[svn-r6252] Purpose:

    Lots of performance improvements & a couple new internal API interfaces.

Description:
    Performance Improvements:
        - Cached file offset & length sizes in shared file struct, to avoid
            constantly looking them up in the FCPL.
        - Generic property improvements:
            - Added "revision" number to generic property classes to speed
                up comparisons.
            - Changed method of storing properties from using a hash-table
                to the TBBT routines in the library.
            - Share the propery names between classes and the lists derived
                from them.
            - Removed redundant 'def_value' buffer from each property.
            - Switching code to use a "copy on write" strategy for
                properties in each list, where the properties in each list
                are shared with the properties in the class, until a
                property's value is changed in a list.
        - Fixed error in layout code which was allocating too many buffers.
        - Redefined public macros of the form (H5open()/H5check, <variable>)
            internally to only be (<variable>), avoiding innumerable useless
            calls to H5open() and H5check_version().
        - Reuse already zeroed buffers in H5F_contig_fill instead of
            constantly re-zeroing them.
        - Don't write fill values if writing entire dataset.
        - Use gettimeofday() system call instead of time() system when
            checking the modification time of a dataset.
        - Added reference counted string API and use it for tracking the
            names of objects opening in a file (for the ID->name code).
        - Removed redundant H5P_get() calls in B-tree routines.
        - Redefine H5T datatype macros internally to the library, to avoid
            calling H5check redundantly.
        - Keep dataspace information for dataset locally instead of reading
            from disk each time.  Added new module to track open objects
            in a file, to allow this (which will be useful eventually for
            some FPH5 metadata caching issues).
        - Remove H5AC_find macro which was inlining metadata cache lookups,
            and call function instead.
        - Remove redundant memset() calls from H5G_namei() routine.
        - Remove redundant checking of object type when locating objects
            in metadata cache and rely on the address only.
        - Create default dataset object to use when default dataset creation
            property list is used to create datasets, bypassing querying
            for all the property list values.
        - Use default I/O vector size when performing raw data with the
            default dataset transfer property list, instead of querying for
            I/O vector size.
        - Remove H5P_DEFAULT internally to the library, replacing it with
            more specific default property list based on the type of
            property list needed.
        - Remove redundant memset() calls in object header message (H5O*)
            routines.
        - Remove redunant memset() calls in data I/O routines.
        - Split free-list allocation routines into malloc() and calloc()-
            like routines, instead of one combined routine.
        - Remove lots of indirection in H5O*() routines.
        - Simplify metadata cache entry comparison routine (used when
            flushing entire cache out).
        - Only enable metadata cache statistics when H5AC_DEBUG is turned
            on, instead of always tracking them.
        - Simplify address comparison macro (H5F_addr_eq).
        - Remove redundant metadata cache entry protections during dataset
            creation by protecting the object header once and making all
            the modifications necessary for the dataset creation before
            unprotecting it.
        - Reduce # of "number of element in extent" computations performed
            by computing and storing the value during dataspace creation.
        - Simplify checking for group location's file information, when file
            has not been involving in file-mounting operations.
        - Use binary encoding for modification time, instead of ASCII.
        - Hoist H5HL_peek calls (to get information in a local heap)
            out of loops in many group routine.
        - Use static variable for iterators of selections, instead of
            dynamically allocation them each time.
        - Lookup & insert new entries in one step, avoiding traversing
            group's B-tree twice.
        - Fixed memory leak in H5Gget_objname_idx() routine (tangential to
            performance improvements, but fixed along the way).
        - Use free-list for reference counted strings.
        - Don't bother copying object names into cached group entries,
            since they are re-created when an object is opened.

        The benchmark I used to measure these results created several thousand
        small (2K) datasets in a file and wrote out the data for them.  This is
        Elena's "regular.c" benchmark.

        These changes resulted in approximately ~4.3x speedup of the
        development branch when compared to the previous code in the
        development branch and ~1.4x speedup compared to the release
        branch.

        Additionally, these changes reduce the total memory used (code and
        data) by the development branch by ~800KB, bringing the development
        branch back into the same ballpark as the release branch.

        I'll send out a more detailed description of the benchmark results
        as a followup note.

    New internal API routines:
        Added "reference counted strings" API for tracking strings that get
            used by multiple owners without duplicating the strings.
        Added "ternary search tree" API for text->object mappings.

Platforms tested:
    Tested h5committest {arabica (fortran), eirene (fortran, C++)
	modi4 (parallel, fortran)}
    Other platforms/configurations tested?
        FreeBSD 4.7 (sleipnir) serial & parallel
        Solaris 2.6 (baldric) serial

1 files changed, 10 insertions, 16 deletions

diff --git a/src/H5Odtype.c b/src/H5Odtype.c
index 1d8b254..4244c41 100644
--- a/src/H5Odtype.c
+++ b/src/H5Odtype.c
@@ -48,7 +48,7 @@ const H5O_class_t H5O_DTYPE[1] = {{
     H5O_dtype_copy,		/* copy the native value	*/
     H5O_dtype_size,		/* size of raw message		*/
     H5O_dtype_reset,		/* reset method			*/
-    H5O_dtype_free,		    /* free method			*/
+    H5O_dtype_free,		/* free method			*/
     H5O_dtype_get_share,	/* get share method		*/
     H5O_dtype_set_share,	/* set share method		*/
     H5O_dtype_debug,		/* debug the message		*/
@@ -227,7 +227,7 @@ H5O_dtype_decode_helper(H5F_t *f, const uint8_t **pp, H5T_t *dt)
                 } /* end if */
 
                 /* Allocate space for the field's datatype */
-                temp_type = H5FL_ALLOC (H5T_t,1);
+                temp_type = H5FL_CALLOC (H5T_t);
                 if (NULL==temp_type)
                     HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
                 temp_type->ent.header = HADDR_UNDEF;
@@ -289,7 +289,7 @@ H5O_dtype_decode_helper(H5F_t *f, const uint8_t **pp, H5T_t *dt)
              */
             dt->u.enumer.nmembs = dt->u.enumer.nalloc = flags & 0xffff;
             assert(dt->u.enumer.nmembs>=0);
-            if (NULL==(dt->parent=H5FL_ALLOC(H5T_t,1)))
+            if (NULL==(dt->parent=H5FL_CALLOC(H5T_t)))
                 HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
             dt->parent->ent.header = HADDR_UNDEF;
             if (H5O_dtype_decode_helper(f, pp, dt->parent)<0)
@@ -343,7 +343,7 @@ H5O_dtype_decode_helper(H5F_t *f, const uint8_t **pp, H5T_t *dt)
             } /* end if */
 
             /* Decode base type of VL information */
-            if (NULL==(dt->parent = H5FL_ALLOC(H5T_t,1)))
+            if (NULL==(dt->parent = H5FL_CALLOC(H5T_t)))
                 HGOTO_ERROR (H5E_DATATYPE, H5E_NOSPACE, FAIL, "memory allocation failed");
             dt->parent->ent.header = HADDR_UNDEF;
             if (H5O_dtype_decode_helper(f, pp, dt->parent)<0)
@@ -381,7 +381,7 @@ H5O_dtype_decode_helper(H5F_t *f, const uint8_t **pp, H5T_t *dt)
                 UINT32DECODE(*pp, dt->u.array.perm[j]);
 
             /* Decode base type of array */
-            if (NULL==(dt->parent = H5FL_ALLOC(H5T_t,1)))
+            if (NULL==(dt->parent = H5FL_CALLOC(H5T_t)))
                 HGOTO_ERROR (H5E_DATATYPE, H5E_NOSPACE, FAIL, "memory allocation failed");
             dt->parent->ent.header = HADDR_UNDEF;
             if (H5O_dtype_decode_helper(f, pp, dt->parent)<0)
@@ -794,7 +794,7 @@ H5O_dtype_decode(H5F_t *f, const uint8_t *p,
     /* check args */
     assert(p);
 
-    if (NULL==(dt = H5FL_ALLOC(H5T_t,1)))
+    if (NULL==(dt = H5FL_CALLOC(H5T_t)))
         HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
     dt->ent.header = HADDR_UNDEF;
 
@@ -1009,18 +1009,12 @@ static herr_t
 H5O_dtype_reset(void *_mesg)
 {
     H5T_t		   *dt = (H5T_t *) _mesg;
-    H5T_t		   *tmp = NULL;
     herr_t      ret_value=SUCCEED;       /* Return value */
 
     FUNC_ENTER_NOAPI(H5O_dtype_reset, FAIL);
 
-    if (dt) {
-        if (NULL==(tmp = H5FL_ALLOC(H5T_t,0)))
-            HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
-        *tmp = *dt;
-        H5T_close(tmp);
-        HDmemset(dt, 0, sizeof(H5T_t));
-    }
+    if (dt)
+        H5T_free(dt);
 
 done:
     FUNC_LEAVE(ret_value);
@@ -1130,8 +1124,8 @@ H5O_dtype_set_share (H5F_t UNUSED *f, void *_mesg/*in,out*/,
     H5G_ent_copy(&(dt->ent),&(sh->u.ent),H5G_COPY_SHALLOW);
 
     /* Reset the names of the copied symbol table entry */
-    dt->ent.user_path = NULL;
-    dt->ent.canon_path = NULL;
+    dt->ent.user_path_r = NULL;
+    dt->ent.canon_path_r = NULL;
 
     /* Note that the datatype is a named datatype */
     dt->state = H5T_STATE_NAMED;