]> arthur.barton.de Git - bup.git/blobdiff - lib/bup/index.py
index.Reader.filter: throw when parent's missing (don't assert)
[bup.git] / lib / bup / index.py
index 014a0ebe0cb83e42c9c4bd02e751d79c189bf278..3b98892b41b6b223bf74c9d4c5779439b718376f 100644 (file)
@@ -1,11 +1,17 @@
-import metadata, os, stat, struct, tempfile
-from bup import xstat
-from bup.helpers import *
 
-EMPTY_SHA = '\0'*20
-FAKE_SHA = '\x01'*20
+from __future__ import absolute_import, print_function
+import errno, os, stat, struct, tempfile
 
-INDEX_HDR = 'BUPI\0\0\0\5'
+from bup import metadata, xstat
+from bup._helpers import UINT_MAX, bytescmp
+from bup.compat import pending_raise, range
+from bup.helpers import (add_error, log, merge_iter, mmap_readwrite,
+                         progress, qprogress, resolve_parent, slashappend)
+
+EMPTY_SHA = b'\0' * 20
+FAKE_SHA = b'\x01' * 20
+
+INDEX_HDR = b'BUPI\0\0\0\7'
 
 # Time values are handled as integer nanoseconds since the epoch in
 # memory, but are written as xstat/metadata timespecs.  This behavior
@@ -14,7 +20,21 @@ INDEX_HDR = 'BUPI\0\0\0\5'
 # Record times (mtime, ctime, atime) as xstat/metadata timespecs, and
 # store all of the times in the index so they won't interfere with the
 # forthcoming metadata cache.
-INDEX_SIG =  '!QQQqQqQqQIIQII20sHIIQ'
+INDEX_SIG = ('!'
+             'Q'                # dev
+             'Q'                # ino
+             'Q'                # nlink
+             'qQ'               # ctime_s, ctime_ns
+             'qQ'               # mtime_s, mtime_ns
+             'qQ'               # atime_s, atime_ns
+             'Q'                # size
+             'I'                # mode
+             'I'                # gitmode
+             '20s'              # sha
+             'H'                # flags
+             'Q'                # children_ofs
+             'I'                # children_n
+             'Q')               # meta_ofs
 
 ENTLEN = struct.calcsize(INDEX_SIG)
 FOOTER_SIG = '!Q'
@@ -30,15 +50,25 @@ class Error(Exception):
 
 class MetaStoreReader:
     def __init__(self, filename):
+        self._closed = False
+        self._file = None
         self._file = open(filename, 'rb')
 
     def close(self):
+        self._closed = True
         if self._file:
             self._file.close()
             self._file = None
 
     def __del__(self):
-        self.close()
+        assert self._closed
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type, value, traceback):
+        with pending_raise(value, rethrow=True):
+            self.close()
 
     def metadata_at(self, ofs):
         self._file.seek(ofs)
@@ -50,9 +80,11 @@ class MetaStoreWriter:
     # truncation or corruption somewhat sensibly.
 
     def __init__(self, filename):
+        self._closed = False
         # Map metadata hashes to bupindex.meta offsets.
         self._offsets = {}
         self._filename = filename
+        self._file = None
         # FIXME: see how slow this is; does it matter?
         m_file = open(filename, 'ab+')
         try:
@@ -68,20 +100,27 @@ class MetaStoreWriter:
             except EOFError:
                 pass
             except:
-                log('index metadata in %r appears to be corrupt' % filename)
+                log('index metadata in %r appears to be corrupt\n' % filename)
                 raise
         finally:
             m_file.close()
         self._file = open(filename, 'ab')
 
     def close(self):
+        self._closed = True
         if self._file:
             self._file.close()
             self._file = None
 
     def __del__(self):
-        # Be optimistic.
-        self.close()
+        assert self._closed
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type, value, traceback):
+        with pending_raise(value, rethrow=False):
+            self.close()
 
     def store(self, metadata):
         meta_encoded = metadata.encode(include_path=False)
@@ -105,7 +144,7 @@ class Level:
         (ofs,n) = (f.tell(), len(self.list))
         if self.list:
             count = len(self.list)
-            #log('popping %r with %d entries\n' 
+            #log('popping %r with %d entries\n'
             #    % (''.join(self.ename), count))
             for e in self.list:
                 e.write(f)
@@ -143,17 +182,19 @@ def _golevel(level, f, ename, newentry, metastore, tmax):
 
 class Entry:
     def __init__(self, basename, name, meta_ofs, tmax):
-        self.basename = str(basename)
-        self.name = str(name)
+        assert basename is None or isinstance(basename, bytes)
+        assert name is None or isinstance(name, bytes)
+        self.basename = basename
+        self.name = name
         self.meta_ofs = meta_ofs
         self.tmax = tmax
         self.children_ofs = 0
         self.children_n = 0
 
     def __repr__(self):
-        return ("(%s,0x%04x,%d,%d,%d,%d,%d,%d,%d,%d,%s/%s,0x%04x,%d,0x%08x/%d)"
+        return ("(%r,0x%04x,%d,%d,%d,%d,%d,%d,%s/%s,0x%04x,%d,0x%08x/%d)"
                 % (self.name, self.dev, self.ino, self.nlink,
-                   self.ctime, self.mtime, self.atime, self.uid, self.gid,
+                   self.ctime, self.mtime, self.atime,
                    self.size, self.mode, self.gitmode,
                    self.flags, self.meta_ofs,
                    self.children_ofs, self.children_n))
@@ -168,47 +209,51 @@ class Entry:
                                ctime[0], ctime[1],
                                mtime[0], mtime[1],
                                atime[0], atime[1],
-                               self.uid, self.gid, self.size, self.mode,
+                               self.size, self.mode,
                                self.gitmode, self.sha, self.flags,
                                self.children_ofs, self.children_n,
                                self.meta_ofs)
-        except (DeprecationWarning, struct.error), e:
+        except (DeprecationWarning, struct.error) as e:
             log('pack error: %s (%r)\n' % (e, self))
             raise
 
-    def from_stat(self, st, meta_ofs, tstart, check_device=True):
-        old = (self.dev if check_device else 0,
-               self.ino, self.nlink, self.ctime, self.mtime,
-               self.uid, self.gid, self.size, self.flags & IX_EXISTS)
-        new = (st.st_dev if check_device else 0,
-               st.st_ino, st.st_nlink, st.st_ctime, st.st_mtime,
-               st.st_uid, st.st_gid, st.st_size, IX_EXISTS)
+    def stale(self, st, check_device=True):
+        if self.size != st.st_size:
+            return True
+        if self.mtime != st.st_mtime:
+            return True
+        if self.sha == EMPTY_SHA:
+            return True
+        if not self.gitmode:
+            return True
+        if self.ctime != st.st_ctime:
+            return True
+        if self.ino != st.st_ino:
+            return True
+        if self.nlink != st.st_nlink:
+            return True
+        if not (self.flags & IX_EXISTS):
+            return True
+        if check_device and (self.dev != st.st_dev):
+            return True
+        return False
+
+    def update_from_stat(self, st, meta_ofs):
+        # Should only be called when the entry is stale(), and
+        # invalidate() should almost certainly be called afterward.
         self.dev = st.st_dev
         self.ino = st.st_ino
         self.nlink = st.st_nlink
         self.ctime = st.st_ctime
         self.mtime = st.st_mtime
         self.atime = st.st_atime
-        self.uid = st.st_uid
-        self.gid = st.st_gid
         self.size = st.st_size
         self.mode = st.st_mode
         self.flags |= IX_EXISTS
         self.meta_ofs = meta_ofs
-        # 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 or old != new \
-              or self.sha == EMPTY_SHA or not self.gitmode:
-            self.invalidate()
         self._fixup()
-        
+
     def _fixup(self):
-        if self.uid < 0:
-            self.uid += 0x100000000
-        if self.gid < 0:
-            self.gid += 0x100000000
-        assert(self.uid >= 0)
-        assert(self.gid >= 0)
         self.mtime = self._fixup_time(self.mtime)
         self.ctime = self._fixup_time(self.ctime)
 
@@ -252,25 +297,51 @@ class Entry:
     def is_fake(self):
         return not self.ctime
 
-    def __cmp__(a, b):
-        return (cmp(b.name, a.name)
-                or cmp(a.is_valid(), b.is_valid())
-                or cmp(a.is_fake(), b.is_fake()))
+    def _cmp(self, other):
+        # Note reversed name ordering
+        bc = bytescmp(other.name, self.name)
+        if bc != 0:
+            return bc
+        vc = self.is_valid() - other.is_valid()
+        if vc != 0:
+            return vc
+        fc = self.is_fake() - other.is_fake()
+        if fc != 0:
+            return fc
+        return 0
+
+    def __eq__(self, other):
+        return self._cmp(other) == 0
+
+    def __ne__(self, other):
+        return self._cmp(other) != 0
+
+    def __lt__(self, other):
+        return self._cmp(other) < 0
+
+    def __gt__(self, other):
+        return self._cmp(other) > 0
+
+    def __le__(self, other):
+        return self._cmp(other) <= 0
+
+    def __ge__(self, other):
+        return self._cmp(other) >= 0
 
     def write(self, f):
-        f.write(self.basename + '\0' + self.packed())
+        f.write(self.basename + b'\0' + self.packed())
 
 
 class NewEntry(Entry):
     def __init__(self, basename, name, tmax, dev, ino, nlink,
                  ctime, mtime, atime,
-                 uid, gid, size, mode, gitmode, sha, flags, meta_ofs,
+                 size, mode, gitmode, sha, flags, meta_ofs,
                  children_ofs, children_n):
         Entry.__init__(self, basename, name, meta_ofs, tmax)
         (self.dev, self.ino, self.nlink, self.ctime, self.mtime, self.atime,
-         self.uid, self.gid, self.size, self.mode, self.gitmode, self.sha,
+         self.size, self.mode, self.gitmode, self.sha,
          self.flags, self.children_ofs, self.children_n
-         ) = (dev, ino, nlink, ctime, mtime, atime, uid, gid,
+         ) = (dev, ino, nlink, ctime, mtime, atime,
               size, mode, gitmode, sha, flags, children_ofs, children_n)
         self._fixup()
 
@@ -278,7 +349,7 @@ class NewEntry(Entry):
 class BlankNewEntry(NewEntry):
     def __init__(self, basename, meta_ofs, tmax):
         NewEntry.__init__(self, basename, basename, tmax,
-                          0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+                          0, 0, 0, 0, 0, 0, 0, 0,
                           0, EMPTY_SHA, 0, meta_ofs, 0, 0)
 
 
@@ -290,9 +361,9 @@ class ExistingEntry(Entry):
         self._ofs = ofs
         (self.dev, self.ino, self.nlink,
          self.ctime, ctime_ns, self.mtime, mtime_ns, self.atime, atime_ns,
-         self.uid, self.gid, self.size, self.mode, self.gitmode, self.sha,
+         self.size, self.mode, self.gitmode, self.sha,
          self.flags, self.children_ofs, self.children_n, self.meta_ofs
-         ) = struct.unpack(INDEX_SIG, str(buffer(m, ofs, ENTLEN)))
+         ) = struct.unpack(INDEX_SIG, m[ofs : ofs + ENTLEN])
         self.atime = xstat.timespec_to_nsecs((self.atime, atime_ns))
         self.mtime = xstat.timespec_to_nsecs((self.mtime, mtime_ns))
         self.ctime = xstat.timespec_to_nsecs((self.ctime, ctime_ns))
@@ -323,22 +394,22 @@ class ExistingEntry(Entry):
 
     def iter(self, name=None, wantrecurse=None):
         dname = name
-        if dname and not dname.endswith('/'):
-            dname += '/'
+        if dname and not dname.endswith(b'/'):
+            dname += b'/'
         ofs = self.children_ofs
         assert(ofs <= len(self._m))
-        assert(self.children_n < 1000000)
-        for i in xrange(self.children_n):
-            eon = self._m.find('\0', ofs)
+        assert(self.children_n <= UINT_MAX)  # i.e. python struct 'I'
+        for i in range(self.children_n):
+            eon = self._m.find(b'\0', ofs)
             assert(eon >= 0)
             assert(eon >= ofs)
             assert(eon > ofs)
-            basename = str(buffer(self._m, ofs, eon-ofs))
+            basename = self._m[ofs : ofs + (eon - ofs)]
             child = ExistingEntry(self, basename, self.name + basename,
                                   self._m, eon+1)
             if (not dname
                  or child.name.startswith(dname)
-                 or child.name.endswith('/') and dname.startswith(child.name)):
+                 or child.name.endswith(b'/') and dname.startswith(child.name)):
                 if not wantrecurse or wantrecurse(child):
                     for e in child.iter(name=name, wantrecurse=wantrecurse):
                         yield e
@@ -348,18 +419,19 @@ class ExistingEntry(Entry):
 
     def __iter__(self):
         return self.iter()
-            
+
 
 class Reader:
     def __init__(self, filename):
+        self.closed = False
         self.filename = filename
-        self.m = ''
+        self.m = b''
         self.writable = False
         self.count = 0
         f = None
         try:
-            f = open(filename, 'r+')
-        except IOError, e:
+            f = open(filename, 'rb+')
+        except IOError as e:
             if e.errno == errno.ENOENT:
                 pass
             else:
@@ -375,10 +447,15 @@ class Reader:
                     self.m = mmap_readwrite(f)
                     self.writable = True
                     self.count = struct.unpack(FOOTER_SIG,
-                          str(buffer(self.m, st.st_size-FOOTLEN, FOOTLEN)))[0]
+                                               self.m[st.st_size - FOOTLEN
+                                                      : st.st_size])[0]
 
-    def __del__(self):
-        self.close()
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type, value, traceback):
+        with pending_raise(value, rethrow=False):
+            self.close()
 
     def __len__(self):
         return int(self.count)
@@ -386,20 +463,20 @@ class Reader:
     def forward_iter(self):
         ofs = len(INDEX_HDR)
         while ofs+ENTLEN <= len(self.m)-FOOTLEN:
-            eon = self.m.find('\0', ofs)
+            eon = self.m.find(b'\0', ofs)
             assert(eon >= 0)
             assert(eon >= ofs)
             assert(eon > ofs)
-            basename = str(buffer(self.m, ofs, eon-ofs))
+            basename = self.m[ofs : ofs + (eon - ofs)]
             yield ExistingEntry(None, basename, basename, self.m, eon+1)
             ofs = eon + 1 + ENTLEN
 
     def iter(self, name=None, wantrecurse=None):
         if len(self.m) > len(INDEX_HDR)+ENTLEN:
             dname = name
-            if dname and not dname.endswith('/'):
-                dname += '/'
-            root = ExistingEntry(None, '/', '/',
+            if dname and not dname.endswith(b'/'):
+                dname += b'/'
+            root = ExistingEntry(None, b'/', b'/',
                                  self.m, len(self.m)-FOOTLEN-ENTLEN)
             for sub in root.iter(name=name, wantrecurse=wantrecurse):
                 yield sub
@@ -409,6 +486,11 @@ class Reader:
     def __iter__(self):
         return self.iter()
 
+    def find(self, name):
+        return next((e for e in self.iter(name, wantrecurse=lambda x : True)
+                     if e.name == name),
+                    None)
+
     def exists(self):
         return self.m
 
@@ -417,50 +499,70 @@ class Reader:
             self.m.flush()
 
     def close(self):
+        self.closed = True
         self.save()
         if self.writable and self.m:
             self.m.close()
             self.m = None
             self.writable = False
 
+    def __del__(self):
+        assert self.closed
+
     def filter(self, prefixes, wantrecurse=None):
         for (rp, path) in reduce_paths(prefixes):
+            any_entries = False
             for e in self.iter(rp, wantrecurse=wantrecurse):
+                any_entries = True
                 assert(e.name.startswith(rp))
                 name = path + e.name[len(rp):]
                 yield (name, e)
-
+            if not any_entries:
+                # Always return at least the top for each prefix.
+                # Otherwise something like "save x/y" will produce
+                # nothing if x is up to date.
+                pe = self.find(rp)
+                if not pe:
+                    raise Exception("cannot find %r" % rp)
+                name = path + pe.name[len(rp):]
+                yield (name, pe)
 
 # FIXME: this function isn't very generic, because it splits the filename
 # in an odd way and depends on a terminating '/' to indicate directories.
 def pathsplit(p):
     """Split a path into a list of elements of the file system hierarchy."""
-    l = p.split('/')
-    l = [i+'/' for i in l[:-1]] + l[-1:]
-    if l[-1] == '':
+    l = p.split(b'/')
+    l = [i + b'/' for i in l[:-1]] + l[-1:]
+    if l[-1] == b'':
         l.pop()  # extra blank caused by terminating '/'
     return l
 
 
 class Writer:
     def __init__(self, filename, metastore, tmax):
+        self.closed = False
         self.rootlevel = self.level = Level([], None)
         self.f = None
         self.count = 0
         self.lastfile = None
         self.filename = None
-        self.filename = filename = realpath(filename)
+        self.filename = filename = resolve_parent(filename)
         self.metastore = metastore
         self.tmax = tmax
         (dir,name) = os.path.split(filename)
-        (ffd,self.tmpname) = tempfile.mkstemp('.tmp', filename, dir)
+        ffd, self.tmpname = tempfile.mkstemp(b'.tmp', filename, dir)
         self.f = os.fdopen(ffd, 'wb', 65536)
         self.f.write(INDEX_HDR)
 
-    def __del__(self):
-        self.abort()
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type, value, traceback):
+        with pending_raise(value, rethrow=False):
+            self.abort()
 
     def abort(self):
+        self.closed = True
         f = self.f
         self.f = None
         if f:
@@ -479,6 +581,7 @@ class Writer:
         assert(self.level == None)
 
     def close(self):
+        self.closed = True
         self.flush()
         f = self.f
         self.f = None
@@ -486,16 +589,19 @@ class Writer:
             f.close()
             os.rename(self.tmpname, self.filename)
 
+    def __del__(self):
+        assert self.closed
+
     def _add(self, ename, entry):
         if self.lastfile and self.lastfile <= ename:
-            raise Error('%r must come before %r' 
-                             % (''.join(e.name), ''.join(self.lastfile)))
-            self.lastfile = e.name
+            raise Error('%r must come before %r'
+                             % (''.join(ename), ''.join(self.lastfile)))
+        self.lastfile = ename
         self.level = _golevel(self.level, self.f, ename, entry,
                               self.metastore, self.tmax)
 
     def add(self, name, st, meta_ofs, hashgen = None):
-        endswith = name.endswith('/')
+        endswith = name.endswith(b'/')
         ename = pathsplit(name)
         basename = ename[-1]
         #log('add: %r %r\n' % (basename, name))
@@ -512,7 +618,6 @@ class Writer:
             e = NewEntry(basename, name, self.tmax,
                          st.st_dev, st.st_ino, st.st_nlink,
                          st.st_ctime, st.st_mtime, st.st_atime,
-                         st.st_uid, st.st_gid,
                          st.st_size, st.st_mode, gitmode, sha, flags,
                          meta_ofs, 0, 0)
         else:
@@ -533,31 +638,48 @@ class Writer:
         return Reader(self.tmpname)
 
 
+def _slashappend_or_add_error(p, caller):
+    """Return p, after ensuring it has a single trailing slash if it names
+    a directory, unless there's an OSError, in which case, call
+    add_error() and return None."""
+    try:
+        st = os.lstat(p)
+    except OSError as e:
+        add_error('%s: %s' % (caller, e))
+        return None
+    else:
+        if stat.S_ISDIR(st.st_mode):
+            return slashappend(p)
+        return p
+
+
+def unique_resolved_paths(paths):
+    "Return a collection of unique resolved paths."
+    rps = (_slashappend_or_add_error(resolve_parent(p), 'unique_resolved_paths')
+           for p in paths)
+    return frozenset((x for x in rps if x is not None))
+
+
 def reduce_paths(paths):
     xpaths = []
     for p in paths:
-        rp = realpath(p)
-        try:
-            st = os.lstat(rp)
-            if stat.S_ISDIR(st.st_mode):
-                rp = slashappend(rp)
-                p = slashappend(p)
-            xpaths.append((rp, p))
-        except OSError, e:
-            add_error('reduce_paths: %s' % e)
+        rp = _slashappend_or_add_error(resolve_parent(p), 'reduce_paths')
+        if rp:
+            xpaths.append((rp, slashappend(p) if rp.endswith(b'/') else p))
     xpaths.sort()
 
     paths = []
     prev = None
     for (rp, p) in xpaths:
-        if prev and (prev == rp 
-                     or (prev.endswith('/') and rp.startswith(prev))):
+        if prev and (prev == rp
+                     or (prev.endswith(b'/') and rp.startswith(prev))):
             continue # already superceded by previous path
         paths.append((rp, p))
         prev = rp
     paths.sort(reverse=True)
     return paths
 
+
 def merge(*iters):
     def pfunc(count, total):
         qprogress('bup: merging indexes (%d/%d)\r' % (count, total))