calibre-web/vendor/babel/messages/mofile.py

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# -*- coding: utf-8 -*-
"""
babel.messages.mofile
~~~~~~~~~~~~~~~~~~~~~
Writing of files in the ``gettext`` MO (machine object) format.
:copyright: (c) 2013 by the Babel Team.
:license: BSD, see LICENSE for more details.
"""
import array
import struct
from babel.messages.catalog import Catalog, Message
from babel._compat import range_type
LE_MAGIC = 0x950412de
BE_MAGIC = 0xde120495
def read_mo(fileobj):
"""Read a binary MO file from the given file-like object and return a
corresponding `Catalog` object.
:param fileobj: the file-like object to read the MO file from
:note: The implementation of this function is heavily based on the
``GNUTranslations._parse`` method of the ``gettext`` module in the
standard library.
"""
catalog = Catalog()
headers = {}
filename = getattr(fileobj, 'name', '')
buf = fileobj.read()
buflen = len(buf)
unpack = struct.unpack
# Parse the .mo file header, which consists of 5 little endian 32
# bit words.
magic = unpack('<I', buf[:4])[0] # Are we big endian or little endian?
if magic == LE_MAGIC:
version, msgcount, origidx, transidx = unpack('<4I', buf[4:20])
ii = '<II'
elif magic == BE_MAGIC:
version, msgcount, origidx, transidx = unpack('>4I', buf[4:20])
ii = '>II'
else:
raise IOError(0, 'Bad magic number', filename)
# Now put all messages from the .mo file buffer into the catalog
# dictionary
for i in range_type(0, msgcount):
mlen, moff = unpack(ii, buf[origidx:origidx + 8])
mend = moff + mlen
tlen, toff = unpack(ii, buf[transidx:transidx + 8])
tend = toff + tlen
if mend < buflen and tend < buflen:
msg = buf[moff:mend]
tmsg = buf[toff:tend]
else:
raise IOError(0, 'File is corrupt', filename)
# See if we're looking at GNU .mo conventions for metadata
if mlen == 0:
# Catalog description
lastkey = key = None
for item in tmsg.splitlines():
item = item.strip()
if not item:
continue
if b':' in item:
key, value = item.split(b':', 1)
lastkey = key = key.strip().lower()
headers[key] = value.strip()
elif lastkey:
headers[lastkey] += b'\n' + item
if b'\x04' in msg: # context
ctxt, msg = msg.split(b'\x04')
else:
ctxt = None
if b'\x00' in msg: # plural forms
msg = msg.split(b'\x00')
tmsg = tmsg.split(b'\x00')
if catalog.charset:
msg = [x.decode(catalog.charset) for x in msg]
tmsg = [x.decode(catalog.charset) for x in tmsg]
else:
if catalog.charset:
msg = msg.decode(catalog.charset)
tmsg = tmsg.decode(catalog.charset)
catalog[msg] = Message(msg, tmsg, context=ctxt)
# advance to next entry in the seek tables
origidx += 8
transidx += 8
catalog.mime_headers = headers.items()
return catalog
def write_mo(fileobj, catalog, use_fuzzy=False):
"""Write a catalog to the specified file-like object using the GNU MO file
format.
>>> from babel.messages import Catalog
>>> from gettext import GNUTranslations
>>> from StringIO import StringIO
>>> catalog = Catalog(locale='en_US')
>>> catalog.add('foo', 'Voh')
<Message ...>
>>> catalog.add((u'bar', u'baz'), (u'Bahr', u'Batz'))
<Message ...>
>>> catalog.add('fuz', 'Futz', flags=['fuzzy'])
<Message ...>
>>> catalog.add('Fizz', '')
<Message ...>
>>> catalog.add(('Fuzz', 'Fuzzes'), ('', ''))
<Message ...>
>>> buf = StringIO()
>>> write_mo(buf, catalog)
>>> buf.seek(0)
>>> translations = GNUTranslations(fp=buf)
>>> translations.ugettext('foo')
u'Voh'
>>> translations.ungettext('bar', 'baz', 1)
u'Bahr'
>>> translations.ungettext('bar', 'baz', 2)
u'Batz'
>>> translations.ugettext('fuz')
u'fuz'
>>> translations.ugettext('Fizz')
u'Fizz'
>>> translations.ugettext('Fuzz')
u'Fuzz'
>>> translations.ugettext('Fuzzes')
u'Fuzzes'
:param fileobj: the file-like object to write to
:param catalog: the `Catalog` instance
:param use_fuzzy: whether translations marked as "fuzzy" should be included
in the output
"""
messages = list(catalog)
if not use_fuzzy:
messages[1:] = [m for m in messages[1:] if not m.fuzzy]
messages.sort()
ids = strs = b''
offsets = []
for message in messages:
# For each string, we need size and file offset. Each string is NUL
# terminated; the NUL does not count into the size.
if message.pluralizable:
msgid = b'\x00'.join([
msgid.encode(catalog.charset) for msgid in message.id
])
msgstrs = []
for idx, string in enumerate(message.string):
if not string:
msgstrs.append(message.id[min(int(idx), 1)])
else:
msgstrs.append(string)
msgstr = b'\x00'.join([
msgstr.encode(catalog.charset) for msgstr in msgstrs
])
else:
msgid = message.id.encode(catalog.charset)
if not message.string:
msgstr = message.id.encode(catalog.charset)
else:
msgstr = message.string.encode(catalog.charset)
if message.context:
msgid = b'\x04'.join([message.context.encode(catalog.charset),
msgid])
offsets.append((len(ids), len(msgid), len(strs), len(msgstr)))
ids += msgid + b'\x00'
strs += msgstr + b'\x00'
# The header is 7 32-bit unsigned integers. We don't use hash tables, so
# the keys start right after the index tables.
keystart = 7 * 4 + 16 * len(messages)
valuestart = keystart + len(ids)
# The string table first has the list of keys, then the list of values.
# Each entry has first the size of the string, then the file offset.
koffsets = []
voffsets = []
for o1, l1, o2, l2 in offsets:
koffsets += [l1, o1 + keystart]
voffsets += [l2, o2 + valuestart]
offsets = koffsets + voffsets
fileobj.write(struct.pack('Iiiiiii',
LE_MAGIC, # magic
0, # version
len(messages), # number of entries
7 * 4, # start of key index
7 * 4 + len(messages) * 8, # start of value index
0, 0 # size and offset of hash table
) + array.array("i", offsets).tostring() + ids + strs)