[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, 6 insertions, 0 deletions

diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 59c2081..07d2468 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -153,6 +153,11 @@ typedef struct H5O_link_soft_t {
     char	*name;			/* Destination name */
 } H5O_link_soft_t;
 
+typedef struct H5O_link_ud_t {
+    void	*udata;			/* Opaque data supplied by the user */
+    size_t       size;                  /* Size of udata */
+} H5O_link_ud_t;
+
 typedef struct H5O_link_t {
     H5L_link_t  type;                   /* Type of link */
     time_t      ctime;                  /* Time link was createed */
@@ -161,6 +166,7 @@ typedef struct H5O_link_t {
     union {
         H5O_link_hard_t hard;           /* Information for hard links */
         H5O_link_soft_t soft;           /* Information for soft links */
+        H5O_link_ud_t ud;               /* Information for user-defined links */
     } u;
 } H5O_link_t;