[svn-r5096] 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)
VS: ----------------------------------------------------------------------

1 files changed, 57 insertions, 0 deletions

diff --git a/src/H5FD.c b/src/H5FD.c
index 02a87d2..8f33140 100644
--- a/src/H5FD.c
+++ b/src/H5FD.c
@@ -38,6 +38,20 @@ 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
@@ -66,6 +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);
 }
 
@@ -801,6 +818,14 @@ 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);
 }
 
@@ -2509,3 +2534,35 @@ 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() */
+