index.py: new format (V3), with inodes, link counts, and 64-bit times.

To allow unambiguous preservation of hard-link structure, index device
numbers, inode numbers (new) and link counts (new) at 64 bits apiece
per GNU libc, which uses uint64_t, uint64_t, and unsigned long respectively.

Take the opportunity to use 64 bits for mtime and ctime as well, both
to be ready for Y2038 and to handle NTFS's zero value (Y1600).

diff --git a/lib/bup/index.py b/lib/bup/index.py
index 010b8b49205a183dce493758b177e0d25a0e1f72..3fde0f968a0d8d4f052ce9c94eec1f3da569738c 100644 (file)
--- a/lib/bup/index.py
+++ b/lib/bup/index.py
@@ -4,12 +4,10 @@ from bup.helpers import *
 
 EMPTY_SHA = '\0'*20
 FAKE_SHA = '\x01'*20
-INDEX_HDR = 'BUPI\0\0\0\2'
+INDEX_HDR = 'BUPI\0\0\0\3'
 
-# FIXME: guess I should have used 64-bit integers to store the mtime/ctime.
-# NTFS mtime=0 corresponds to the year 1600, which can't be stored in a 32-bit
-# time_t.  Next time we update the bupindex format, keep that in mind.
-INDEX_SIG = '!IiiIIQII20sHII'
+# Use 64-bit integers for mtime/ctime to handle NTFS zero (Y1600) and Y2038.
+INDEX_SIG = '!QQQqqIIQII20sHII'
 
 ENTLEN = struct.calcsize(INDEX_SIG)
 FOOTER_SIG = '!Q'
@@ -78,7 +76,7 @@ class Entry:
 
     def __repr__(self):
         return ("(%s,0x%04x,%d,%d,%d,%d,%d,%s/%s,0x%04x,0x%08x/%d)" 
-                % (self.name, self.dev,
+                % (self.name, self.dev, self.ino, self.nlink,
                    self.ctime, self.mtime, self.uid, self.gid,
                    self.size, oct(self.mode), oct(self.gitmode),
                    self.flags, self.children_ofs, self.children_n))
@@ -86,7 +84,8 @@ class Entry:
     def packed(self):
         try:
             return struct.pack(INDEX_SIG,
-                           self.dev, self.ctime, self.mtime, 
+                           self.dev, self.ino, self.nlink,
+                           self.ctime, self.mtime, 
                            self.uid, self.gid, self.size, self.mode,
                            self.gitmode, self.sha, self.flags,
                            self.children_ofs, self.children_n)
@@ -95,13 +94,15 @@ class Entry:
             raise
 
     def from_stat(self, st, tstart):
-        old = (self.dev, self.ctime, self.mtime,
+        old = (self.dev, self.ino, self.nlink, self.ctime, self.mtime,
                self.uid, self.gid, self.size, self.flags & IX_EXISTS)
-        new = (st.st_dev,
+        new = (st.st_dev, st.st_ino, st.st_nlink,
                xstat.fstime_floor_secs(st.st_ctime),
                xstat.fstime_floor_secs(st.st_mtime),
                st.st_uid, st.st_gid, st.st_size, IX_EXISTS)
         self.dev = st.st_dev
+        self.ino = st.st_ino
+        self.nlink = st.st_nlink
         self.ctime = xstat.fstime_floor_secs(st.st_ctime)
         self.mtime = xstat.fstime_floor_secs(st.st_mtime)
         self.uid = st.st_uid
@@ -125,9 +126,7 @@ class Entry:
         self.ctime = self._fixup_time(self.ctime)
 
     def _fixup_time(self, t):
-        if t < -0x80000000:  # can happen in NTFS on 64-bit linux
-            return 0
-        elif self.tmax != None and t > self.tmax:
+        if self.tmax != None and t > self.tmax:
             return self.tmax
         else:
             return t
@@ -176,13 +175,14 @@ class Entry:
 
 
 class NewEntry(Entry):
-    def __init__(self, basename, name, tmax, dev, ctime, mtime, uid, gid,
-                 size, mode, gitmode, sha, flags, children_ofs, children_n):
+    def __init__(self, basename, name, tmax, dev, ino, nlink, ctime, mtime,
+                 uid, gid, size, mode, gitmode, sha, flags,
+                 children_ofs, children_n):
         Entry.__init__(self, basename, name, tmax)
-        (self.dev, self.ctime, self.mtime, self.uid, self.gid,
-         self.size, self.mode, self.gitmode, self.sha,
+        (self.dev, self.ino, self.nlink, self.ctime, self.mtime,
+         self.uid, self.gid, self.size, self.mode, self.gitmode, self.sha,
          self.flags, self.children_ofs, self.children_n
-         ) = (dev, int(ctime), int(mtime), uid, gid,
+         ) = (dev, ino, nlink, int(ctime), int(mtime), uid, gid,
               size, mode, gitmode, sha, flags, children_ofs, children_n)
         self._fixup()
 
@@ -190,7 +190,7 @@ class NewEntry(Entry):
 class BlankNewEntry(NewEntry):
     def __init__(self, basename, tmax):
         NewEntry.__init__(self, basename, basename, tmax,
-                          0, 0, 0, 0, 0, 0, 0,
+                          0, 0, 0, 0, 0, 0, 0, 0, 0,
                           0, EMPTY_SHA, 0, 0, 0)
 
 
@@ -200,8 +200,8 @@ class ExistingEntry(Entry):
         self.parent = parent
         self._m = m
         self._ofs = ofs
-        (self.dev, self.ctime, self.mtime, self.uid, self.gid,
-         self.size, self.mode, self.gitmode, self.sha,
+        (self.dev, self.ino, self.nlink, self.ctime, self.mtime,
+         self.uid, self.gid, self.size, self.mode, self.gitmode, self.sha,
          self.flags, self.children_ofs, self.children_n
          ) = struct.unpack(INDEX_SIG, str(buffer(m, ofs, ENTLEN)))
 
@@ -414,7 +414,8 @@ class Writer:
         if st:
             isdir = stat.S_ISDIR(st.st_mode)
             assert(isdir == endswith)
-            e = NewEntry(basename, name, self.tmax, st.st_dev,
+            e = NewEntry(basename, name, self.tmax,
+                         st.st_dev, st.st_ino, st.st_nlink,
                          xstat.fstime_floor_secs(st.st_ctime),
                          xstat.fstime_floor_secs(st.st_mtime),
                          st.st_uid, st.st_gid,