[svn-r18205] Description:

    Add prototype of new H5Oexists() API routine.

Tested on:
    Mac OS X/32 10.6.2 (amazon)
    (further tests pending shortly)

1 files changed, 74 insertions, 30 deletions

diff --git a/src/H5Gtraverse.c b/src/H5Gtraverse.c
index 4c287d5..e9f3010 100644
--- a/src/H5Gtraverse.c
+++ b/src/H5Gtraverse.c
@@ -43,8 +43,13 @@
 
 /* User data for path traversal routine */
 typedef struct {
+    /* down */
+    hbool_t chk_exists;         /* Flag to indicate we are checking if object exists */
+
+    /* up */
     H5G_loc_t *obj_loc;         /* Object location */
-} H5G_trav_ud1_t;
+    hbool_t exists;             /* Indicate if object exists */
+} H5G_trav_slink_t;
 
 /* Private macros */
 
@@ -53,15 +58,15 @@ static char *H5G_comp_g = NULL;                 /*component buffer      */
 static size_t H5G_comp_alloc_g = 0;             /*sizeof component buffer */
 
 /* PRIVATE PROTOTYPES */
-static herr_t H5G_traverse_link_cb(H5G_loc_t *grp_loc, const char *name,
+static herr_t H5G_traverse_slink_cb(H5G_loc_t *grp_loc, const char *name,
     const H5O_link_t *lnk, H5G_loc_t *obj_loc, void *_udata/*in,out*/,
     H5G_own_loc_t *own_loc/*out*/);
 static herr_t H5G_traverse_ud(const H5G_loc_t *grp_loc, const H5O_link_t *lnk,
-    H5G_loc_t *obj_loc/*in,out*/, size_t *nlinks/*in,out*/, hid_t lapl_id,
-    hid_t dxpl_id);
+    H5G_loc_t *obj_loc/*in,out*/, unsigned target, size_t *nlinks/*in,out*/,
+    hbool_t *obj_exists, hid_t lapl_id, hid_t dxpl_id);
 static herr_t H5G_traverse_slink(const H5G_loc_t *grp_loc, const H5O_link_t *lnk,
-    H5G_loc_t *obj_loc/*in,out*/, size_t *nlinks/*in,out*/, hid_t lapl_id,
-    hid_t dxpl_id);
+    H5G_loc_t *obj_loc/*in,out*/, unsigned target, size_t *nlinks/*in,out*/,
+    hbool_t *obj_exists, hid_t lapl_id, hid_t dxpl_id);
 static herr_t H5G_traverse_mount(H5G_loc_t *loc/*in,out*/);
 static herr_t H5G_traverse_real(const H5G_loc_t *loc, const char *name,
     unsigned target, size_t *nlinks, H5G_traverse_t op, void *op_data,
@@ -97,9 +102,9 @@ H5G_traverse_term_interface(void)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5G_traverse_link_cb
+ * Function:	H5G_traverse_slink_cb
  *
- * Purpose:	Callback for link traversal.  This routine sets the
+ * Purpose:	Callback for soft link traversal.  This routine sets the
  *              correct information for the object location.
  *
  * Return:	Non-negative on success/Negative on failure
@@ -110,20 +115,29 @@ H5G_traverse_term_interface(void)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5G_traverse_link_cb(H5G_loc_t UNUSED *grp_loc, const char UNUSED *name, const H5O_link_t UNUSED *lnk,
-    H5G_loc_t *obj_loc, void *_udata/*in,out*/, H5G_own_loc_t *own_loc/*out*/)
+H5G_traverse_slink_cb(H5G_loc_t UNUSED *grp_loc, const char UNUSED *name,
+    const H5O_link_t UNUSED *lnk, H5G_loc_t *obj_loc, void *_udata/*in,out*/,
+    H5G_own_loc_t *own_loc/*out*/)
 {
-    H5G_trav_ud1_t *udata = (H5G_trav_ud1_t *)_udata;   /* User data passed in */
+    H5G_trav_slink_t *udata = (H5G_trav_slink_t *)_udata;   /* User data passed in */
     herr_t ret_value = SUCCEED;         /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5G_traverse_link_cb)
+    FUNC_ENTER_NOAPI_NOINIT(H5G_traverse_slink_cb)
 
     /* Check for dangling soft link */
-    if(obj_loc == NULL)
-        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "component not found")
+    if(obj_loc == NULL) {
+        if(udata->chk_exists)
+            udata->exists = FALSE;
+        else
+            HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "component not found")
+    } /* end if */
+    else {
+        /* Copy new location information for resolved object */
+        H5O_loc_copy(udata->obj_loc->oloc, obj_loc->oloc, H5_COPY_DEEP);
 
-    /* Copy new location information for resolved object */
-    H5O_loc_copy(udata->obj_loc->oloc, obj_loc->oloc, H5_COPY_DEEP);
+        /* Indicate that the object exists */
+        udata->exists = TRUE;
+    } /* end else */
 
 done:
     /* Indicate that this callback didn't take ownership of the group *
@@ -131,7 +145,7 @@ done:
     *own_loc = H5G_OWN_NONE;
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5G_traverse_link_cb() */
+} /* end H5G_traverse_slink_cb() */
 
 
 /*-------------------------------------------------------------------------
@@ -149,8 +163,8 @@ done:
  */
 static herr_t
 H5G_traverse_ud(const H5G_loc_t *grp_loc/*in,out*/, const H5O_link_t *lnk,
-    H5G_loc_t *obj_loc/*in,out*/, size_t *nlinks/*in,out*/, hid_t _lapl_id,
-    hid_t dxpl_id)
+    H5G_loc_t *obj_loc/*in,out*/, unsigned target, size_t *nlinks/*in,out*/,
+    hbool_t *obj_exists, hid_t _lapl_id, hid_t dxpl_id)
 {
     const H5L_class_t   *link_class;       /* User-defined link class */
     hid_t               cb_return = -1;         /* The ID the user-defined callback returned */
@@ -222,8 +236,25 @@ H5G_traverse_ud(const H5G_loc_t *grp_loc/*in,out*/, const H5O_link_t *lnk,
         HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set nlink info")
 
     /* User-defined callback function */
-    if((cb_return = (link_class->trav_func)(lnk->name, cur_grp, lnk->u.ud.udata, lnk->u.ud.size, lapl_id)) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADATOM, FAIL, "traversal callback returned invalid ID")
+    cb_return = (link_class->trav_func)(lnk->name, cur_grp, lnk->u.ud.udata, lnk->u.ud.size, lapl_id);
+
+    /* Check for failing to locate the object */
+    if(cb_return < 0) {
+        /* Check if we just needed to know if the object exists */
+        if(target & H5G_TARGET_EXISTS) {
+            /* Clear any errors from the stack */
+            H5E_clear_stack(NULL);
+
+            /* Indicate that the object doesn't exist */
+            *obj_exists = FALSE;
+
+            /* Get out now */
+            HGOTO_DONE(SUCCEED);
+        } /* end if */
+        /* else, we really needed to open the object */
+        else
+            HGOTO_ERROR(H5E_ARGS, H5E_BADATOM, FAIL, "traversal callback returned invalid ID")
+    } /* end if */
 
     /* Get the oloc from the ID the user callback returned */
     switch(H5I_get_type(cb_return)) {
@@ -306,10 +337,10 @@ done:
  */
 static herr_t
 H5G_traverse_slink(const H5G_loc_t *grp_loc, const H5O_link_t *lnk,
-    H5G_loc_t *obj_loc/*in,out*/, size_t *nlinks/*in,out*/, hid_t lapl_id,
-    hid_t dxpl_id)
+    H5G_loc_t *obj_loc/*in,out*/, unsigned target, size_t *nlinks/*in,out*/,
+    hbool_t *obj_exists, hid_t lapl_id, hid_t dxpl_id)
 {
-    H5G_trav_ud1_t      udata;                  /* User data to pass to link traversal callback */
+    H5G_trav_slink_t      udata;                  /* User data to pass to link traversal callback */
     H5G_name_t          tmp_obj_path;           /* Temporary copy of object's path */
     hbool_t             tmp_obj_path_set = FALSE;       /* Flag to indicate that tmp object path is initialized */
     H5O_loc_t           tmp_grp_oloc;           /* Temporary copy of group entry */
@@ -347,12 +378,17 @@ H5G_traverse_slink(const H5G_loc_t *grp_loc, const H5O_link_t *lnk,
     tmp_obj_path_set = TRUE;
 
     /* Set up user data for traversal callback */
+    udata.chk_exists = (target & H5G_TARGET_EXISTS) ? TRUE : FALSE;
+    udata.exists = FALSE;
     udata.obj_loc = obj_loc;
 
     /* Traverse the link */
-    if(H5G_traverse_real(&tmp_grp_loc, lnk->u.soft.name, H5G_TARGET_NORMAL, nlinks, H5G_traverse_link_cb, &udata, lapl_id, dxpl_id) < 0)
+    if(H5G_traverse_real(&tmp_grp_loc, lnk->u.soft.name, target, nlinks, H5G_traverse_slink_cb, &udata, lapl_id, dxpl_id) < 0)
 	HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "unable to follow symbolic link")
 
+    /* Pass back information about whether the object exists */
+    *obj_exists = udata.exists;
+
 done:
     /* Restore object's group hier. path */
     if(tmp_obj_path_set) {
@@ -464,7 +500,7 @@ done:
 herr_t
 H5G_traverse_special(const H5G_loc_t *grp_loc, const H5O_link_t *lnk,
     unsigned target, size_t *nlinks, hbool_t last_comp,
-    H5G_loc_t *obj_loc, hid_t lapl_id, hid_t dxpl_id)
+    H5G_loc_t *obj_loc, hbool_t *obj_exists, hid_t lapl_id, hid_t dxpl_id)
 {
     herr_t ret_value = SUCCEED;         /* Return value */
 
@@ -485,7 +521,7 @@ H5G_traverse_special(const H5G_loc_t *grp_loc, const H5O_link_t *lnk,
             (0 == (target & H5G_TARGET_SLINK) || !last_comp)) {
         if((*nlinks)-- <= 0)
             HGOTO_ERROR(H5E_LINK, H5E_NLINKS, FAIL, "too many links")
-        if(H5G_traverse_slink(grp_loc, lnk, obj_loc, nlinks, lapl_id, dxpl_id) < 0)
+        if(H5G_traverse_slink(grp_loc, lnk, obj_loc, (target & H5G_TARGET_EXISTS), nlinks, obj_exists, lapl_id, dxpl_id) < 0)
             HGOTO_ERROR(H5E_LINK, H5E_TRAVERSE, FAIL, "symbolic link traversal failed")
     } /* end if */
 
@@ -498,7 +534,7 @@ H5G_traverse_special(const H5G_loc_t *grp_loc, const H5O_link_t *lnk,
             (0 == (target & H5G_TARGET_UDLINK) || !last_comp) ) {
         if((*nlinks)-- <= 0)
             HGOTO_ERROR(H5E_LINK, H5E_NLINKS, FAIL, "too many links")
-        if(H5G_traverse_ud(grp_loc, lnk, obj_loc, nlinks, lapl_id, dxpl_id) < 0)
+        if(H5G_traverse_ud(grp_loc, lnk, obj_loc, (target & H5G_TARGET_EXISTS), nlinks, obj_exists, lapl_id, dxpl_id) < 0)
             HGOTO_ERROR(H5E_LINK, H5E_TRAVERSE, FAIL, "user-defined link traversal failed")
     } /* end if */
 
@@ -634,6 +670,7 @@ H5G_traverse_real(const H5G_loc_t *_loc, const char *name, unsigned target,
     while((name = H5G_component(name, &nchars)) && *name) {
         const char *s;                  /* Temporary string pointer */
         htri_t lookup_status;           /* Status from object lookup */
+        hbool_t obj_exists;             /* Whether the object exists */
 
 	/*
 	 * Copy the component name into a null-terminated buffer so
@@ -663,6 +700,7 @@ H5G_traverse_real(const H5G_loc_t *_loc, const char *name, unsigned target,
         /* Get information for object in current group */
         if((lookup_status = H5G_obj_lookup(grp_loc.oloc, H5G_comp_g, &lnk/*out*/, dxpl_id)) < 0)
             HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "can't look up component")
+        obj_exists = FALSE;
 
         /* If the lookup was OK, build object location and traverse special links, etc. */
         if(lookup_status) {
@@ -676,9 +714,12 @@ H5G_traverse_real(const H5G_loc_t *_loc, const char *name, unsigned target,
                 HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "cannot initialize object location")
             obj_loc_valid = TRUE;
 
+            /* Assume object exists */
+            obj_exists = TRUE;
+
             /* Perform any special traversals that the link needs */
             /* (soft links, user-defined links, file mounting, etc.) */
-            if(H5G_traverse_special(&grp_loc, &lnk, target, nlinks, last_comp, &obj_loc, lapl_id, dxpl_id) < 0)
+            if(H5G_traverse_special(&grp_loc, &lnk, target, nlinks, last_comp, &obj_loc, &obj_exists, lapl_id, dxpl_id) < 0)
                 HGOTO_ERROR(H5E_LINK, H5E_TRAVERSE, FAIL, "special link traversal failed")
         } /* end if */
 
@@ -690,7 +731,10 @@ H5G_traverse_real(const H5G_loc_t *_loc, const char *name, unsigned target,
             /* Set callback parameters appropriately, based on link being found */
             if(lookup_status) {
                 cb_lnk = &lnk;
-                cb_loc = &obj_loc;
+                if(obj_exists)
+                    cb_loc = &obj_loc;
+                else
+                    cb_loc = NULL;
             } /* end if */
             else {
                 HDassert(!obj_loc_valid);