[svn-r12528] Added User-Defined links to the library.

Users can create external links using H5L_create_external().  These links
point to an object in another HDF5 file.  Users can alter the behavior of
external links or create new kinds of links by registering callbacks
using the H5L interface.

Added tests, tools support, etc.

Also a number of other, minor changes have been made (some restructuring of
the H5L interface, for instance).

Additional documentation and examples are forthcoming.

1 files changed, 56 insertions, 2 deletions

diff --git a/tools/lib/h5trav.c b/tools/lib/h5trav.c
index f5c6e91..2ff927c 100644
--- a/tools/lib/h5trav.c
+++ b/tools/lib/h5trav.c
@@ -462,7 +462,7 @@ static int traverse( hid_t loc_id,
    */
 
   case H5G_LINK:
-   {
+  {
     /* increment */
     inserted_objs++;
 
@@ -489,9 +489,60 @@ static int traverse( hid_t loc_id,
 
    break;
 
+  /*-------------------------------------------------------------------------
+   * H5G_UDLINK
+   *-------------------------------------------------------------------------
+   */
+
+  case H5G_UDLINK:
+  {
+    H5L_linkinfo_t linkbuf;
+
+    /* increment */
+    inserted_objs++;
+
+    /* add object to table */
+    trav_table_add(HADDR_UNDEF, path, H5G_UDLINK, table );
+
+    /* Get type of link */
+    H5E_BEGIN_TRY {
+
+    /* get link class info */
+    H5Lget_linkinfo( loc_id, path, &linkbuf, H5P_DEFAULT);
+    } H5E_END_TRY;
+
+    if(linkbuf.linkclass == H5L_LINK_EXTERNAL)
+    {
+      if (statbuf.linklen>0)
+      {
+      char *targbuf;
+      char *objname;
+
+      targbuf = HDmalloc(statbuf.linklen);
+      assert(targbuf);
+      H5Gget_linkval(loc_id,path,statbuf.linklen,targbuf);
+      H5Lunpack_elink_val(targbuf, NULL, &objname);
+      if (print)
+        printf(" %-10s %s -> %s %s\n", "ext link", path, targbuf, objname);
+      free(targbuf);
+      }
+      else
+      {
+      if (print)
+        printf(" %-10s %s ->\n", "udlink", path);
+      }
+    }
+    else  /* Unknown user-defined type */
+    {
+      if (print)
+        printf(" %-10s %s ->\n", "UD link type", path);
+    }
+  }
+  break;
+
 
   default:
-    HDfprintf(stderr, "traverse: Unknown object!\n");
+    HDfprintf(stderr, "traverse: Unknown object %d!\n", type); /* JAMES */
     return (-1);
    break;
 
@@ -548,6 +599,9 @@ void h5trav_printinfo(int nobjs, trav_info_t *travi)
   case H5G_LINK:
    printf(" %-10s %s\n", "link", travi[i].name );
    break;
+  case H5G_UDLINK:
+   printf(" %-10s %s\n", "User defined link", travi[i].name );
+   break;
   default:
    printf(" %-10s %s\n", "User defined object", travi[i].name );
    break;