Test and document path handling of H5Lcreate_* API (#3829)

2 files changed, 270 insertions, 7 deletions

diff --git a/src/H5Lpublic.h b/src/H5Lpublic.h
index 03b47c5..2bf3c53 100644
--- a/src/H5Lpublic.h
+++ b/src/H5Lpublic.h
@@ -260,9 +260,13 @@ H5_DLL herr_t H5Lcopy(hid_t src_loc, const char *src_name, hid_t dst_loc, const
  *          location and name, respectively, of the new hard link.
  *
  *          \p cur_name and \p dst_name are interpreted relative to \p cur_loc
- *          and \p dst_loc, respectively. If \p cur_loc and \p dst_loc are the
- *          same location, the HDF5 macro #H5L_SAME_LOC can be used for either
- *          parameter (but not both).
+ *          and \p dst_loc, respectively. If a given name begins with \c /,
+ *          then it will be interpreted as absolute path in the file.
+ *          The names of the created links will be the last element of
+ *          each provided path. Prior elements in each path are used to
+ *          locate the parent groups of each new link. If \p cur_loc and
+ *          \p dst_loc are the same location, the HDF5 macro
+ *          #H5L_SAME_LOC can be used for either parameter (but not both).
  *
  *          \p lcpl_id and \p lapl_id are the link creation and access property
  *          lists associated with the new link.
@@ -321,8 +325,10 @@ H5_DLL herr_t H5Lcreate_hard_async(hid_t cur_loc_id, const char *cur_name, hid_t
  *
  *          \p link_loc_id and \p link_name specify the location and name,
  *          respectively, of the new soft link. \p link_name is interpreted
- *          relative to \p link_loc_id and must contain only the name of the soft
- *          link; \p link_name may not contain any additional path elements.
+ *          as a path relative to \p link_loc_id, or an absolute path if it
+ *          begins with \c /. The name of the created link will be the last
+ *          element of the provided path. Prior elements in the path are
+ *          used to locate the parent group of the new link.
  *
  *          If \p link_loc_id is a group identifier, the object pointed to by
  *          \p link_name will be accessed as a member of that group. If
@@ -1190,7 +1196,11 @@ H5_DLL herr_t H5Lvisit_by_name2(hid_t loc_id, const char *group_name, H5_index_t
  *          named \p link_name at the location specified in \p link_loc_id with
  *          user-specified data \p udata.
  *
- *          \p link_name is interpreted relative to \p link_loc_id.
+ *          \p link_name is interpreted relative to \p link_loc_id. If
+ *          \p link_name begins with \c /, then it will be interpreted as
+ *          an absolute path in the file. The name of the created link
+ *          will be the last element of the provided path. Prior elements
+ *          in the path are used to locate the parent group of the new link.
  *
  *          Valid values for the link class of the new link, \p link_type,
  *          include #H5L_TYPE_EXTERNAL and any user-defined link classes that
@@ -1307,7 +1317,10 @@ H5_DLL herr_t H5Lunpack_elink_val(const void *ext_linkval /*in*/, size_t link_si
  *
  *          \p link_loc_id and \p link_name specify the location and name,
  *          respectively, of the new link. \p link_name is interpreted relative
- *          to \p link_loc_id.
+ *          to \p link_loc_id. If \p link_name begins with \c /, then it is
+ *          interpreted as an absolute path in the file. The name of the created
+ *          link will be the last element of the provided path. Prior elements in
+ *          the path are used to locate the parent group of the new link.
  *
  *          \p lcpl_id is the link creation property list used in creating the
  *          new link.
diff --git a/test/links.c b/test/links.c
index 99e0114..e068d71 100644
--- a/test/links.c
+++ b/test/links.c
@@ -22624,6 +22624,253 @@ error:
 } /* end timestamps() */
 
 /*-------------------------------------------------------------------------
+ * Function:    link_path_handling
+ *
+ * Purpose:     Create hard and soft links by relative and absolute paths
+ *
+ * Return:      Success:        0
+ *              Failure:        -1
+ *-------------------------------------------------------------------------
+ */
+static int
+link_path_handling(hid_t fapl, bool new_format)
+{
+
+    hid_t file_id = (H5I_INVALID_HID);
+    hid_t grp1 = (H5I_INVALID_HID), grp2 = (H5I_INVALID_HID);
+    char  filename[NAME_BUF_SIZE];
+
+    if (new_format)
+        TESTING("H5Lcreate path handling (w/new group format)");
+    else
+        TESTING("H5Lcreate path handling");
+
+    /* Create file */
+    h5_fixname(FILENAME[0], fapl, filename, sizeof(filename));
+
+    if ((file_id = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
+        TEST_ERROR;
+
+    /* Create two groups */
+    if ((grp1 = H5Gcreate2(file_id, "grp1", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+    if ((grp2 = H5Gcreate2(grp1, "grp2", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* Create hard link to grp1 that resides in grp2 by relative path */
+    if (H5Lcreate_hard(file_id, "grp1", grp1, "grp2/relative_hard_link", H5P_DEFAULT, H5P_DEFAULT) < 0)
+        TEST_ERROR;
+
+    if (H5Lexists(grp2, "relative_hard_link", H5P_DEFAULT) <= 0)
+        TEST_ERROR;
+
+    /* Create soft link to grp1 that resides in grp2 by relative path */
+    if (H5Lcreate_soft("/grp1", grp1, "grp2/relative_soft_link", H5P_DEFAULT, H5P_DEFAULT) < 0)
+        TEST_ERROR;
+
+    if (H5Lexists(grp2, "relative_soft_link", H5P_DEFAULT) <= 0)
+        TEST_ERROR;
+
+    /* Create hard link to grp1 that resides in grp2 by absolute path */
+    if (H5Lcreate_hard(file_id, "grp1", grp1, "/grp1/grp2/absolute_hard_link", H5P_DEFAULT, H5P_DEFAULT) < 0)
+        TEST_ERROR;
+
+    if (H5Lexists(grp2, "absolute_hard_link", H5P_DEFAULT) <= 0)
+        TEST_ERROR;
+
+    /* Create soft link to grp1 that resides in grp2 by absolute path */
+    if (H5Lcreate_soft("/grp1", grp1, "/grp1/grp2/absolute_soft_link", H5P_DEFAULT, H5P_DEFAULT) < 0)
+        TEST_ERROR;
+
+    if (H5Lexists(grp2, "absolute_soft_link", H5P_DEFAULT) <= 0)
+        TEST_ERROR;
+
+    /* Close groups and file */
+    if (H5Gclose(grp1) < 0)
+        TEST_ERROR;
+    if (H5Gclose(grp2) < 0)
+        TEST_ERROR;
+    if (H5Fclose(file_id) < 0)
+        TEST_ERROR;
+
+    PASSED();
+    return SUCCEED;
+
+error:
+    H5E_BEGIN_TRY
+    {
+        H5Gclose(grp1);
+        H5Gclose(grp2);
+        H5Fclose(file_id);
+    }
+    H5E_END_TRY
+    return FAIL;
+}
+
+/*-------------------------------------------------------------------------
+ * Function:    ext_link_path_handling
+ *
+ * Purpose:     Create external links by relative and absolute paths
+ *
+ * Return:      Success:        0
+ *              Failure:        -1
+ *-------------------------------------------------------------------------
+ */
+static int
+ext_link_path_handling(hid_t fapl, bool new_format)
+{
+
+    hid_t file_id = (H5I_INVALID_HID);
+    hid_t grp1 = (H5I_INVALID_HID), grp2 = (H5I_INVALID_HID);
+    char  filename[NAME_BUF_SIZE];
+
+    if (new_format)
+        TESTING("H5Lcreate external link path handling (w/new group format)");
+    else
+        TESTING("H5Lcreate external link path handling");
+
+    /* Create file */
+    h5_fixname(FILENAME[0], fapl, filename, sizeof(filename));
+
+    if ((file_id = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
+        TEST_ERROR;
+
+    /* Create two groups */
+    if ((grp1 = H5Gcreate2(file_id, "grp1", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+    if ((grp2 = H5Gcreate2(grp1, "grp2", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* Create external link to nonexistent object by relative path */
+    if (H5Lcreate_external("nonexistent_file", "nonexistent_object", grp1, "grp2/relative_ext_link",
+                           H5P_DEFAULT, H5P_DEFAULT) < 0)
+        TEST_ERROR;
+
+    if (H5Lexists(grp2, "relative_ext_link", H5P_DEFAULT) <= 0)
+        TEST_ERROR;
+
+    /* Create external link to nonexistent object by absolute path */
+    if (H5Lcreate_external("nonexistent_file", "nonexistent_object", grp1, "/grp1/grp2/relative_soft_link",
+                           H5P_DEFAULT, H5P_DEFAULT) < 0)
+        TEST_ERROR;
+
+    if (H5Lexists(grp2, "relative_soft_link", H5P_DEFAULT) <= 0)
+        TEST_ERROR;
+
+    /* Close groups and file */
+    if (H5Gclose(grp1) < 0)
+        TEST_ERROR;
+    if (H5Gclose(grp2) < 0)
+        TEST_ERROR;
+    if (H5Fclose(file_id) < 0)
+        TEST_ERROR;
+
+    PASSED();
+    return SUCCEED;
+
+error:
+    H5E_BEGIN_TRY
+    {
+        H5Gclose(grp1);
+        H5Gclose(grp2);
+        H5Fclose(file_id);
+    }
+    H5E_END_TRY
+    return FAIL;
+}
+
+/*-------------------------------------------------------------------------
+ * Function:    ud_link_path_handling
+ *
+ * Purpose:     Create user-defined links by relative and absolute paths
+ *
+ * Return:      Success:        0
+ *              Failure:        -1
+ *-------------------------------------------------------------------------
+ */
+static int
+ud_link_path_handling(hid_t fapl, bool new_format)
+{
+
+    hid_t       file_id = (H5I_INVALID_HID);
+    hid_t       grp1 = (H5I_INVALID_HID), grp2 = (H5I_INVALID_HID);
+    char        filename[NAME_BUF_SIZE];
+    H5L_info2_t li;
+
+    if (new_format)
+        TESTING("H5Lcreate ud link path handling (w/new group format)");
+    else
+        TESTING("H5Lcreate ud link path handling");
+
+    /* Create file */
+    h5_fixname(FILENAME[0], fapl, filename, sizeof(filename));
+
+    if ((file_id = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
+        TEST_ERROR;
+
+    /* Create two groups */
+    if ((grp1 = H5Gcreate2(file_id, "grp1", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+    if ((grp2 = H5Gcreate2(grp1, "grp2", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* Check that UD hard links are not registered */
+    if (H5Lis_registered((H5L_type_t)UD_HARD_TYPE) != false)
+        TEST_ERROR;
+
+    /* Register "user-defined hard links" with the library */
+    if (H5Lregister(UD_hard_class) < 0)
+        TEST_ERROR;
+
+    /* Check that UD hard links are registered */
+    if (H5Lis_registered((H5L_type_t)UD_HARD_TYPE) != true)
+        TEST_ERROR;
+
+    if (H5Lget_info2(file_id, "grp1", &li, H5P_DEFAULT) < 0)
+        TEST_ERROR;
+
+    /* Create user-defined (hard) link to grp1 by relative path */
+    if (H5Lcreate_ud(grp1, "grp2/relative_ud_link", (H5L_type_t)UD_HARD_TYPE, &(li.u.token),
+                     sizeof(li.u.token), H5P_DEFAULT, H5P_DEFAULT) < 0)
+        TEST_ERROR;
+
+    if (H5Lexists(grp2, "relative_ud_link", H5P_DEFAULT) <= 0)
+        TEST_ERROR;
+
+    /* Create user-defined (hard) link to grp1 by absolute path */
+    if (H5Lcreate_ud(grp1, "/grp1/grp2/absolute_ud_link", (H5L_type_t)UD_HARD_TYPE, &(li.u.token),
+                     sizeof(li.u.token), H5P_DEFAULT, H5P_DEFAULT) < 0)
+        TEST_ERROR;
+
+    if (H5Lexists(grp2, "absolute_ud_link", H5P_DEFAULT) <= 0)
+        TEST_ERROR;
+
+    /* Close groups and file */
+    if (H5Gclose(grp1) < 0)
+        TEST_ERROR;
+    if (H5Gclose(grp2) < 0)
+        TEST_ERROR;
+    if (H5Fclose(file_id) < 0)
+        TEST_ERROR;
+    if (H5Lunregister((H5L_type_t)UD_HARD_TYPE) < 0)
+        TEST_ERROR;
+
+    PASSED();
+    return SUCCEED;
+
+error:
+    H5E_BEGIN_TRY
+    {
+        H5Gclose(grp1);
+        H5Gclose(grp2);
+        H5Fclose(file_id);
+        H5Lunregister((H5L_type_t)UD_HARD_TYPE);
+    }
+    H5E_END_TRY
+    return FAIL;
+}
+
+/*-------------------------------------------------------------------------
  * Function:    main
  *
  * Purpose:     Test links
@@ -22697,6 +22944,7 @@ main(void)
             nerrors += ck_new_links(my_fapl, new_format) < 0 ? 1 : 0;
             nerrors += long_links(my_fapl, new_format) < 0 ? 1 : 0;
             nerrors += toomany(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += link_path_handling(my_fapl, new_format) < 0 ? 1 : 0;
 
             /* Test new H5L link creation routine */
             nerrors += test_lcpl(my_fapl, new_format);
@@ -22804,6 +23052,7 @@ main(void)
                     nerrors += external_open_twice(my_fapl, new_format) < 0 ? 1 : 0;
                     nerrors += external_link_with_committed_datatype(my_fapl, new_format) < 0 ? 1 : 0;
                     nerrors += external_link_public_macros(my_fapl, new_format) < 0 ? 1 : 0;
+                    nerrors += ext_link_path_handling(my_fapl, new_format) < 0 ? 1 : 0;
                 } /* with/without external file cache */
             }
 
@@ -22826,6 +23075,7 @@ main(void)
             nerrors += ud_callbacks_deprec(my_fapl, new_format) < 0 ? 1 : 0;
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
             nerrors += ud_link_errors(my_fapl, new_format) < 0 ? 1 : 0;
+            nerrors += ud_link_path_handling(my_fapl, new_format) < 0 ? 1 : 0;
             nerrors += lapl_udata(my_fapl, new_format) < 0 ? 1 : 0;
             nerrors += lapl_nlinks(my_fapl, new_format) < 0 ? 1 : 0;
 #ifndef H5_NO_DEPRECATED_SYMBOLS