Cleanup/refactor: Add new BLI_string_util.

Things like `BLI_uniquename` had nothing, but really nothing to do in
BLI_path_util files!

Also, got rid of length limitation in `BLI_uniquename_cb`, we can use
alloca here to avoid overhead of malloc while keeping free size (within
reasonable limits of course).

1 files changed, 207 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/string_utils.c b/source/blender/blenlib/intern/string_utils.c
new file mode 100644
index 00000000000..a7427b6848e
--- /dev/null
+++ b/source/blender/blenlib/intern/string_utils.c
@@ -0,0 +1,207 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2017 by the Blender FOundation.
+ * All rights reserved.
+ *
+ * Contributor(s): none yet.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ * 
+ */
+
+/** \file blender/blenlib/intern/string_utils.c
+ *  \ingroup bli
+ */
+
+#include <ctype.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_listbase.h"
+#include "BLI_string.h"
+#include "BLI_string_utf8.h"
+#include "BLI_string_utils.h"
+#include "BLI_utildefines.h"
+
+#include "DNA_listBase.h"
+
+
+#ifdef __GNUC__
+#  pragma GCC diagnostic error "-Wsign-conversion"
+#endif
+
+/**
+ * Looks for a numeric suffix preceded by delim character on the end of
+ * name, puts preceding part into *left and value of suffix into *nr.
+ * Returns the length of *left.
+ *
+ * Foo.001 -> "Foo", 1
+ * Returning the length of "Foo"
+ *
+ * \param left  Where to return copy of part preceding delim
+ * \param nr  Where to return value of numeric suffix
+ * \param name  String to split
+ * \param delim  Delimiter character
+ * \return  Length of \a left
+ */
+int BLI_split_name_num(char *left, int *nr, const char *name, const char delim)
+{
+	const size_t name_len = strlen(name);
+
+	*nr = 0;
+	memcpy(left, name, (name_len + 1) * sizeof(char));
+
+	/* name doesn't end with a delimiter "foo." */
+	if ((name_len > 1 && name[name_len - 1] == delim) == 0) {
+		int a = name_len;
+		while (a--) {
+			if (name[a] == delim) {
+				left[a] = '\0';  /* truncate left part here */
+				*nr = atol(name + a + 1);
+				/* casting down to an int, can overflow for large numbers */
+				if (*nr < 0)
+					*nr = 0;
+				return a;
+			}
+			else if (isdigit(name[a]) == 0) {
+				/* non-numeric suffix - give up */
+				break;
+			}
+		}
+	}
+
+	return name_len;
+}
+
+
+/* Unique name utils. */
+
+/**
+ * Ensures name is unique (according to criteria specified by caller in unique_check callback),
+ * incrementing its numeric suffix as necessary. Returns true if name had to be adjusted.
+ *
+ * \param unique_check  Return true if name is not unique
+ * \param arg  Additional arg to unique_check--meaning is up to caller
+ * \param defname  To initialize name if latter is empty
+ * \param delim  Delimits numeric suffix in name
+ * \param name  Name to be ensured unique
+ * \param name_len  Maximum length of name area
+ * \return true if there if the name was changed
+ */
+bool BLI_uniquename_cb(
+        UniquenameCheckCallback unique_check, void *arg, const char *defname, char delim, char *name, size_t name_len)
+{
+	if (name[0] == '\0') {
+		BLI_strncpy(name, defname, name_len);
+	}
+
+	if (unique_check(arg, name)) {
+		char numstr[16];
+		char *tempname = alloca(name_len);
+		char *left = alloca(name_len);
+		int number;
+		int len = BLI_split_name_num(left, &number, name, delim);
+		do {
+			/* add 1 to account for \0 */
+			const size_t numlen = BLI_snprintf(numstr, sizeof(numstr), "%c%03d", delim, ++number) + 1;
+
+			/* highly unlikely the string only has enough room for the number
+			 * but support anyway */
+			if ((len == 0) || (numlen >= name_len)) {
+				/* number is know not to be utf-8 */
+				BLI_strncpy(tempname, numstr, name_len);
+			}
+			else {
+				char *tempname_buf;
+				tempname_buf = tempname + BLI_strncpy_utf8_rlen(tempname, left, name_len - numlen);
+				memcpy(tempname_buf, numstr, numlen);
+			}
+		} while (unique_check(arg, tempname));
+
+		BLI_strncpy(name, tempname, name_len);
+
+		return true;
+	}
+
+	return false;
+}
+
+/* little helper macro for BLI_uniquename */
+#ifndef GIVE_STRADDR
+#  define GIVE_STRADDR(data, offset) ( ((char *)data) + offset)
+#endif
+
+/* Generic function to set a unique name. It is only designed to be used in situations
+ * where the name is part of the struct.
+ *
+ * For places where this is used, see constraint.c for example...
+ *
+ *  name_offs: should be calculated using offsetof(structname, membername) macro from stddef.h
+ *  len: maximum length of string (to prevent overflows, etc.)
+ *  defname: the name that should be used by default if none is specified already
+ *  delim: the character which acts as a delimiter between parts of the name
+ */
+static bool uniquename_find_dupe(ListBase *list, void *vlink, const char *name, int name_offs)
+{
+	Link *link;
+
+	for (link = list->first; link; link = link->next) {
+		if (link != vlink) {
+			if (STREQ(GIVE_STRADDR(link, name_offs), name)) {
+				return true;
+			}
+		}
+	}
+
+	return false;
+}
+
+static bool uniquename_unique_check(void *arg, const char *name)
+{
+	struct {ListBase *lb; void *vlink; int name_offs; } *data = arg;
+	return uniquename_find_dupe(data->lb, data->vlink, name, data->name_offs);
+}
+
+/**
+ * Ensures that the specified block has a unique name within the containing list,
+ * incrementing its numeric suffix as necessary. Returns true if name had to be adjusted.
+ *
+ * \param list  List containing the block
+ * \param vlink  The block to check the name for
+ * \param defname  To initialize block name if latter is empty
+ * \param delim  Delimits numeric suffix in name
+ * \param name_offs  Offset of name within block structure
+ * \param name_len  Maximum length of name area
+ */
+bool BLI_uniquename(ListBase *list, void *vlink, const char *defname, char delim, int name_offs, size_t name_len)
+{
+	struct {ListBase *lb; void *vlink; int name_offs; } data;
+	data.lb = list;
+	data.vlink = vlink;
+	data.name_offs = name_offs;
+
+	BLI_assert(name_len > 1);
+
+	/* See if we are given an empty string */
+	if (ELEM(NULL, vlink, defname))
+		return false;
+
+	return BLI_uniquename_cb(uniquename_unique_check, &data, defname, delim, GIVE_STRADDR(vlink, name_offs), name_len);
+}