From: Aidan Hobson Sayers <aidanhs@cantab.net>
Date: Fri, 17 Jul 2020 21:59:04 +0000 (+0100)
Subject: Eliminate redundant check of index start against ctime
X-Git-Tag: 0.31~24
X-Git-Url: https://arthur.barton.de/cgi-bin/gitweb.cgi?p=bup.git;a=commitdiff_plain;h=68e087e6f2f2311ac784b204c0de72dcddb08934

Eliminate redundant check of index start against ctime

When (the first version of) this check was added 10 years ago in
b4b4ef116880, it was presumably to ensure that "index; save; touch;
index" in the same second would flag a file as needing saving.

Since then, tmax has been added in the indexing process to solve the
problem by capping timestamps stored in the index. This capping means
that a file with ctime in the same second as an indexing start will
be picked up on both the indexes in the example above - there's no need
to special case the check.

Signed-off-by: Aidan Hobson Sayers <aidanhs@cantab.net>
Reviewed-by: Rob Browning <rlb@defaultvalue.org>
Tested-by: Rob Browning <rlb@defaultvalue.org>
---

diff --git a/lib/bup/index.py b/lib/bup/index.py
index ae62018..051bdb3 100644
--- a/lib/bup/index.py
+++ b/lib/bup/index.py
@@ -200,7 +200,7 @@ class Entry:
             log('pack error: %s (%r)\n' % (e, self))
             raise
 
-    def stale(self, st, tstart, check_device=True):
+    def stale(self, st, check_device=True):
         if self.size != st.st_size:
             return True
         if self.mtime != st.st_mtime:
@@ -219,10 +219,6 @@ class Entry:
             return True
         if check_device and (self.dev != st.st_dev):
             return True
-        # Check that the ctime's "second" is at or after tstart's.
-        ctime_sec_in_ns = xstat.fstime_floor_secs(st.st_ctime) * 10**9
-        if ctime_sec_in_ns >= tstart:
-            return True
         return False
 
     def update_from_stat(self, st, meta_ofs):
diff --git a/lib/cmd/index-cmd.py b/lib/cmd/index-cmd.py
index fbaa029..b3925b3 100755
--- a/lib/cmd/index-cmd.py
+++ b/lib/cmd/index-cmd.py
@@ -85,13 +85,12 @@ def clear_index(indexfile):
 
 
 def update_index(top, excluded_paths, exclude_rxs, xdev_exceptions, out=None):
-    # tmax and start must be epoch nanoseconds.
+    # tmax must be epoch nanoseconds.
     tmax = (time.time() - 1) * 10**9
     ri = index.Reader(indexfile)
     msw = index.MetaStoreWriter(indexfile + b'.meta')
     wi = index.Writer(indexfile, msw, tmax)
     rig = IterHelper(ri.iter(name=top))
-    tstart = int(time.time()) * 10**9
 
     hlinks = hlinkdb.HLinkDB(indexfile + b'.hlink')
 
@@ -131,7 +130,7 @@ def update_index(top, excluded_paths, exclude_rxs, xdev_exceptions, out=None):
 
         if rig.cur and rig.cur.name == path:    # paths that already existed
             need_repack = False
-            if(rig.cur.stale(pst, tstart, check_device=opt.check_device)):
+            if(rig.cur.stale(pst, check_device=opt.check_device)):
                 try:
                     meta = metadata.from_path(path, statinfo=pst)
                 except (OSError, IOError) as e: