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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/ntfs/collate.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/ntfs/collate.c')
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diff --git a/fs/ntfs/collate.c b/fs/ntfs/collate.c
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+/*
+ * collate.c - NTFS kernel collation handling. Part of the Linux-NTFS project.
+ *
+ * Copyright (c) 2004 Anton Altaparmakov
+ *
+ * This program/include file 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/include file 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 (in the main directory of the Linux-NTFS
+ * distribution in the file COPYING); if not, write to the Free Software
+ * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "collate.h"
+#include "debug.h"
+#include "ntfs.h"
+
+static int ntfs_collate_binary(ntfs_volume *vol,
+ const void *data1, const int data1_len,
+ const void *data2, const int data2_len)
+{
+ int rc;
+
+ ntfs_debug("Entering.");
+ rc = memcmp(data1, data2, min(data1_len, data2_len));
+ if (!rc && (data1_len != data2_len)) {
+ if (data1_len < data2_len)
+ rc = -1;
+ else
+ rc = 1;
+ }
+ ntfs_debug("Done, returning %i", rc);
+ return rc;
+}
+
+static int ntfs_collate_ntofs_ulong(ntfs_volume *vol,
+ const void *data1, const int data1_len,
+ const void *data2, const int data2_len)
+{
+ int rc;
+ u32 d1, d2;
+
+ ntfs_debug("Entering.");
+ // FIXME: We don't really want to bug here.
+ BUG_ON(data1_len != data2_len);
+ BUG_ON(data1_len != 4);
+ d1 = le32_to_cpup(data1);
+ d2 = le32_to_cpup(data2);
+ if (d1 < d2)
+ rc = -1;
+ else {
+ if (d1 == d2)
+ rc = 0;
+ else
+ rc = 1;
+ }
+ ntfs_debug("Done, returning %i", rc);
+ return rc;
+}
+
+typedef int (*ntfs_collate_func_t)(ntfs_volume *, const void *, const int,
+ const void *, const int);
+
+static ntfs_collate_func_t ntfs_do_collate0x0[3] = {
+ ntfs_collate_binary,
+ NULL/*ntfs_collate_file_name*/,
+ NULL/*ntfs_collate_unicode_string*/,
+};
+
+static ntfs_collate_func_t ntfs_do_collate0x1[4] = {
+ ntfs_collate_ntofs_ulong,
+ NULL/*ntfs_collate_ntofs_sid*/,
+ NULL/*ntfs_collate_ntofs_security_hash*/,
+ NULL/*ntfs_collate_ntofs_ulongs*/,
+};
+
+/**
+ * ntfs_collate - collate two data items using a specified collation rule
+ * @vol: ntfs volume to which the data items belong
+ * @cr: collation rule to use when comparing the items
+ * @data1: first data item to collate
+ * @data1_len: length in bytes of @data1
+ * @data2: second data item to collate
+ * @data2_len: length in bytes of @data2
+ *
+ * Collate the two data items @data1 and @data2 using the collation rule @cr
+ * and return -1, 0, ir 1 if @data1 is found, respectively, to collate before,
+ * to match, or to collate after @data2.
+ *
+ * For speed we use the collation rule @cr as an index into two tables of
+ * function pointers to call the appropriate collation function.
+ */
+int ntfs_collate(ntfs_volume *vol, COLLATION_RULE cr,
+ const void *data1, const int data1_len,
+ const void *data2, const int data2_len) {
+ int i;
+
+ ntfs_debug("Entering.");
+ /*
+ * FIXME: At the moment we only support COLLATION_BINARY and
+ * COLLATION_NTOFS_ULONG, so we BUG() for everything else for now.
+ */
+ BUG_ON(cr != COLLATION_BINARY && cr != COLLATION_NTOFS_ULONG);
+ i = le32_to_cpu(cr);
+ BUG_ON(i < 0);
+ if (i <= 0x02)
+ return ntfs_do_collate0x0[i](vol, data1, data1_len,
+ data2, data2_len);
+ BUG_ON(i < 0x10);
+ i -= 0x10;
+ if (likely(i <= 3))
+ return ntfs_do_collate0x1[i](vol, data1, data1_len,
+ data2, data2_len);
+ BUG();
+ return 0;
+}