import re

import time

from git.compat import (

PY3,

xrange,

string_types,

defenc

)

from git.objects.util import (

parse_date,

Serializable,

altz_to_utctz_str,

)

from git.util import (

Actor,

LockedFD,

LockFile,

assure_directory_exists,

to_native_path,

bin_to_hex,

file_contents_ro_filepath

)

import os.path as osp

__all__ = ["RefLog", "RefLogEntry"]

class RefLogEntry(tuple):

"""Named tuple allowing easy access to the revlog data fields"""

_re_hexsha_only = re.compile('^[0-9A-Fa-f]{40}$')

__slots__ = tuple()

def __repr__(self):

"""Representation of ourselves in git reflog format"""

res = self.format()

if PY3:

return res

else:

# repr must return a string, which it will auto-encode from unicode using the default encoding.

# This usually fails, so we encode ourselves

return res.encode(defenc)

def format(self):

""":return: a string suitable to be placed in a reflog file"""

act = self.actor

time = self.time

return u"{0} {1} {2} <{3}> {4!s} {5}\t{6}\n".format(self.oldhexsha,

self.newhexsha,

act.name,

act.email,

time[0],

altz_to_utctz_str(time[1]),

self.message)

@property

def oldhexsha(self):

"""The hexsha to the commit the ref pointed to before the change"""

return self[0]

@property

def newhexsha(self):

"""The hexsha to the commit the ref now points to, after the change"""

return self[1]

@property

def actor(self):

"""Actor instance, providing access"""

return self[2]

@property

def time(self):

"""time as tuple:

* [0] = int(time)

* [1] = int(timezone_offset) in time.altzone format """

return self[3]

@property

def message(self):

"""Message describing the operation that acted on the reference"""

return self[4]

@classmethod

def new(self, oldhexsha, newhexsha, actor, time, tz_offset, message):

""":return: New instance of a RefLogEntry"""

if not isinstance(actor, Actor):

raise ValueError("Need actor instance, got %s" % actor)

# END check types

return RefLogEntry((oldhexsha, newhexsha, actor, (time, tz_offset), message))

@classmethod

def from_line(cls, line):

""":return: New RefLogEntry instance from the given revlog line.

:param line: line bytes without trailing newline

:raise ValueError: If line could not be parsed"""

line = line.decode(defenc)

fields = line.split('\t', 1)

if len(fields) == 1:

info, msg = fields[0], None

elif len(fields) == 2:

info, msg = fields

else:

raise ValueError("Line must have up to two TAB-separated fields."

" Got %s" % repr(line))

# END handle first split

oldhexsha = info[:40]

newhexsha = info[41:81]

for hexsha in (oldhexsha, newhexsha):

if not cls._re_hexsha_only.match(hexsha):

raise ValueError("Invalid hexsha: %r" % (hexsha,))

# END if hexsha re doesn't match

# END for each hexsha

email_end = info.find('>', 82)

if email_end == -1:

raise ValueError("Missing token: >")

# END handle missing end brace

actor = Actor._from_string(info[82:email_end + 1])

time, tz_offset = parse_date(info[email_end + 2:])

return RefLogEntry((oldhexsha, newhexsha, actor, (time, tz_offset), msg))

class RefLog(list, Serializable):

"""A reflog contains reflog entries, each of which defines a certain state

of the head in question. Custom query methods allow to retrieve log entries

by date or by other criteria.

Reflog entries are orded, the first added entry is first in the list, the last

entry, i.e. the last change of the head or reference, is last in the list."""

__slots__ = ('_path', )

def __new__(cls, filepath=None):

inst = super(RefLog, cls).__new__(cls)

return inst

def __init__(self, filepath=None):

"""Initialize this instance with an optional filepath, from which we will

initialize our data. The path is also used to write changes back using

the write() method"""

self._path = filepath

if filepath is not None:

self._read_from_file()

# END handle filepath

def _read_from_file(self):

try:

fmap = file_contents_ro_filepath(self._path, stream=True, allow_mmap=True)

except OSError:

# it is possible and allowed that the file doesn't exist !

return

# END handle invalid log

try:

self._deserialize(fmap)

finally:

fmap.close()

# END handle closing of handle

#{ Interface

@classmethod

def from_file(cls, filepath):

"""

:return: a new RefLog instance containing all entries from the reflog

at the given filepath

:param filepath: path to reflog

:raise ValueError: If the file could not be read or was corrupted in some way"""

return cls(filepath)

@classmethod

def path(cls, ref):

"""

:return: string to absolute path at which the reflog of the given ref

instance would be found. The path is not guaranteed to point to a valid

file though.

:param ref: SymbolicReference instance"""

return osp.join(ref.repo.git_dir, "logs", to_native_path(ref.path))

@classmethod

def iter_entries(cls, stream):

"""

:return: Iterator yielding RefLogEntry instances, one for each line read

sfrom the given stream.

:param stream: file-like object containing the revlog in its native format

or basestring instance pointing to a file to read"""

new_entry = RefLogEntry.from_line

if isinstance(stream, string_types):

stream = file_contents_ro_filepath(stream)

# END handle stream type

while True:

line = stream.readline()

if not line:

return

yield new_entry(line.strip())

# END endless loop

stream.close()

@classmethod

def entry_at(cls, filepath, index):

""":return: RefLogEntry at the given index

:param filepath: full path to the index file from which to read the entry

:param index: python list compatible index, i.e. it may be negative to

specifiy an entry counted from the end of the list

:raise IndexError: If the entry didn't exist

.. note:: This method is faster as it only parses the entry at index, skipping

all other lines. Nonetheless, the whole file has to be read if

the index is negative

"""

fp = open(filepath, 'rb')

if index < 0:

return RefLogEntry.from_line(fp.readlines()[index].strip())

else:

# read until index is reached

for i in xrange(index + 1):

line = fp.readline()

if not line:

break

# END abort on eof

# END handle runup

if i != index or not line:

raise IndexError

# END handle exception

return RefLogEntry.from_line(line.strip())

# END handle index

def to_file(self, filepath):

"""Write the contents of the reflog instance to a file at the given filepath.

:param filepath: path to file, parent directories are assumed to exist"""

lfd = LockedFD(filepath)

assure_directory_exists(filepath, is_file=True)

fp = lfd.open(write=True, stream=True)

try:

self._serialize(fp)

lfd.commit()

except:

# on failure it rolls back automatically, but we make it clear

lfd.rollback()

raise

# END handle change

@classmethod

def append_entry(cls, config_reader, filepath, oldbinsha, newbinsha, message):

"""Append a new log entry to the revlog at filepath.

:param config_reader: configuration reader of the repository - used to obtain

user information. May also be an Actor instance identifying the committer directly.

May also be None

:param filepath: full path to the log file

:param oldbinsha: binary sha of the previous commit

:param newbinsha: binary sha of the current commit

:param message: message describing the change to the reference

:param write: If True, the changes will be written right away. Otherwise

the change will not be written

:return: RefLogEntry objects which was appended to the log

:note: As we are append-only, concurrent access is not a problem as we

do not interfere with readers."""

if len(oldbinsha) != 20 or len(newbinsha) != 20:

raise ValueError("Shas need to be given in binary format")

# END handle sha type

assure_directory_exists(filepath, is_file=True)

first_line = message.split('\n')[0]

committer = isinstance(config_reader, Actor) and config_reader or Actor.committer(config_reader)

entry = RefLogEntry((

bin_to_hex(oldbinsha).decode('ascii'),

bin_to_hex(newbinsha).decode('ascii'),

committer, (int(time.time()), time.altzone), first_line

))

lf = LockFile(filepath)

lf._obtain_lock_or_raise()

fd = open(filepath, 'ab')

try:

fd.write(entry.format().encode(defenc))

finally:

fd.close()

lf._release_lock()

# END handle write operation

return entry

def write(self):

"""Write this instance's data to the file we are originating from

:return: self"""

if self._path is None:

raise ValueError("Instance was not initialized with a path, use to_file(...) instead")

# END assert path

self.to_file(self._path)

return self

#} END interface

#{ Serializable Interface

def _serialize(self, stream):

write = stream.write

# write all entries

for e in self:

write(e.format().encode(defenc))

# END for each entry

def _deserialize(self, stream):

self.extend(self.iter_entries(stream))

#} END serializable interface