comparison mercurial/util.py @ 4827:89defeae88f3

turn util.opener into a class

4826:15efc1d06143

def encodedopener(openerfn, fn):
    def o(path, *args, **kw):
        return openerfn(fn(path), *args, **kw)
    return o

def opener(base, audit=True):
    """
    return a function that opens files relative to base

    this function is used to hide the details of COW semantics and
    remote file access from higher level code.
    """
    def mktempcopy(name, emptyok=False):
        d, fn = os.path.split(name)
        fd, temp = tempfile.mkstemp(prefix='.%s-' % fn, dir=d)
        os.close(fd)
        # Temporary files are created with mode 0600, which is usually not
        # what we want.  If the original file already exists, just copy
        # its mode.  Otherwise, manually obey umask.
        try:
            st_mode = os.lstat(name).st_mode
        except OSError, inst:
            if inst.errno != errno.ENOENT:
                raise
            st_mode = 0666 & ~_umask
        os.chmod(temp, st_mode)
        if emptyok:
            return temp
        try:
            try:
                ifp = posixfile(name, "rb")
            except IOError, inst:
                if inst.errno == errno.ENOENT:
                    return temp
                if not getattr(inst, 'filename', None):
                    inst.filename = name
                raise
            ofp = posixfile(temp, "wb")
            for chunk in filechunkiter(ifp):
                ofp.write(chunk)
            ifp.close()
            ofp.close()
        except:
            try: os.unlink(temp)
            except: pass
            raise
        return temp

    class atomictempfile(posixfile):
        """the file will only be copied when rename is called"""
        def __init__(self, name, mode):
            self.__name = name
            self.temp = mktempcopy(name, emptyok=('w' in mode))
            posixfile.__init__(self, self.temp, mode)
        def rename(self):
            if not self.closed:
                posixfile.close(self)
                rename(self.temp, localpath(self.__name))
        def __del__(self):
            if not self.closed:
                try:
                    os.unlink(self.temp)
                except: pass
                posixfile.close(self)

    def o(path, mode="r", text=False, atomictemp=False):
        if audit:
            audit_path(path)
        f = os.path.join(base, path)

        if not text and "b" not in mode:
            mode += "b" # for that other OS

        if mode[0] != "r":

            if atomictemp:
                return atomictempfile(f, mode)
            if nlink > 1:
                rename(mktempcopy(f), f)
        return posixfile(f, mode)

    return o

class chunkbuffer(object):
    """Allow arbitrary sized chunks of data to be efficiently read from an
    iterator over chunks of arbitrary size."""

4827:89defeae88f3

def encodedopener(openerfn, fn):
    def o(path, *args, **kw):
        return openerfn(fn(path), *args, **kw)
    return o

def mktempcopy(name, emptyok=False):
    """Create a temporary file with the same contents from name

    The permission bits are copied from the original file.

    If the temporary file is going to be truncated immediately, you
    can use emptyok=True as an optimization.

    Returns the name of the temporary file.
    """
    d, fn = os.path.split(name)
    fd, temp = tempfile.mkstemp(prefix='.%s-' % fn, dir=d)
    os.close(fd)
    # Temporary files are created with mode 0600, which is usually not
    # what we want.  If the original file already exists, just copy
    # its mode.  Otherwise, manually obey umask.
    try:
        st_mode = os.lstat(name).st_mode
    except OSError, inst:
        if inst.errno != errno.ENOENT:
            raise
        st_mode = 0666 & ~_umask
    os.chmod(temp, st_mode)
    if emptyok:
        return temp
    try:
        try:
            ifp = posixfile(name, "rb")
        except IOError, inst:
            if inst.errno == errno.ENOENT:
                return temp
            if not getattr(inst, 'filename', None):
                inst.filename = name
            raise
        ofp = posixfile(temp, "wb")
        for chunk in filechunkiter(ifp):
            ofp.write(chunk)
        ifp.close()
        ofp.close()
    except:
        try: os.unlink(temp)
        except: pass
        raise
    return temp

class atomictempfile(posixfile):
    """file-like object that atomically updates a file

    All writes will be redirected to a temporary copy of the original
    file.  When rename is called, the copy is renamed to the original
    name, making the changes visible.
    """
    def __init__(self, name, mode):
        self.__name = name
        self.temp = mktempcopy(name, emptyok=('w' in mode))
        posixfile.__init__(self, self.temp, mode)

    def rename(self):
        if not self.closed:
            posixfile.close(self)
            rename(self.temp, localpath(self.__name))

    def __del__(self):
        if not self.closed:
            try:
                os.unlink(self.temp)
            except: pass
            posixfile.close(self)

class opener(object):
    """Open files relative to a base directory

    This class is used to hide the details of COW semantics and
    remote file access from higher level code.
    """
    def __init__(self, base, audit=True):
        self.base = base
        self.audit = audit

    def __call__(self, path, mode="r", text=False, atomictemp=False):
        if self.audit:
            audit_path(path)
        f = os.path.join(self.base, path)

        if not text and "b" not in mode:
            mode += "b" # for that other OS

        if mode[0] != "r":

            if atomictemp:
                return atomictempfile(f, mode)
            if nlink > 1:
                rename(mktempcopy(f), f)
        return posixfile(f, mode)

class chunkbuffer(object):
    """Allow arbitrary sized chunks of data to be efficiently read from an
    iterator over chunks of arbitrary size."""