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-rw-r--r--Build/source/texk/kpathsea/str-llist.c93
1 files changed, 93 insertions, 0 deletions
diff --git a/Build/source/texk/kpathsea/str-llist.c b/Build/source/texk/kpathsea/str-llist.c
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+/* str-llist.c: implementation of a linked list of strings.
+
+ Copyright 1993, 2008 Karl Berry.
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this library; if not, see <http://www.gnu.org/licenses/>. */
+
+#include <kpathsea/config.h>
+
+#include <kpathsea/str-llist.h>
+
+
+/* Add the new string STR to the end of the list L. */
+
+void
+str_llist_add (str_llist_type *l, string str)
+{
+ str_llist_elt_type *e;
+ str_llist_elt_type *new_elt = XTALLOC1 (str_llist_elt_type);
+
+ /* The new element will be at the end of the list. */
+ STR_LLIST (*new_elt) = str;
+ STR_LLIST_MOVED (*new_elt) = false;
+ STR_LLIST_NEXT (*new_elt) = NULL;
+
+ /* Find the current end of the list. */
+ for (e = *l; e && STR_LLIST_NEXT (*e); e = STR_LLIST_NEXT (*e))
+ ;
+
+ if (!e)
+ *l = new_elt;
+ else
+ STR_LLIST_NEXT (*e) = new_elt;
+}
+
+/* Move an element towards the top. The idea is that when a file is
+ found in a given directory, later files will likely be in that same
+ directory, and looking for the file in all the directories in between
+ is thus a waste. */
+
+void
+str_llist_float (str_llist_type *l, str_llist_elt_type *mover)
+{
+ str_llist_elt_type *last_moved, *unmoved;
+
+ /* If we've already moved this element, never mind. */
+ if (STR_LLIST_MOVED (*mover))
+ return;
+
+ /* Find the first unmoved element (to insert before). We're
+ guaranteed this will terminate, since MOVER itself is currently
+ unmoved, and it must be in L (by hypothesis). */
+ for (last_moved = NULL, unmoved = *l; STR_LLIST_MOVED (*unmoved);
+ last_moved = unmoved, unmoved = STR_LLIST_NEXT (*unmoved))
+ ;
+
+ /* If we are the first unmoved element, nothing to relink. */
+ if (unmoved != mover)
+ { /* Remember `mover's current successor, so we can relink `mover's
+ predecessor to it. */
+ str_llist_elt_type *before_mover;
+ str_llist_elt_type *after_mover = STR_LLIST_NEXT (*mover);
+
+ /* Find `mover's predecessor. */
+ for (before_mover = unmoved; STR_LLIST_NEXT (*before_mover) != mover;
+ before_mover = STR_LLIST_NEXT (*before_mover))
+ ;
+
+ /* `before_mover' now links to `after_mover'. */
+ STR_LLIST_NEXT (*before_mover) = after_mover;
+
+ /* Insert `mover' before `unmoved' and after `last_moved' (or at
+ the head of the list). */
+ STR_LLIST_NEXT (*mover) = unmoved;
+ if (!last_moved)
+ *l = mover;
+ else
+ STR_LLIST_NEXT (*last_moved) = mover;
+ }
+
+ /* We've moved it. */
+ STR_LLIST_MOVED (*mover) = true;
+}