[svn-r5094] Purpose:

    Bug Fix

Description:
    The H5Gget_objinfo() function was not setting the 'fileno' field in the
    H5G_stat_t struct passed in.

Solution:
    Added a "file serial number" to each file currently open in the library
    and put that in the 'fileno' field.  If a file is opened twice (with
    H5Fopen) and the VFL driver detects that it is the same file (i.e. the
    two file structures have the same "shared file info" in the library's
    memory structures), they will have the same serial number.

    This serial number has two drawbacks:
        - If a VFL driver doesn't/can't detect that two calls to H5Fopen with
            the same file actually _are_ the same file, each will get a
            different serial number
        - If the same file is closed and re-opened, the serial number will be
            different.

    It is be possible to fix the second drawback for many VFL drivers, but it
    would be a lot of effort and probably isn't worth it until we've got a
    good reason to do it.  Dunno if we'll ever be able to fix the first
    drawback...

Platforms tested:
    FreeBSD 4.5 (sleipnir)

6 files changed, 103 insertions, 1 deletions

diff --git a/src/H5F.c b/src/H5F.c
index 60bb13c..a938dc5 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -2505,7 +2505,7 @@ H5F_sizeof_size(H5F_t *f)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5F_get_intent
+ * Function:	H5F_get_driver_id
  *
  * Purpose:	Quick and dirty routine to retrieve the file's 'driver_id' value
  *          (Mainly added to stop non-file routines from poking about in the
@@ -2532,6 +2532,43 @@ H5F_get_driver_id(H5F_t *f)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5F_get_fileno
+ *
+ * Purpose:	Quick and dirty routine to retrieve the file's 'fileno' value
+ *          (Mainly added to stop non-file routines from poking about in the
+ *          H5F_t data structure)
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol <koziol@ncsa.uiuc.edu>
+ *		March 27, 2002
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_get_fileno(const H5F_t *f, unsigned long *filenum)
+{
+    herr_t	ret_value = SUCCEED;
+
+    FUNC_ENTER(H5F_get_fileno, FAIL);
+
+    assert(f);
+    assert(f->shared);
+    assert(f->shared->lf);
+    assert(filenum);
+
+    /* Retrieve the file's serial number */
+    if(H5FD_get_fileno(f->shared->lf,filenum)<0)
+	HRETURN_ERROR(H5E_FILE, H5E_BADRANGE, FAIL, "can't retrieve fileno");
+
+done:
+    FUNC_LEAVE(ret_value);
+} /* end H5F_get_fileno() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5F_block_read
  *
  * Purpose:	Reads some data from a file/server/etc into a buffer.
diff --git a/src/H5FD.c b/src/H5FD.c
index 59bd1a1..29c1498 100644
--- a/src/H5FD.c
+++ b/src/H5FD.c
@@ -37,6 +37,21 @@ static haddr_t H5FD_real_alloc(H5FD_t *file, H5FD_mem_t type, hsize_t size);
 /* Declare a PQ free list to manage the metadata accumulator buffer */
 H5FL_BLK_DEFINE_STATIC(meta_accum);
 
+/* Static local variables */
+
+/* Global count of the number of H5FD_t's handed out.  This is used as a
+ * "serial number" for files that are currently open and is used for the
+ * 'fileno[2]' field in H5G_stat_t.  However, if a VFL driver is not able
+ * to detect whether two files are the same, a file that has been opened
+ * by H5Fopen more than once with that VFL driver will have two different
+ * serial numbers.  :-/
+ *
+ * Also, if a file is opened, the 'fileno[2]' field is retrieved for an
+ * object and the file is closed and re-opened, the 'fileno[2]' value will
+ * be different.
+ */
+static unsigned long file_serial_no[2];
+
 
 /*-------------------------------------------------------------------------
  * Function:	H5FD_init_interface
@@ -65,6 +80,9 @@ H5FD_init_interface(void)
 		      "unable to initialize interface");
     }
 
+    /* Reset the file serial numbers */
+    HDmemset(file_serial_no,0,sizeof(file_serial_no));
+
     FUNC_LEAVE(SUCCEED);
 }
 
@@ -798,6 +816,14 @@ H5FD_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxaddr)
     if (H5FD_query(file, &(file->feature_flags))<0)
         HRETURN_ERROR(H5E_VFL, H5E_CANTINIT, NULL, "unable to query file driver");
 
+    /* Increment the global serial number & assign it to this H5FD_t object */
+    if(++file_serial_no[0]==0) {
+        /* (Just error out if we wrap both numbers around for now...) */
+        if(++file_serial_no[1]==0)
+            HRETURN_ERROR(H5E_VFL, H5E_CANTINIT, NULL, "unable to get file serial number");
+    } /* end if */
+    HDmemcpy(file->fileno,file_serial_no,sizeof(file_serial_no));
+
     FUNC_LEAVE(file);
 }
 
@@ -2507,3 +2533,35 @@ H5FD_flush(H5FD_t *file)
 
     FUNC_LEAVE(SUCCEED);
 }
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_get_fileno
+ *
+ * Purpose:	Quick and dirty routine to retrieve the file's 'fileno' value
+ *          (Mainly added to stop non-file routines from poking about in the
+ *          H5FD_t data structure)
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol <koziol@ncsa.uiuc.edu>
+ *		March 27, 2002
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5FD_get_fileno(const H5FD_t *file, unsigned long *filenum)
+{
+    FUNC_ENTER(H5FD_get_fileno, FAIL);
+
+    assert(file);
+    assert(filenum);
+
+    /* Retrieve the file's serial number */
+    HDmemcpy(filenum,file->fileno,sizeof(file->fileno));
+
+    FUNC_LEAVE(SUCCEED);
+} /* end H5F_get_fileno() */
+
diff --git a/src/H5FDprivate.h b/src/H5FDprivate.h
index 70f83d5..9d1dc3a 100644
--- a/src/H5FDprivate.h
+++ b/src/H5FDprivate.h
@@ -39,5 +39,6 @@ __DLL__ herr_t H5FD_read(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t a
 __DLL__ herr_t H5FD_write(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, hsize_t size,
 		  const void *buf);
 __DLL__ herr_t H5FD_flush(H5FD_t *file);
+__DLL__ herr_t H5FD_get_fileno(const H5FD_t *file, unsigned long *filenum);
 
 #endif /* !_H5FDprivate_H */
diff --git a/src/H5FDpublic.h b/src/H5FDpublic.h
index cdd4679..815a940 100644
--- a/src/H5FDpublic.h
+++ b/src/H5FDpublic.h
@@ -151,6 +151,7 @@ typedef struct H5FD_free_t {
 struct H5FD_t {
     hid_t		driver_id;	/*driver ID for this file	*/
     const H5FD_class_t	*cls;		/*constant class info		*/
+    unsigned long       fileno[2];      /* File serial number */
 
     unsigned long feature_flags;  /* VFL Driver feature Flags */
     hsize_t     threshold;      /* Threshold for alignment              */
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 6a2dfed..971cf2d 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -269,6 +269,7 @@ struct H5S_t;
 __DLL__ herr_t H5F_init(void);
 __DLL__ unsigned H5F_get_intent(H5F_t *f);
 __DLL__ hid_t H5F_get_driver_id(H5F_t *f);
+__DLL__ herr_t H5F_get_fileno(const H5F_t *f, unsigned long *filenum);
 
 /* Functions that operate on array storage */
 __DLL__ herr_t H5F_arr_create(H5F_t *f,
diff --git a/src/H5G.c b/src/H5G.c
index 92470e7..5787378 100644
--- a/src/H5G.c
+++ b/src/H5G.c
@@ -2083,6 +2083,10 @@ H5G_get_objinfo (H5G_entry_t *loc, const char *name, hbool_t follow_link,
 	    statbuf->type = H5G_get_type(&obj_ent);
 	    H5E_clear(); /*clear errors resulting from checking type*/
 	}
+
+        /* Common code to retrieve the file's fileno */
+        if(H5F_get_fileno(obj_ent.file,statbuf->fileno)<0)
+            HRETURN_ERROR (H5E_FILE, H5E_BADVALUE, FAIL, "unable to read fileno");
     }
 
     FUNC_LEAVE (SUCCEED);