]> wimlib.net Git - wimlib/blobdiff - src/swm.c
Refactor SWM code into swm.c
[wimlib] / src / swm.c
diff --git a/src/swm.c b/src/swm.c
new file mode 100644 (file)
index 0000000..58e594f
--- /dev/null
+++ b/src/swm.c
@@ -0,0 +1,194 @@
+/*
+ * swm.c
+ *
+ * Functions to help handle split WIMs.
+ */
+
+/*
+ * Copyright (C) 2012, 2013 Eric Biggers
+ *
+ * This file is part of wimlib, a library for working with WIM files.
+ *
+ * wimlib 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 3 of the License, or (at your option)
+ * any later version.
+ *
+ * wimlib 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 wimlib; if not, see http://www.gnu.org/licenses/.
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include "wimlib/error.h"
+#include "wimlib/lookup_table.h"
+#include "wimlib/swm.h"
+#include "wimlib/wim.h"
+
+static int
+move_lte_to_table(struct wim_lookup_table_entry *lte, void *combined_table)
+{
+       hlist_del(&lte->hash_list);
+       lookup_table_insert((struct wim_lookup_table*)combined_table, lte);
+       return 0;
+}
+
+static void
+lookup_table_join(struct wim_lookup_table *combined_table,
+                 struct wim_lookup_table *part_table)
+{
+       for_lookup_table_entry(part_table, move_lte_to_table, combined_table);
+       part_table->num_entries = 0;
+}
+
+/*
+ * merge_lookup_tables() - Merge lookup tables from the parts of a split WIM.
+ *
+ * @w specifies the first part, while @additional_swms and @num_additional_swms
+ * specify an array of pointers to the WIMStruct's for additional split WIM parts.
+ *
+ * The reason we join the lookup tables is so we only have to search one lookup
+ * table to find the location of a resource in the entire WIM.
+ */
+void
+merge_lookup_tables(WIMStruct *w,
+                   WIMStruct **additional_swms,
+                   unsigned num_additional_swms)
+{
+       for (unsigned i = 0; i < num_additional_swms; i++)
+               lookup_table_join(w->lookup_table, additional_swms[i]->lookup_table);
+}
+
+static int
+move_lte_to_orig_table(struct wim_lookup_table_entry *lte, void *_wim)
+{
+       WIMStruct *wim = _wim;
+       if (lte->wim != wim) {
+               move_lte_to_table(lte, lte->wim->lookup_table);
+               wim->lookup_table->num_entries--;
+       }
+       return 0;
+}
+
+/* Undo merge_lookup_tables(), given the first WIM part that contains the merged
+ * lookup table. */
+void
+unmerge_lookup_table(WIMStruct *wim)
+{
+       for_lookup_table_entry(wim->lookup_table, move_lte_to_orig_table, wim);
+}
+
+/*
+ * verify_swm_set: - Sanity checks to make sure a set of WIMs correctly
+ *                  correspond to a spanned set.
+ *
+ * @w:
+ *     Part 1 of the set.
+ *
+ * @additional_swms:
+ *     All parts of the set other than part 1.
+ *
+ * @num_additional_swms:
+ *     Number of WIMStructs in @additional_swms.  Or, the total number of parts
+ *     in the set minus 1.
+ *
+ * @return:
+ *     0 on success; WIMLIB_ERR_SPLIT_INVALID if the set is not valid.
+ */
+int
+verify_swm_set(WIMStruct *w, WIMStruct **additional_swms,
+              unsigned num_additional_swms)
+{
+       unsigned total_parts = w->hdr.total_parts;
+       int ctype;
+       const u8 *guid;
+
+       if (total_parts != num_additional_swms + 1) {
+               ERROR("`%"TS"' says there are %u parts in the spanned set, "
+                     "but %"TS"%u part%"TS" provided",
+                     w->filename, total_parts,
+                     (num_additional_swms + 1 < total_parts) ? T("only ") : T(""),
+                     num_additional_swms + 1,
+                     (num_additional_swms) ? T("s were") : T(" was"));
+               return WIMLIB_ERR_SPLIT_INVALID;
+       }
+       if (w->hdr.part_number != 1) {
+               ERROR("WIM `%"TS"' is not the first part of the split WIM.",
+                     w->filename);
+               return WIMLIB_ERR_SPLIT_INVALID;
+       }
+       for (unsigned i = 0; i < num_additional_swms; i++) {
+               if (additional_swms[i]->hdr.total_parts != total_parts) {
+                       ERROR("WIM `%"TS"' says there are %u parts in the "
+                             "spanned set, but %u parts were provided",
+                             additional_swms[i]->filename,
+                             additional_swms[i]->hdr.total_parts,
+                             total_parts);
+                       return WIMLIB_ERR_SPLIT_INVALID;
+               }
+       }
+
+       /* keep track of ctype and guid just to make sure they are the same for
+        * all the WIMs. */
+       ctype = wimlib_get_compression_type(w);
+       guid = w->hdr.guid;
+
+       {
+               /* parts_to_swms is not allocated at function scope because it
+                * should only be allocated after num_additional_swms was
+                * checked to be the same as w->hdr.total_parts.  Otherwise, it
+                * could be unexpectedly high and cause a stack overflow. */
+               WIMStruct *parts_to_swms[num_additional_swms];
+               ZERO_ARRAY(parts_to_swms);
+               for (unsigned i = 0; i < num_additional_swms; i++) {
+
+                       WIMStruct *swm = additional_swms[i];
+
+                       if (wimlib_get_compression_type(swm) != ctype) {
+                               ERROR("The split WIMs do not all have the same "
+                                     "compression type");
+                               return WIMLIB_ERR_SPLIT_INVALID;
+                       }
+                       if (memcmp(guid, swm->hdr.guid, WIM_GID_LEN) != 0) {
+                               ERROR("The split WIMs do not all have the same "
+                                     "GUID");
+                               return WIMLIB_ERR_SPLIT_INVALID;
+                       }
+                       if (swm->hdr.part_number == 1) {
+                               ERROR("WIMs `%"TS"' and `%"TS"' both are marked "
+                                     "as the first WIM in the spanned set",
+                                     w->filename, swm->filename);
+                               return WIMLIB_ERR_SPLIT_INVALID;
+                       }
+                       if (swm->hdr.part_number == 0 ||
+                           swm->hdr.part_number > total_parts)
+                       {
+                               ERROR("WIM `%"TS"' says it is part %u in the "
+                                     "spanned set, but the part number must "
+                                     "be in the range [1, %u]",
+                                     swm->filename, swm->hdr.part_number, total_parts);
+                               return WIMLIB_ERR_SPLIT_INVALID;
+                       }
+                       if (parts_to_swms[swm->hdr.part_number - 2])
+                       {
+                               ERROR("`%"TS"' and `%"TS"' are both marked as "
+                                     "part %u of %u in the spanned set",
+                                     parts_to_swms[swm->hdr.part_number - 2]->filename,
+                                     swm->filename,
+                                     swm->hdr.part_number,
+                                     total_parts);
+                               return WIMLIB_ERR_SPLIT_INVALID;
+                       } else {
+                               parts_to_swms[swm->hdr.part_number - 2] = swm;
+                       }
+               }
+       }
+       return 0;
+}