if (s->frm_length == 0 ||
+        my_pread(s->file, tmp,  sizeof(tmp), s->frm_start_pos + 64, MYF(MY_NABP)) ||
+        tmp[0] != 0 || tmp[1] != AZ_FRMVER_LEN)
+    {
+      s->frmver_length= 0;
+    }
+    else
+    {
+      s->frmver_length= tmp[1];
+      memcpy(s->frmver, tmp+2, s->frmver_length);
+    }
   }
   else if (buffer[0] == gz_magic[0]  && buffer[1] == gz_magic[1])
   {
diff --git a/storage/archive/azlib.h b/storage/archive/azlib.h
index 09f61afcd28..2971705b2f1 100644
--- a/storage/archive/azlib.h
+++ b/storage/archive/azlib.h
@@ -198,6 +198,7 @@ extern "C" {
 #define AZ_BUFSIZE_READ 32768
 #define AZ_BUFSIZE_WRITE 16384
 
+#define AZ_FRMVER_LEN 16 /* same as MY_UUID_SIZE in 10.0.2 */
 
 typedef struct azio_stream {
   z_stream stream;
@@ -227,6 +228,8 @@ typedef struct azio_stream {
   unsigned char dirty;   /* State of file */
   unsigned int frm_start_pos;   /* Position for start of FRM */
   unsigned int frm_length;   /* Position for start of FRM */
+  unsigned char frmver[AZ_FRMVER_LEN];
+  unsigned int frmver_length;
   unsigned int comment_start_pos;   /* Position for start of comment */
   unsigned int comment_length;   /* Position for start of comment */
 } azio_stream;
diff --git a/storage/archive/ha_archive.cc b/storage/archive/ha_archive.cc
index 515ebf8cf3d..9f164da3359 100644
--- a/storage/archive/ha_archive.cc
+++ b/storage/archive/ha_archive.cc
@@ -673,33 +673,12 @@ int ha_archive::frm_copy(azio_stream *src, azio_stream *dst)
 
 int ha_archive::frm_compare(azio_stream *s)
 {
-  int rc= 0;
-  const uchar *frm_ptr= 0;
-  uchar *azfrm_ptr= 0;
-  size_t frm_len;
-
-  /* no frm = no discovery. perhaps it's a partitioned table */
-  if (table->s->read_frm_image(&frm_ptr, &frm_len))
-    goto err;
-
-  if (!(azfrm_ptr= (uchar *) my_malloc(s->frm_length,
-                                       MYF(MY_THREAD_SPECIFIC | MY_WME))))
-    goto err;
-
-  rc= 1;
+  if (!s->frmver_length)
+    return 0; // Old pre-10.0 archive table. Never rediscover.
 
-  if (frm_len != s->frm_length)
-    goto err;
-
-  if (azread_frm(s, azfrm_ptr))
-    goto err;
-
-  rc= memcmp(frm_ptr, azfrm_ptr, frm_len);
-
-err:
-  my_free(const_cast<uchar*>(frm_ptr));
-  my_free(azfrm_ptr);
-  return rc;
+  LEX_CUSTRING *ver= &table->s->tabledef_version;
+  return ver->length != s->frmver_length ||
+         memcmp(ver->str,  s->frmver, ver->length);
 }