VOL FEATURE

3 files changed, 547 insertions, 13 deletions

diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index 2239d64..9956b06 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -37,6 +37,7 @@ set (examples
     h5_vds-percival
     h5_vds-percival-unlim
     h5_vds-percival-unlim-maxmin
+    h5_vol_external_log_native
 )
 
 foreach (example ${examples})
diff --git a/examples/Makefile.am b/examples/Makefile.am
index 8c6540f..ae6c092 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -32,25 +32,27 @@ INSTALL_TOP_FILES = README
 # it would try to compile them instead of using the h5cc script.
 # Use the boilerplate in config/examples.am instead.
 EXAMPLE_PROG = h5_write h5_read h5_extend_write h5_chunk_read h5_compound \
-           h5_crtgrpd h5_subset h5_cmprss h5_rdwt h5_crtgrpar h5_extend \
-           h5_crtatt h5_crtgrp h5_crtdat \
-           h5_group h5_select h5_attribute h5_mount h5_reference h5_drivers \
-           h5_ref2reg h5_extlink h5_elink_unix2win h5_shared_mesg h5_vds h5_vds-exc \
-           h5_vds-exclim h5_vds-eiger h5_vds-simpleIO h5_vds-percival \
-           h5_vds-percival-unlim h5_vds-percival-unlim-maxmin
+            h5_crtgrpd h5_subset h5_cmprss h5_rdwt h5_crtgrpar h5_extend \
+            h5_crtatt h5_crtgrp h5_crtdat \
+            h5_group h5_select h5_attribute h5_mount h5_reference h5_drivers \
+            h5_ref2reg h5_extlink h5_elink_unix2win h5_shared_mesg h5_vds h5_vds-exc \
+            h5_vds-exclim h5_vds-eiger h5_vds-simpleIO h5_vds-percival \
+            h5_vds-percival-unlim h5_vds-percival-unlim-maxmin \
+            h5_vol_external_log_native
 TEST_SCRIPT=testh5cc.sh 
 TEST_EXAMPLES_SCRIPT=$(INSTALL_SCRIPT_FILES)
 
 # Install files
 # List all file that should be installed in examples directory
 INSTALL_FILES = h5_write.c h5_read.c h5_extend_write.c h5_chunk_read.c   \
-          h5_crtgrpd.c h5_subset.c h5_cmprss.c h5_rdwt.c h5_crtgrpar.c \
-          h5_extend.c h5_crtatt.c h5_crtgrp.c h5_crtdat.c \
-          h5_compound.c h5_group.c h5_select.c h5_attribute.c h5_mount.c \
-          h5_reference.c h5_drivers.c h5_extlink.c h5_elink_unix2win.c   \
-          h5_ref2reg.c h5_shared_mesg.c ph5example.c h5_vds.c h5_vds-exc.c \
-          h5_vds-exclim.c h5_vds-eiger.c h5_vds-simpleIO.c h5_vds-percival.c \
-          h5_vds-percival-unlim.c h5_vds-percival-unlim-maxmin.c
+            h5_crtgrpd.c h5_subset.c h5_cmprss.c h5_rdwt.c h5_crtgrpar.c \
+            h5_extend.c h5_crtatt.c h5_crtgrp.c h5_crtdat.c \
+            h5_compound.c h5_group.c h5_select.c h5_attribute.c h5_mount.c \
+            h5_reference.c h5_drivers.c h5_extlink.c h5_elink_unix2win.c   \
+            h5_ref2reg.c h5_shared_mesg.c ph5example.c h5_vds.c h5_vds-exc.c \
+            h5_vds-exclim.c h5_vds-eiger.c h5_vds-simpleIO.c h5_vds-percival.c \
+            h5_vds-percival-unlim.c h5_vds-percival-unlim-maxmin.c \
+            h5_vol_external_log_native.c
 
 
 
@@ -127,6 +129,7 @@ h5_vds-simpleIO: $(srcdir)/h5_vds-simpleIO.c
 h5_vds-percival: $(srcdir)/h5_vds-percival.c
 h5_vds-percival-unlim: $(srcdir)/h5_vds-percival-unlim.c
 h5_vds-percival-unlim-maxmin: $(srcdir)/h5_vds-percival-unlim-maxmin.c
+h5_vol_external_log_native: $(srcdir)/h5_vol_external_log_native.c
 
 if BUILD_SHARED_SZIP_CONDITIONAL
 LD_LIBRARY_PATH=$(LL_PATH)
diff --git a/examples/h5_vol_external_log_native.c b/examples/h5_vol_external_log_native.c
new file mode 100644
index 0000000..945588a
--- /dev/null
+++ b/examples/h5_vol_external_log_native.c
@@ -0,0 +1,530 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include "hdf5.h"
+
+#define LOG 502
+
+static herr_t H5VL_log_init(hid_t vipl_id);
+static herr_t H5VL_log_term(hid_t vtpl_id);
+
+/* Datatype callbacks */
+static void *H5VL_log_datatype_commit(void *obj, H5VL_loc_params_t loc_params, const char *name, hid_t type_id, hid_t lcpl_id, hid_t tcpl_id, hid_t tapl_id, hid_t dxpl_id, void **req);
+static void *H5VL_log_datatype_open(void *obj, H5VL_loc_params_t loc_params, const char *name, hid_t tapl_id, hid_t dxpl_id, void **req);
+static herr_t H5VL_log_datatype_get(void *dt, H5VL_datatype_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
+static herr_t H5VL_log_datatype_close(void *dt, hid_t dxpl_id, void **req);
+
+/* Dataset callbacks */
+static void *H5VL_log_dataset_create(void *obj, H5VL_loc_params_t loc_params, const char *name, hid_t dcpl_id, hid_t dapl_id, hid_t dxpl_id, void **req);
+static void *H5VL_log_dataset_open(void *obj, H5VL_loc_params_t loc_params, const char *name, hid_t dapl_id, hid_t dxpl_id, void **req);
+static herr_t H5VL_log_dataset_read(void *dset, hid_t mem_type_id, hid_t mem_space_id,
+                                    hid_t file_space_id, hid_t plist_id, void *buf, void **req);
+static herr_t H5VL_log_dataset_write(void *dset, hid_t mem_type_id, hid_t mem_space_id,
+                                     hid_t file_space_id, hid_t plist_id, const void *buf, void **req);
+static herr_t H5VL_log_dataset_close(void *dset, hid_t dxpl_id, void **req);
+
+/* File callbacks */
+static void *H5VL_log_file_create(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, hid_t dxpl_id, void **req);
+static void *H5VL_log_file_open(const char *name, unsigned flags, hid_t fapl_id, hid_t dxpl_id, void **req);
+static herr_t H5VL_log_file_get(void *file, H5VL_file_get_t get_type, hid_t dxpl_id, void **req, va_list arguments);
+static herr_t H5VL_log_file_close(void *file, hid_t dxpl_id, void **req);
+
+/* Group callbacks */
+static void *H5VL_log_group_create(void *obj, H5VL_loc_params_t loc_params, const char *name, hid_t gcpl_id, hid_t gapl_id, hid_t dxpl_id, void **req);
+static herr_t H5VL_log_group_close(void *grp, hid_t dxpl_id, void **req);
+
+/* Link callbacks */
+
+/* Object callbacks */
+static void *H5VL_log_object_open(void *obj, H5VL_loc_params_t loc_params, H5I_type_t *opened_type, hid_t dxpl_id, void **req);
+static herr_t H5VL_log_object_specific(void *obj, H5VL_loc_params_t loc_params, H5VL_object_specific_t specific_type, hid_t dxpl_id, void **req, va_list arguments);
+
+hid_t native_driver_id = -1;
+
+static const H5VL_class_t H5VL_log_g = {
+    0,
+    LOG,
+    "log",					/* name */
+    H5VL_log_init,                              /* initialize */
+    H5VL_log_term,                              /* terminate */
+    sizeof(hid_t),
+    NULL,
+    NULL,
+    {                                           /* attribute_cls */
+        NULL, //H5VL_log_attr_create,                /* create */
+        NULL, //H5VL_log_attr_open,                  /* open */
+        NULL, //H5VL_log_attr_read,                  /* read */
+        NULL, //H5VL_log_attr_write,                 /* write */
+        NULL, //H5VL_log_attr_get,                   /* get */
+        NULL, //H5VL_log_attr_specific,              /* specific */
+        NULL, //H5VL_log_attr_optional,              /* optional */
+        NULL  //H5VL_log_attr_close                  /* close */
+    },
+    {                                           /* dataset_cls */
+        H5VL_log_dataset_create,                    /* create */
+        H5VL_log_dataset_open,                      /* open */
+        H5VL_log_dataset_read,                      /* read */
+        H5VL_log_dataset_write,                     /* write */
+        NULL, //H5VL_log_dataset_get,               /* get */
+        NULL, //H5VL_log_dataset_specific,          /* specific */
+        NULL, //H5VL_log_dataset_optional,          /* optional */
+        H5VL_log_dataset_close                      /* close */
+    },
+    {                                               /* datatype_cls */
+        H5VL_log_datatype_commit,                   /* commit */
+        H5VL_log_datatype_open,                     /* open */
+        H5VL_log_datatype_get,                      /* get_size */
+        NULL, //H5VL_log_datatype_specific,         /* specific */
+        NULL, //H5VL_log_datatype_optional,         /* optional */
+        H5VL_log_datatype_close                     /* close */
+    },
+    {                                           /* file_cls */
+        H5VL_log_file_create,                      /* create */
+        H5VL_log_file_open,                        /* open */
+        H5VL_log_file_get,                         /* get */
+        NULL, //H5VL_log_file_specific,            /* specific */
+        NULL, //H5VL_log_file_optional,            /* optional */
+        H5VL_log_file_close                        /* close */
+    },
+    {                                           /* group_cls */
+        H5VL_log_group_create,                     /* create */
+        NULL, //H5VL_log_group_open,               /* open */
+        NULL, //H5VL_log_group_get,                /* get */
+        NULL, //H5VL_log_group_specific,           /* specific */
+        NULL, //H5VL_log_group_optional,           /* optional */
+        H5VL_log_group_close                       /* close */
+    },
+    {                                           /* link_cls */
+        NULL, //H5VL_log_link_create,                /* create */
+        NULL, //H5VL_log_link_copy,                  /* copy */
+        NULL, //H5VL_log_link_move,                  /* move */
+        NULL, //H5VL_log_link_get,                   /* get */
+        NULL, //H5VL_log_link_specific,              /* specific */
+        NULL, //H5VL_log_link_optional,              /* optional */
+    },
+    {                                           /* object_cls */
+        H5VL_log_object_open,                        /* open */
+        NULL, //H5VL_log_object_copy,                /* copy */
+        NULL, //H5VL_log_object_get,                 /* get */
+        H5VL_log_object_specific,                    /* specific */
+        NULL, //H5VL_log_object_optional,            /* optional */
+    },
+    {
+        NULL,
+        NULL,
+        NULL
+    },
+    NULL
+};
+
+typedef struct H5VL_log_t {
+    void   *under_object;
+} H5VL_log_t;
+
+static herr_t
+visit_cb(hid_t oid, const char *name,
+         const H5O_info_t *oinfo, void *udata)
+{
+    ssize_t len;
+    char n[25];
+
+    if(H5Iget_type(oid) == H5I_GROUP) {
+        len = H5VLget_driver_name(oid, n, 50);
+        printf ("Visiting GROUP VOL name = %s  %d\n", n, len);
+    }
+    if(H5Iget_type(oid) == H5I_DATASET) 
+        printf("visiting dataset\n");
+    if(H5Iget_type(oid) == H5I_DATATYPE) 
+        printf("visiting datatype\n");
+
+    return 1;
+} /* end h5_verify_cached_stabs_cb() */
+
+int main(int argc, char **argv) {
+        const char file_name[]="large_dataset.h5";
+	const char group_name[]="/Group";
+	const char dataset_name[]="Data";
+	char fullpath[500];
+	hid_t file_id;
+	hid_t group_id;
+	hid_t dataspaceId;
+        hid_t datasetId;
+        hid_t acc_tpl;
+        hid_t under_fapl;
+        hid_t vol_id, vol_id2;
+        hid_t int_id;
+        hid_t attr;
+        hid_t space;
+	const unsigned int nelem=60;
+	int *data;
+	unsigned int i;
+	hsize_t dims[1];
+        ssize_t len;
+        char name[25];
+        static hsize_t      ds_size[2] = {10, 20};
+
+        under_fapl = H5Pcreate (H5P_FILE_ACCESS);
+        H5Pset_fapl_native(under_fapl);
+        assert(H5VLis_registered("native") == 1);
+
+        vol_id = H5VLregister (&H5VL_log_g);
+        assert(vol_id > 0);
+        assert(H5VLis_registered("log") == 1);
+
+        vol_id2 = H5VLget_driver_id("log");
+        H5VLinitialize(vol_id2, H5P_DEFAULT);
+        H5VLclose(vol_id2);
+
+        native_driver_id = H5VLget_driver_id("native");
+        assert(native_driver_id > 0);
+
+        acc_tpl = H5Pcreate (H5P_FILE_ACCESS);
+        H5Pset_vol(acc_tpl, vol_id, &under_fapl);
+
+	file_id = H5Fcreate(file_name, H5F_ACC_TRUNC, H5P_DEFAULT, acc_tpl);
+        len = H5VLget_driver_name(file_id, name, 25);
+        printf ("FILE VOL name = %s  %d\n", name, len);
+
+	group_id = H5Gcreate2(file_id, group_name, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+        len = H5VLget_driver_name(group_id, name, 50);
+        printf ("GROUP VOL name = %s  %d\n", name, len);
+
+        int_id = H5Tcopy(H5T_NATIVE_INT);
+        H5Tcommit2(file_id, "int", int_id, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
+        len = H5VLget_driver_name(int_id, name, 50);
+        printf ("DT COMMIT name = %s  %d\n", name, len);
+        H5Tclose(int_id);
+
+        int_id = H5Topen2(file_id, "int", H5P_DEFAULT);
+        len = H5VLget_driver_name(int_id, name, 50);
+        printf ("DT OPEN name = %s  %d\n", name, len);
+        H5Tclose(int_id);
+
+        int_id = H5Oopen(file_id,"int",H5P_DEFAULT);
+        len = H5VLget_driver_name(int_id, name, 50);
+        printf ("DT OOPEN name = %s  %d\n", name, len);
+
+        len = H5Fget_name(file_id, name, 50);
+        printf("name = %d  %s\n", len, name);
+
+	data = malloc (sizeof(int)*nelem);
+	for(i=0;i<nelem;++i)
+	  data[i]=i;
+
+	dims [0] = 60;
+	dataspaceId = H5Screate_simple(1, dims, NULL); 
+        space = H5Screate_simple (2, ds_size, ds_size);
+
+	sprintf(fullpath,"%s/%s",group_name,dataset_name);
+	datasetId = H5Dcreate2(file_id,fullpath,H5T_NATIVE_INT,dataspaceId,H5P_DEFAULT,H5P_DEFAULT,H5P_DEFAULT);
+	H5Sclose(dataspaceId);
+
+        len = H5VLget_driver_name(datasetId, name, 50);
+        printf ("DSET name = %s  %d\n", name, len);
+
+	H5Dwrite(datasetId, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, data);
+	H5Dclose(datasetId);
+
+        H5Ovisit2(file_id, H5_INDEX_NAME, H5_ITER_NATIVE, visit_cb, NULL, H5O_INFO_ALL);
+
+	free (data);
+        H5Oclose(int_id);
+        H5Sclose (space);
+	H5Gclose(group_id);
+#if 0
+
+        attr = H5Acreate2(group_id, "attr1", int_id, space, H5P_DEFAULT, H5P_DEFAULT);
+        int_id = H5Aget_type(attr);
+        len = H5VLget_driver_name(int_id, name, 50);
+        printf ("DT OPEN name = %s  %d\n", name, len);
+
+        H5Aclose (attr);
+
+        int_id = H5Oopen(file_id,"int",H5P_DEFAULT);
+        len = H5VLget_driver_name(int_id, name, 50);
+        printf ("DT OOPEN name = %s  %d\n", name, len);
+        H5Oclose(int_id);
+
+
+	H5Fclose(file_id);
+	file_id = H5Fopen(file_name, H5F_ACC_RDWR, H5P_DEFAULT);//acc_tpl);
+        H5Fflush(file_id, H5F_SCOPE_GLOBAL);
+#endif
+
+	H5Fclose(file_id);
+        H5Pclose(acc_tpl);
+        H5Pclose(under_fapl);
+
+        H5VLclose(native_driver_id);
+        H5VLterminate(vol_id, H5P_DEFAULT);
+        H5VLunregister (vol_id);
+        assert(H5VLis_registered("log") == 0);
+	return 0;
+}
+
+static herr_t H5VL_log_init(hid_t vipl_id)
+{
+    printf("------- LOG INIT\n");
+    return 0;
+}
+
+static herr_t H5VL_log_term(hid_t vtpl_id)
+{
+    printf("------- LOG TERM\n");
+    return 0;
+}
+
+static void *
+H5VL_log_file_create(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, hid_t dxpl_id, void **req)
+{
+    hid_t under_fapl;
+    H5VL_log_t *file;
+
+    file = (H5VL_log_t *)calloc(1, sizeof(H5VL_log_t));
+
+    under_fapl = *((hid_t *)H5Pget_vol_info(fapl_id));
+    file->under_object = H5VLfile_create(name, flags, fcpl_id, under_fapl, dxpl_id, req);
+
+    printf("------- LOG H5Fcreate\n");
+    return (void *)file;
+}
+
+static void *
+H5VL_log_file_open(const char *name, unsigned flags, hid_t fapl_id, hid_t dxpl_id, void **req)
+{
+    hid_t under_fapl;
+    H5VL_log_t *file;
+
+    file = (H5VL_log_t *)calloc(1, sizeof(H5VL_log_t));
+
+    under_fapl = *((hid_t *)H5Pget_vol_info(fapl_id));
+    file->under_object = H5VLfile_open(name, flags, under_fapl, dxpl_id, req);
+
+    printf("------- LOG H5Fopen\n");
+    return (void *)file;
+}
+
+static herr_t 
+H5VL_log_file_get(void *file, H5VL_file_get_t get_type, hid_t dxpl_id, void **req, va_list arguments)
+{
+    H5VL_log_t *f = (H5VL_log_t *)file;
+
+    H5VLfile_get(f->under_object, native_driver_id, get_type, dxpl_id, req, arguments);
+
+    printf("------- LOG H5Fget %d\n", get_type);
+    return 1;
+}
+static herr_t 
+H5VL_log_file_close(void *file, hid_t dxpl_id, void **req)
+{
+    H5VL_log_t *f = (H5VL_log_t *)file;
+
+    H5VLfile_close(f->under_object, native_driver_id, dxpl_id, req);
+    free(f);
+
+    printf("------- LOG H5Fclose\n");
+    return 1;
+}
+
+static void *
+H5VL_log_group_create(void *obj, H5VL_loc_params_t loc_params, const char *name, 
+                      hid_t gcpl_id, hid_t gapl_id, hid_t dxpl_id, void **req)
+{
+    H5VL_log_t *group;
+    H5VL_log_t *o = (H5VL_log_t *)obj;
+
+    group = (H5VL_log_t *)calloc(1, sizeof(H5VL_log_t));
+
+    group->under_object = H5VLgroup_create(o->under_object, loc_params, native_driver_id, name, gcpl_id,  gapl_id, dxpl_id, req);
+
+    printf("------- LOG H5Gcreate\n");
+    return (void *)group;
+}
+
+static herr_t 
+H5VL_log_group_close(void *grp, hid_t dxpl_id, void **req)
+{
+    H5VL_log_t *g = (H5VL_log_t *)grp;
+
+    H5VLgroup_close(g->under_object, native_driver_id, dxpl_id, req);
+    free(g);
+
+    printf("------- LOG H5Gclose\n");
+    return 1;
+}
+
+static void *
+H5VL_log_datatype_commit(void *obj, H5VL_loc_params_t loc_params, const char *name, 
+                         hid_t type_id, hid_t lcpl_id, hid_t tcpl_id, hid_t tapl_id, hid_t dxpl_id, void **req)
+{
+    H5VL_log_t *dt;
+    H5VL_log_t *o = (H5VL_log_t *)obj;
+
+    dt = (H5VL_log_t *)calloc(1, sizeof(H5VL_log_t));
+
+    dt->under_object = H5VLdatatype_commit(o->under_object, loc_params, native_driver_id, name, 
+                                           type_id, lcpl_id, tcpl_id, tapl_id, dxpl_id, req);
+
+    printf("------- LOG H5Tcommit\n");
+    return dt;
+}
+static void *
+H5VL_log_datatype_open(void *obj, H5VL_loc_params_t loc_params, const char *name, hid_t tapl_id, hid_t dxpl_id, void **req)
+{
+    H5VL_log_t *dt;
+    H5VL_log_t *o = (H5VL_log_t *)obj;  
+
+    dt = (H5VL_log_t *)calloc(1, sizeof(H5VL_log_t));
+
+    dt->under_object = H5VLdatatype_open(o->under_object, loc_params, native_driver_id, name, tapl_id, dxpl_id, req);
+
+    printf("------- LOG H5Topen\n");
+    return (void *)dt;
+}
+
+static herr_t 
+H5VL_log_datatype_get(void *dt, H5VL_datatype_get_t get_type, hid_t dxpl_id, void **req, va_list arguments)
+{
+    H5VL_log_t *o = (H5VL_log_t *)dt;
+    herr_t ret_value;
+
+    ret_value = H5VLdatatype_get(o->under_object, native_driver_id, get_type, dxpl_id, req, arguments);
+
+    printf("------- LOG datatype get\n");
+    return ret_value;
+}
+
+static herr_t 
+H5VL_log_datatype_close(void *dt, hid_t dxpl_id, void **req)
+{
+    H5VL_log_t *type = (H5VL_log_t *)dt;
+
+    assert(type->under_object);
+
+    H5VLdatatype_close(type->under_object, native_driver_id, dxpl_id, req);
+    free(type);
+
+    printf("------- LOG H5Tclose\n");
+    return 1;
+}
+
+static void *
+H5VL_log_object_open(void *obj, H5VL_loc_params_t loc_params, H5I_type_t *opened_type, hid_t dxpl_id, void **req)
+{
+    H5VL_log_t *new_obj;
+    H5VL_log_t *o = (H5VL_log_t *)obj;
+
+    new_obj = (H5VL_log_t *)calloc(1, sizeof(H5VL_log_t));
+    
+    new_obj->under_object = H5VLobject_open(o->under_object, loc_params, native_driver_id, opened_type, dxpl_id, req);
+
+    printf("------- LOG H5Oopen\n");
+    return (void *)new_obj;
+}
+
+static herr_t 
+H5VL_log_object_specific(void *obj, H5VL_loc_params_t loc_params, H5VL_object_specific_t specific_type, 
+                         hid_t dxpl_id, void **req, va_list arguments)
+{
+    H5VL_log_t *o = (H5VL_log_t *)obj;
+
+    H5VLobject_specific(o->under_object, loc_params, native_driver_id, specific_type, dxpl_id, req, arguments);
+
+    printf("------- LOG Object specific\n");
+    return 1;
+}
+
+static void *
+H5VL_log_dataset_create(void *obj, H5VL_loc_params_t loc_params, const char *name, hid_t dcpl_id, hid_t dapl_id, hid_t dxpl_id, void **req) 
+{
+    H5VL_log_t *dset;
+    H5VL_log_t *o = (H5VL_log_t *)obj;
+
+    dset = (H5VL_log_t *)calloc(1, sizeof(H5VL_log_t));
+
+    dset->under_object = H5VLdataset_create(o->under_object, loc_params, native_driver_id, name, dcpl_id,  dapl_id, dxpl_id, req);
+
+    printf("------- LOG H5Dcreate\n");
+    return (void *)dset;
+}
+
+static void *
+H5VL_log_dataset_open(void *obj, H5VL_loc_params_t loc_params, const char *name, hid_t dapl_id, hid_t dxpl_id, void **req)
+{
+    H5VL_log_t *dset;
+    H5VL_log_t *o = (H5VL_log_t *)obj;
+
+    dset = (H5VL_log_t *)calloc(1, sizeof(H5VL_log_t));
+
+    dset->under_object = H5VLdataset_open(o->under_object, loc_params, native_driver_id, name, dapl_id, dxpl_id, req);
+
+    printf("------- LOG H5Dopen\n");
+    return (void *)dset;
+}
+
+static herr_t 
+H5VL_log_dataset_read(void *dset, hid_t mem_type_id, hid_t mem_space_id,
+                      hid_t file_space_id, hid_t plist_id, void *buf, void **req)
+{
+    H5VL_log_t *d = (H5VL_log_t *)dset;
+
+    H5VLdataset_read(d->under_object, native_driver_id, mem_type_id, mem_space_id, file_space_id, 
+                     plist_id, buf, req);
+
+    printf("------- LOG H5Dread\n");
+    return 1;
+}
+static herr_t 
+H5VL_log_dataset_write(void *dset, hid_t mem_type_id, hid_t mem_space_id,
+                       hid_t file_space_id, hid_t plist_id, const void *buf, void **req)
+{
+    H5VL_log_t *d = (H5VL_log_t *)dset;
+
+    H5VLdataset_write(d->under_object, native_driver_id, mem_type_id, mem_space_id, file_space_id, 
+                     plist_id, buf, req);
+
+    printf("------- LOG H5Dwrite\n");
+    return 1;
+}
+static herr_t 
+H5VL_log_dataset_close(void *dset, hid_t dxpl_id, void **req)
+{
+    H5VL_log_t *d = (H5VL_log_t *)dset;
+
+    H5VLdataset_close(d->under_object, native_driver_id, dxpl_id, req);
+    free(d);
+
+    printf("------- LOG H5Dclose\n");
+    return 1;
+}
+
+#if 0
+static void *H5VL_log_attr_create(void *obj, H5VL_loc_params_t loc_params, const char *attr_name, hid_t acpl_id, hid_t aapl_id, hid_t dxpl_id, void **req){    
+static herr_t H5VL_log_attr_close(void *attr, hid_t dxpl_id, void **req){
+
+/* Datatype callbacks */
+
+
+/* Dataset callbacks */
+static void *H5VL_log_dataset_create(void *obj, H5VL_loc_params_t loc_params, const char *name, hid_t dcpl_id, hid_t dapl_id, hid_t dxpl_id, void **req){
+static herr_t H5VL_log_dataset_close(void *dset, hid_t dxpl_id, void **req){
+
+/* File callbacks */
+
+    
+static void *H5VL_log_file_open(const char *name, unsigned flags, hid_t fapl_id, hid_t dxpl_id, void **req){
+
+
+/* Group callbacks */
+
+static void *H5VL_log_group_open(void *obj, H5VL_loc_params_t loc_params, const char *name, hid_t gapl_id, hid_t dxpl_id, void **req){
+static herr_t H5VL_log_group_get(void *obj, H5VL_group_get_t get_type, hid_t dxpl_id, void **req, va_list arguments){
+
+
+/* Link callbacks */
+
+/* Object callbacks */
+
+
+#endif