|
|
# linelog - efficient cache for annotate data
|
|
|
#
|
|
|
# Copyright 2018 Google LLC.
|
|
|
#
|
|
|
# This software may be used and distributed according to the terms of the
|
|
|
# GNU General Public License version 2 or any later version.
|
|
|
"""linelog is an efficient cache for annotate data inspired by SCCS Weaves.
|
|
|
|
|
|
SCCS Weaves are an implementation of
|
|
|
https://en.wikipedia.org/wiki/Interleaved_deltas. See
|
|
|
mercurial/helptext/internals/linelog.txt for an exploration of SCCS weaves
|
|
|
and how linelog works in detail.
|
|
|
|
|
|
Here's a hacker's summary: a linelog is a program which is executed in
|
|
|
the context of a revision. Executing the program emits information
|
|
|
about lines, including the revision that introduced them and the line
|
|
|
number in the file at the introducing revision. When an insertion or
|
|
|
deletion is performed on the file, a jump instruction is used to patch
|
|
|
in a new body of annotate information.
|
|
|
"""
|
|
|
|
|
|
from __future__ import annotations
|
|
|
|
|
|
import abc
|
|
|
import struct
|
|
|
import typing
|
|
|
|
|
|
from typing import (
|
|
|
List,
|
|
|
)
|
|
|
|
|
|
from .thirdparty import attr
|
|
|
|
|
|
# Force pytype to use the non-vendored package
|
|
|
if typing.TYPE_CHECKING:
|
|
|
# noinspection PyPackageRequirements
|
|
|
import attr
|
|
|
|
|
|
from . import pycompat
|
|
|
|
|
|
_llentry = struct.Struct(b'>II')
|
|
|
|
|
|
|
|
|
class LineLogError(Exception):
|
|
|
"""Error raised when something bad happens internally in linelog."""
|
|
|
|
|
|
|
|
|
@attr.s
|
|
|
class lineinfo:
|
|
|
# Introducing revision of this line.
|
|
|
rev = attr.ib()
|
|
|
# Line number for this line in its introducing revision.
|
|
|
linenum = attr.ib()
|
|
|
# Private. Offset in the linelog program of this line. Used internally.
|
|
|
_offset = attr.ib()
|
|
|
|
|
|
|
|
|
@attr.s
|
|
|
class annotateresult:
|
|
|
rev = attr.ib()
|
|
|
lines = attr.ib(type=List[lineinfo])
|
|
|
_eof = attr.ib()
|
|
|
|
|
|
def __iter__(self):
|
|
|
return iter(self.lines)
|
|
|
|
|
|
|
|
|
class _llinstruction: # pytype: disable=ignored-metaclass
|
|
|
__metaclass__ = abc.ABCMeta
|
|
|
|
|
|
@abc.abstractmethod
|
|
|
def __init__(self, op1, op2):
|
|
|
pass
|
|
|
|
|
|
@abc.abstractmethod
|
|
|
def __str__(self):
|
|
|
pass
|
|
|
|
|
|
def __repr__(self):
|
|
|
return str(self)
|
|
|
|
|
|
@abc.abstractmethod
|
|
|
def __eq__(self, other):
|
|
|
pass
|
|
|
|
|
|
@abc.abstractmethod
|
|
|
def encode(self):
|
|
|
"""Encode this instruction to the binary linelog format."""
|
|
|
|
|
|
@abc.abstractmethod
|
|
|
def execute(self, rev, pc, emit):
|
|
|
"""Execute this instruction.
|
|
|
|
|
|
Args:
|
|
|
rev: The revision we're annotating.
|
|
|
pc: The current offset in the linelog program.
|
|
|
emit: A function that accepts a single lineinfo object.
|
|
|
|
|
|
Returns:
|
|
|
The new value of pc. Returns None if exeuction should stop
|
|
|
(that is, we've found the end of the file.)
|
|
|
"""
|
|
|
|
|
|
|
|
|
class _jge(_llinstruction):
|
|
|
"""If the current rev is greater than or equal to op1, jump to op2."""
|
|
|
|
|
|
def __init__(self, op1, op2):
|
|
|
self._cmprev = op1
|
|
|
self._target = op2
|
|
|
|
|
|
def __str__(self):
|
|
|
return 'JGE %d %d' % (self._cmprev, self._target)
|
|
|
|
|
|
def __eq__(self, other):
|
|
|
return (
|
|
|
type(self) == type(other)
|
|
|
and self._cmprev == other._cmprev
|
|
|
and self._target == other._target
|
|
|
)
|
|
|
|
|
|
def encode(self):
|
|
|
return _llentry.pack(self._cmprev << 2, self._target)
|
|
|
|
|
|
def execute(self, rev, pc, emit):
|
|
|
if rev >= self._cmprev:
|
|
|
return self._target
|
|
|
return pc + 1
|
|
|
|
|
|
|
|
|
class _jump(_llinstruction):
|
|
|
"""Unconditional jumps are expressed as a JGE with op1 set to 0."""
|
|
|
|
|
|
def __init__(self, op1, op2):
|
|
|
if op1 != 0:
|
|
|
raise LineLogError(b"malformed JUMP, op1 must be 0, got %d" % op1)
|
|
|
self._target = op2
|
|
|
|
|
|
def __str__(self):
|
|
|
return 'JUMP %d' % (self._target)
|
|
|
|
|
|
def __eq__(self, other):
|
|
|
return type(self) == type(other) and self._target == other._target
|
|
|
|
|
|
def encode(self):
|
|
|
return _llentry.pack(0, self._target)
|
|
|
|
|
|
def execute(self, rev, pc, emit):
|
|
|
return self._target
|
|
|
|
|
|
|
|
|
class _eof(_llinstruction):
|
|
|
"""EOF is expressed as a JGE that always jumps to 0."""
|
|
|
|
|
|
def __init__(self, op1, op2):
|
|
|
if op1 != 0:
|
|
|
raise LineLogError(b"malformed EOF, op1 must be 0, got %d" % op1)
|
|
|
if op2 != 0:
|
|
|
raise LineLogError(b"malformed EOF, op2 must be 0, got %d" % op2)
|
|
|
|
|
|
def __str__(self):
|
|
|
return r'EOF'
|
|
|
|
|
|
def __eq__(self, other):
|
|
|
return type(self) == type(other)
|
|
|
|
|
|
def encode(self):
|
|
|
return _llentry.pack(0, 0)
|
|
|
|
|
|
def execute(self, rev, pc, emit):
|
|
|
return None
|
|
|
|
|
|
|
|
|
class _jl(_llinstruction):
|
|
|
"""If the current rev is less than op1, jump to op2."""
|
|
|
|
|
|
def __init__(self, op1, op2):
|
|
|
self._cmprev = op1
|
|
|
self._target = op2
|
|
|
|
|
|
def __str__(self):
|
|
|
return 'JL %d %d' % (self._cmprev, self._target)
|
|
|
|
|
|
def __eq__(self, other):
|
|
|
return (
|
|
|
type(self) == type(other)
|
|
|
and self._cmprev == other._cmprev
|
|
|
and self._target == other._target
|
|
|
)
|
|
|
|
|
|
def encode(self):
|
|
|
return _llentry.pack(1 | (self._cmprev << 2), self._target)
|
|
|
|
|
|
def execute(self, rev, pc, emit):
|
|
|
if rev < self._cmprev:
|
|
|
return self._target
|
|
|
return pc + 1
|
|
|
|
|
|
|
|
|
class _line(_llinstruction):
|
|
|
"""Emit a line."""
|
|
|
|
|
|
def __init__(self, op1, op2):
|
|
|
# This line was introduced by this revision number.
|
|
|
self._rev = op1
|
|
|
# This line had the specified line number in the introducing revision.
|
|
|
self._origlineno = op2
|
|
|
|
|
|
def __str__(self):
|
|
|
return 'LINE %d %d' % (self._rev, self._origlineno)
|
|
|
|
|
|
def __eq__(self, other):
|
|
|
return (
|
|
|
type(self) == type(other)
|
|
|
and self._rev == other._rev
|
|
|
and self._origlineno == other._origlineno
|
|
|
)
|
|
|
|
|
|
def encode(self):
|
|
|
return _llentry.pack(2 | (self._rev << 2), self._origlineno)
|
|
|
|
|
|
def execute(self, rev, pc, emit):
|
|
|
emit(lineinfo(self._rev, self._origlineno, pc))
|
|
|
return pc + 1
|
|
|
|
|
|
|
|
|
def _decodeone(data, offset):
|
|
|
"""Decode a single linelog instruction from an offset in a buffer."""
|
|
|
try:
|
|
|
op1, op2 = _llentry.unpack_from(data, offset)
|
|
|
except struct.error as e:
|
|
|
raise LineLogError(b'reading an instruction failed: %r' % e)
|
|
|
opcode = op1 & 0b11
|
|
|
op1 = op1 >> 2
|
|
|
if opcode == 0:
|
|
|
if op1 == 0:
|
|
|
if op2 == 0:
|
|
|
return _eof(op1, op2)
|
|
|
return _jump(op1, op2)
|
|
|
return _jge(op1, op2)
|
|
|
elif opcode == 1:
|
|
|
return _jl(op1, op2)
|
|
|
elif opcode == 2:
|
|
|
return _line(op1, op2)
|
|
|
raise NotImplementedError(b'Unimplemented opcode %r' % opcode)
|
|
|
|
|
|
|
|
|
class linelog:
|
|
|
"""Efficient cache for per-line history information."""
|
|
|
|
|
|
def __init__(self, program=None, maxrev=0):
|
|
|
if program is None:
|
|
|
# We pad the program with an extra leading EOF so that our
|
|
|
# offsets will match the C code exactly. This means we can
|
|
|
# interoperate with the C code.
|
|
|
program = [_eof(0, 0), _eof(0, 0)]
|
|
|
self._program = program
|
|
|
self._lastannotate = None
|
|
|
self._maxrev = maxrev
|
|
|
|
|
|
def __eq__(self, other):
|
|
|
return (
|
|
|
type(self) == type(other)
|
|
|
and self._program == other._program
|
|
|
and self._maxrev == other._maxrev
|
|
|
)
|
|
|
|
|
|
def __repr__(self):
|
|
|
return '<linelog at %s: maxrev=%d size=%d>' % (
|
|
|
hex(id(self)),
|
|
|
self._maxrev,
|
|
|
len(self._program),
|
|
|
)
|
|
|
|
|
|
def debugstr(self):
|
|
|
fmt = '%%%dd %%s' % len(str(len(self._program)))
|
|
|
return pycompat.sysstr(b'\n').join(
|
|
|
fmt % (idx, i) for idx, i in enumerate(self._program[1:], 1)
|
|
|
)
|
|
|
|
|
|
@classmethod
|
|
|
def fromdata(cls, buf):
|
|
|
if len(buf) % _llentry.size != 0:
|
|
|
raise LineLogError(
|
|
|
b"invalid linelog buffer size %d (must be a multiple of %d)"
|
|
|
% (len(buf), _llentry.size)
|
|
|
)
|
|
|
expected = len(buf) / _llentry.size
|
|
|
fakejge = _decodeone(buf, 0)
|
|
|
if isinstance(fakejge, _jump):
|
|
|
maxrev = 0
|
|
|
elif isinstance(fakejge, (_jge, _jl)):
|
|
|
maxrev = fakejge._cmprev
|
|
|
else:
|
|
|
raise LineLogError(
|
|
|
'Expected one of _jump, _jge, or _jl. Got %s.'
|
|
|
% type(fakejge).__name__
|
|
|
)
|
|
|
assert isinstance(fakejge, (_jump, _jge, _jl)) # help pytype
|
|
|
numentries = fakejge._target
|
|
|
if expected != numentries:
|
|
|
raise LineLogError(
|
|
|
b"corrupt linelog data: claimed"
|
|
|
b" %d entries but given data for %d entries"
|
|
|
% (expected, numentries)
|
|
|
)
|
|
|
instructions = [_eof(0, 0)]
|
|
|
for offset in range(1, numentries):
|
|
|
instructions.append(_decodeone(buf, offset * _llentry.size))
|
|
|
return cls(instructions, maxrev=maxrev)
|
|
|
|
|
|
def encode(self):
|
|
|
hdr = _jge(self._maxrev, len(self._program)).encode()
|
|
|
return hdr + b''.join(i.encode() for i in self._program[1:])
|
|
|
|
|
|
def clear(self):
|
|
|
self._program = []
|
|
|
self._maxrev = 0
|
|
|
self._lastannotate = None
|
|
|
|
|
|
def replacelines_vec(self, rev, a1, a2, blines):
|
|
|
return self.replacelines(
|
|
|
rev, a1, a2, 0, len(blines), _internal_blines=blines
|
|
|
)
|
|
|
|
|
|
def replacelines(self, rev, a1, a2, b1, b2, _internal_blines=None):
|
|
|
"""Replace lines [a1, a2) with lines [b1, b2)."""
|
|
|
if self._lastannotate:
|
|
|
# TODO(augie): make replacelines() accept a revision at
|
|
|
# which we're editing as well as a revision to mark
|
|
|
# responsible for the edits. In hg-experimental it's
|
|
|
# stateful like this, so we're doing the same thing to
|
|
|
# retain compatibility with absorb until that's imported.
|
|
|
ar = self._lastannotate
|
|
|
else:
|
|
|
ar = self.annotate(rev)
|
|
|
# ar = self.annotate(self._maxrev)
|
|
|
if a1 > len(ar.lines):
|
|
|
raise LineLogError(
|
|
|
b'%d contains %d lines, tried to access line %d'
|
|
|
% (rev, len(ar.lines), a1)
|
|
|
)
|
|
|
elif a1 == len(ar.lines):
|
|
|
# Simulated EOF instruction since we're at EOF, which
|
|
|
# doesn't have a "real" line.
|
|
|
a1inst = _eof(0, 0)
|
|
|
a1info = lineinfo(0, 0, ar._eof)
|
|
|
else:
|
|
|
a1info = ar.lines[a1]
|
|
|
a1inst = self._program[a1info._offset]
|
|
|
programlen = self._program.__len__
|
|
|
oldproglen = programlen()
|
|
|
appendinst = self._program.append
|
|
|
|
|
|
# insert
|
|
|
blineinfos = []
|
|
|
bappend = blineinfos.append
|
|
|
if b1 < b2:
|
|
|
# Determine the jump target for the JGE at the start of
|
|
|
# the new block.
|
|
|
tgt = oldproglen + (b2 - b1 + 1)
|
|
|
# Jump to skip the insert if we're at an older revision.
|
|
|
appendinst(_jl(rev, tgt))
|
|
|
for linenum in range(b1, b2):
|
|
|
if _internal_blines is None:
|
|
|
bappend(lineinfo(rev, linenum, programlen()))
|
|
|
appendinst(_line(rev, linenum))
|
|
|
else:
|
|
|
newrev, newlinenum = _internal_blines[linenum]
|
|
|
bappend(lineinfo(newrev, newlinenum, programlen()))
|
|
|
appendinst(_line(newrev, newlinenum))
|
|
|
# delete
|
|
|
if a1 < a2:
|
|
|
if a2 > len(ar.lines):
|
|
|
raise LineLogError(
|
|
|
b'%d contains %d lines, tried to access line %d'
|
|
|
% (rev, len(ar.lines), a2)
|
|
|
)
|
|
|
elif a2 == len(ar.lines):
|
|
|
endaddr = ar._eof
|
|
|
else:
|
|
|
endaddr = ar.lines[a2]._offset
|
|
|
if a2 > 0 and rev < self._maxrev:
|
|
|
# If we're here, we're deleting a chunk of an old
|
|
|
# commit, so we need to be careful and not touch
|
|
|
# invisible lines between a2-1 and a2 (IOW, lines that
|
|
|
# are added later).
|
|
|
endaddr = ar.lines[a2 - 1]._offset + 1
|
|
|
appendinst(_jge(rev, endaddr))
|
|
|
# copy instruction from a1
|
|
|
a1instpc = programlen()
|
|
|
appendinst(a1inst)
|
|
|
# if a1inst isn't a jump or EOF, then we need to add an unconditional
|
|
|
# jump back into the program here.
|
|
|
if not isinstance(a1inst, (_jump, _eof)):
|
|
|
appendinst(_jump(0, a1info._offset + 1))
|
|
|
# Patch instruction at a1, which makes our patch live.
|
|
|
self._program[a1info._offset] = _jump(0, oldproglen)
|
|
|
|
|
|
# Update self._lastannotate in place. This serves as a cache to avoid
|
|
|
# expensive "self.annotate" in this function, when "replacelines" is
|
|
|
# used continuously.
|
|
|
if len(self._lastannotate.lines) > a1:
|
|
|
self._lastannotate.lines[a1]._offset = a1instpc
|
|
|
else:
|
|
|
assert isinstance(a1inst, _eof)
|
|
|
self._lastannotate._eof = a1instpc
|
|
|
self._lastannotate.lines[a1:a2] = blineinfos
|
|
|
self._lastannotate.rev = max(self._lastannotate.rev, rev)
|
|
|
|
|
|
if rev > self._maxrev:
|
|
|
self._maxrev = rev
|
|
|
|
|
|
def annotate(self, rev):
|
|
|
pc = 1
|
|
|
lines: List[lineinfo] = []
|
|
|
executed = 0
|
|
|
# Sanity check: if instructions executed exceeds len(program), we
|
|
|
# hit an infinite loop in the linelog program somehow and we
|
|
|
# should stop.
|
|
|
while pc is not None and executed < len(self._program):
|
|
|
inst = self._program[pc]
|
|
|
lastpc = pc
|
|
|
pc = inst.execute(rev, pc, lines.append)
|
|
|
executed += 1
|
|
|
if pc is not None:
|
|
|
raise LineLogError(
|
|
|
r'Probably hit an infinite loop in linelog. Program:\n'
|
|
|
+ self.debugstr()
|
|
|
)
|
|
|
ar = annotateresult(rev, lines, lastpc)
|
|
|
self._lastannotate = ar
|
|
|
return ar
|
|
|
|
|
|
@property
|
|
|
def maxrev(self):
|
|
|
return self._maxrev
|
|
|
|
|
|
# Stateful methods which depend on the value of the last
|
|
|
# annotation run. This API is for compatiblity with the original
|
|
|
# linelog, and we should probably consider refactoring it.
|
|
|
@property
|
|
|
def annotateresult(self):
|
|
|
"""Return the last annotation result. C linelog code exposed this."""
|
|
|
return [(l.rev, l.linenum) for l in self._lastannotate.lines]
|
|
|
|
|
|
def getoffset(self, line):
|
|
|
return self._lastannotate.lines[line]._offset
|
|
|
|
|
|
def getalllines(self, start=0, end=0):
|
|
|
"""Get all lines that ever occurred in [start, end).
|
|
|
|
|
|
Passing start == end == 0 means "all lines ever".
|
|
|
|
|
|
This works in terms of *internal* program offsets, not line numbers.
|
|
|
"""
|
|
|
pc = start or 1
|
|
|
lines = []
|
|
|
# only take as many steps as there are instructions in the
|
|
|
# program - if we don't find an EOF or our stop-line before
|
|
|
# then, something is badly broken.
|
|
|
for step in range(len(self._program)):
|
|
|
inst = self._program[pc]
|
|
|
nextpc = pc + 1
|
|
|
if isinstance(inst, _jump):
|
|
|
nextpc = inst._target
|
|
|
elif isinstance(inst, _eof):
|
|
|
return lines
|
|
|
elif isinstance(inst, (_jl, _jge)):
|
|
|
pass
|
|
|
elif isinstance(inst, _line):
|
|
|
lines.append((inst._rev, inst._origlineno))
|
|
|
else:
|
|
|
raise LineLogError(b"Illegal instruction %r" % inst)
|
|
|
if nextpc == end:
|
|
|
return lines
|
|
|
pc = nextpc
|
|
|
raise LineLogError(b"Failed to perform getalllines")
|
|
|
|
