dirstate-item: implement `v1_mtime` with higher level block

This is much easier to read and maintain.

Differential Revision: https://phab.mercurial-scm.org/D11375

mercurial/pure/parsers.py

@@ -1,799 +1,792 b''
 # parsers.py - Python implementation of parsers.c
 #
 # Copyright 2009 Olivia Mackall <[e-mail]> and others
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import struct
 import zlib
 
 from ..node import (
     nullrev,
     sha1nodeconstants,
 )
 from ..thirdparty import attr
 from .. import (
     error,
     pycompat,
     revlogutils,
     util,
 )
 
 from ..revlogutils import nodemap as nodemaputil
 from ..revlogutils import constants as revlog_constants
 
 stringio = pycompat.bytesio
 
 
 _pack = struct.pack
 _unpack = struct.unpack
 _compress = zlib.compress
 _decompress = zlib.decompress
 
 
 # a special value used internally for `size` if the file come from the other parent
 FROM_P2 = -2
 
 # a special value used internally for `size` if the file is modified/merged/added
 NONNORMAL = -1
 
 # a special value used internally for `time` if the time is ambigeous
 AMBIGUOUS_TIME = -1
 
 
 @attr.s(slots=True, init=False)
 class DirstateItem(object):
     """represent a dirstate entry
 
     It contains:
 
     - state (one of 'n', 'a', 'r', 'm')
     - mode,
     - size,
     - mtime,
     """
 
     _wc_tracked = attr.ib()
     _p1_tracked = attr.ib()
     _p2_tracked = attr.ib()
     # the three item above should probably be combined
     #
     # However it is unclear if they properly cover some of the most advanced
     # merge case. So we should probably wait on this to be settled.
     _merged = attr.ib()
     _clean_p1 = attr.ib()
     _clean_p2 = attr.ib()
     _possibly_dirty = attr.ib()
     _mode = attr.ib()
     _size = attr.ib()
     _mtime = attr.ib()
 
     def __init__(
         self,
         wc_tracked=False,
         p1_tracked=False,
         p2_tracked=False,
         merged=False,
         clean_p1=False,
         clean_p2=False,
         possibly_dirty=False,
         parentfiledata=None,
     ):
         if merged and (clean_p1 or clean_p2):
             msg = b'`merged` argument incompatible with `clean_p1`/`clean_p2`'
             raise error.ProgrammingError(msg)
 
         self._wc_tracked = wc_tracked
         self._p1_tracked = p1_tracked
         self._p2_tracked = p2_tracked
         self._merged = merged
         self._clean_p1 = clean_p1
         self._clean_p2 = clean_p2
         self._possibly_dirty = possibly_dirty
         if parentfiledata is None:
             self._mode = None
             self._size = None
             self._mtime = None
         else:
             self._mode = parentfiledata[0]
             self._size = parentfiledata[1]
             self._mtime = parentfiledata[2]
 
     @classmethod
     def new_added(cls):
         """constructor to help legacy API to build a new "added" item
 
         Should eventually be removed
         """
         instance = cls()
         instance._wc_tracked = True
         instance._p1_tracked = False
         instance._p2_tracked = False
         return instance
 
     @classmethod
     def new_merged(cls):
         """constructor to help legacy API to build a new "merged" item
 
         Should eventually be removed
         """
         instance = cls()
         instance._wc_tracked = True
         instance._p1_tracked = True  # might not be True because of rename ?
         instance._p2_tracked = True  # might not be True because of rename ?
         instance._merged = True
         return instance
 
     @classmethod
     def new_from_p2(cls):
         """constructor to help legacy API to build a new "from_p2" item
 
         Should eventually be removed
         """
         instance = cls()
         instance._wc_tracked = True
         instance._p1_tracked = False  # might actually be True
         instance._p2_tracked = True
         instance._clean_p2 = True
         return instance
 
     @classmethod
     def new_possibly_dirty(cls):
         """constructor to help legacy API to build a new "possibly_dirty" item
 
         Should eventually be removed
         """
         instance = cls()
         instance._wc_tracked = True
         instance._p1_tracked = True
         instance._possibly_dirty = True
         return instance
 
     @classmethod
     def new_normal(cls, mode, size, mtime):
         """constructor to help legacy API to build a new "normal" item
 
         Should eventually be removed
         """
         assert size != FROM_P2
         assert size != NONNORMAL
         instance = cls()
         instance._wc_tracked = True
         instance._p1_tracked = True
         instance._mode = mode
         instance._size = size
         instance._mtime = mtime
         return instance
 
     @classmethod
     def from_v1_data(cls, state, mode, size, mtime):
         """Build a new DirstateItem object from V1 data
 
         Since the dirstate-v1 format is frozen, the signature of this function
         is not expected to change, unlike the __init__ one.
         """
         if state == b'm':
             return cls.new_merged()
         elif state == b'a':
             return cls.new_added()
         elif state == b'r':
             instance = cls()
             instance._wc_tracked = False
             if size == NONNORMAL:
                 instance._merged = True
                 instance._p1_tracked = (
                     True  # might not be True because of rename ?
                 )
                 instance._p2_tracked = (
                     True  # might not be True because of rename ?
                 )
             elif size == FROM_P2:
                 instance._clean_p2 = True
                 instance._p1_tracked = (
                     False  # We actually don't know (file history)
                 )
                 instance._p2_tracked = True
             else:
                 instance._p1_tracked = True
             return instance
         elif state == b'n':
             if size == FROM_P2:
                 return cls.new_from_p2()
             elif size == NONNORMAL:
                 return cls.new_possibly_dirty()
             elif mtime == AMBIGUOUS_TIME:
                 instance = cls.new_normal(mode, size, 42)
                 instance._mtime = None
                 instance._possibly_dirty = True
                 return instance
             else:
                 return cls.new_normal(mode, size, mtime)
         else:
             raise RuntimeError(b'unknown state: %s' % state)
 
     def set_possibly_dirty(self):
         """Mark a file as "possibly dirty"
 
         This means the next status call will have to actually check its content
         to make sure it is correct.
         """
         self._possibly_dirty = True
 
     def set_untracked(self):
         """mark a file as untracked in the working copy
 
         This will ultimately be called by command like `hg remove`.
         """
         # backup the previous state (useful for merge)
         self._wc_tracked = False
         self._mode = None
         self._size = None
         self._mtime = None
 
     @property
     def mode(self):
         return self.v1_mode()
 
     @property
     def size(self):
         return self.v1_size()
 
     @property
     def mtime(self):
         return self.v1_mtime()
 
     @property
     def state(self):
         """
         States are:
           n  normal
           m  needs merging
           r  marked for removal
           a  marked for addition
 
         XXX This "state" is a bit obscure and mostly a direct expression of the
         dirstatev1 format. It would make sense to ultimately deprecate it in
         favor of the more "semantic" attributes.
         """
         return self.v1_state()
 
     @property
     def tracked(self):
         """True is the file is tracked in the working copy"""
         return self._wc_tracked
 
     @property
     def added(self):
         """True if the file has been added"""
         return self._wc_tracked and not (self._p1_tracked or self._p2_tracked)
 
     @property
     def merged(self):
         """True if the file has been merged
 
         Should only be set if a merge is in progress in the dirstate
         """
         return self._wc_tracked and self._merged
 
     @property
     def from_p2(self):
         """True if the file have been fetched from p2 during the current merge
 
         This is only True is the file is currently tracked.
 
         Should only be set if a merge is in progress in the dirstate
         """
         if not self._wc_tracked:
             return False
         return self._clean_p2 or (not self._p1_tracked and self._p2_tracked)
 
     @property
     def from_p2_removed(self):
         """True if the file has been removed, but was "from_p2" initially
 
         This property seems like an abstraction leakage and should probably be
         dealt in this class (or maybe the dirstatemap) directly.
         """
         return self.removed and self._clean_p2
 
     @property
     def removed(self):
         """True if the file has been removed"""
         return not self._wc_tracked and (self._p1_tracked or self._p2_tracked)
 
     @property
     def merged_removed(self):
         """True if the file has been removed, but was "merged" initially
 
         This property seems like an abstraction leakage and should probably be
         dealt in this class (or maybe the dirstatemap)  directly.
         """
         return self.removed and self._merged
 
     @property
     def dm_nonnormal(self):
         """True is the entry is non-normal in the dirstatemap sense
 
         There is no reason for any code, but the dirstatemap one to use this.
         """
         return self.v1_state() != b'n' or self.v1_mtime() == AMBIGUOUS_TIME
 
     @property
     def dm_otherparent(self):
         """True is the entry is `otherparent` in the dirstatemap sense
 
         There is no reason for any code, but the dirstatemap one to use this.
         """
         return self.v1_size() == FROM_P2
 
     def v1_state(self):
         """return a "state" suitable for v1 serialization"""
         if not (self._p1_tracked or self._p2_tracked or self._wc_tracked):
             # the object has no state to record, this is -currently-
             # unsupported
             raise RuntimeError('untracked item')
         elif self.removed:
             return b'r'
         elif self.merged:
             return b'm'
         elif self.added:
             return b'a'
         else:
             return b'n'
 
     def v1_mode(self):
         """return a "mode" suitable for v1 serialization"""
         return self._mode if self._mode is not None else 0
 
     def v1_size(self):
         """return a "size" suitable for v1 serialization"""
         if not (self._p1_tracked or self._p2_tracked or self._wc_tracked):
             # the object has no state to record, this is -currently-
             # unsupported
             raise RuntimeError('untracked item')
         elif self.merged_removed:
             return NONNORMAL
         elif self.from_p2_removed:
             return FROM_P2
         elif self.removed:
             return 0
         elif self.merged:
             return FROM_P2
         elif self.added:
             return NONNORMAL
         elif self.from_p2:
             return FROM_P2
         elif self._possibly_dirty:
             return self._size if self._size is not None else NONNORMAL
         else:
             return self._size
 
     def v1_mtime(self):
         """return a "mtime" suitable for v1 serialization"""
         if not (self._p1_tracked or self._p2_tracked or self._wc_tracked):
             # the object has no state to record, this is -currently-
             # unsupported
             raise RuntimeError('untracked item')
-        elif not self._wc_tracked:
+        elif self.removed:
             return 0
         elif self._possibly_dirty:
             return AMBIGUOUS_TIME
-        elif self._merged:
-            return AMBIGUOUS_TIME
-        elif not (self._p1_tracked or self._p2_tracked) and self._wc_tracked:
+        elif self.merged:
             return AMBIGUOUS_TIME
-        elif self._clean_p2 and self._wc_tracked:
-            return AMBIGUOUS_TIME
-        elif not self._p1_tracked and self._p2_tracked and self._wc_tracked:
+        elif self.added:
             return AMBIGUOUS_TIME
-        elif self._wc_tracked:
-            if self._mtime is None:
-                return 0
-            else:
-                return self._mtime
+        elif self.from_p2:
+            return AMBIGUOUS_TIME
         else:
-            raise RuntimeError('unreachable')
+            return self._mtime if self._mtime is not None else 0
 
     def need_delay(self, now):
         """True if the stored mtime would be ambiguous with the current time"""
         return self.v1_state() == b'n' and self.v1_mtime() == now
 
 
 def gettype(q):
     return int(q & 0xFFFF)
 
 
 class BaseIndexObject(object):
     # Can I be passed to an algorithme implemented in Rust ?
     rust_ext_compat = 0
     # Format of an index entry according to Python's `struct` language
     index_format = revlog_constants.INDEX_ENTRY_V1
     # Size of a C unsigned long long int, platform independent
     big_int_size = struct.calcsize(b'>Q')
     # Size of a C long int, platform independent
     int_size = struct.calcsize(b'>i')
     # An empty index entry, used as a default value to be overridden, or nullrev
     null_item = (
         0,
         0,
         0,
         -1,
         -1,
         -1,
         -1,
         sha1nodeconstants.nullid,
         0,
         0,
         revlog_constants.COMP_MODE_INLINE,
         revlog_constants.COMP_MODE_INLINE,
     )
 
     @util.propertycache
     def entry_size(self):
         return self.index_format.size
 
     @property
     def nodemap(self):
         msg = b"index.nodemap is deprecated, use index.[has_node|rev|get_rev]"
         util.nouideprecwarn(msg, b'5.3', stacklevel=2)
         return self._nodemap
 
     @util.propertycache
     def _nodemap(self):
         nodemap = nodemaputil.NodeMap({sha1nodeconstants.nullid: nullrev})
         for r in range(0, len(self)):
             n = self[r][7]
             nodemap[n] = r
         return nodemap
 
     def has_node(self, node):
         """return True if the node exist in the index"""
         return node in self._nodemap
 
     def rev(self, node):
         """return a revision for a node
 
         If the node is unknown, raise a RevlogError"""
         return self._nodemap[node]
 
     def get_rev(self, node):
         """return a revision for a node
 
         If the node is unknown, return None"""
         return self._nodemap.get(node)
 
     def _stripnodes(self, start):
         if '_nodemap' in vars(self):
             for r in range(start, len(self)):
                 n = self[r][7]
                 del self._nodemap[n]
 
     def clearcaches(self):
         self.__dict__.pop('_nodemap', None)
 
     def __len__(self):
         return self._lgt + len(self._extra)
 
     def append(self, tup):
         if '_nodemap' in vars(self):
             self._nodemap[tup[7]] = len(self)
         data = self._pack_entry(len(self), tup)
         self._extra.append(data)
 
     def _pack_entry(self, rev, entry):
         assert entry[8] == 0
         assert entry[9] == 0
         return self.index_format.pack(*entry[:8])
 
     def _check_index(self, i):
         if not isinstance(i, int):
             raise TypeError(b"expecting int indexes")
         if i < 0 or i >= len(self):
             raise IndexError
 
     def __getitem__(self, i):
         if i == -1:
             return self.null_item
         self._check_index(i)
         if i >= self._lgt:
             data = self._extra[i - self._lgt]
         else:
             index = self._calculate_index(i)
             data = self._data[index : index + self.entry_size]
         r = self._unpack_entry(i, data)
         if self._lgt and i == 0:
             offset = revlogutils.offset_type(0, gettype(r[0]))
             r = (offset,) + r[1:]
         return r
 
     def _unpack_entry(self, rev, data):
         r = self.index_format.unpack(data)
         r = r + (
             0,
             0,
             revlog_constants.COMP_MODE_INLINE,
             revlog_constants.COMP_MODE_INLINE,
         )
         return r
 
     def pack_header(self, header):
         """pack header information as binary"""
         v_fmt = revlog_constants.INDEX_HEADER
         return v_fmt.pack(header)
 
     def entry_binary(self, rev):
         """return the raw binary string representing a revision"""
         entry = self[rev]
         p = revlog_constants.INDEX_ENTRY_V1.pack(*entry[:8])
         if rev == 0:
             p = p[revlog_constants.INDEX_HEADER.size :]
         return p
 
 
 class IndexObject(BaseIndexObject):
     def __init__(self, data):
         assert len(data) % self.entry_size == 0, (
             len(data),
             self.entry_size,
             len(data) % self.entry_size,
         )
         self._data = data
         self._lgt = len(data) // self.entry_size
         self._extra = []
 
     def _calculate_index(self, i):
         return i * self.entry_size
 
     def __delitem__(self, i):
         if not isinstance(i, slice) or not i.stop == -1 or i.step is not None:
             raise ValueError(b"deleting slices only supports a:-1 with step 1")
         i = i.start
         self._check_index(i)
         self._stripnodes(i)
         if i < self._lgt:
             self._data = self._data[: i * self.entry_size]
             self._lgt = i
             self._extra = []
         else:
             self._extra = self._extra[: i - self._lgt]
 
 
 class PersistentNodeMapIndexObject(IndexObject):
     """a Debug oriented class to test persistent nodemap
 
     We need a simple python object to test API and higher level behavior. See
     the Rust implementation for  more serious usage. This should be used only
     through the dedicated `devel.persistent-nodemap` config.
     """
 
     def nodemap_data_all(self):
         """Return bytes containing a full serialization of a nodemap
 
         The nodemap should be valid for the full set of revisions in the
         index."""
         return nodemaputil.persistent_data(self)
 
     def nodemap_data_incremental(self):
         """Return bytes containing a incremental update to persistent nodemap
 
         This containst the data for an append-only update of the data provided
         in the last call to `update_nodemap_data`.
         """
         if self._nm_root is None:
             return None
         docket = self._nm_docket
         changed, data = nodemaputil.update_persistent_data(
             self, self._nm_root, self._nm_max_idx, self._nm_docket.tip_rev
         )
 
         self._nm_root = self._nm_max_idx = self._nm_docket = None
         return docket, changed, data
 
     def update_nodemap_data(self, docket, nm_data):
         """provide full block of persisted binary data for a nodemap
 
         The data are expected to come from disk. See `nodemap_data_all` for a
         produceur of such data."""
         if nm_data is not None:
             self._nm_root, self._nm_max_idx = nodemaputil.parse_data(nm_data)
             if self._nm_root:
                 self._nm_docket = docket
             else:
                 self._nm_root = self._nm_max_idx = self._nm_docket = None
 
 
 class InlinedIndexObject(BaseIndexObject):
     def __init__(self, data, inline=0):
         self._data = data
         self._lgt = self._inline_scan(None)
         self._inline_scan(self._lgt)
         self._extra = []
 
     def _inline_scan(self, lgt):
         off = 0
         if lgt is not None:
             self._offsets = [0] * lgt
         count = 0
         while off <= len(self._data) - self.entry_size:
             start = off + self.big_int_size
             (s,) = struct.unpack(
                 b'>i',
                 self._data[start : start + self.int_size],
             )
             if lgt is not None:
                 self._offsets[count] = off
             count += 1
             off += self.entry_size + s
         if off != len(self._data):
             raise ValueError(b"corrupted data")
         return count
 
     def __delitem__(self, i):
         if not isinstance(i, slice) or not i.stop == -1 or i.step is not None:
             raise ValueError(b"deleting slices only supports a:-1 with step 1")
         i = i.start
         self._check_index(i)
         self._stripnodes(i)
         if i < self._lgt:
             self._offsets = self._offsets[:i]
             self._lgt = i
             self._extra = []
         else:
             self._extra = self._extra[: i - self._lgt]
 
     def _calculate_index(self, i):
         return self._offsets[i]
 
 
 def parse_index2(data, inline, revlogv2=False):
     if not inline:
         cls = IndexObject2 if revlogv2 else IndexObject
         return cls(data), None
     cls = InlinedIndexObject
     return cls(data, inline), (0, data)
 
 
 def parse_index_cl_v2(data):
     return IndexChangelogV2(data), None
 
 
 class IndexObject2(IndexObject):
     index_format = revlog_constants.INDEX_ENTRY_V2
 
     def replace_sidedata_info(
         self,
         rev,
         sidedata_offset,
         sidedata_length,
         offset_flags,
         compression_mode,
     ):
         """
         Replace an existing index entry's sidedata offset and length with new
         ones.
         This cannot be used outside of the context of sidedata rewriting,
         inside the transaction that creates the revision `rev`.
         """
         if rev < 0:
             raise KeyError
         self._check_index(rev)
         if rev < self._lgt:
             msg = b"cannot rewrite entries outside of this transaction"
             raise KeyError(msg)
         else:
             entry = list(self[rev])
             entry[0] = offset_flags
             entry[8] = sidedata_offset
             entry[9] = sidedata_length
             entry[11] = compression_mode
             entry = tuple(entry)
             new = self._pack_entry(rev, entry)
             self._extra[rev - self._lgt] = new
 
     def _unpack_entry(self, rev, data):
         data = self.index_format.unpack(data)
         entry = data[:10]
         data_comp = data[10] & 3
         sidedata_comp = (data[10] & (3 << 2)) >> 2
         return entry + (data_comp, sidedata_comp)
 
     def _pack_entry(self, rev, entry):
         data = entry[:10]
         data_comp = entry[10] & 3
         sidedata_comp = (entry[11] & 3) << 2
         data += (data_comp | sidedata_comp,)
 
         return self.index_format.pack(*data)
 
     def entry_binary(self, rev):
         """return the raw binary string representing a revision"""
         entry = self[rev]
         return self._pack_entry(rev, entry)
 
     def pack_header(self, header):
         """pack header information as binary"""
         msg = 'version header should go in the docket, not the index: %d'
         msg %= header
         raise error.ProgrammingError(msg)
 
 
 class IndexChangelogV2(IndexObject2):
     index_format = revlog_constants.INDEX_ENTRY_CL_V2
 
     def _unpack_entry(self, rev, data, r=True):
         items = self.index_format.unpack(data)
         entry = items[:3] + (rev, rev) + items[3:8]
         data_comp = items[8] & 3
         sidedata_comp = (items[8] >> 2) & 3
         return entry + (data_comp, sidedata_comp)
 
     def _pack_entry(self, rev, entry):
         assert entry[3] == rev, entry[3]
         assert entry[4] == rev, entry[4]
         data = entry[:3] + entry[5:10]
         data_comp = entry[10] & 3
         sidedata_comp = (entry[11] & 3) << 2
         data += (data_comp | sidedata_comp,)
         return self.index_format.pack(*data)
 
 
 def parse_index_devel_nodemap(data, inline):
     """like parse_index2, but alway return a PersistentNodeMapIndexObject"""
     return PersistentNodeMapIndexObject(data), None
 
 
 def parse_dirstate(dmap, copymap, st):
     parents = [st[:20], st[20:40]]
     # dereference fields so they will be local in loop
     format = b">cllll"
     e_size = struct.calcsize(format)
     pos1 = 40
     l = len(st)
 
     # the inner loop
     while pos1 < l:
         pos2 = pos1 + e_size
         e = _unpack(b">cllll", st[pos1:pos2])  # a literal here is faster
         pos1 = pos2 + e[4]
         f = st[pos2:pos1]
         if b'\0' in f:
             f, c = f.split(b'\0')
             copymap[f] = c
         dmap[f] = DirstateItem.from_v1_data(*e[:4])
     return parents
 
 
 def pack_dirstate(dmap, copymap, pl, now):
     now = int(now)
     cs = stringio()
     write = cs.write
     write(b"".join(pl))
     for f, e in pycompat.iteritems(dmap):
         if e.need_delay(now):
             # The file was last modified "simultaneously" with the current
             # write to dirstate (i.e. within the same second for file-
             # systems with a granularity of 1 sec). This commonly happens
             # for at least a couple of files on 'update'.
             # The user could change the file without changing its size
             # within the same second. Invalidate the file's mtime in
             # dirstate, forcing future 'status' calls to compare the
             # contents of the file if the size is the same. This prevents
             # mistakenly treating such files as clean.
             e.set_possibly_dirty()
 
         if f in copymap:
             f = b"%s\0%s" % (f, copymap[f])
         e = _pack(
             b">cllll",
             e.v1_state(),
             e.v1_mode(),
             e.v1_size(),
             e.v1_mtime(),
             len(f),
         )
         write(e)
         write(f)
     return cs.getvalue()