[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, 37 insertions, 3 deletions

diff --git a/src/H5P.c b/src/H5P.c
index 9a87b90..5c96586 100644
--- a/src/H5P.c
+++ b/src/H5P.c
@@ -30,6 +30,7 @@
 #include "H5Fprivate.h"		/* Files		  	        */
 #include "H5FLprivate.h"	/* Free lists                           */
 #include "H5Iprivate.h"		/* IDs			  		*/
+#include "H5Lprivate.h"		/* Links				*/
 #include "H5MMprivate.h"	/* Memory management			*/
 #include "H5Ppkg.h"		/* Property lists		  	*/
 
@@ -57,6 +58,7 @@ hid_t H5P_CLS_DATATYPE_ACCESS_g     = FAIL;
 hid_t H5P_CLS_ATTRIBUTE_CREATE_g    = FAIL;
 hid_t H5P_CLS_OBJECT_COPY_g         = FAIL;
 hid_t H5P_CLS_LINK_CREATE_g         = FAIL;
+hid_t H5P_CLS_LINK_ACCESS_g         = FAIL;
 hid_t H5P_CLS_STRING_CREATE_g         = FAIL;
 
 /*
@@ -77,6 +79,7 @@ hid_t H5P_LST_DATATYPE_ACCESS_g     = FAIL;
 hid_t H5P_LST_ATTRIBUTE_CREATE_g    = FAIL;
 hid_t H5P_LST_OBJECT_COPY_g         = FAIL;
 hid_t H5P_LST_LINK_CREATE_g         = FAIL;
+hid_t H5P_LST_LINK_ACCESS_g         = FAIL;
 
 /* Track the revision count of a class, to make comparisons faster */
 static unsigned H5P_next_rev=0;
@@ -233,6 +236,13 @@ H5P_init_interface(void)
 {
     H5P_genclass_t  *root_class;    /* Pointer to root property list class created */
     H5P_genclass_t  *pclass;        /* Pointer to property list class to create */
+    /* Link access property class variables.  In sequence, they are,
+     * - Access property list class to modify
+     * - Default value for "user-supplied data"
+     * - Default value for "max number of soft links to traverse"
+     */
+    H5P_genclass_t  *lacc_class;    /* Pointer to link access property list class created */
+    int nlinks = H5L_NLINKS_DEF;
     /* Group creation property class variables.  In sequence, they are,
      * - Creation property list class to modify
      * - Default value for "group info"
@@ -314,6 +324,28 @@ H5P_init_interface(void)
              HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
     } /* end if */
 
+    /* Create link property classes (which need to be inherited by later classes */
+    /* Allocate the link access class */
+    HDassert(H5P_CLS_LINK_ACCESS_g == (-1));
+    if(NULL == (lacc_class = H5P_create_class(root_class, "link access", 1, NULL, NULL, NULL, NULL, NULL, NULL)))
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINIT, FAIL, "class initialization failed")
+
+    /* Register the link access class */
+    if((H5P_CLS_LINK_ACCESS_g = H5I_register(H5I_GENPROP_CLS, lacc_class)) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTREGISTER, FAIL, "can't register property list class")
+
+    /* Get the number of properties in the class */
+    if(H5P_get_nprops_pclass(lacc_class, &nprops, FALSE) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "can't query number of properties")
+
+    /* Assume that if there are properties in the class, they are the default ones */
+    if(nprops == 0) {
+        /* Register property for number of links traversed */
+        if(H5P_register(lacc_class, H5L_NLINKS_NAME, H5L_NLINKS_SIZE,
+                 &nlinks, NULL, NULL, NULL, NULL, NULL, NULL, NULL) < 0)
+             HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+    } /* end if */
+
     /* Register the group creation and group access property classes */
     /* (Register the group property classes before file property classes, so
      *  file creation property class can inherit from group creation property
@@ -344,7 +376,7 @@ H5P_init_interface(void)
 
     /* Allocate the group access class */
     HDassert(H5P_CLS_GROUP_ACCESS_g == (-1));
-    if(NULL == (pclass = H5P_create_class(root_class, "group access", 1, NULL, NULL, NULL, NULL, NULL, NULL)))
+    if(NULL == (pclass = H5P_create_class(lacc_class, "group access", 1, NULL, NULL, NULL, NULL, NULL, NULL)))
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINIT, FAIL, "class initialization failed");
 
     /* Register the group access class */
@@ -384,7 +416,7 @@ H5P_init_interface(void)
 
     /* Allocate the dataset access class */
     assert(H5P_CLS_DATASET_ACCESS_g==(-1));
-    if (NULL==(pclass = H5P_create_class (root_class,"dataset access",1,NULL,NULL,NULL,NULL,NULL,NULL)))
+    if (NULL==(pclass = H5P_create_class (lacc_class,"dataset access",1,NULL,NULL,NULL,NULL,NULL,NULL)))
         HGOTO_ERROR (H5E_PLIST, H5E_CANTINIT, FAIL, "class initialization failed");
 
     /* Register the dataset access class */
@@ -424,7 +456,7 @@ H5P_init_interface(void)
 
     /* Allocate the datatype access class */
     assert(H5P_CLS_DATATYPE_ACCESS_g==(-1));
-    if (NULL==(pclass = H5P_create_class (root_class,"datatype access",1,NULL /*H5T_acs_create*/,NULL,NULL /*H5T_acs_copy*/,NULL,NULL /*H5T_acs_close*/,NULL)))
+    if (NULL==(pclass = H5P_create_class (lacc_class,"datatype access",1,NULL /*H5T_acs_create*/,NULL,NULL /*H5T_acs_copy*/,NULL,NULL /*H5T_acs_close*/,NULL)))
         HGOTO_ERROR (H5E_PLIST, H5E_CANTINIT, FAIL, "class initialization failed");
 
     /* Register the datatype access class */
@@ -536,6 +568,7 @@ H5P_term_interface(void)
                         H5P_LST_ATTRIBUTE_CREATE_g =
                         H5P_LST_OBJECT_COPY_g =
                         H5P_LST_LINK_CREATE_g =
+                        H5P_LST_LINK_ACCESS_g =
                         H5P_LST_MOUNT_g = (-1);
                 } /* end if */
             } /* end if */
@@ -561,6 +594,7 @@ H5P_term_interface(void)
                         H5P_CLS_ATTRIBUTE_CREATE_g =
                         H5P_CLS_OBJECT_COPY_g =
                         H5P_CLS_LINK_CREATE_g =
+                        H5P_CLS_LINK_ACCESS_g =
                         H5P_CLS_MOUNT_g = (-1);
                 } /* end if */
             } /* end if */