Implement support for loading of Virtual File Drivers as plugins

Fix plugin caching for VOL connector and VFD plugins

Fix H5Eget_auto2/H5Eauto_is_v2 to not clear error stack

MANIFEST

@@ -1263,6 +1263,8 @@
 ./test/ntypes.c
 ./test/null_vol_connector.c
 ./test/null_vol_connector.h
+./test/null_vfd_plugin.c
+./test/null_vfd_plugin.h
 ./test/objcopy.c
 ./test/objcopy_ref.c
 ./test/ohdr.c
@@ -1371,6 +1373,7 @@
 ./test/vds_swmr_reader.c
 ./test/vds_swmr_writer.c
 ./test/vfd.c
+./test/vfd_plugin.c
 ./test/vol.c
 ./test/vol_plugin.c
 

bin/trace

@@ -53,6 +53,7 @@ $Source = "";
                "H5D_scatter_func_t"         => "DS",
                "H5FD_mpio_xfer_t"           => "Dt",
                "H5D_vds_view_t"             => "Dv",
+               "H5FD_class_value_t"         => "DV",
                "herr_t"                     => "e",
                "H5E_auto1_t"                => "Ea",
                "H5E_auto2_t"                => "EA",

src/H5E.c

@@ -1532,16 +1532,22 @@ H5Eget_auto2(hid_t estack_id, H5E_auto2_t *func /*out*/, void **client_data /*ou
     H5E_auto_op_t op;                  /* Error stack function */
     herr_t        ret_value = SUCCEED; /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    /* Don't clear the error stack! :-) */
+    FUNC_ENTER_API_NOCLEAR(FAIL)
     H5TRACE3("e", "ixx", estack_id, func, client_data);
 
     if (estack_id == H5E_DEFAULT) {
         if (NULL == (estack = H5E__get_my_stack())) /*lint !e506 !e774 Make lint 'constant value Boolean' in
                                                        non-threaded case */
             HGOTO_ERROR(H5E_ERROR, H5E_CANTGET, FAIL, "can't get current error stack")
     } /* end if */
-    else if (NULL == (estack = (H5E_t *)H5I_object_verify(estack_id, H5I_ERROR_STACK)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a error stack ID")
+    else {
+        /* Only clear the error stack if it's not the default stack */
+        H5E_clear_stack(NULL);
+
+        if (NULL == (estack = (H5E_t *)H5I_object_verify(estack_id, H5I_ERROR_STACK)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a error stack ID")
+    } /* end else */
 
     /* Get the automatic error reporting information */
     if (H5E__get_auto(estack, &op, client_data) < 0)
@@ -1598,8 +1604,13 @@ H5Eset_auto2(hid_t estack_id, H5E_auto2_t func, void *client_data)
                                                        non-threaded case */
             HGOTO_ERROR(H5E_ERROR, H5E_CANTGET, FAIL, "can't get current error stack")
     } /* end if */
-    else if (NULL == (estack = (H5E_t *)H5I_object_verify(estack_id, H5I_ERROR_STACK)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a error stack ID")
+    else {
+        /* Only clear the error stack if it's not the default stack */
+        H5E_clear_stack(NULL);
+
+        if (NULL == (estack = (H5E_t *)H5I_object_verify(estack_id, H5I_ERROR_STACK)))
+                HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a error stack ID")
+    } /* end else */
 
 #ifndef H5_NO_DEPRECATED_SYMBOLS
     /* Get the automatic error reporting information */
@@ -1646,16 +1657,22 @@ H5Eauto_is_v2(hid_t estack_id, unsigned *is_stack)
     H5E_t *estack;              /* Error stack to operate on */
     herr_t ret_value = SUCCEED; /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    /* Don't clear the error stack! :-) */
+    FUNC_ENTER_API_NOCLEAR(FAIL)
     H5TRACE2("e", "i*Iu", estack_id, is_stack);
 
     if (estack_id == H5E_DEFAULT) {
         if (NULL == (estack = H5E__get_my_stack())) /*lint !e506 !e774 Make lint 'constant value Boolean' in
                                                        non-threaded case */
             HGOTO_ERROR(H5E_ERROR, H5E_CANTGET, FAIL, "can't get current error stack")
     } /* end if */
-    else if (NULL == (estack = (H5E_t *)H5I_object_verify(estack_id, H5I_ERROR_STACK)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a error stack ID")
+    else {
+        /* Only clear the error stack if it's not the default stack */
+        H5E_clear_stack(NULL);
+
+        if (NULL == (estack = (H5E_t *)H5I_object_verify(estack_id, H5I_ERROR_STACK)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a error stack ID")
+    } /* end else */
 
     /* Check if the error stack reporting function is the "newer" stack type */
     if (is_stack)

src/H5FD.c

@@ -300,6 +300,62 @@ H5FD_register(const void *_cls, size_t size, hbool_t app_ref)
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD_register() */
 
+/*-------------------------------------------------------------------------
+ * Function:    H5FDis_driver_registered_by_name
+ *
+ * Purpose:     Tests whether a VFD class has been registered or not
+ *              according to a supplied driver name.
+ *
+ * Return:      >0 if a VFD with that name has been registered
+ *              0 if a VFD with that name has NOT been registered
+ *              <0 on errors
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5FDis_driver_registered_by_name(const char *driver_name)
+{
+    htri_t ret_value = FALSE; /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE1("t", "*s", driver_name);
+
+    /* Check if driver with this name is registered */
+    if ((ret_value = H5FD_is_driver_registered_by_name(driver_name)) < 0)
+        HGOTO_ERROR(H5E_VFL, H5E_CANTGET, FAIL, "can't check if VFD is registered")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5FDis_driver_registered_by_name() */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FDis_driver_registered_by_value
+ *
+ * Purpose:     Tests whether a VFD class has been registered or not
+ *              according to a supplied driver value (ID).
+ *
+ * Return:      >0 if a VFD with that value has been registered
+ *              0 if a VFD with that value hasn't been registered
+ *              <0 on errors
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5FDis_driver_registered_by_value(H5FD_class_value_t driver_value)
+{
+    htri_t ret_value = FALSE;
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE1("t", "DV", driver_value);
+
+    /* Check if driver with this value is registered */
+    if ((ret_value = H5FD_is_driver_registered_by_value(driver_value)) < 0)
+        HGOTO_ERROR(H5E_VFL, H5E_CANTGET, FAIL, "can't check if VFD is registered")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5FDis_driver_registered_by_value() */
+
 /*-------------------------------------------------------------------------
  * Function:    H5FDunregister
  *

src/H5FDcore.c

@@ -33,6 +33,9 @@
 #include "H5Pprivate.h"  /* Property lists               */
 #include "H5SLprivate.h" /* Skip lists                   */
 
+/* For HDF5 plugin functionality */
+#include "H5PLextern.h"
+
 /* The driver identification number, initialized at runtime */
 static hid_t H5FD_CORE_g = 0;
 
@@ -151,6 +154,7 @@ static herr_t  H5FD__core_unlock(H5FD_t *_file);
 static herr_t  H5FD__core_delete(const char *filename, hid_t fapl_id);
 
 static const H5FD_class_t H5FD_core_g = {
+    H5FD_CORE_VALUE,          /* value                */
     "core",                   /* name                 */
     MAXADDR,                  /* maxaddr              */
     H5F_CLOSE_WEAK,           /* fc_degree            */
@@ -1743,3 +1747,19 @@ H5FD__core_delete(const char *filename, hid_t fapl_id)
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD__core_delete() */
+
+/* These two functions are necessary to allow loading of
+ * this VFD as a plugin.
+ */
+
+H5PL_type_t
+H5PLget_plugin_type(void)
+{
+    return H5PL_TYPE_VFD;
+}
+
+const void *
+H5PLget_plugin_info(void)
+{
+    return &H5FD_core_g;
+}

src/H5FDcore.h

@@ -21,6 +21,7 @@
 #define H5FDcore_H
 
 #define H5FD_CORE (H5FD_core_init())
+#define H5FD_CORE_VALUE H5_VFD_CORE
 
 #ifdef __cplusplus
 extern "C" {

src/H5FDdirect.c

@@ -32,6 +32,9 @@
 #include "H5MMprivate.h" /* Memory management        */
 #include "H5Pprivate.h"  /* Property lists           */
 
+/* For HDF5 plugin functionality */
+#include "H5PLextern.h"
+
 #ifdef H5_HAVE_DIRECT
 
 /* The driver identification number, initialized at runtime */
@@ -140,6 +143,7 @@ static herr_t  H5FD__direct_unlock(H5FD_t *_file);
 static herr_t  H5FD__direct_delete(const char *filename, hid_t fapl_id);
 
 static const H5FD_class_t H5FD_direct_g = {
+    H5FD_DIRECT_VALUE,          /* value                */
     "direct",                   /* name                 */
     MAXADDR,                    /* maxaddr              */
     H5F_CLOSE_WEAK,             /* fc_degree            */
@@ -1407,4 +1411,20 @@ H5FD__direct_delete(const char *filename, hid_t H5_ATTR_UNUSED fapl_id)
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD__direct_delete() */
 
+/* These two functions are necessary to allow loading of
+ * this VFD as a plugin.
+ */
+
+H5PL_type_t
+H5PLget_plugin_type(void)
+{
+    return H5PL_TYPE_VFD;
+}
+
+const void *
+H5PLget_plugin_info(void)
+{
+    return &H5FD_direct_g;
+}
+
 #endif /* H5_HAVE_DIRECT */

src/H5FDdirect.h

@@ -22,8 +22,10 @@
 
 #ifdef H5_HAVE_DIRECT
 #define H5FD_DIRECT (H5FD_direct_init())
+#define H5FD_DIRECT_VALUE H5_VFD_DIRECT
 #else
 #define H5FD_DIRECT (H5I_INVALID_HID)
+#define H5FD_DIRECT_VALUE H5_VFD_INVALID
 #endif /* H5_HAVE_DIRECT */
 
 #ifdef H5_HAVE_DIRECT

src/H5FDfamily.c

@@ -44,6 +44,9 @@
 #include "H5MMprivate.h" /* Memory management            */
 #include "H5Pprivate.h"  /* Property lists            */
 
+/* For HDF5 plugin functionality */
+#include "H5PLextern.h"
+
 /* The size of the member name buffers */
 #define H5FD_FAM_MEMB_NAME_BUF_SIZE 4096
 
@@ -105,6 +108,7 @@ static herr_t  H5FD__family_delete(const char *filename, hid_t fapl_id);
 
 /* The class struct */
 static const H5FD_class_t H5FD_family_g = {
+    H5FD_FAMILY_VALUE,          /* value                */
     "family",                   /* name                 */
     HADDR_MAX,                  /* maxaddr              */
     H5F_CLOSE_WEAK,             /* fc_degree            */
@@ -1436,3 +1440,19 @@ H5FD__family_delete(const char *filename, hid_t fapl_id)
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD__family_delete() */
+
+/* These two functions are necessary to allow loading of
+ * this VFD as a plugin.
+ */
+
+H5PL_type_t
+H5PLget_plugin_type(void)
+{
+    return H5PL_TYPE_VFD;
+}
+
+const void *
+H5PLget_plugin_info(void)
+{
+    return &H5FD_family_g;
+}

src/H5FDfamily.h

@@ -21,6 +21,7 @@
 #define H5FDfamily_H
 
 #define H5FD_FAMILY (H5FD_family_init())
+#define H5FD_FAMILY_VALUE H5_VFD_FAMILY
 
 #ifdef __cplusplus
 extern "C" {

src/H5FDhdfs.c

@@ -31,6 +31,9 @@
 #include "H5Iprivate.h"  /* IDs                      */
 #include "H5MMprivate.h" /* Memory management        */
 
+/* For HDF5 plugin functionality */
+#include "H5PLextern.h"
+
 #ifdef H5_HAVE_LIBHDFS
 
 /* HDFS routines */
@@ -278,6 +281,7 @@ static herr_t  H5FD__hdfs_truncate(H5FD_t *_file, hid_t dxpl_id, hbool_t closing
 static herr_t H5FD__hdfs_validate_config(const H5FD_hdfs_fapl_t *fa);
 
 static const H5FD_class_t H5FD_hdfs_g = {
+    H5FD_HDFS_VALUE,          /* value                */
     "hdfs",                   /* name                 */
     MAXADDR,                  /* maxaddr              */
     H5F_CLOSE_WEAK,           /* fc_degree            */
@@ -1644,4 +1648,20 @@ H5FD__hdfs_truncate(H5FD_t H5_ATTR_UNUSED *_file, hid_t H5_ATTR_UNUSED dxpl_id,
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD__hdfs_truncate() */
 
+/* These two functions are necessary to allow loading of
+ * this VFD as a plugin.
+ */
+
+H5PL_type_t
+H5PLget_plugin_type(void)
+{
+    return H5PL_TYPE_VFD;
+}
+
+const void *
+H5PLget_plugin_info(void)
+{
+    return &H5FD_hdfs_g;
+}
+
 #endif /* H5_HAVE_LIBHDFS */

src/H5FDhdfs.h

@@ -24,8 +24,10 @@
 
 #ifdef H5_HAVE_LIBHDFS
 #define H5FD_HDFS (H5FD_hdfs_init())
+#define H5FD_HDFS_VALUE H5_VFD_HDFS
 #else /* H5_HAVE_LIBHDFS */
 #define H5FD_HDFS (H5I_INVALID_HID)
+#define H5FD_HDFS_VALUE H5_VFD_INVALID
 #endif /* H5_HAVE_LIBHDFS */
 
 #ifdef H5_HAVE_LIBHDFS