Remove some internal use of API calls and H5E_BEGIN_TRY/H5E_END_TRY (H…

…DFGroup#4624)

src/H5Fint.c

@@ -1029,19 +1029,24 @@ H5F_prefix_open_file(bool try, H5F_t **_file, H5F_t *primary_file, H5F_prefix_op
  *
  * Purpose:     Check the file signature to detect an HDF5 file.
  *
- * Return:      true/false/FAIL
+ * Return:      SUCCEED/FAIL
  *-------------------------------------------------------------------------
  */
-htri_t
-H5F__is_hdf5(const char *name, hid_t fapl_id)
+herr_t
+H5F__is_hdf5(const char *name, hid_t fapl_id, bool *is_hdf5)
 {
-    H5FD_t       *lf        = NULL;        /* Low-level file struct            */
-    H5F_shared_t *shared    = NULL;        /* Shared part of file              */
-    haddr_t       sig_addr  = HADDR_UNDEF; /* Address of hdf5 file signature    */
-    htri_t        ret_value = FAIL;        /* Return value                     */
+    H5FD_t       *lf         = NULL;        /* Low-level file struct            */
+    H5F_shared_t *shared     = NULL;        /* Shared part of file              */
+    haddr_t       sig_addr   = HADDR_UNDEF; /* Address of hdf5 file signature    */
+    bool          found_hdf5 = false;       /* Found an HDF5 file */
+    herr_t        ret_value  = SUCCEED;     /* Return value                     */
 
     FUNC_ENTER_PACKAGE
 
+    /* Check output parameter */
+    if (!is_hdf5)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid output param");
+
     /* Open the file */
     /* NOTE:    This now uses the fapl_id that was passed in, so H5Fis_accessible()
      *          should work with arbitrary VFDs, unlike H5Fis_hdf5().
@@ -1056,20 +1061,24 @@ H5F__is_hdf5(const char *name, hid_t fapl_id)
      * to read through it will fail so we have to try this first.
      */
     if (NULL != (shared = H5F__sfile_search(lf)))
-        ret_value = true;
+        found_hdf5 = true;
     else {
         /* The file is an HDF5 file if the HDF5 file signature can be found */
-        if (H5FD_locate_signature(lf, &sig_addr) < 0)
+        if (H5FD_locate_signature(lf, &sig_addr) < 0) {
+            H5FD_close(lf);
             HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, FAIL, "error while trying to locate file signature");
-        ret_value = (HADDR_UNDEF != sig_addr);
+        }
+        found_hdf5 = H5_addr_defined(sig_addr);
     }
 
-done:
     /* Close the file */
-    if (lf)
-        if (H5FD_close(lf) < 0 && true == ret_value)
-            HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "unable to close file");
+    if (H5FD_close(lf) < 0 && found_hdf5)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "unable to close file");
 
+    /* Set output parameter */
+    *is_hdf5 = found_hdf5;
+
+done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5F__is_hdf5() */
 

src/H5Fpkg.h

@@ -411,7 +411,7 @@ H5_DLLVAR htri_t ignore_disabled_locks_g;
 H5_DLL herr_t H5F__post_open(H5F_t *f);
 H5_DLL H5F_t *H5F__reopen(H5F_t *f);
 H5_DLL herr_t H5F__flush(H5F_t *f);
-H5_DLL htri_t H5F__is_hdf5(const char *name, hid_t fapl_id);
+H5_DLL herr_t H5F__is_hdf5(const char *name, hid_t fapl_id, bool *is_hdf5);
 H5_DLL herr_t H5F__get_file_image(H5F_t *f, void *buf_ptr, size_t buf_len, size_t *image_len);
 H5_DLL herr_t H5F__get_info(H5F_t *f, H5F_info2_t *finfo);
 H5_DLL herr_t H5F__format_convert(H5F_t *f);

src/H5VLcallback.c

@@ -3533,11 +3533,9 @@ H5VL__file_open_find_connector_cb(H5PL_type_t plugin_type, const void *plugin_in
     H5P_genplist_t                  *fapl_plist;
     H5P_genplist_t                  *fapl_plist_copy;
     bool                             is_accessible = false; /* Whether file is accessible */
-    ssize_t                          num_errors    = 0;
-    herr_t                           status;
-    hid_t                            connector_id = H5I_INVALID_HID;
-    hid_t                            fapl_id      = H5I_INVALID_HID;
-    herr_t                           ret_value    = H5_ITER_CONT;
+    hid_t                            connector_id  = H5I_INVALID_HID;
+    hid_t                            fapl_id       = H5I_INVALID_HID;
+    herr_t                           ret_value     = H5_ITER_CONT;
 
     FUNC_ENTER_PACKAGE
 
@@ -3572,30 +3570,10 @@ H5VL__file_open_find_connector_cb(H5PL_type_t plugin_type, const void *plugin_in
     vol_cb_args.args.is_accessible.fapl_id    = fapl_id;
     vol_cb_args.args.is_accessible.accessible = &is_accessible;
 
-    /* Store current error stack size */
-    if ((num_errors = H5Eget_num(H5E_DEFAULT)) < 0)
-        HGOTO_ERROR(H5E_ERROR, H5E_CANTGET, H5_ITER_ERROR, "can't get current error stack size");
+    if (H5VL_file_specific(NULL, &vol_cb_args, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, H5_ITER_ERROR, "error when checking for accessible HDF5 file");
 
-    /* Check if file is accessible with given VOL connector */
-    H5E_BEGIN_TRY
-    {
-        status = H5VL_file_specific(NULL, &vol_cb_args, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL);
-    }
-    H5E_END_TRY
-
-    if (status < 0) {
-        ssize_t new_num_errors = 0;
-
-        /* Pop any errors generated by the above call */
-        if ((new_num_errors = H5Eget_num(H5E_DEFAULT)) < 0)
-            HGOTO_ERROR(H5E_ERROR, H5E_CANTGET, H5_ITER_ERROR, "can't get current error stack size");
-        if (new_num_errors > num_errors) {
-            new_num_errors -= num_errors;
-            if (H5Epop(H5E_DEFAULT, (size_t)new_num_errors) < 0)
-                HGOTO_ERROR(H5E_ERROR, H5E_CANTRELEASE, H5_ITER_ERROR, "can't sanitize error stack");
-        }
-    }
-    else if (status == SUCCEED && is_accessible) {
+    if (is_accessible) {
         /* If the file was accessible with the current VOL connector, return
          * the FAPL with that VOL connector set on it.
          */

src/H5VLconnector.h

@@ -441,6 +441,14 @@ typedef enum H5VL_file_specific_t {
     H5VL_FILE_FLUSH,         /* Flush file                       */
     H5VL_FILE_REOPEN,        /* Reopen the file                  */
     H5VL_FILE_IS_ACCESSIBLE, /* Check if a file is accessible    */
+                             /* Note for VOL connector authors:  */
+                             /*  Only return an error from this  */
+                             /*  callback if it is not possible  */
+                             /*  to determine if a file (or      */
+                             /*  container) is accessible.       */
+                             /*  It is _not_ an error to return  */
+                             /*  a 'false' value for the         */
+                             /*  'accessible' argument.          */
     H5VL_FILE_DELETE,        /* Delete a file                    */
     H5VL_FILE_IS_EQUAL       /* Check if two files are the same  */
 } H5VL_file_specific_t;

src/H5VLmodule.h

@@ -362,6 +362,10 @@
  *     htri_t H5Fis_accessible(const char *container_name, hid_t fapl_id)
  * \endcode
  *
+ * Note also that an error is only returned if it is not possible to determine
+ * if a file (or container) is accessible.  It is not an error to return 'false'
+ * for whether the file is accessible.
+ *
  * <h4> H5Oget_info[1|2]() → H5Oget_info3() and H5Oget_native_info()</h4>
  * The \ref H5Oget_info1() and \ref H5Oget_info2() family of HDF5 API calls are often
  * used by user code to obtain information about an object in the file, however

src/H5VLnative_file.c

@@ -339,15 +339,10 @@ H5VL__native_file_specific(void *obj, H5VL_file_specific_args_t *args, hid_t H5_
 
         /* H5Fis_accessible */
         case H5VL_FILE_IS_ACCESSIBLE: {
-            htri_t result;
-
-            if ((result = H5F__is_hdf5(args->args.is_accessible.filename, args->args.is_accessible.fapl_id)) <
-                0)
+            if (H5F__is_hdf5(args->args.is_accessible.filename, args->args.is_accessible.fapl_id,
+                             args->args.is_accessible.accessible) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "error in HDF5 file check");
 
-            /* Set 'out' value */
-            *args->args.is_accessible.accessible = (bool)result;
-
             break;
         }