[svn-r29182] Re-commit of HDFFV-8740 fix, which adds the ability to configure

external dataset storage path behavior.

This check-in fixes a bug in the original check-in where the
external path stored in the file struct was not copied on reopen
causing subsequent dataset operations to fail.

Tested on: 64-bit Ubuntu 15.10 (Linux 4.2.0 x86_64) gcc 5.2.1
           autotools serial w/ fortran and C++
           autotools parallel (MPICH 3.1.4) w/ fortran

1 files changed, 111 insertions, 2 deletions

diff --git a/src/H5Dint.c b/src/H5Dint.c
index 3e2d212..fe34718 100644
--- a/src/H5Dint.c
+++ b/src/H5Dint.c
@@ -63,6 +63,8 @@ static herr_t H5D__cache_dataspace_info(const H5D_t *dset);
 static herr_t H5D__init_space(H5F_t *file, const H5D_t *dset, const H5S_t *space);
 static herr_t H5D__update_oh_info(H5F_t *file, hid_t dxpl_id, H5D_t *dset,
     hid_t dapl_id);
+static herr_t H5D_build_extfile_prefix(const H5D_t *dset, hid_t dapl_id,
+    char **extfile_prefix);
 static herr_t H5D__open_oid(H5D_t *dataset, hid_t dapl_id, hid_t dxpl_id);
 static herr_t H5D__init_storage(const H5D_io_info_t *io_info, hbool_t full_overwrite,
     hsize_t old_dim[]);
@@ -982,6 +984,84 @@ done:
 } /* end H5D__update_oh_info() */
 
 
+/*--------------------------------------------------------------------------
+ * Function:    H5D_build_extfile_prefix
+ *
+ * Purpose:     Determine the external file prefix to be used and store
+ *              it in extfile_prefix. Stores an empty string if no prefix
+ *              should be used.
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Steffen Kiess
+ *              October 16, 2015
+ *--------------------------------------------------------------------------
+ */
+static herr_t
+H5D_build_extfile_prefix(const H5D_t *dset, hid_t dapl_id, char **extfile_prefix /*out*/)
+{
+    char            *prefix = NULL;       /* prefix used to look for the file               */
+    char            *extpath = NULL;      /* absolute path of directory the HDF5 file is in */
+    size_t          extpath_len;          /* length of extpath                              */
+    size_t          prefix_len;           /* length of prefix                               */
+    size_t          extfile_prefix_len;   /* length of expanded prefix                      */
+    H5P_genplist_t  *plist = NULL;        /* Property list pointer                          */
+    herr_t          ret_value = SUCCEED;  /* Return value                                   */
+    
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HDassert(dset);
+    HDassert(dset->oloc.file);
+
+    extpath = H5F_EXTPATH(dset->oloc.file);
+    HDassert(extpath);
+
+    /* XXX: Future thread-safety note - getenv is not required
+     *      to be reentrant.
+     */
+    prefix = HDgetenv("HDF5_EXTFILE_PREFIX");
+
+    if(prefix == NULL || *prefix == '\0') {
+        /* Set prefix to value of H5D_ACS_EFILE_PREFIX_NAME 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, H5D_ACS_EFILE_PREFIX_NAME, &prefix) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get external file prefix")
+    } /* end if */
+
+    /* Prefix has to be checked for NULL / empty string again because the
+     * code above might have updated it.
+     */
+    if(prefix == NULL || *prefix == '\0' || HDstrcmp(prefix, ".") == 0) {
+        /* filename is interpreted as relative to the current directory,
+         * does not need to be expanded
+         */
+        if(NULL == (*extfile_prefix = (char *)H5MM_strdup("")))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
+    } /* end if */
+    else {
+        if (HDstrncmp(prefix, "${ORIGIN}", HDstrlen("${ORIGIN}")) == 0) {
+            /* Replace ${ORIGIN} at beginning of prefix by directory of HDF5 file */
+            extpath_len = HDstrlen(extpath);
+            prefix_len = HDstrlen(prefix);
+            extfile_prefix_len = extpath_len + prefix_len - HDstrlen("${ORIGIN}") + 1;
+        
+            if(NULL == (*extfile_prefix = (char *)H5MM_malloc(extfile_prefix_len)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to allocate buffer")
+            HDsnprintf(*extfile_prefix, extfile_prefix_len, "%s%s", extpath, prefix + HDstrlen("${ORIGIN}"));
+        } /* end if */
+        else {
+            if(NULL == (*extfile_prefix = (char *)H5MM_strdup(prefix)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
+        } /* end else */
+    } /* end else */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5D_build_extfile_prefix() */
+
+
 /*-------------------------------------------------------------------------
  * Function:	H5D__create
  *
@@ -1151,6 +1231,10 @@ H5D__create(H5F_t *file, hid_t type_id, const H5S_t *space, hid_t dcpl_id,
     /* Indicate that the layout information was initialized */
     layout_init = TRUE;
 
+    /* Set the external file prefix */
+    if(H5D_build_extfile_prefix(new_dset, dapl_id, &new_dset->shared->extfile_prefix) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to initialize external file prefix")
+
     /* Add the dataset to the list of opened objects in the file */
     if(H5FO_top_incr(new_dset->oloc.file, new_dset->oloc.addr) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINC, NULL, "can't incr object ref. count")
@@ -1195,6 +1279,7 @@ done:
             } /* end if */
             if(new_dset->shared->dcpl_id != 0 && H5I_dec_ref(new_dset->shared->dcpl_id) < 0)
                 HDONE_ERROR(H5E_DATASET, H5E_CANTDEC, NULL, "unable to decrement ref count on property list")
+            new_dset->shared->extfile_prefix = (char *)H5MM_xfree(new_dset->shared->extfile_prefix);
             new_dset->shared = H5FL_FREE(H5D_shared_t, new_dset->shared);
         } /* end if */
         new_dset->oloc.file = NULL;
@@ -1288,7 +1373,8 @@ H5D_open(const H5G_loc_t *loc, hid_t dapl_id, hid_t dxpl_id)
 {
     H5D_shared_t    *shared_fo = NULL;
     H5D_t           *dataset = NULL;
-    H5D_t           *ret_value = NULL;          /* Return value */
+    char            *extfile_prefix = NULL;  /* Expanded external file prefix */
+    H5D_t           *ret_value = NULL;       /* Return value */
 
     FUNC_ENTER_NOAPI(NULL)
 
@@ -1307,6 +1393,10 @@ H5D_open(const H5G_loc_t *loc, hid_t dapl_id, hid_t dxpl_id)
     if(H5G_name_copy(&(dataset->path), loc->path, H5_COPY_SHALLOW) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTCOPY, NULL, "can't copy path")
 
+    /* Get the external file prefix */
+    if(H5D_build_extfile_prefix(dataset, dapl_id, &extfile_prefix) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to initialize external file prefix")
+
     /* Check if dataset was already open */
     if(NULL == (shared_fo = (H5D_shared_t *)H5FO_opened(dataset->oloc.file, dataset->oloc.addr))) {
         /* Clear any errors from H5FO_opened() */
@@ -1326,6 +1416,12 @@ H5D_open(const H5G_loc_t *loc, hid_t dapl_id, hid_t dxpl_id)
 
         /* We're the first dataset to use the the shared info */
         dataset->shared->fo_count = 1;
+
+        /* Set the external file prefix */
+        dataset->shared->extfile_prefix = extfile_prefix;
+        /* Prevent string from being freed during done: */
+        extfile_prefix = NULL;
+
     } /* end if */
     else {
         /* Point to shared info */
@@ -1334,6 +1430,12 @@ H5D_open(const H5G_loc_t *loc, hid_t dapl_id, hid_t dxpl_id)
         /* Increment # of datasets using shared information */
         shared_fo->fo_count++;
 
+        /* Check whether the external file prefix of the already open dataset
+         * matches the new external file prefix
+         */
+        if(HDstrcmp(extfile_prefix, dataset->shared->extfile_prefix) != 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTOPENOBJ, NULL, "new external file prefix does not match external file prefix of already open dataset")
+
         /* Check if the object has been opened through the top file yet */
         if(H5FO_top_count(dataset->oloc.file, dataset->oloc.addr) == 0) {
             /* Open the object through this top file */
@@ -1350,11 +1452,15 @@ H5D_open(const H5G_loc_t *loc, hid_t dapl_id, hid_t dxpl_id)
     ret_value = dataset;
 
 done:
+    extfile_prefix = (char *)H5MM_xfree(extfile_prefix);
+
     if(ret_value == NULL) {
         /* Free the location--casting away const*/
         if(dataset) {
-            if(shared_fo == NULL)   /* Need to free shared fo */
+            if(shared_fo == NULL && dataset->shared) {   /* Need to free shared fo */
+                dataset->shared->extfile_prefix = (char *)H5MM_xfree(dataset->shared->extfile_prefix);
                 dataset->shared = H5FL_FREE(H5D_shared_t, dataset->shared);
+            }
 
             H5O_loc_free(&(dataset->oloc));
             H5G_name_free(&(dataset->path));
@@ -1658,6 +1764,9 @@ H5D_close(H5D_t *dataset)
         if(dataset->shared->layout.ops->dest && (dataset->shared->layout.ops->dest)(dataset, H5AC_ind_read_dxpl_id) < 0)
             HDONE_ERROR(H5E_DATASET, H5E_CANTRELEASE, FAIL, "unable to destroy layout info")
 
+        /* Free the external file prefix */
+        dataset->shared->extfile_prefix = (char *)H5MM_xfree(dataset->shared->extfile_prefix);
+
         /* Release layout, fill-value, efl & pipeline messages */
         if(dataset->shared->dcpl_id != H5P_DATASET_CREATE_DEFAULT)
             free_failed |= (H5O_msg_reset(H5O_PLINE_ID, &dataset->shared->dcpl_cache.pline) < 0) ||