[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, 53 insertions, 23 deletions

diff --git a/src/H5Gstab.c b/src/H5Gstab.c
index 12d0ccb..e5e2535 100644
--- a/src/H5Gstab.c
+++ b/src/H5Gstab.c
@@ -12,6 +12,7 @@
 #include "H5private.h"
 #include "H5Eprivate.h"
 #include "H5Fpkg.h"         /*file access                             */
+#include "H5FLprivate.h"	/*Free Lists	  */
 #include "H5Gpkg.h"
 #include "H5HLprivate.h"
 #include "H5MMprivate.h"
@@ -21,6 +22,9 @@
 static int		interface_initialize_g = 0;
 #define INTERFACE_INIT	NULL
 
+/* Declare extern the PQ free list for the wrapped strings */
+H5FL_BLK_EXTERN(str_buf);
+
 /* Private prototypes */
 static herr_t H5G_insert_name(H5G_entry_t *loc, H5G_entry_t *obj,
         const char *name);
@@ -95,7 +99,7 @@ H5G_stab_create(H5F_t *f, size_t init, H5G_entry_t *self/*out*/)
      * Insert the symbol table message into the object header and the symbol
      * table entry.
      */
-    if (H5O_modify(self, H5O_STAB, H5O_NEW_MESG, H5O_FLAG_CONSTANT, &stab)<0) {
+    if (H5O_modify(self, H5O_STAB, H5O_NEW_MESG, H5O_FLAG_CONSTANT, 1, &stab)<0) {
 	H5O_close(self);
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "can't create message");
     }
@@ -160,8 +164,8 @@ H5G_stab_find(H5G_entry_t *grp_ent, const char *name,
     /* change OBJ_ENT only if found */
     else {
         if (obj_ent) {
-            /* do a deep copy */
-            if (H5G_ent_copy(obj_ent, &(udata.ent),H5G_COPY_DEEP)<0)
+            /* do a NULL copy, since the obj_ent name will be constructed in H5G_insert_name() */
+            if (H5G_ent_copy(obj_ent, &(udata.ent),H5G_COPY_NULL)<0)
                 HGOTO_ERROR(H5E_DATATYPE, H5E_CANTOPENOBJ, FAIL, "unable to copy entry");
 
             /* insert the name into the symbol entry OBJ_ENT */
@@ -224,7 +228,7 @@ H5G_stab_insert(H5G_entry_t *grp_ent, const char *name, H5G_entry_t *obj_ent)
     udata.operation = H5G_OPER_INSERT;
     udata.name = name;
     udata.heap_addr = stab.heap_addr;
-    H5G_ent_copy(&(udata.ent),obj_ent,H5G_COPY_SHALLOW); /* Shallow copy here, deep copy happens in H5G_node_insert() callback() */
+    H5G_ent_copy(&(udata.ent),obj_ent,H5G_COPY_NULL); /* NULL copy here, no copies happens in H5G_node_insert() callback() */
 
     /* insert */
     if (H5B_insert(grp_ent->file, H5B_SNODE, stab.btree_addr, split_ratios, &udata) < 0)
@@ -301,6 +305,8 @@ done:
 static herr_t 
 H5G_insert_name(H5G_entry_t *loc, H5G_entry_t *obj, const char *name)
 {
+    char *new_user_path;        /* Pointer to new user path */
+    char *new_canon_path;       /* Pointer to new canonical path */
     size_t  name_len;           /* Length of name to append */
     size_t  user_path_len;      /* Length of location's user path name */
     size_t  canon_path_len;     /* Length of location's canonical path name */
@@ -313,55 +319,79 @@ H5G_insert_name(H5G_entry_t *loc, H5G_entry_t *obj, const char *name)
     assert(name);
  
     /* Only attempt to build a new name if the location's name exists */
-    if(loc->canon_path) {
+    if(loc->canon_path_r) {
+        const char *loc_user_path;      /* Pointer to raw string for user path */
+        const char *loc_canon_path;     /* Pointer to raw string for canonical path */
 
         /* Reset the object's previous names, if they exist */
-        H5MM_xfree(obj->user_path);
-        H5MM_xfree(obj->canon_path);
+        if(obj->user_path_r) {
+            H5RS_decr(obj->user_path_r);
+            obj->user_path_r=NULL;
+        } /* end if */
+        if(obj->canon_path_r) {
+            H5RS_decr(obj->canon_path_r);
+            obj->canon_path_r=NULL;
+        } /* end if */
         obj->user_path_hidden=0;
 
         /* Get the length of the strings involved */
-        user_path_len = HDstrlen(loc->user_path);
-        canon_path_len = HDstrlen(loc->canon_path);
+        user_path_len = H5RS_len(loc->user_path_r);
+        canon_path_len = H5RS_len(loc->canon_path_r);
         name_len = HDstrlen(name);
 
         /* Modify the object's user path */
 
+        /* Get the raw string for the user path */
+        loc_user_path=H5RS_GET_STR(loc->user_path_r);
+        assert(loc_user_path);
+
         /* The location's user path already ends in a '/' separator */
-        if ('/'==loc->user_path[user_path_len-1]) {
-            if (NULL==(obj->user_path = H5MM_malloc (user_path_len+name_len+1)))
+        if ('/'==loc_user_path[user_path_len-1]) {
+            if (NULL==(new_user_path = H5FL_BLK_MALLOC(str_buf,user_path_len+name_len+1)))
                 HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
-            HDstrcpy(obj->user_path, loc->user_path);
+            HDstrcpy(new_user_path, loc_user_path);
         } /* end if */
         /* The location's user path needs a separator */
         else {
-            if (NULL==(obj->user_path = H5MM_malloc (user_path_len+1+name_len+1)))
+            if (NULL==(new_user_path = H5FL_BLK_MALLOC(str_buf,user_path_len+1+name_len+1)))
                 HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
-            HDstrcpy(obj->user_path, loc->user_path);
-            HDstrcat(obj->user_path, "/");
+            HDstrcpy(new_user_path, loc_user_path);
+            HDstrcat(new_user_path, "/");
         } /* end else */
 
         /* Append the component's name */
-        HDstrcat(obj->user_path, name);
+        HDstrcat(new_user_path, name);
+
+        /* Give ownership of the user path to the entry */
+        obj->user_path_r=H5RS_own(new_user_path);
+        assert(obj->user_path_r);
 
         /* Modify the object's canonical path */
 
+        /* Get the raw string for the canonical path */
+        loc_canon_path=H5RS_GET_STR(loc->canon_path_r);
+        assert(loc_canon_path);
+
         /* The location's canonical path already ends in a '/' separator */
-        if ('/'==loc->canon_path[canon_path_len-1]) {
-            if (NULL==(obj->canon_path = H5MM_malloc (canon_path_len+name_len+1)))
+        if ('/'==loc_canon_path[canon_path_len-1]) {
+            if (NULL==(new_canon_path = H5FL_BLK_MALLOC(str_buf,canon_path_len+name_len+1)))
                 HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
-            HDstrcpy(obj->canon_path, loc->canon_path);
+            HDstrcpy(new_canon_path, loc_canon_path);
         } /* end if */
         /* The location's canonical path needs a separator */
         else {
-            if (NULL==(obj->canon_path = H5MM_malloc (canon_path_len+1+name_len+1)))
+            if (NULL==(new_canon_path = H5FL_BLK_MALLOC(str_buf,canon_path_len+1+name_len+1)))
                 HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
-            HDstrcpy(obj->canon_path, loc->canon_path);
-            HDstrcat(obj->canon_path, "/");
+            HDstrcpy(new_canon_path, loc_canon_path);
+            HDstrcat(new_canon_path, "/");
         } /* end else */
 
         /* Append the component's name */
-        HDstrcat(obj->canon_path, name);
+        HDstrcat(new_canon_path, name);
+
+        /* Give ownership of the canonical path to the entry */
+        obj->canon_path_r=H5RS_own(new_canon_path);
+        assert(obj->canon_path_r);
     } /* end if */
 
 done: