VFD plugins (#602)

* Implement support for loading of Virtual File Drivers as plugins

Fix plugin caching for VOL connector and VFD plugins

Fix plugin iteration to skip paths that can't be opened

* Enable dynamic loading of VFDs with HDF5_DRIVER environment variable

* Temporarily disable error reporting during H5F_open double file open

* Default to using HDstat in h5_get_file_size for unknown VFDs

* Use macros for some environment variables that HDF5 interprets

* Update "null" and "ctl testing" VFDs

1 files changed, 56 insertions, 0 deletions

diff --git a/tools/src/h5diff/h5diff_common.c b/tools/src/h5diff/h5diff_common.c
index b669087..3d89936 100644
--- a/tools/src/h5diff/h5diff_common.c
+++ b/tools/src/h5diff/h5diff_common.c
@@ -48,6 +48,12 @@ static struct h5_long_options l_opts[] = {{"help", no_arg, 'h'},
                                           {"vol-value-2", require_arg, '4'},
                                           {"vol-name-2", require_arg, '5'},
                                           {"vol-info-2", require_arg, '6'},
+                                          {"vfd-value-1", require_arg, '7'},
+                                          {"vfd-name-1", require_arg, '8'},
+                                          {"vfd-info-1", require_arg, '9'},
+                                          {"vfd-value-2", require_arg, '0'},
+                                          {"vfd-name-2", require_arg, 'Y'},
+                                          {"vfd-info-2", require_arg, 'Z'},
                                           {NULL, 0, '\0'}};
 
 /*-------------------------------------------------------------------------
@@ -432,6 +438,38 @@ parse_command_line(int argc, const char *argv[], const char **fname1, const char
             case '6':
                 opts->vol_info[1].info_string = H5_optarg;
                 break;
+
+            case '7':
+                opts->vfd_info[0].type    = VFD_BY_VALUE;
+                opts->vfd_info[0].u.value = (H5FD_class_value_t)HDatoi(H5_optarg);
+                opts->custom_vfd[0]       = TRUE;
+                break;
+
+            case '8':
+                opts->vfd_info[0].type   = VFD_BY_NAME;
+                opts->vfd_info[0].u.name = H5_optarg;
+                opts->custom_vol[0]      = TRUE;
+                break;
+
+            case '9':
+                opts->vfd_info[0].info = (const void *)H5_optarg;
+                break;
+
+            case '0':
+                opts->vfd_info[1].type    = VFD_BY_VALUE;
+                opts->vfd_info[1].u.value = (H5FD_class_value_t)HDatoi(H5_optarg);
+                opts->custom_vfd[1]       = TRUE;
+                break;
+
+            case 'Y':
+                opts->vfd_info[1].type   = VFD_BY_NAME;
+                opts->vfd_info[1].u.name = H5_optarg;
+                opts->custom_vfd[1]      = TRUE;
+                break;
+
+            case 'Z':
+                opts->vfd_info[1].info = (const void *)H5_optarg;
+                break;
         }
     }
 
@@ -657,6 +695,24 @@ usage(void)
     PRINTVALSTREAM(rawoutstream,
                    "   --vol-info-2            VOL-specific info to pass to the VOL connector used for\n");
     PRINTVALSTREAM(rawoutstream, "                           opening the second HDF5 file specified\n");
+    PRINTVALSTREAM(rawoutstream,
+                   "   --vfd-value-1           Value (ID) of the VFL driver to use for opening the\n");
+    PRINTVALSTREAM(rawoutstream, "                           first HDF5 file specified\n");
+    PRINTVALSTREAM(rawoutstream,
+                   "   --vfd-name-1            Name of the VFL driver to use for opening the first\n");
+    PRINTVALSTREAM(rawoutstream, "                           HDF5 file specified\n");
+    PRINTVALSTREAM(rawoutstream,
+                   "   --vfd-info-1            VFD-specific info to pass to the VFL driver used for\n");
+    PRINTVALSTREAM(rawoutstream, "                           opening the first HDF5 file specified\n");
+    PRINTVALSTREAM(rawoutstream,
+                   "   --vfd-value-2           Value (ID) of the VFL driver to use for opening the\n");
+    PRINTVALSTREAM(rawoutstream, "                           second HDF5 file specified\n");
+    PRINTVALSTREAM(rawoutstream,
+                   "   --vfd-name-2            Name of the VFL driver to use for opening the second\n");
+    PRINTVALSTREAM(rawoutstream, "                           HDF5 file specified\n");
+    PRINTVALSTREAM(rawoutstream,
+                   "   --vfd-info-2            VFD-specific info to pass to the VFL driver used for\n");
+    PRINTVALSTREAM(rawoutstream, "                           opening the second HDF5 file specified\n");
     PRINTVALSTREAM(rawoutstream, "   --follow-symlinks\n");
     PRINTVALSTREAM(rawoutstream,
                    "         Follow symbolic links (soft links and external links and compare the)\n");