[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, 8 insertions, 0 deletions

diff --git a/tools/testfiles/tall-2B.ddl b/tools/testfiles/tall-2B.ddl
index 4969987..002156e 100644
--- a/tools/testfiles/tall-2B.ddl
+++ b/tools/testfiles/tall-2B.ddl
@@ -44,6 +44,11 @@ GROUP "/" {
          }
       }
       GROUP "g1.2" {
+         EXTERNAL_LINK "extlink" {
+            LINKCLASS 64
+            TARGETFILE "somefile"
+            TARGETPATH "somepath"
+}
          GROUP "g1.2.1" {
             SOFTLINK "slink" {
                LINKTARGET "somevalue"
@@ -60,6 +65,9 @@ GROUP "/" {
          DATATYPE  H5T_IEEE_F32BE
          DATASPACE  SIMPLE { ( 3, 5 ) / ( 3, 5 ) }
       }
+      USERDEFINED_LINK "udlink" {
+         LINKCLASS 187
+      }
    }
 }
 }