HDFFV-10658: setting and getting properties in API context:

1. external file prefix and VDS prefix.
2. the datatype, dataspace, and LCPL of the dataset for VOL connector.

6 files changed, 391 insertions, 42 deletions

diff --git a/src/H5CX.c b/src/H5CX.c
index b56d66d..2bfe559 100644
--- a/src/H5CX.c
+++ b/src/H5CX.c
@@ -189,6 +189,10 @@ typedef struct H5CX_t {
     hid_t dcpl_id;              /* DCPL ID for API operation */
     H5P_genplist_t *dcpl;       /* Dataset Creation Property List */
 
+    /* DAPL */
+    hid_t dapl_id;              /* DAPL ID for API operation */
+    H5P_genplist_t *dapl;       /* Dataset Access Property List */
+
     /* Internal: Object tagging info */
     haddr_t tag;                /* Current object's tag (ohdr chunk #0 address) */
 
@@ -275,8 +279,20 @@ typedef struct H5CX_t {
     hbool_t nlinks_valid;       /* Whether number of soft / UD links to traverse is valid */
 
     /* Cached DCPL properties */
-    hbool_t do_min_dset_ohdr;   /* Whether to minimize dataset object header */
-    hbool_t do_min_dset_ohdr_valid;   /* Whether minimize dataset object header flag is valid */
+    hbool_t   do_min_dset_ohdr;   /* Whether to minimize dataset object header */
+    hbool_t   do_min_dset_ohdr_valid;   /* Whether minimize dataset object header flag is valid */
+    hid_t     vl_prop_dset_type_id;
+    hbool_t   vl_prop_dset_type_id_valid;
+    hid_t     vl_prop_dset_space_id;
+    hbool_t   vl_prop_dset_space_id_valid;
+    hid_t     vl_prop_dset_lcpl_id;
+    hbool_t   vl_prop_dset_lcpl_id_valid;
+
+    /* Cached DAPL properties */
+    char *extfile_prefix;
+    hbool_t extfile_prefix_valid;
+    char *vds_prefix;
+    hbool_t vds_prefix_valid;
 
     /* Cached VOL settings */
     H5VL_connector_prop_t vol_connector_prop;  /* Property for VOL connector ID & info */
@@ -336,8 +352,17 @@ typedef struct H5CX_lapl_cache_t {
 /* (Same as the cached DXPL struct, above, except for the default DCPL) */
 typedef struct H5CX_dcpl_cache_t {
     hbool_t do_min_dset_ohdr;   /* Whether to minimize dataset object header */
+    hid_t   vl_prop_dset_type_id;
+    hid_t   vl_prop_dset_space_id;
+    hid_t   vl_prop_dset_lcpl_id;
 } H5CX_dcpl_cache_t;
 
+/* Typedef for cached default dataset access property list information */
+/* (Same as the cached DXPL struct, above, except for the default DXPL) */
+typedef struct H5CX_dapl_cache_t {
+    char *extfile_prefix;
+    char *vds_prefix;
+} H5CX_dapl_cache_t;
 
 /********************/
 /* Local Prototypes */
@@ -374,6 +399,9 @@ static H5CX_lapl_cache_t H5CX_def_lapl_cache;
 /* Define a "default" dataset creation property list cache structure to use for default DCPLs */
 static H5CX_dcpl_cache_t H5CX_def_dcpl_cache;
 
+/* Define a "default" dataset access property list cache structure to use for default DAPLs */
+static H5CX_dapl_cache_t H5CX_def_dapl_cache;
+
 /* Declare a static free list to manage H5CX_node_t structs */
 H5FL_DEFINE_STATIC(H5CX_node_t);
 
@@ -398,6 +426,7 @@ H5CX__init_package(void)
     H5P_genplist_t *dx_plist;           /* Data transfer property list */
     H5P_genplist_t *la_plist;           /* Link access property list */
     H5P_genplist_t *dc_plist;           /* Dataset creation property list */
+    H5P_genplist_t *da_plist;           /* Dataset access property list */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_STATIC
@@ -511,6 +540,32 @@ H5CX__init_package(void)
     if(H5P_get(dc_plist, H5D_CRT_MIN_DSET_HDR_SIZE_NAME, &H5CX_def_dcpl_cache.do_min_dset_ohdr) < 0)
         HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve dataset minimize flag")
 
+    if(H5P_get(dc_plist, H5VL_PROP_DSET_TYPE_ID, &H5CX_def_dcpl_cache.vl_prop_dset_type_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for datatype id")
+    if(H5P_get(dc_plist, H5VL_PROP_DSET_SPACE_ID, &H5CX_def_dcpl_cache.vl_prop_dset_space_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for space id")
+    if(H5P_get(dc_plist, H5VL_PROP_DSET_LCPL_ID, &H5CX_def_dcpl_cache.vl_prop_dset_lcpl_id) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get property value for lcpl id")
+
+
+
+    /* Reset the "default DAPL cache" information */
+    HDmemset(&H5CX_def_dapl_cache, 0, sizeof(H5CX_dapl_cache_t));
+
+    /* Get the default DAPL cache information */
+
+    /* Get the default dataset access property list */
+    if(NULL == (da_plist = (H5P_genplist_t *)H5I_object(H5P_DATASET_ACCESS_DEFAULT)))
+        HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "not a dataset create property list")
+
+    /* Get the prefix for the external file */
+    if(H5P_peek(da_plist, H5D_ACS_EFILE_PREFIX_NAME, &H5CX_def_dapl_cache.extfile_prefix) < 0)
+        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve prefix for external file")
+
+    /* Get the prefix for the VDS file */
+    if(H5P_peek(da_plist, H5D_ACS_VDS_PREFIX_NAME, &H5CX_def_dapl_cache.vds_prefix) < 0)
+        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve prefix for VDS")
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5CX__init_package() */
@@ -634,6 +689,8 @@ H5CX__push_common(H5CX_node_t *cnode)
 
     /* Set non-zero context info */
     cnode->ctx.dxpl_id = H5P_DATASET_XFER_DEFAULT;
+    cnode->ctx.dcpl_id = H5P_DATASET_CREATE_DEFAULT;
+    cnode->ctx.dapl_id = H5P_DATASET_ACCESS_DEFAULT;
     cnode->ctx.lapl_id = H5P_LINK_ACCESS_DEFAULT;
     cnode->ctx.tag = H5AC__INVALID_TAG;
     cnode->ctx.ring = H5AC_RING_USER;
@@ -1083,6 +1140,7 @@ H5CX_set_apl(hid_t *acspl_id, const H5P_libclass_t *libclass,
         *acspl_id = *libclass->def_plist_id;
     else {
         htri_t is_lapl;         /* Whether the access property list is (or is derived from) a link access property list */
+        htri_t is_dapl;         /* Whether the access property list is (or is derived from) a dataset access property list */
 
 #ifdef H5CX_DEBUG
         /* Sanity check the access property list class */
@@ -1096,6 +1154,12 @@ H5CX_set_apl(hid_t *acspl_id, const H5P_libclass_t *libclass,
         else if(is_lapl)
             (*head)->ctx.lapl_id = *acspl_id;
 
+        /* Check for dataset access property and set API context if so */
+        if((is_dapl = H5P_class_isa(*libclass->pclass, *H5P_CLS_DACC->pclass)) < 0)
+            HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "can't check for dataset access class")
+        else if(is_dapl)
+            (*head)->ctx.dapl_id = *acspl_id;
+
 #ifdef H5_HAVE_PARALLEL
         /* If this routine is not guaranteed to be collective (i.e. it doesn't
          * modify the structural metadata in a file), check if the application
@@ -2324,6 +2388,180 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5CX_get_vl_prop_dset_type_id
+ *
+ * Purpose:     Retrieves the datatype ID of the dataset for VOL connector
+ *
+ * Return:      Non-negative on success / Negative on failure
+ *
+ * Programmer:  Raymond Lu
+ *              March 12, 2019
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5CX_get_vl_prop_dset_type_id(hid_t *dset_type_id)
+{
+    H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity check */
+    HDassert(dset_type_id);
+    HDassert(head && *head);
+    HDassert(H5P_DEFAULT != (*head)->ctx.dcpl_id);
+
+    H5CX_RETRIEVE_PROP_VALID(dcpl, H5P_DATASET_CREATE_DEFAULT, H5VL_PROP_DSET_TYPE_ID, vl_prop_dset_type_id);
+
+    /* Get the value */
+    *dset_type_id = (*head)->ctx.vl_prop_dset_type_id;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5CX_get_vl_prop_dset_type_id */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5CX_get_vl_prop_dset_space_id
+ *
+ * Purpose:     Retrieves the space ID of the dataset for VOL connector
+ *
+ * Return:      Non-negative on success / Negative on failure
+ *
+ * Programmer:  Raymond Lu
+ *              March 12, 2019
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5CX_get_vl_prop_dset_space_id(hid_t *dset_space_id)
+{
+    H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity check */
+    HDassert(dset_space_id);
+    HDassert(head && *head);
+    HDassert(H5P_DEFAULT != (*head)->ctx.dcpl_id);
+
+    H5CX_RETRIEVE_PROP_VALID(dcpl, H5P_DATASET_CREATE_DEFAULT, H5VL_PROP_DSET_SPACE_ID, vl_prop_dset_space_id);
+
+    /* Get the value */
+    *dset_space_id = (*head)->ctx.vl_prop_dset_space_id;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5CX_get_vl_prop_dset_space_id */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5CX_get_vl_prop_dset_space_id
+ *
+ * Purpose:     Retrieves the LCPL ID of the dataset for VOL connector
+ *
+ * Return:      Non-negative on success / Negative on failure
+ *
+ * Programmer:  Raymond Lu
+ *              March 12, 2019
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5CX_get_vl_prop_dset_lcpl_id(hid_t *dset_lcpl_id)
+{
+    H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity check */
+    HDassert(dset_lcpl_id);
+    HDassert(head && *head);
+    HDassert(H5P_DEFAULT != (*head)->ctx.dcpl_id);
+
+    H5CX_RETRIEVE_PROP_VALID(dcpl, H5P_DATASET_CREATE_DEFAULT, H5VL_PROP_DSET_TYPE_ID, vl_prop_dset_lcpl_id);
+
+    /* Get the value */
+    *dset_lcpl_id = (*head)->ctx.vl_prop_dset_lcpl_id;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5CX_get_vl_prop_dset_lcpl_id */
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5CX_get_ext_file_prefix
+ *
+ * Purpose:     Retrieves the prefix for external file
+ *
+ * Return:      Non-negative on success / Negative on failure
+ *
+ * Programmer:  Raymond Lu
+ *              March 6, 2019
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5CX_get_ext_file_prefix(char **extfile_prefix)
+{
+    H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    HDassert(extfile_prefix);
+    HDassert(head && *head);
+    HDassert(H5P_DEFAULT != (*head)->ctx.dapl_id);
+
+    H5CX_RETRIEVE_PROP_VALID(dapl, H5P_DATASET_ACCESS_DEFAULT, H5D_ACS_EFILE_PREFIX_NAME, extfile_prefix);
+
+    /* Get the value */
+    *extfile_prefix = (*head)->ctx.extfile_prefix;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5CX_get_ext_file_prefix */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5CX_get_vds_prefix
+ *
+ * Purpose:     Retrieves the prefix for VDS
+ *
+ * Return:      Non-negative on success / Negative on failure
+ *
+ * Programmer:  Raymond Lu
+ *              March 6, 2019
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5CX_get_vds_prefix(char **vds_prefix)
+{
+    H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    HDassert(vds_prefix);
+    HDassert(head && *head);
+    HDassert(H5P_DEFAULT != (*head)->ctx.dapl_id);
+
+    H5CX_RETRIEVE_PROP_VALID(dapl, H5P_DATASET_ACCESS_DEFAULT, H5D_ACS_VDS_PREFIX_NAME, vds_prefix);
+
+    /* Get the value */
+    *vds_prefix = (*head)->ctx.vds_prefix;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5CX_get_vds_prefix */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5CX_set_tag
  *
  * Purpose:     Sets the object tag for the current API call context.
@@ -2639,6 +2877,106 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5CX_set_nlinks() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5CX_set_vl_prop_dset_type_id
+ *
+ * Purpose:     Sets the datatype ID of the dataset for the current API call context.
+ *
+ * Return:      Non-negative on success / Negative on failure
+ *
+ * Programmer:  Raymond Lu
+ *              March 12, 2019
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5CX_set_vl_prop_dset_type_id(hid_t dset_type_id)
+{
+    H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity check */
+    HDassert(head && *head);
+
+    /* Set the API context value */
+    (*head)->ctx.vl_prop_dset_type_id = dset_type_id;
+
+    /* Mark the value as valid */
+    (*head)->ctx.vl_prop_dset_type_id_valid = TRUE;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5CX_set_vl_prop_dset_type_id */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5CX_set_vl_prop_dset_space_id
+ *
+ * Purpose:     Sets the data space ID of the dataset for the current API call context.
+ *
+ * Return:      Non-negative on success / Negative on failure
+ *
+ * Programmer:  Raymond Lu
+ *              March 12, 2019
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5CX_set_vl_prop_dset_space_id(hid_t dset_space_id)
+{
+    H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity check */
+    HDassert(head && *head);
+
+    /* Set the API context value */
+    (*head)->ctx.vl_prop_dset_space_id = dset_space_id;
+
+    /* Mark the value as valid */
+    (*head)->ctx.vl_prop_dset_space_id_valid = TRUE;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5CX_set_vl_prop_dset_space_id */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5CX_set_vl_prop_dset_lcpl_id
+ *
+ * Purpose:     Sets the LCPL ID of the dataset for the current API call context.
+ *
+ * Return:      Non-negative on success / Negative on failure
+ *
+ * Programmer:  Raymond Lu
+ *              March 12, 2019
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5CX_set_vl_prop_dset_lcpl_id(hid_t dset_lcpl_id)
+{
+    H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity check */
+    HDassert(head && *head);
+
+    /* Set the API context value */
+    (*head)->ctx.vl_prop_dset_lcpl_id = dset_lcpl_id;
+
+    /* Mark the value as valid */
+    (*head)->ctx.vl_prop_dset_lcpl_id_valid = TRUE;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+}
+
 #ifdef H5_HAVE_PARALLEL
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5CXprivate.h b/src/H5CXprivate.h
index 80f1ac4..f022d8e 100644
--- a/src/H5CXprivate.h
+++ b/src/H5CXprivate.h
@@ -126,6 +126,13 @@ H5_DLL herr_t H5CX_get_nlinks(size_t *nlinks);
 
 /* "Getter" routines for DCPL properties cached in API context */
 H5_DLL herr_t H5CX_get_dset_min_ohdr_flag(hbool_t *dset_min_ohdr_flag);
+H5_DLL herr_t H5CX_get_vl_prop_dset_type_id(hid_t *dset_type_id);
+H5_DLL herr_t H5CX_get_vl_prop_dset_space_id(hid_t *dset_space_id);
+H5_DLL herr_t H5CX_get_vl_prop_dset_lcpl_id(hid_t *dset_lcpl_id);
+
+/* "Getter" routines for DAPL properties cached in API context */
+H5_DLL herr_t H5CX_get_ext_file_prefix(char **prefix_extfile);
+H5_DLL herr_t H5CX_get_vds_prefix(char **prefix_vds);
 
 /* "Setter" routines for API context info */
 H5_DLL void H5CX_set_tag(haddr_t tag);
@@ -145,6 +152,11 @@ H5_DLL herr_t H5CX_set_io_xfer_mode(H5FD_mpio_xfer_t io_xfer_mode);
 H5_DLL herr_t H5CX_set_vlen_alloc_info(H5MM_allocate_t alloc_func,
     void *alloc_info, H5MM_free_t free_func, void *free_info);
 
+/* "Setter" routines for DCPL properties cached in API context */
+H5_DLL herr_t H5CX_set_vl_prop_dset_type_id(hid_t dset_type_id);
+H5_DLL herr_t H5CX_set_vl_prop_dset_space_id(hid_t dset_space_id);
+H5_DLL herr_t H5CX_set_vl_prop_dset_lcpl_id(hid_t dset_lcpl_id);
+
 /* "Setter" routines for LAPL properties cached in API context */
 H5_DLL herr_t H5CX_set_nlinks(size_t nlinks);
 
diff --git a/src/H5D.c b/src/H5D.c
index fc350f2..a50518d 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -135,6 +135,9 @@ H5Dcreate2(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
         if(TRUE != H5P_isa_class(dcpl_id, H5P_DATASET_CREATE))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "dcpl_id is not a dataset create property list ID")
 
+    /* Set the DCPL for the API context */
+    H5CX_set_dcpl(dcpl_id);
+
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&dapl_id, H5P_CLS_DACC, loc_id, TRUE) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
@@ -148,12 +151,9 @@ H5Dcreate2(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
 
     /* Set creation properties */
-    if(H5P_set(plist, H5VL_PROP_DSET_TYPE_ID, &type_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for datatype id")
-    if(H5P_set(plist, H5VL_PROP_DSET_SPACE_ID, &space_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for space id")
-    if(H5P_set(plist, H5VL_PROP_DSET_LCPL_ID, &lcpl_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for lcpl id")
+    H5CX_set_vl_prop_dset_type_id(type_id);
+    H5CX_set_vl_prop_dset_space_id(space_id);
+    H5CX_set_vl_prop_dset_lcpl_id(lcpl_id);
 
     /* Set location parameters */
     loc_params.type         = H5VL_OBJECT_BY_SELF;
@@ -228,6 +228,9 @@ H5Dcreate_anon(hid_t loc_id, hid_t type_id, hid_t space_id, hid_t dcpl_id,
         if(TRUE != H5P_isa_class(dcpl_id, H5P_DATASET_CREATE))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not dataset create property list ID")
 
+    /* Set the DCPL for the API context */
+    H5CX_set_dcpl(dcpl_id);
+
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&dapl_id, H5P_CLS_DACC, loc_id, TRUE) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
@@ -241,10 +244,8 @@ H5Dcreate_anon(hid_t loc_id, hid_t type_id, hid_t space_id, hid_t dcpl_id,
         HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, H5I_INVALID_HID, "can't find object for ID")
 
     /* set creation properties */
-    if(H5P_set(plist, H5VL_PROP_DSET_TYPE_ID, &type_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for datatype id")
-    if(H5P_set(plist, H5VL_PROP_DSET_SPACE_ID, &space_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for space id")
+    H5CX_set_vl_prop_dset_type_id(type_id);
+    H5CX_set_vl_prop_dset_space_id(space_id);
 
     /* Set location parameters */
     loc_params.type     = H5VL_OBJECT_BY_SELF;
diff --git a/src/H5Ddeprec.c b/src/H5Ddeprec.c
index 76827b4..70e6f70 100644
--- a/src/H5Ddeprec.c
+++ b/src/H5Ddeprec.c
@@ -136,6 +136,9 @@ H5Dcreate1(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
         if(TRUE != H5P_isa_class(dcpl_id, H5P_DATASET_CREATE))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not dataset create property list ID")
 
+    /* Set the DCPL for the API context */
+    H5CX_set_dcpl(dcpl_id);
+
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&dapl_id, H5P_CLS_DACC, loc_id, TRUE) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
@@ -145,12 +148,9 @@ H5Dcreate1(hid_t loc_id, const char *name, hid_t type_id, hid_t space_id,
         HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, H5I_INVALID_HID, "can't find object for ID")
 
     /* set creation properties */
-    if(H5P_set(plist, H5VL_PROP_DSET_TYPE_ID, &type_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for datatype id")
-    if(H5P_set(plist, H5VL_PROP_DSET_SPACE_ID, &space_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for space id")
-    if(H5P_set(plist, H5VL_PROP_DSET_LCPL_ID, &lcpl_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, H5I_INVALID_HID, "can't set property value for lcpl id")
+    H5CX_set_vl_prop_dset_type_id(type_id);
+    H5CX_set_vl_prop_dset_space_id(space_id);
+    H5CX_set_vl_prop_dset_lcpl_id(lcpl_id);
 
     /* Set location parameters */
     loc_params.type = H5VL_OBJECT_BY_SELF;
diff --git a/src/H5Dint.c b/src/H5Dint.c
index 384c66b..ae9a40e 100644
--- a/src/H5Dint.c
+++ b/src/H5Dint.c
@@ -488,9 +488,6 @@ H5D__new(hid_t dcpl_id, hbool_t creating, hbool_t vl_type)
         new_dset->dcpl_id = H5P_copy_plist(plist, FALSE);
     } /* end else */
 
-    /* Set the DCPL for the API context */
-    H5CX_set_dcpl(new_dset->dcpl_id);
-
     /* Set return value */
     ret_value = new_dset;
 
@@ -1083,8 +1080,7 @@ done:
  *--------------------------------------------------------------------------
  */
 static herr_t
-H5D__build_file_prefix(const H5D_t *dset, hid_t dapl_id, const char *prefix_type,
-    char **file_prefix /*out*/)
+H5D__build_file_prefix(const H5D_t *dset, hid_t dapl_id, const char *prefix_type, char **file_prefix /*out*/)
 {
     char            *prefix = NULL;       /* prefix used to look for the file               */
     char            *filepath = NULL;     /* absolute path of directory the HDF5 file is in */
@@ -1105,20 +1101,22 @@ H5D__build_file_prefix(const H5D_t *dset, hid_t dapl_id, const char *prefix_type
     /* XXX: Future thread-safety note - getenv is not required
      *      to be reentrant.
      */
-    if(HDstrcmp(prefix_type, H5D_ACS_VDS_PREFIX_NAME) == 0)
+    if(HDstrcmp(prefix_type, H5D_ACS_VDS_PREFIX_NAME) == 0) {
         prefix = HDgetenv("HDF5_VDS_PREFIX");
-    else if(HDstrcmp(prefix_type, H5D_ACS_EFILE_PREFIX_NAME) == 0)
+
+        if(prefix == NULL || *prefix == '\0') {
+            if(H5CX_get_vds_prefix(&prefix) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get the prefix for vds file")
+        }
+    } else if(HDstrcmp(prefix_type, H5D_ACS_EFILE_PREFIX_NAME) == 0) {
         prefix = HDgetenv("HDF5_EXTFILE_PREFIX");
-    else
-        HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "prefix name is not sensible")
 
-    if(prefix == NULL || *prefix == '\0') {
-        /* Set prefix to value of prefix_type property */
-        if(NULL == (plist = H5P_object_verify(dapl_id, H5P_DATASET_ACCESS)))
-            HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
-        if(H5P_peek(plist, prefix_type, &prefix) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get file prefix")
-    } /* end if */
+        if(prefix == NULL || *prefix == '\0') {
+            if(H5CX_get_ext_file_prefix(&prefix) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get the prefix for the external file")
+        }
+    } else
+        HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "prefix name is not sensible")
 
     /* Prefix has to be checked for NULL / empty string again because the
      * code above might have updated it.
@@ -1552,8 +1550,10 @@ H5D_open(const H5G_loc_t *loc, hid_t dapl_id)
     ret_value = dataset;
 
 done:
-    extfile_prefix = (char *)H5MM_xfree(extfile_prefix);
-    vds_prefix = (char *)H5MM_xfree(vds_prefix);
+    if(extfile_prefix)
+        extfile_prefix = (char *)H5MM_xfree(extfile_prefix);
+    if(vds_prefix)
+        vds_prefix = (char *)H5MM_xfree(vds_prefix);
 
     if(ret_value == NULL) {
         /* Free the location--casting away const*/
diff --git a/src/H5VLnative_dataset.c b/src/H5VLnative_dataset.c
index 8f7351c..ac25c55 100644
--- a/src/H5VLnative_dataset.c
+++ b/src/H5VLnative_dataset.c
@@ -18,6 +18,7 @@
 #define H5D_FRIEND              /* Suppress error about including H5Dpkg    */
 
 #include "H5private.h"          /* Generic Functions                        */
+#include "H5CXprivate.h"        /* API Contexts                             */
 #include "H5Dpkg.h"             /* Datasets                                 */
 #include "H5Eprivate.h"         /* Error handling                           */
 #include "H5Fprivate.h"         /* Files                                    */
@@ -62,12 +63,9 @@ H5VL__native_dataset_create(void *obj, const H5VL_loc_params_t *loc_params,
         HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, NULL, "can't find object for ID")
 
     /* Get creation properties */
-    if(H5P_get(plist, H5VL_PROP_DSET_TYPE_ID, &type_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for datatype id")
-    if(H5P_get(plist, H5VL_PROP_DSET_SPACE_ID, &space_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for space id")
-    if(H5P_get(plist, H5VL_PROP_DSET_LCPL_ID, &lcpl_id) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get property value for lcpl id")
+    H5CX_get_vl_prop_dset_type_id(&type_id);
+    H5CX_get_vl_prop_dset_space_id(&space_id);
+    H5CX_get_vl_prop_dset_lcpl_id(&lcpl_id);
 
     /* Check arguments */
     if(H5G_loc_real(obj, loc_params->obj_type, &loc) < 0)