Switches the tagged metadata list from a skip list to a hash table (#1925)

1 files changed, 20 insertions, 15 deletions

diff --git a/src/H5Cpkg.h b/src/H5Cpkg.h
index 61c3afc..5caa051 100644
--- a/src/H5Cpkg.h
+++ b/src/H5Cpkg.h
@@ -3566,15 +3566,17 @@ if ( ( (entry_ptr) == NULL ) ||                                                \
  *
  * The fields of this structure are discussed individually below:
  *
- * tag:    Address (i.e. "tag") of the object header for all the entries
+ * tag:         Address (i.e. "tag") of the object header for all the entries
  *              corresponding to parts of that object.
  *
- * head: Head of doubly-linked list of all entries belonging to the tag.
+ * head:        Head of doubly-linked list of all entries belonging to the tag.
  *
- * entry_cnt: Number of entries on linked list of entries for this tag.
+ * entry_cnt:   Number of entries on linked list of entries for this tag.
  *
- * corked: Boolean flag indicating whether entries for this object can be
- *         evicted.
+ * corked:      Boolean flag indicating whether entries for this object can be
+ *              evicted.
+ *
+ * hh:          uthash hash table handle (must be last)
  *
  ****************************************************************************/
 typedef struct H5C_tag_info_t {
@@ -3582,6 +3584,9 @@ typedef struct H5C_tag_info_t {
     H5C_cache_entry_t *head;    /* Head of the list of entries for this tag */
     size_t entry_cnt;           /* Number of entries on list */
     hbool_t corked;             /* Whether this object is corked */
+
+    /* Hash table fields */
+    UT_hash_handle hh; /* Hash table handle (must be LAST) */
 } H5C_tag_info_t;
 
 
@@ -3974,17 +3979,17 @@ typedef struct H5C_tag_info_t {
  *
  * The following fields are maintained to facilitate this.
  *
- * tag_list: A skip list to track entries that belong to an object.
- *                Each H5C_tag_info_t struct on the tag list corresponds to
- *                a particular object in the file.  Tagged entries can be
- *                flushed or evicted as a group, or corked to prevent entries
- *                from being evicted from the cache.
+ * tag_list:        A collection to track entries that belong to an object.
+ *                  Each H5C_tag_info_t struct on the tag list corresponds to
+ *                  a particular object in the file.  Tagged entries can be
+ *                  flushed or evicted as a group, or corked to prevent entries
+ *                  from being evicted from the cache.
  *
- *                "Global" entries, like the superblock and the file's
- *                freelist, as well as shared entries like global
- *                heaps and shared object header messages, are not tagged.
+ *                  "Global" entries, like the superblock and the file's
+ *                  freelist, as well as shared entries like global
+ *                  heaps and shared object header messages, are not tagged.
  *
- * ignore_tags:    Boolean flag to disable tag validation during entry insertion.
+ * ignore_tags:     Boolean flag to disable tag validation during entry insertion.
  *
  * num_objs_corked: Unsigned integer field containing the number of objects
  *                  that are "corked".  The "corked" status of an object is
@@ -4863,7 +4868,7 @@ struct H5C_t {
 #endif /* H5C_DO_SANITY_CHECKS */
 
     /* Fields for maintaining list of tagged entries */
-    H5SL_t *                    tag_list;
+    H5C_tag_info_t *            tag_list;
     hbool_t                     ignore_tags;
     uint32_t                    num_objs_corked;