Optimize searches for directory structures by keeping a pointer to struct directory in struct name.

* src/common.h (struct name): New member `directory' replaces
dir_contents. Rearrange members.
(rebase_directory): Change signature.
(scan_directory): Change signature.
(name_fill_directory)
(directory_contents, safe_directory_contents): New prototypes.
(append_incremental_renames): Change signature.
(replace_prefix): New proto.
* src/compare.c (diff_dumpdir): Use directory_contents + scan_directory.
* src/create.c
* src/incremen.c (replace_prefix): Move to misc.c
(rebase_directory): Rewrite.
(scan_directory): Return pointer to struct directory.
(directory_contents, safe_directory_contents): New functions.
(get_directory_contents): Remove.
(name_fill_directory): New function.
(append_incremental_renames): Rewrite. This also fixes a memory leak.
* src/names.c (name_gather, addname): Reflect changes in struct name.
(add_hierarchy_to_namelist): Rewrite using name_fill_directory and
directory_contents.
(rebase_child_list): Update call to rebase_directory.
(collect_and_sort_names): Optimize

* src/misc.c (replace_prefix): New function.
* src/names.c (add_hierarchy_to_namelist): Use new get_directory_contents.

* tests/incr05.at: New test case.
* tests/incr06.at: New test case.
* tests/Makefile.am, test/testsuite.at: Add incr05.at and incr06.at.

* doc/Makefile.am (check-options): Improve rule.
* doc/tar.texi, NEWS: Update.

src/common.h

@@ -320,26 +320,32 @@ GLOBAL const char **archive_name_cursor;
 /* Output index file name.  */
 GLOBAL char const *index_file_name;
 
+/* Opaque structure for keeping directory meta-data */
+struct directory;
+
 /* Structure for keeping track of filenames and lists thereof.  */
 struct name
   {
     struct name *next;          /* Link to the next element */
     struct name *prev;          /* Link to the previous element */
+
+    char *name;                 /* File name or globbing pattern */
+    size_t length;		/* cached strlen (name) */
+    int matching_flags;		/* wildcard flags if name is a pattern */
+
     int change_dir;		/* Number of the directory to change to.
 				   Set with the -C option. */
     uintmax_t found_count;	/* number of times a matching file has
 				   been found */
-    int matching_flags;		/* this name is a regexp, not literal */
     
-    size_t length;		/* cached strlen(name) */
-    char *name;
-
-    /* The following members are used for incremental dumps only */
-    char const *dir_contents;	/* directory contents  */
+    /* The following members are used for incremental dumps only,
+       if this struct name represents a directory;
+       see incremen.c */
+    struct directory *directory;/* directory meta-data and contents */
     struct name *parent;        /* pointer to the parent hierarchy */
     struct name *child;         /* pointer to the first child */
     struct name *sibling;       /* pointer to the next sibling */
-    char *caname;               /* canonical name */ 
+    char *caname;               /* canonical name */
   };
 
 /* Obnoxious test to see if dimwit is trying to dump the archive.  */
@@ -505,16 +511,21 @@ char *dumpdir_locate (dumpdir_t dump, const char *name);
 char *dumpdir_next (dumpdir_iter_t itr);
 char *dumpdir_first (dumpdir_t dump, int all, dumpdir_iter_t *pitr);
 
-const char *scan_directory (char *dir_name, dev_t device, bool cmdline);
-const char *append_incremental_renames (const char *dump);
+struct directory *scan_directory (char *dir, dev_t device, bool cmdline);
+void name_fill_directory (struct name *name, dev_t device, bool cmdline);
+const char *directory_contents (struct directory *dir);
+const char *safe_directory_contents (struct directory *dir);
+
+void rebase_directory (struct directory *dir,
+		       const char *samp, size_t slen,
+		       const char *repl, size_t rlen);
+
+void append_incremental_renames (struct directory *dir);
 void read_directory_file (void);
 void write_directory_file (void);
 void purge_directory (char const *directory_name);
 void list_dumpdir (char *buffer, size_t size);
 void update_parent_directory (const char *name);
-void rebase_directory (const char *name, size_t old_prefix_len,
-		       const char *old_prefix,
-		       const char *new_prefix);
 
 size_t dumpdir_size (const char *p);
 bool is_dumpdir (struct tar_stat_info *stat_info);
@@ -558,7 +569,7 @@ off_t off_from_header (const char *buf, size_t size);
 size_t size_from_header (const char *buf, size_t size);
 time_t time_from_header (const char *buf, size_t size);
 uid_t uid_from_header (const char *buf, size_t size);
-uintmax_t uintmax_from_header (const char * buf, size_t size);
+uintmax_t uintmax_from_header (const char *buf, size_t size);
 
 void list_archive (void);
 void print_for_mkdir (char *dirname, int length, mode_t mode);
@@ -578,6 +589,8 @@ char *quote_copy_string (const char *str);
 int unquote_string (char *str);
 char *zap_slashes (char *name);
 char *normalize_filename (const char *name);
+void replace_prefix (char **pname, const char *samp, size_t slen,
+		     const char *repl, size_t rlen);
 
 void code_ns_fraction (int ns, char *p);
 char const *code_timespec (struct timespec ts, char *sbuf);

src/compare.c

@@ -380,7 +380,8 @@ diff_dumpdir (void)
   else
     dev = stat_data.st_dev;
 
-  dumpdir_buffer = scan_directory (current_stat_info.file_name, dev, false);
+  dumpdir_buffer = directory_contents
+                    (scan_directory (current_stat_info.file_name, dev, false));
 
   if (dumpdir_buffer)
     {

src/create.c

@@ -1116,11 +1116,12 @@ dump_dir0 (char *directory,
 
       if (!incremental_option)
 	finish_header (st, blk, block_ordinal);
-      else if (gnu_list_name->dir_contents)
+      else if (gnu_list_name->directory)
 	{
 	  if (archive_format == POSIX_FORMAT)
 	    {
-	      xheader_store ("GNU.dumpdir", st, gnu_list_name->dir_contents);
+	      xheader_store ("GNU.dumpdir", st,
+			     safe_directory_contents (gnu_list_name->directory));
 	      finish_header (st, blk, block_ordinal);
 	    }
 	  else
@@ -1132,11 +1133,8 @@ dump_dir0 (char *directory,
 	      const char *buffer, *p_buffer;
 
 	      block_ordinal = current_block_ordinal ();
-	      buffer = gnu_list_name->dir_contents;
-	      if (buffer)
-		totsize = dumpdir_size (buffer);
-	      else
-		totsize = 0;
+	      buffer = safe_directory_contents (gnu_list_name->directory);
+	      totsize = dumpdir_size (buffer);
 	      OFF_TO_CHARS (totsize, blk->header.size);
 	      finish_header (st, blk, block_ordinal);
 	      p_buffer = buffer;
@@ -1304,7 +1302,7 @@ create_archive (void)
 	    memcpy (buffer, p, plen);
 	    if (! ISSLASH (buffer[plen - 1]))
 	      buffer[plen++] = DIRECTORY_SEPARATOR;
-	    q = gnu_list_name->dir_contents;
+	    q = directory_contents (gnu_list_name->directory);
 	    if (q)
 	      while (*q)
 		{

src/incremen.c

@@ -290,24 +290,6 @@ attach_directory (const char *name)
 }
 		 
 
-static void
-replace_prefix (char **pname, const char *samp, size_t slen,
-		const char *repl, size_t rlen)
-{
-  char *name = *pname;
-  size_t nlen = strlen (name);
-  if (nlen > slen && memcmp (name, samp, slen) == 0 && ISSLASH (name[slen]))
-    {
-      if (rlen > slen)
-	{
-	  name = xrealloc (name, nlen - slen + rlen + 1);
-	  *pname = name;
-	}
-      memmove (name + rlen, name + slen, nlen - slen + 1);
-      memcpy (name, repl, rlen);
-    }
-}
-
 void
 dirlist_replace_prefix (const char *pref, const char *repl)
 {
@@ -389,18 +371,15 @@ remove_directory (const char *caname)
 }
 #endif
 
-/* Find a directory entry for NAME.  If first OLD_PREFIX_LEN
-   bytes of its name match OLD_PREFIX, replace them with
-   NEW_PREFIX. */
+/* If first OLD_PREFIX_LEN bytes of DIR->NAME name match OLD_PREFIX,
+   replace them with NEW_PREFIX. */
 void
-rebase_directory (const char *name, size_t old_prefix_len,
-		  const char *old_prefix,
-		  const char *new_prefix)
+rebase_directory (struct directory *dir,
+		  const char *old_prefix, size_t old_prefix_len,
+		  const char *new_prefix, size_t new_prefix_len)
 {
-  struct directory *dir = find_directory (name);
-  if (dir)
-    replace_prefix (&dir->name, old_prefix, old_prefix_len,
-		    new_prefix, strlen (new_prefix));
+  replace_prefix (&dir->name, old_prefix, old_prefix_len,
+		  new_prefix, new_prefix_len);
 }
 
 /* Return a directory entry for a given combination of device and inode
@@ -696,8 +675,10 @@ makedumpdir (struct directory *directory, const char *dir)
 /* Recursively scan the given directory DIR.
    DEVICE is the device number where DIR resides (for --one-file-system).
    If CMDLINE is true, the directory name was explicitly listed in the
-   command line. */
-const char *
+   command line.
+   Unless *PDIR is NULL, store there a pointer to the struct directory
+   describing DIR. */
+struct directory *
 scan_directory (char *dir, dev_t device, bool cmdline)
 {
   char *dirp = savedir (dir);	/* for scanning directory */
@@ -730,7 +711,7 @@ scan_directory (char *dir, dev_t device, bool cmdline)
   directory = procdir (name_buffer, &stat_data, device,
 		       (cmdline ? PD_FORCE_INIT : 0),
 		       &ch);
-      
+  
   name_length = strlen (name_buffer); 
   if (! ISSLASH (name_buffer[name_length - 1]))
     {
@@ -808,13 +789,30 @@ scan_directory (char *dir, dev_t device, bool cmdline)
   if (dirp)
     free (dirp);
 
-  return directory->dump ? directory->dump->contents : NULL;
+  return directory;
 }
 
+/* Return pointer to the contents of the directory DIR */
 const char *
-get_directory_contents (char *dir, dev_t device, bool force)
+directory_contents (struct directory *dir)
 {
-  return scan_directory (dir, device, force);
+  if (!dir)
+    return NULL;
+  return dir->dump ? dir->dump->contents : NULL;
+}
+
+/* A "safe" version of directory_contents, which never returns NULL. */
+const char *
+safe_directory_contents (struct directory *dir)
+{
+  const char *ret = directory_contents (dir);
+  return ret ? ret : "\0\0\0\0";
+}
+
+void
+name_fill_directory (struct name *name, dev_t device, bool cmdline)
+{
+  name->directory = scan_directory (name->name, device, cmdline);
 }
 
 
@@ -877,17 +875,19 @@ store_rename (struct directory *dir, struct obstack *stk)
     }
 }
 
-const char *
-append_incremental_renames (const char *dump)
+void
+append_incremental_renames (struct directory *dir)
 {
   struct obstack stk;
   size_t size;
   struct directory *dp;
+  const char *dump;
   
   if (dirhead == NULL)
-    return dump;
+    return;
 
   obstack_init (&stk);
+  dump = directory_contents (dir);
   if (dump)
     {
       size = dumpdir_size (dump) - 1;
@@ -902,11 +902,10 @@ append_incremental_renames (const char *dump)
   if (obstack_object_size (&stk) != size)
     {
       obstack_1grow (&stk, 0);
-      dump = obstack_finish (&stk);
+      dumpdir_free (dir->dump);
+      dir->dump = dumpdir_create (obstack_finish (&stk));
     }
-  else
-    obstack_free (&stk, NULL);
-  return dump;
+  obstack_free (&stk, NULL);
 }
 
 

src/misc.c

@@ -236,6 +236,25 @@ normalize_filename (const char *name)
   return zap_slashes (canonicalize_filename_mode (name, CAN_MISSING));
 }
 
+
+void
+replace_prefix (char **pname, const char *samp, size_t slen,
+		const char *repl, size_t rlen)
+{
+  char *name = *pname;
+  size_t nlen = strlen (name);
+  if (nlen > slen && memcmp (name, samp, slen) == 0 && ISSLASH (name[slen]))
+    {
+      if (rlen > slen)
+	{
+	  name = xrealloc (name, nlen - slen + rlen + 1);
+	  *pname = name;
+	}
+      memmove (name + rlen, name + slen, nlen - slen + 1);
+      memcpy (name, repl, rlen);
+    }
+}
+
 
 /* Handling numbers.  */
 
@@ -777,3 +796,4 @@ page_aligned_alloc (void **ptr, size_t size)
   *ptr = xmalloc (size1);
   return ptr_align (*ptr, alignment);
 }
+

src/names.c

@@ -418,7 +418,7 @@ name_gather (void)
 	  buffer->next = 0;
 	  buffer->found_count = 0;
 	  buffer->matching_flags = matching_flags;
-	  buffer->dir_contents = NULL;
+	  buffer->directory = NULL;
 	  buffer->parent = NULL;
 	  
 	  namelist = buffer;
@@ -461,7 +461,7 @@ addname (char const *string, int change_dir, struct name *parent)
   name->found_count = 0;
   name->matching_flags = matching_flags;
   name->change_dir = change_dir;
-  name->dir_contents = NULL;
+  name->directory = NULL;
   name->parent = parent;
   
   *nametail = name;
@@ -767,12 +767,11 @@ compare_names (struct name const *n1, struct name const *n2)
 static void
 add_hierarchy_to_namelist (struct name *name, dev_t device, bool cmdline)
 {
-  char *file_name = name->name;
-  const char *buffer = scan_directory (file_name, device, cmdline);
+  const char *buffer;
   
-  if (! buffer)
-    name->dir_contents = "\0\0\0\0";
-  else
+  name_fill_directory (name, device, cmdline);
+  buffer = directory_contents (name->directory);
+  if (buffer)
     {
       struct name *child_head = NULL, *child_tail = NULL;
       size_t name_length = name->length;
@@ -785,8 +784,7 @@ add_hierarchy_to_namelist (struct name *name, dev_t device, bool cmdline)
       size_t string_length;
       int change_dir = name->change_dir;
 
-      name->dir_contents = buffer;
-      strcpy (namebuf, file_name);
+      strcpy (namebuf, name->name);
       if (! ISSLASH (namebuf[name_length - 1]))
 	{
 	  namebuf[name_length++] = '/';
@@ -866,8 +864,9 @@ rebase_child_list (struct name *child, struct name *parent)
       child->name = newp;
       child->length = size;
 
-      rebase_directory (child->name, old_prefix_len, child->parent->name,
-			new_prefix);
+      rebase_directory (child->directory,
+			child->parent->name, old_prefix_len, 
+			new_prefix, new_prefix_len);
     }
 }
 
@@ -915,7 +914,7 @@ collect_and_sort_names (void)
   num_names = 0;
   for (name = namelist; name; name = name->next, num_names++)
     {
-      if (name->found_count || name->dir_contents)
+      if (name->found_count || name->directory)
 	continue;
       if (name->matching_flags & EXCLUDE_WILDCARDS)
 	/* NOTE: EXCLUDE_ANCHORED is not relevant here */
@@ -990,7 +989,7 @@ collect_and_sort_names (void)
       for (name = namelist; name && name->name[0] == 0; name++)
 	;
       if (name)
-	name->dir_contents = append_incremental_renames (name->dir_contents);
+	append_incremental_renames (name->directory);
     }
 }