[svn-r11712] Purpose:

    New feature

Description:
    Check in baseline for compact group revisions, which radically revises the
source code for managing groups and object headers.

WARNING!!!!  WARNING!!!!  WARNING!!!!  WARNING!!!!  WARNING!!!!  WARNING!!!!
WARNING!!!!  WARNING!!!!  WARNING!!!!  WARNING!!!!  WARNING!!!!  WARNING!!!!

    This initiates the "unstable" phase of the 1.7.x branch, leading up
to the 1.8.0 release.  Please test this code, but do _NOT_ keep files created
with it - the format will change again before the release and you will not
be able to read your old files!!!

WARNING!!!!  WARNING!!!!  WARNING!!!!  WARNING!!!!  WARNING!!!!  WARNING!!!!
WARNING!!!!  WARNING!!!!  WARNING!!!!  WARNING!!!!  WARNING!!!!  WARNING!!!!


Solution:
    There's too many changes to really describe them all, but some of them
include:
    - Stop abusing the H5G_entry_t structure and split it into two separate
        structures for non-symbol table node use within the library: H5O_loc_t
        for object locations in a file and H5G_name_t to store the path to
        an opened object.  H5G_entry_t is now only used for storing symbol
        table entries on disk.

    - Retire H5G_namei() in favor of a more general mechanism for traversing
        group paths and issuing callbacks on objects located.  This gets us out
        of the business of hacking H5G_namei() for new features, generally.

    - Revised H5O* routines to take a H5O_loc_t instead of H5G_entry_t

    - Lots more...

Platforms tested:
    h5committested and maybe another dozen configurations.... :-)

1 files changed, 228 insertions, 224 deletions

diff --git a/src/H5R.c b/src/H5R.c
index fce6c7a..fa5b97d 100644
--- a/src/H5R.c
+++ b/src/H5R.c
@@ -12,29 +12,30 @@
  * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-#define H5F_PACKAGE		/*suppress error about including H5Fpkg	  */
-
 /* Interface initialization */
 #define H5_INTERFACE_INIT_FUNC	H5R_init_interface
 
 
-#include "H5private.h"		/* Generic Functions */
-#include "H5Iprivate.h"		/* ID Functions */
-#include "H5Dprivate.h"		/* Datasets */
-#include "H5Eprivate.h"		/* Error handling */
-#include "H5Fpkg.h"		/* Files */
-#include "H5Gprivate.h"		/* Groups */
-#include "H5HGprivate.h"    /* Global Heaps */
-#include "H5MMprivate.h"    /* Memory Management */
-#include "H5Rprivate.h"		/* References */
-#include "H5Sprivate.h"		/* Dataspace functions			*/
-#include "H5Tprivate.h"		/* Datatypes */
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5Fprivate.h"         /* File access				*/
+#include "H5Gprivate.h"		/* Groups				*/
+#include "H5HGprivate.h"	/* Global Heaps				*/
+#include "H5Iprivate.h"		/* IDs			  		*/
+#include "H5MMprivate.h"	/* Memory management			*/
+#include "H5Rprivate.h"		/* References				*/
+#include "H5Sprivate.h"		/* Dataspaces 				*/
+
+/* Local macro definitions */
+
+/* Number of reserved IDs in ID group */
+#define H5R_RESERVED_ATOMS  0
 
 /* Static functions */
-static herr_t H5R_create(void *ref, H5G_entry_t *loc, const char *name,
+static herr_t H5R_create(void *ref, H5G_loc_t *loc, const char *name,
         H5R_type_t ref_type, H5S_t *space, hid_t dxpl_id);
 static hid_t H5R_dereference(H5F_t *file, hid_t dxpl_id, H5R_type_t ref_type, void *_ref);
-static H5S_t * H5R_get_region(H5F_t *file, hid_t dxpl_id, H5R_type_t ref_type, void *_ref);
+static H5S_t * H5R_get_region(H5F_t *file, hid_t dxpl_id, void *_ref);
 static H5G_obj_t H5R_get_obj_type(H5F_t *file, hid_t dxpl_id, H5R_type_t ref_type, void *_ref);
 
 
@@ -60,7 +61,7 @@ H5R_init_interface(void)
     /* Initialize the atom group for the file IDs */
     if (H5I_register_type(H5I_REFERENCE, H5I_REFID_HASHSIZE, H5R_RESERVED_ATOMS,
 		       (H5I_free_t)NULL)<0)
-	HGOTO_ERROR (H5E_REFERENCE, H5E_CANTINIT, FAIL, "unable to initialize interface");
+	HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "unable to initialize interface");
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
@@ -113,7 +114,7 @@ H5R_term_interface(void)
  USAGE
     herr_t H5R_create(ref, loc, name, ref_type, space)
         void *ref;          OUT: Reference created
-        H5G_entry_t *loc;   IN: File location used to locate object pointed to
+        H5G_loc_t *loc;     IN: File location used to locate object pointed to
         const char *name;   IN: Name of object at location LOC_ID of object
                                     pointed to
         H5R_type_t ref_type;    IN: Type of reference to create
@@ -133,25 +134,25 @@ H5R_term_interface(void)
  REVISION LOG
 --------------------------------------------------------------------------*/
 static herr_t
-H5R_create(void *_ref, H5G_entry_t *loc, const char *name, H5R_type_t ref_type, H5S_t *space, hid_t dxpl_id)
+H5R_create(void *_ref, H5G_loc_t *loc, const char *name, H5R_type_t ref_type, H5S_t *space, hid_t dxpl_id)
 {
-    H5G_stat_t sb;              /* Stat buffer for retrieving OID */
-    herr_t      ret_value=SUCCEED;       /* Return value */
+    H5G_stat_t sb;                      /* Stat buffer for retrieving OID */
+    herr_t ret_value = SUCCEED;         /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5R_create);
+    FUNC_ENTER_NOAPI_NOINIT(H5R_create)
 
-    assert(_ref);
-    assert(loc);
-    assert(name);
-    assert(ref_type>H5R_BADTYPE || ref_type<H5R_MAXTYPE);
+    HDassert(_ref);
+    HDassert(loc);
+    HDassert(name);
+    HDassert(ref_type > H5R_BADTYPE || ref_type < H5R_MAXTYPE);
 
-    if (H5G_get_objinfo (loc, name, 0, &sb, dxpl_id)<0)
-        HGOTO_ERROR (H5E_REFERENCE, H5E_NOTFOUND, FAIL, "unable to stat object");
+    if(H5G_get_objinfo(loc, name, 0, &sb, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_NOTFOUND, FAIL, "unable to stat object")
 
     switch(ref_type) {
         case H5R_OBJECT:
         {
-            hobj_ref_t *ref=(hobj_ref_t *)_ref; /* Get pointer to correct type of reference struct */
+            hobj_ref_t *ref = (hobj_ref_t *)_ref; /* Get pointer to correct type of reference struct */
 
             *ref=sb.u.obj.objno;
             break;
@@ -160,7 +161,7 @@ H5R_create(void *_ref, H5G_entry_t *loc, const char *name, H5R_type_t ref_type,
         case H5R_DATASET_REGION:
         {
             H5HG_t hobjid;      /* Heap object ID */
-            hdset_reg_ref_t *ref=(hdset_reg_ref_t *)_ref; /* Get pointer to correct type of reference struct */
+            hdset_reg_ref_t *ref = (hdset_reg_ref_t *)_ref; /* Get pointer to correct type of reference struct */
             hssize_t buf_size;  /* Size of buffer needed to serialize selection */
             uint8_t *p;       /* Pointer to OID to store */
             uint8_t *buf;     /* Buffer to store serialized selection in */
@@ -170,51 +171,51 @@ H5R_create(void *_ref, H5G_entry_t *loc, const char *name, H5R_type_t ref_type,
             /* Set up information for dataset region */
 
             /* Return any previous heap block to the free list if we are garbage collecting */
-            if(loc->file->shared->gc_ref) {
+            if(H5F_GC_REF(loc->oloc->file)) {
                 /* Check for an existing heap ID in the reference */
-                for(u=0, heapid_found=0, p=(uint8_t *)ref; u<H5R_DSET_REG_REF_BUF_SIZE; u++)
-                    if(p[u]!=0) {
-                        heapid_found=1;
+                for(u = 0, heapid_found = 0, p = (uint8_t *)ref; u < H5R_DSET_REG_REF_BUF_SIZE; u++)
+                    if(p[u] != 0) {
+                        heapid_found = 1;
                         break;
                     } /* end if */
 
-                if(heapid_found!=0) {
+                if(heapid_found != 0) {
 /* Return heap block to free list */
                 } /* end if */
             } /* end if */
 
             /* Zero the heap ID out, may leak heap space if user is re-using reference and doesn't have garbage collection on */
-            HDmemset(ref,H5R_DSET_REG_REF_BUF_SIZE,0);
+            HDmemset(ref, H5R_DSET_REG_REF_BUF_SIZE, 0);
 
             /* Get the amount of space required to serialize the selection */
-            if ((buf_size = H5S_SELECT_SERIAL_SIZE(space)) < 0)
-                HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "Invalid amount of space for serializing selection");
+            if((buf_size = H5S_SELECT_SERIAL_SIZE(space)) < 0)
+                HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "Invalid amount of space for serializing selection")
 
             /* Increase buffer size to allow for the dataset OID */
-            buf_size+=sizeof(haddr_t);
+            buf_size += sizeof(haddr_t);
 
             /* Allocate the space to store the serialized information */
-            H5_CHECK_OVERFLOW(buf_size,hssize_t,size_t);
-            if (NULL==(buf = H5MM_malloc((size_t)buf_size)))
-                HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
+            H5_CHECK_OVERFLOW(buf_size, hssize_t, size_t);
+            if(NULL == (buf = H5MM_malloc((size_t)buf_size)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
 
             /* Serialize information for dataset OID */
-            p=(uint8_t *)buf;
-            H5F_addr_encode(loc->file,&p,sb.u.obj.objno);
+            p = (uint8_t *)buf;
+            H5F_addr_encode(loc->oloc->file, &p, sb.u.obj.objno);
 
             /* Serialize the selection */
-            if (H5S_SELECT_SERIALIZE(space,p) < 0)
-                HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCOPY, FAIL, "Unable to serialize selection");
+            if(H5S_SELECT_SERIALIZE(space, p) < 0)
+                HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCOPY, FAIL, "Unable to serialize selection")
 
             /* Save the serialized buffer for later */
-            H5_CHECK_OVERFLOW(buf_size,hssize_t,size_t);
-            if(H5HG_insert(loc->file,dxpl_id,(size_t)buf_size,buf,&hobjid)<0)
-                HGOTO_ERROR(H5E_REFERENCE, H5E_WRITEERROR, FAIL, "Unable to serialize selection");
+            H5_CHECK_OVERFLOW(buf_size, hssize_t, size_t);
+            if(H5HG_insert(loc->oloc->file, dxpl_id, (size_t)buf_size, buf, &hobjid) < 0)
+                HGOTO_ERROR(H5E_REFERENCE, H5E_WRITEERROR, FAIL, "Unable to serialize selection")
 
             /* Serialize the heap ID and index for storage in the file */
-            p=(uint8_t *)ref;
-            H5F_addr_encode(loc->file,&p,hobjid.addr);
-            INT32ENCODE(p,hobjid.idx);
+            p = (uint8_t *)ref;
+            H5F_addr_encode(loc->oloc->file, &p, hobjid.addr);
+            INT32ENCODE(p, hobjid.idx);
 
             /* Free the buffer we serialized data in */
             H5MM_xfree(buf);
@@ -222,17 +223,17 @@ H5R_create(void *_ref, H5G_entry_t *loc, const char *name, H5R_type_t ref_type,
         }
 
         case H5R_INTERNAL:
-            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "Internal references are not yet supported");
+            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "Internal references are not yet supported")
 
         case H5R_BADTYPE:
         case H5R_MAXTYPE:
         default:
             assert("unknown reference type" && 0);
-            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)");
+            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)")
     } /* end switch */
 
 done:
-    FUNC_LEAVE_NOAPI(ret_value);
+    FUNC_LEAVE_NOAPI(ret_value)
 }   /* end H5R_create() */
 
 
@@ -266,33 +267,33 @@ done:
 herr_t
 H5Rcreate(void *ref, hid_t loc_id, const char *name, H5R_type_t ref_type, hid_t space_id)
 {
-    H5G_entry_t *loc = NULL;        /* File location */
+    H5G_loc_t   loc;            /* File location */
     H5S_t	*space = NULL;          /* Pointer to dataspace containing region */
-    herr_t      ret_value;       /* Return value */
+    herr_t      ret_value;      /* Return value */
 
-    FUNC_ENTER_API(H5Rcreate, FAIL);
+    FUNC_ENTER_API(H5Rcreate, FAIL)
     H5TRACE5("e","xisRti",ref,loc_id,name,ref_type,space_id);
 
     /* Check args */
-    if(ref==NULL)
-        HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer");
-    if (NULL==(loc=H5G_loc (loc_id)))
-        HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
-    if (!name || !*name)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name given");
-    if(ref_type<=H5R_BADTYPE || ref_type>=H5R_MAXTYPE)
-        HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type");
-    if(ref_type!=H5R_OBJECT && ref_type!=H5R_DATASET_REGION)
-        HGOTO_ERROR (H5E_ARGS, H5E_UNSUPPORTED, FAIL, "reference type not supported");
-    if (space_id!=(-1) && (NULL==(space=H5I_object_verify(space_id,H5I_DATASPACE))))
-        HGOTO_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace");
+    if(ref == NULL)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer")
+    if(H5G_loc(loc_id, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+    if(!name || !*name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name given")
+    if(ref_type <= H5R_BADTYPE || ref_type >= H5R_MAXTYPE)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type")
+    if(ref_type != H5R_OBJECT && ref_type != H5R_DATASET_REGION)
+        HGOTO_ERROR(H5E_ARGS, H5E_UNSUPPORTED, FAIL, "reference type not supported")
+    if(space_id != (-1) && (NULL == (space = H5I_object_verify(space_id, H5I_DATASPACE))))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
 
     /* Create reference */
-    if ((ret_value=H5R_create(ref,loc,name,ref_type,space, H5AC_dxpl_id))<0)
-        HGOTO_ERROR (H5E_REFERENCE, H5E_CANTINIT, FAIL, "unable to create reference");
+    if((ret_value = H5R_create(ref, &loc, name, ref_type, space, H5AC_dxpl_id)) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "unable to create reference")
 
 done:
-    FUNC_LEAVE_API(ret_value);
+    FUNC_LEAVE_API(ret_value)
 }   /* end H5Rcreate() */
 
 
@@ -321,52 +322,50 @@ done:
 static hid_t
 H5R_dereference(H5F_t *file, hid_t dxpl_id, H5R_type_t ref_type, void *_ref)
 {
-    H5D_t *dset;                /* Pointer to dataset to open */
-    H5T_t *type;                /* Pointer to datatype to open */
-    H5G_t *group;               /* Pointer to group to open */
-    H5G_entry_t ent;            /* Symbol table entry */
+    H5O_loc_t oloc;             /* Object location */
+    H5G_name_t path;            /* Path of object */
+    H5G_loc_t loc;              /* Group location */
     uint8_t *p;                 /* Pointer to OID to store */
     int oid_type;               /* type of object being dereferenced */
     hid_t ret_value;
 
-    FUNC_ENTER_NOAPI_NOINIT(H5R_dereference);
+    FUNC_ENTER_NOAPI_NOINIT(H5R_dereference)
 
-    assert(_ref);
-    assert(ref_type>H5R_BADTYPE || ref_type<H5R_MAXTYPE);
-    assert(file);
+    HDassert(_ref);
+    HDassert(ref_type > H5R_BADTYPE || ref_type < H5R_MAXTYPE);
+    HDassert(file);
 
-    /* Initialize the symbol table entry */
-    H5G_ent_reset(&ent);
-    ent.type=H5G_NOTHING_CACHED;
-    ent.file=file;
+    /* Initialize the object location */
+    H5O_loc_reset(&oloc);
+    oloc.file = file;
 
     switch(ref_type) {
         case H5R_OBJECT:
         {
-            hobj_ref_t *ref=(hobj_ref_t *)_ref; /* Only object references currently supported */
+            hobj_ref_t *ref = (hobj_ref_t *)_ref; /* Only object references currently supported */
 
-            ent.header=*ref;
+            oloc.addr = *ref;
         } /* end case */
         break;
 
         case H5R_DATASET_REGION:
         {
-            hdset_reg_ref_t *ref=(hdset_reg_ref_t *)_ref; /* Get pointer to correct type of reference struct */
+            hdset_reg_ref_t *ref = (hdset_reg_ref_t *)_ref; /* Get pointer to correct type of reference struct */
             H5HG_t hobjid;  /* Heap object ID */
             uint8_t *buf;   /* Buffer to store serialized selection in */
 
             /* Get the heap ID for the dataset region */
-            p=(uint8_t *)ref;
-            H5F_addr_decode(ent.file,(const uint8_t **)&p,&(hobjid.addr));
-            INT32DECODE(p,hobjid.idx);
+            p = (uint8_t *)ref;
+            H5F_addr_decode(oloc.file, (const uint8_t **)&p, &(hobjid.addr));
+            INT32DECODE(p, hobjid.idx);
 
             /* Get the dataset region from the heap (allocate inside routine) */
-            if((buf=H5HG_read(ent.file,dxpl_id,&hobjid,NULL))==NULL)
-                HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, FAIL, "Unable to read dataset region information");
+            if((buf = H5HG_read(oloc.file, dxpl_id, &hobjid, NULL)) == NULL)
+                HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, FAIL, "Unable to read dataset region information")
 
             /* Get the object oid for the dataset */
-            p=(uint8_t *)buf;
-            H5F_addr_decode(ent.file,(const uint8_t **)&p,&(ent.header));
+            p = (uint8_t *)buf;
+            H5F_addr_decode(oloc.file, (const uint8_t **)&p, &(oloc.addr));
 
             /* Free the buffer allocated in H5HG_read() */
             H5MM_xfree(buf);
@@ -374,62 +373,79 @@ H5R_dereference(H5F_t *file, hid_t dxpl_id, H5R_type_t ref_type, void *_ref)
         break;
 
         case H5R_INTERNAL:
-            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "Internal references are not yet supported");
+            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "Internal references are not yet supported")
 
         case H5R_BADTYPE:
         case H5R_MAXTYPE:
         default:
-            assert("unknown reference type" && 0);
-            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)");
+            HDassert("unknown reference type" && 0);
+            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)")
     } /* end switch */
 
     /* Check to make certain that this object hasn't been deleted since the reference was created */
-    if(H5O_link(&ent,0,dxpl_id)<=0)
-        HGOTO_ERROR(H5E_REFERENCE, H5E_LINKCOUNT, FAIL, "dereferencing deleted object");
+    if(H5O_link(&oloc, 0, dxpl_id) <= 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_LINKCOUNT, FAIL, "dereferencing deleted object")
+
+    /* Construct a group location for opening the object */
+    H5G_name_reset(&path);
+    loc.oloc = &oloc;
+    loc.path = &path;
 
     /* Open the object */
-    oid_type=H5G_get_type(&ent,dxpl_id);
+    oid_type = H5O_obj_type(&oloc, dxpl_id);
     switch(oid_type) {
         case H5G_GROUP:
-            if ((group=H5G_open(&ent,dxpl_id)) == NULL)
-                HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "not found");
-
-            /* Create an atom for the group */
-            if ((ret_value = H5I_register(H5I_GROUP, group)) < 0) {
-                H5G_close(group);
-                HGOTO_ERROR(H5E_SYM, H5E_CANTREGISTER, FAIL, "can't register group");
-            }
+            {
+                H5G_t *group;               /* Pointer to group to open */
+
+                if((group = H5G_open(&loc, dxpl_id)) == NULL)
+                    HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "not found")
+
+                /* Create an atom for the group */
+                if((ret_value = H5I_register(H5I_GROUP, group)) < 0) {
+                    H5G_close(group);
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTREGISTER, FAIL, "can't register group")
+                } /* end if */
+            } /* end case */
             break;
 
         case H5G_TYPE:
-            if ((type=H5T_open(&ent, dxpl_id)) == NULL)
-                HGOTO_ERROR(H5E_DATATYPE, H5E_NOTFOUND, FAIL, "not found");
-
-            /* Create an atom for the datatype */
-            if ((ret_value = H5I_register(H5I_DATATYPE, type)) < 0) {
-                H5T_close(type);
-                HGOTO_ERROR(H5E_DATATYPE, H5E_CANTREGISTER, FAIL, "can't register datatype");
-            }
+            {
+                H5T_t *type;                /* Pointer to datatype to open */
+
+                if((type = H5T_open(&loc, dxpl_id)) == NULL)
+                    HGOTO_ERROR(H5E_DATATYPE, H5E_NOTFOUND, FAIL, "not found")
+
+                /* Create an atom for the datatype */
+                if((ret_value = H5I_register(H5I_DATATYPE, type)) < 0) {
+                    H5T_close(type);
+                    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTREGISTER, FAIL, "can't register datatype")
+                } /* end if */
+            } /* end case */
             break;
 
         case H5G_DATASET:
-            /* Open the dataset */
-            if ((dset=H5D_open(&ent,dxpl_id))==NULL)
-                HGOTO_ERROR(H5E_DATASET, H5E_NOTFOUND, FAIL, "not found");
-
-            /* Create an atom for the dataset */
-            if ((ret_value = H5I_register(H5I_DATASET, dset)) < 0) {
-                H5D_close(dset);
-                HGOTO_ERROR(H5E_DATASET, H5E_CANTREGISTER, FAIL, "can't register dataset");
-            }
+            {
+                H5D_t *dset;                /* Pointer to dataset to open */
+
+                /* Open the dataset */
+                if((dset = H5D_open(&loc, dxpl_id)) == NULL)
+                    HGOTO_ERROR(H5E_DATASET, H5E_NOTFOUND, FAIL, "not found")
+
+                /* Create an atom for the dataset */
+                if((ret_value = H5I_register(H5I_DATASET, dset)) < 0) {
+                    H5D_close(dset);
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTREGISTER, FAIL, "can't register dataset")
+                } /* end if */
+            } /* end case */
             break;
 
         default:
-            HGOTO_ERROR(H5E_REFERENCE, H5E_BADTYPE, FAIL, "can't identify type of object referenced");
+            HGOTO_ERROR(H5E_REFERENCE, H5E_BADTYPE, FAIL, "can't identify type of object referenced")
      } /* end switch */
 
 done:
-    FUNC_LEAVE_NOAPI(ret_value);
+    FUNC_LEAVE_NOAPI(ret_value)
 }   /* end H5R_dereference() */
 
 
@@ -458,30 +474,30 @@ done:
 hid_t
 H5Rdereference(hid_t id, H5R_type_t ref_type, void *_ref)
 {
-    H5G_entry_t *loc = NULL;    /* Symbol table entry */
-    H5F_t *file=NULL;       /* File object */
+    H5G_loc_t loc;      /* Group location */
+    H5F_t *file = NULL; /* File object */
     hid_t ret_value;
 
-    FUNC_ENTER_API(H5Rdereference, FAIL);
+    FUNC_ENTER_API(H5Rdereference, FAIL)
     H5TRACE3("i","iRtx",id,ref_type,_ref);
 
     /* Check args */
-    if (NULL == (loc = H5G_loc(id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
-    if(ref_type<=H5R_BADTYPE || ref_type>=H5R_MAXTYPE)
-        HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type");
-    if(_ref==NULL)
-        HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer");
+    if(H5G_loc(id, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+    if(ref_type <= H5R_BADTYPE || ref_type >= H5R_MAXTYPE)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type")
+    if(_ref == NULL)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer")
 
     /* Get the file pointer from the entry */
-    file=loc->file;
+    file = loc.oloc->file;
 
     /* Create reference */
-    if ((ret_value=H5R_dereference(file, H5AC_dxpl_id, ref_type, _ref))<0)
-        HGOTO_ERROR (H5E_REFERENCE, H5E_CANTINIT, FAIL, "unable dereference object");
+    if((ret_value = H5R_dereference(file, H5AC_dxpl_id, ref_type, _ref)) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "unable dereference object")
 
 done:
-    FUNC_LEAVE_API(ret_value);
+    FUNC_LEAVE_API(ret_value)
 }   /* end H5Rdereference() */
 
 
@@ -493,7 +509,6 @@ done:
  USAGE
     H5S_t *H5R_get_region(file, ref_type, ref)
         H5F_t *file;        IN: File the object being dereferenced is within
-        H5R_type_t ref_type;    UNUSED
         void *ref;          IN: Reference to open.
 
  RETURNS
@@ -508,52 +523,50 @@ done:
  REVISION LOG
 --------------------------------------------------------------------------*/
 static H5S_t *
-H5R_get_region(H5F_t *file, hid_t dxpl_id, H5R_type_t UNUSED ref_type, void *_ref)
+H5R_get_region(H5F_t *file, hid_t dxpl_id, void *_ref)
 {
-    H5G_entry_t ent;            /* Symbol table entry */
+    H5O_loc_t oloc;             /* Object location */
     uint8_t *p;                 /* Pointer to OID to store */
-    hdset_reg_ref_t *ref=(hdset_reg_ref_t *)_ref; /* Get pointer to correct type of reference struct */
+    hdset_reg_ref_t *ref = (hdset_reg_ref_t *)_ref; /* Get pointer to correct type of reference struct */
     H5HG_t hobjid;  /* Heap object ID */
     uint8_t *buf;   /* Buffer to store serialized selection in */
     H5S_t *ret_value;
 
-    FUNC_ENTER_NOAPI_NOINIT(H5R_get_region);
+    FUNC_ENTER_NOAPI_NOINIT(H5R_get_region)
 
-    assert(_ref);
-    assert(ref_type==H5R_DATASET_REGION);
-    assert(file);
+    HDassert(_ref);
+    HDassert(file);
 
-    /* Initialize the symbol table entry */
-    H5G_ent_reset(&ent);
-    ent.type=H5G_NOTHING_CACHED;
-    ent.file=file;
+    /* Initialize the object location */
+    H5O_loc_reset(&oloc);
+    oloc.file = file;
 
     /* Get the heap ID for the dataset region */
-    p=(uint8_t *)ref;
-    H5F_addr_decode(ent.file,(const uint8_t **)&p,&(hobjid.addr));
+    p = (uint8_t *)ref;
+    H5F_addr_decode(oloc.file, (const uint8_t **)&p, &(hobjid.addr));
     INT32DECODE(p,hobjid.idx);
 
     /* Get the dataset region from the heap (allocate inside routine) */
-    if((buf=H5HG_read(ent.file,dxpl_id,&hobjid,NULL))==NULL)
-        HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, NULL, "Unable to read dataset region information");
+    if((buf = H5HG_read(oloc.file, dxpl_id, &hobjid, NULL)) == NULL)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, NULL, "Unable to read dataset region information")
 
     /* Get the object oid for the dataset */
-    p=(uint8_t *)buf;
-    H5F_addr_decode(ent.file,(const uint8_t **)&p,&(ent.header));
+    p = (uint8_t *)buf;
+    H5F_addr_decode(oloc.file, (const uint8_t **)&p, &(oloc.addr));
 
     /* Open and copy the dataset's dataspace */
-    if ((ret_value=H5S_read(&ent, dxpl_id)) == NULL)
-        HGOTO_ERROR(H5E_DATASPACE, H5E_NOTFOUND, NULL, "not found");
+    if((ret_value = H5S_read(&oloc, dxpl_id)) == NULL)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_NOTFOUND, NULL, "not found")
 
     /* Unserialize the selection */
-    if (H5S_select_deserialize(ret_value,p) < 0)
-        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, NULL, "can't deserialize selection");
+    if(H5S_select_deserialize(ret_value, p) < 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, NULL, "can't deserialize selection")
 
     /* Free the buffer allocated in H5HG_read() */
     H5MM_xfree(buf);
 
 done:
-    FUNC_LEAVE_NOAPI(ret_value);
+    FUNC_LEAVE_NOAPI(ret_value)
 }   /* end H5R_get_region() */
 
 
@@ -581,37 +594,33 @@ done:
  REVISION LOG
 --------------------------------------------------------------------------*/
 hid_t
-H5Rget_region(hid_t id, H5R_type_t ref_type, void *_ref)
+H5Rget_region(hid_t id, H5R_type_t ref_type, void *ref)
 {
-    H5G_entry_t *loc = NULL;    /* Symbol table entry */
-    H5S_t *space = NULL;    /* dataspace object */
-    H5F_t *file=NULL;       /* File object */
+    H5G_loc_t loc;          /* Object's group location */
+    H5S_t *space = NULL;    /* Dataspace object */
     hid_t ret_value;
 
-    FUNC_ENTER_API(H5Rget_region, FAIL);
-    H5TRACE3("i","iRtx",id,ref_type,_ref);
+    FUNC_ENTER_API(H5Rget_region, FAIL)
+    H5TRACE3("i","iRtx",id,ref_type,ref);
 
     /* Check args */
-    if (NULL == (loc = H5G_loc(id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location");
-    if(ref_type!=H5R_DATASET_REGION)
-        HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type");
-    if(_ref==NULL)
-        HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer");
-
-    /* Get the file pointer from the entry */
-    file=loc->file;
+    if(H5G_loc(id, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+    if(ref_type != H5R_DATASET_REGION)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type")
+    if(ref == NULL)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer")
 
     /* Get the dataspace with the correct region selected */
-    if ((space=H5R_get_region(file,H5AC_ind_dxpl_id,ref_type,_ref))==NULL)
-        HGOTO_ERROR (H5E_REFERENCE, H5E_CANTCREATE, FAIL, "unable to create dataspace");
+    if((space = H5R_get_region(loc.oloc->file, H5AC_ind_dxpl_id, ref)) == NULL)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCREATE, FAIL, "unable to create dataspace")
 
     /* Atomize */
-    if ((ret_value=H5I_register (H5I_DATASPACE, space))<0)
-        HGOTO_ERROR (H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register dataspace atom");
+    if((ret_value = H5I_register (H5I_DATASPACE, space)) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register dataspace atom")
 
 done:
-    FUNC_LEAVE_API(ret_value);
+    FUNC_LEAVE_API(ret_value)
 }   /* end H5Rget_region() */
 
 
@@ -640,48 +649,47 @@ done:
 static H5G_obj_t
 H5R_get_obj_type(H5F_t *file, hid_t dxpl_id, H5R_type_t ref_type, void *_ref)
 {
-    H5G_entry_t ent;            /* Symbol table entry */
+    H5O_loc_t oloc;             /* Object location */
     uint8_t *p;                 /* Pointer to OID to store */
     H5G_obj_t ret_value;        /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5R_get_obj_type);
+    FUNC_ENTER_NOAPI_NOINIT(H5R_get_obj_type)
 
-    assert(file);
-    assert(_ref);
+    HDassert(file);
+    HDassert(_ref);
 
     /* Initialize the symbol table entry */
-    H5G_ent_reset(&ent);
-    ent.type=H5G_NOTHING_CACHED;
-    ent.file=file;
+    H5O_loc_reset(&oloc);
+    oloc.file = file;
 
     switch(ref_type) {
         case H5R_OBJECT:
         {
-            hobj_ref_t *ref=(hobj_ref_t *)_ref; /* Only object references currently supported */
+            hobj_ref_t *ref = (hobj_ref_t *)_ref; /* Only object references currently supported */
 
             /* Get the object oid */
-            ent.header=*ref;
+            oloc.addr = *ref;
         } /* end case */
         break;
 
         case H5R_DATASET_REGION:
         {
-            hdset_reg_ref_t *ref=(hdset_reg_ref_t *)_ref; /* Get pointer to correct type of reference struct */
+            hdset_reg_ref_t *ref = (hdset_reg_ref_t *)_ref; /* Get pointer to correct type of reference struct */
             H5HG_t hobjid;  /* Heap object ID */
             uint8_t *buf;   /* Buffer to store serialized selection in */
 
             /* Get the heap ID for the dataset region */
-            p=(uint8_t *)ref;
-            H5F_addr_decode(ent.file,(const uint8_t **)&p,&(hobjid.addr));
-            INT32DECODE(p,hobjid.idx);
+            p = (uint8_t *)ref;
+            H5F_addr_decode(oloc.file, (const uint8_t **)&p, &(hobjid.addr));
+            INT32DECODE(p, hobjid.idx);
 
             /* Get the dataset region from the heap (allocate inside routine) */
-            if((buf=H5HG_read(ent.file,dxpl_id,&hobjid,NULL))==NULL)
-                HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, H5G_UNKNOWN, "Unable to read dataset region information");
+            if((buf = H5HG_read(oloc.file, dxpl_id, &hobjid, NULL)) == NULL)
+                HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, H5G_UNKNOWN, "Unable to read dataset region information")
 
             /* Get the object oid for the dataset */
-            p=(uint8_t *)buf;
-            H5F_addr_decode(ent.file,(const uint8_t **)&p,&(ent.header));
+            p = (uint8_t *)buf;
+            H5F_addr_decode(oloc.file, (const uint8_t **)&p, &(oloc.addr));
 
             /* Free the buffer allocated in H5HG_read() */
             H5MM_xfree(buf);
@@ -689,24 +697,24 @@ H5R_get_obj_type(H5F_t *file, hid_t dxpl_id, H5R_type_t ref_type, void *_ref)
         break;
 
         case H5R_INTERNAL:
-            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, H5G_UNKNOWN, "Internal references are not yet supported");
+            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, H5G_UNKNOWN, "Internal references are not yet supported")
 
         case H5R_BADTYPE:
         case H5R_MAXTYPE:
         default:
-            assert("unknown reference type" && 0);
-            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, H5G_UNKNOWN, "internal error (unknown reference type)");
+            HDassert("unknown reference type" && 0);
+            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, H5G_UNKNOWN, "internal error (unknown reference type)")
     } /* end switch */
 
     /* Check to make certain that this object hasn't been deleted since the reference was created */
-    if(H5O_link(&ent,0,dxpl_id)<=0)
-        HGOTO_ERROR(H5E_REFERENCE, H5E_LINKCOUNT, H5G_UNKNOWN, "dereferencing deleted object");
+    if(H5O_link(&oloc, 0, dxpl_id) <= 0)
+        HGOTO_ERROR(H5E_REFERENCE, H5E_LINKCOUNT, H5G_UNKNOWN, "dereferencing deleted object")
 
     /* Get the OID type */
-    ret_value=H5G_get_type(&ent,dxpl_id);
+    ret_value = H5O_obj_type(&oloc,dxpl_id);
 
 done:
-    FUNC_LEAVE_NOAPI(ret_value);
+    FUNC_LEAVE_NOAPI(ret_value)
 }   /* end H5R_get_obj_type() */
 
 
@@ -734,31 +742,27 @@ done:
  REVISION LOG
 --------------------------------------------------------------------------*/
 H5G_obj_t
-H5Rget_obj_type(hid_t id, H5R_type_t ref_type, void *_ref)
+H5Rget_obj_type(hid_t id, H5R_type_t ref_type, void *ref)
 {
-    H5G_entry_t *loc = NULL;    /* Symbol table entry */
-    H5F_t *file=NULL;       /* File object */
+    H5G_loc_t loc;          /* Object location */
     H5G_obj_t ret_value;
 
-    FUNC_ENTER_API(H5Rget_obj_type, H5G_UNKNOWN);
-    H5TRACE3("Go","iRtx",id,ref_type,_ref);
+    FUNC_ENTER_API(H5Rget_obj_type, H5G_UNKNOWN)
+    H5TRACE3("Go","iRtx",id,ref_type,ref);
 
     /* Check args */
-    if (NULL == (loc = H5G_loc(id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5G_UNKNOWN, "not a location");
-    if(ref_type<=H5R_BADTYPE || ref_type>=H5R_MAXTYPE)
-        HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, H5G_UNKNOWN, "invalid reference type");
-    if(_ref==NULL)
-        HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, H5G_UNKNOWN, "invalid reference pointer");
-
-    /* Get the file pointer from the entry */
-    file=loc->file;
+    if(H5G_loc(id, &loc) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5G_UNKNOWN, "not a location")
+    if(ref_type <= H5R_BADTYPE || ref_type >= H5R_MAXTYPE)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5G_UNKNOWN, "invalid reference type")
+    if(ref == NULL)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5G_UNKNOWN, "invalid reference pointer")
 
     /* Get the object information */
-    if ((ret_value=H5R_get_obj_type(file,H5AC_ind_dxpl_id,ref_type,_ref))<0)
-	HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, H5G_UNKNOWN, "unable to determine object type");
+    if((ret_value = H5R_get_obj_type(loc.oloc->file, H5AC_ind_dxpl_id, ref_type, ref)) < 0)
+	HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, H5G_UNKNOWN, "unable to determine object type")
 
 done:
-    FUNC_LEAVE_API(ret_value);
+    FUNC_LEAVE_API(ret_value)
 }   /* end H5Rget_obj_type() */