-/* LBS: An LFS-inspired filesystem backup system
- * Copyright (C) 2007 Michael Vrable
+/* Cumulus: Smart Filesystem Backup to Dumb Servers
*
- * Handling of metadata written to backup snapshots. This manages the writing
+ * Copyright (C) 2007-2008 The Regents of the University of California
+ * Written by Michael Vrable <mvrable@cs.ucsd.edu>
+ *
+ * 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.
+ */
+
+/* Handling of metadata written to backup snapshots. This manages the writing
* of file metadata into new backup snapshots, including breaking the metadata
* log apart across separate objects. Eventually this should include unified
* handling of the statcache, and re-use of metadata between snapshots.
#include <string>
#include <iostream>
+#include <map>
#include "metadata.h"
+#include "localdb.h"
#include "ref.h"
#include "store.h"
#include "util.h"
using std::list;
+using std::map;
using std::string;
using std::ostream;
using std::ostringstream;
static const size_t LBS_METADATA_BLOCK_SIZE = 65536;
+// If true, forces a full write of metadata: will not include pointers to
+// metadata in old snapshots.
+bool flag_full_metadata = false;
+
/* TODO: Move to header file */
+extern LocalDb *db;
void add_segment(const string& segment);
/* Like strcmp, but sorts in the order that files will be visited in the
return pathcmp(slash1 + 1, slash2 + 1);
}
+/* Encode a dictionary of string key/value pairs into a sequence of lines of
+ * the form "key: value". If it exists, the key "name" is treated specially
+ * and will be listed first. */
+static string encode_dict(const map<string, string>& dict)
+{
+ string result;
+
+ if (dict.find("name") != dict.end()) {
+ result += "name: " + dict.at("name") + "\n";
+ }
+
+ for (map<string, string>::const_iterator i = dict.begin();
+ i != dict.end(); ++i) {
+ if (i->first == "name")
+ continue;
+ result += i->first + ": " + i->second + "\n";
+ }
+
+ return result;
+}
+
MetadataWriter::MetadataWriter(TarSegmentStore *store,
const char *path,
const char *snapshot_name,
throw IOException("Error opening statcache");
}
- found_match = false;
old_metadata_eof = false;
this->store = store;
{
const char *path_str = path.c_str();
while (!old_metadata_eof) {
- string old_path = uri_decode(old_metadata["path"]);
+ string old_path = uri_decode(old_metadata["name"]);
int cmp = pathcmp(old_path.c_str(), path_str);
- if (cmp == 0) {
- found_match = true;
+ if (cmp == 0)
return true;
- } else if (cmp > 0) {
- found_match = false;
+ else if (cmp > 0)
return false;
- } else {
+ else
read_statcache();
- }
}
- found_match = false;
return false;
}
/* Does a file appear to be unchanged from the previous time it was backed up,
- * based on stat information?
- *
- * TODO: Notice files that were modified as they were being backed up the last
- * time. */
+ * based on stat information? */
bool MetadataWriter::is_unchanged(const struct stat *stat_buf)
{
+ if (old_metadata.find("volatile") != old_metadata.end()
+ && parse_int(old_metadata["volatile"]) != 0)
+ return false;
+
if (old_metadata.find("ctime") == old_metadata.end())
return false;
if (stat_buf->st_ctime != parse_int(old_metadata["ctime"]))
s++;
}
- ObjectReference *r = ObjectReference::parse(ref);
- if (r != NULL) {
- blocks.push_back(*r);
- delete r;
- }
+ ObjectReference r = ObjectReference::parse(ref);
+ if (!r.is_null())
+ blocks.push_back(r);
}
return blocks;
ObjectReference indirect;
for (list<MetadataItem>::iterator i = items.begin();
i != items.end(); ++i) {
+ // If indirectly referencing any other metadata logs, be sure those
+ // segments are properly referenced.
+ if (i->reused) {
+ add_segment(i->ref.get_segment());
+ db->UseSegment(i->ref.get_segment(), 1.0);
+ }
+
// Write out an indirect reference to any previous objects which could
// be reused
if (!i->reused || !indirect.merge(i->ref)) {
ObjectReference ref = meta->get_ref();
metadata_root << "@" << ref.to_string() << "\n";
add_segment(ref.get_segment());
+ db->UseSegment(ref.get_segment(), 1.0);
delete meta;
item.reused = false;
item.text += encode_dict(info) + "\n";
- if (info == old_metadata) {
- ObjectReference *ref = ObjectReference::parse(old_metadata_loc);
- if (ref != NULL) {
+ if (info == old_metadata && !flag_full_metadata) {
+ ObjectReference ref = ObjectReference::parse(old_metadata_loc);
+ if (!ref.is_null()) {
item.reused = true;
- item.ref = *ref;
- delete ref;
+ item.ref = ref;
}
}
root->write(store);
root->checksum();
add_segment(root->get_ref().get_segment());
+ db->UseSegment(root->get_ref().get_segment(), 1.0);
ObjectReference ref = root->get_ref();
delete root;