Mercurial > hg
view mercurial/encoding.py @ 17651:3b49c28658f6
store: rename "openertype" argument to "vfstype"
author | FUJIWARA Katsunori <foozy@lares.dti.ne.jp> |
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date | Fri, 31 Aug 2012 02:06:29 +0900 |
parents | e7cfe3587ea4 |
children | 404feac78b8a |
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# encoding.py - character transcoding support for Mercurial # # Copyright 2005-2009 Matt Mackall <mpm@selenic.com> 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. import error import unicodedata, locale, os def _getpreferredencoding(): ''' On darwin, getpreferredencoding ignores the locale environment and always returns mac-roman. http://bugs.python.org/issue6202 fixes this for Python 2.7 and up. This is the same corrected code for earlier Python versions. However, we can't use a version check for this method, as some distributions patch Python to fix this. Instead, we use it as a 'fixer' for the mac-roman encoding, as it is unlikely that this encoding is the actually expected. ''' try: locale.CODESET except AttributeError: # Fall back to parsing environment variables :-( return locale.getdefaultlocale()[1] oldloc = locale.setlocale(locale.LC_CTYPE) locale.setlocale(locale.LC_CTYPE, "") result = locale.nl_langinfo(locale.CODESET) locale.setlocale(locale.LC_CTYPE, oldloc) return result _encodingfixers = { '646': lambda: 'ascii', 'ANSI_X3.4-1968': lambda: 'ascii', 'mac-roman': _getpreferredencoding } try: encoding = os.environ.get("HGENCODING") if not encoding: encoding = locale.getpreferredencoding() or 'ascii' encoding = _encodingfixers.get(encoding, lambda: encoding)() except locale.Error: encoding = 'ascii' encodingmode = os.environ.get("HGENCODINGMODE", "strict") fallbackencoding = 'ISO-8859-1' class localstr(str): '''This class allows strings that are unmodified to be round-tripped to the local encoding and back''' def __new__(cls, u, l): s = str.__new__(cls, l) s._utf8 = u return s def __hash__(self): return hash(self._utf8) # avoid collisions in local string space def tolocal(s): """ Convert a string from internal UTF-8 to local encoding All internal strings should be UTF-8 but some repos before the implementation of locale support may contain latin1 or possibly other character sets. We attempt to decode everything strictly using UTF-8, then Latin-1, and failing that, we use UTF-8 and replace unknown characters. The localstr class is used to cache the known UTF-8 encoding of strings next to their local representation to allow lossless round-trip conversion back to UTF-8. >>> u = 'foo: \\xc3\\xa4' # utf-8 >>> l = tolocal(u) >>> l 'foo: ?' >>> fromlocal(l) 'foo: \\xc3\\xa4' >>> u2 = 'foo: \\xc3\\xa1' >>> d = { l: 1, tolocal(u2): 2 } >>> d # no collision {'foo: ?': 1, 'foo: ?': 2} >>> 'foo: ?' in d False >>> l1 = 'foo: \\xe4' # historical latin1 fallback >>> l = tolocal(l1) >>> l 'foo: ?' >>> fromlocal(l) # magically in utf-8 'foo: \\xc3\\xa4' """ try: try: # make sure string is actually stored in UTF-8 u = s.decode('UTF-8') if encoding == 'UTF-8': # fast path return s r = u.encode(encoding, "replace") if u == r.decode(encoding): # r is a safe, non-lossy encoding of s return r return localstr(s, r) except UnicodeDecodeError: # we should only get here if we're looking at an ancient changeset try: u = s.decode(fallbackencoding) r = u.encode(encoding, "replace") if u == r.decode(encoding): # r is a safe, non-lossy encoding of s return r return localstr(u.encode('UTF-8'), r) except UnicodeDecodeError: u = s.decode("utf-8", "replace") # last ditch return u.encode(encoding, "replace") # can't round-trip except LookupError, k: raise error.Abort(k, hint="please check your locale settings") def fromlocal(s): """ Convert a string from the local character encoding to UTF-8 We attempt to decode strings using the encoding mode set by HGENCODINGMODE, which defaults to 'strict'. In this mode, unknown characters will cause an error message. Other modes include 'replace', which replaces unknown characters with a special Unicode character, and 'ignore', which drops the character. """ # can we do a lossless round-trip? if isinstance(s, localstr): return s._utf8 try: return s.decode(encoding, encodingmode).encode("utf-8") except UnicodeDecodeError, inst: sub = s[max(0, inst.start - 10):inst.start + 10] raise error.Abort("decoding near '%s': %s!" % (sub, inst)) except LookupError, k: raise error.Abort(k, hint="please check your locale settings") # How to treat ambiguous-width characters. Set to 'wide' to treat as wide. wide = (os.environ.get("HGENCODINGAMBIGUOUS", "narrow") == "wide" and "WFA" or "WF") def colwidth(s): "Find the column width of a string for display in the local encoding" return ucolwidth(s.decode(encoding, 'replace')) def ucolwidth(d): "Find the column width of a Unicode string for display" eaw = getattr(unicodedata, 'east_asian_width', None) if eaw is not None: return sum([eaw(c) in wide and 2 or 1 for c in d]) return len(d) def getcols(s, start, c): '''Use colwidth to find a c-column substring of s starting at byte index start''' for x in xrange(start + c, len(s)): t = s[start:x] if colwidth(t) == c: return t def lower(s): "best-effort encoding-aware case-folding of local string s" try: s.decode('ascii') # throw exception for non-ASCII character return s.lower() except UnicodeDecodeError: pass try: if isinstance(s, localstr): u = s._utf8.decode("utf-8") else: u = s.decode(encoding, encodingmode) lu = u.lower() if u == lu: return s # preserve localstring return lu.encode(encoding) except UnicodeError: return s.lower() # we don't know how to fold this except in ASCII except LookupError, k: raise error.Abort(k, hint="please check your locale settings") def upper(s): "best-effort encoding-aware case-folding of local string s" try: s.decode('ascii') # throw exception for non-ASCII character return s.upper() except UnicodeDecodeError: pass try: if isinstance(s, localstr): u = s._utf8.decode("utf-8") else: u = s.decode(encoding, encodingmode) uu = u.upper() if u == uu: return s # preserve localstring return uu.encode(encoding) except UnicodeError: return s.upper() # we don't know how to fold this except in ASCII except LookupError, k: raise error.Abort(k, hint="please check your locale settings") def toutf8b(s): '''convert a local, possibly-binary string into UTF-8b This is intended as a generic method to preserve data when working with schemes like JSON and XML that have no provision for arbitrary byte strings. As Mercurial often doesn't know what encoding data is in, we use so-called UTF-8b. If a string is already valid UTF-8 (or ASCII), it passes unmodified. Otherwise, unsupported bytes are mapped to UTF-16 surrogate range, uDC00-uDCFF. Principles of operation: - ASCII and UTF-8 data successfully round-trips and is understood by Unicode-oriented clients - filenames and file contents in arbitrary other encodings can have be round-tripped or recovered by clueful clients - local strings that have a cached known UTF-8 encoding (aka localstr) get sent as UTF-8 so Unicode-oriented clients get the Unicode data they want - because we must preserve UTF-8 bytestring in places such as filenames, metadata can't be roundtripped without help (Note: "UTF-8b" often refers to decoding a mix of valid UTF-8 and arbitrary bytes into an internal Unicode format that can be re-encoded back into the original. Here we are exposing the internal surrogate encoding as a UTF-8 string.) ''' if isinstance(s, localstr): return s._utf8 try: if s.decode('utf-8'): return s except UnicodeDecodeError: # surrogate-encode any characters that don't round-trip s2 = s.decode('utf-8', 'ignore').encode('utf-8') r = "" pos = 0 for c in s: if s2[pos:pos + 1] == c: r += c pos += 1 else: r += unichr(0xdc00 + ord(c)).encode('utf-8') return r def fromutf8b(s): '''Given a UTF-8b string, return a local, possibly-binary string. return the original binary string. This is a round-trip process for strings like filenames, but metadata that's was passed through tolocal will remain in UTF-8. >>> m = "\\xc3\\xa9\\x99abcd" >>> n = toutf8b(m) >>> n '\\xc3\\xa9\\xed\\xb2\\x99abcd' >>> fromutf8b(n) == m True ''' # fast path - look for uDxxx prefixes in s if "\xed" not in s: return s u = s.decode("utf-8") r = "" for c in u: if ord(c) & 0xff00 == 0xdc00: r += chr(ord(c) & 0xff) else: r += c.encode("utf-8") return r