[svn-r13245] Added "superblock extension" object header to hold shared object header

information, rather than storing it directly in the superblock.
This should make future updates to the superblock much less painful.

Tested on Windows, kagiso, and smirom.

1 files changed, 44 insertions, 3 deletions

diff --git a/src/H5Fsuper.c b/src/H5Fsuper.c
index c8ff253..e6bd53c 100644
--- a/src/H5Fsuper.c
+++ b/src/H5Fsuper.c
@@ -242,13 +242,17 @@ H5F_read_superblock(H5F_t *f, hid_t dxpl_id, H5G_loc_t *root_loc, haddr_t addr,
     HDmemcpy(shared->btree_k, btree_k, sizeof(unsigned) * (size_t)H5B_NUM_BTREE_ID);    /* Keep a local copy also */
 
     H5F_addr_decode(f, (const uint8_t **)&p, &shared->base_addr/*out*/);
-    H5F_addr_decode(f, (const uint8_t **)&p, &shared->freespace_addr/*out*/);
+    H5F_addr_decode(f, (const uint8_t **)&p, &(shared->extension_addr)/*out*/);
+
     /* If the superblock version is greater than 1, read in the shared OH message table information */
-    if(super_vers > HDF5_SUPERBLOCK_VERSION_1) {
+#ifdef JAMES
+    if(super_vers >= HDF5_SUPERBLOCK_VERSION_2) {
         H5F_addr_decode(f, (const uint8_t **)&p, &shared->sohm_addr/*out*/);
         shared->sohm_vers = *p++;
         shared->sohm_nindexes = *p++;
     }
+#endif /* JAMES */
+
     H5F_addr_decode(f, (const uint8_t **)&p, &stored_eoa/*out*/);
     H5F_addr_decode(f, (const uint8_t **)&p, &shared->driver_addr/*out*/);
     if(H5G_obj_ent_decode(f, (const uint8_t **)&p, root_loc->oloc/*out*/) < 0)
@@ -388,6 +392,39 @@ H5F_read_superblock(H5F_t *f, hid_t dxpl_id, H5G_loc_t *root_loc, haddr_t addr,
     if (H5FD_set_eoa(lf, H5FD_MEM_SUPER, stored_eoa) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to set end-of-address marker for file")
 
+    /* Read the file's superblock extension, if there is one. */
+    if(shared->extension_addr != HADDR_UNDEF && super_vers >= HDF5_SUPERBLOCK_VERSION_2) {
+        H5O_loc_t ext_loc;
+/* JAMES        H5O_shmesg_table_t sohm_table; */
+
+        H5O_loc_reset(&ext_loc);
+        ext_loc.file = f;
+        ext_loc.addr = shared->extension_addr;
+
+        /* JAMES: bump the number of open objects to avoid closing the file here */
+        f->nopen_objs++;
+        if(H5O_open(&ext_loc) < 0)
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENFILE, FAIL, "unable to open superblock extension")
+
+        if(NULL == H5O_msg_read(&ext_loc, H5O_SHMESG_ID, &shared->sohm_table, dxpl_id)) {
+            H5E_clear_stack(NULL);
+            shared->sohm_addr = HADDR_UNDEF;
+            shared->sohm_nindexes = 0;
+            shared->sohm_vers = 0;
+        } else {
+            shared->sohm_addr = shared->sohm_table.addr;
+            shared->sohm_vers = shared->sohm_table.version;
+            shared->sohm_nindexes = shared->sohm_table.nindexes;
+        }
+        /* JAMES
+        HDassert(sohm_table.addr == shared->sohm_addr);
+        HDassert(sohm_table.version == shared->sohm_vers);
+        HDassert(sohm_table.nindexes == shared->sohm_nindexes);
+*/
+        if(H5O_close(&ext_loc) < 0)
+            HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENFILE, FAIL, "unable to close superblock extension")
+        f->nopen_objs--;
+    }
 
     /* Decode shared object header message information and store it in the
      * fcpl */
@@ -622,12 +659,16 @@ H5F_write_superblock(H5F_t *f, hid_t dxpl_id)
     }
 
     H5F_addr_encode(f, &p, f->shared->base_addr);
-    H5F_addr_encode(f, &p, f->shared->freespace_addr);
+    H5F_addr_encode(f, &p, f->shared->extension_addr);
+
+#ifdef JAMES
     if(super_vers >= HDF5_SUPERBLOCK_VERSION_2) {
       H5F_addr_encode(f, &p, f->shared->sohm_addr);
       *p++ = f->shared->sohm_vers;
       *p++ = f->shared->sohm_nindexes;
     }
+#endif /* JAMES */
+
     H5F_addr_encode(f, &p, H5FD_get_eoa(f->shared->lf, H5FD_MEM_SUPER));
     H5F_addr_encode(f, &p, f->shared->driver_addr);
     if(H5G_obj_ent_encode(f, &p, H5G_oloc(f->shared->root_grp))<0)