view mercurial/util.py @ 884:087771ebe2e6

Fix walk code for files that do not exist anywhere, and unhandled types.

Prior to this, a file that did not exist was reported as showing up in
the filesystem, as were files of unsupported types (such as fifos).

Now, an error message is printed and nothing is returned in such cases.

This change also moves the commands.pathto function to the util module,
as the walk code needs it to print non-confusing error messages.

# util.py - utility functions and platform specfic implementations
#
# Copyright 2005 K. Thananchayan <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

import os, errno
from demandload import *
demandload(globals(), "re")

def unique(g):
    seen = {}
    for f in g:
        if f not in seen:
            seen[f] = 1
            yield f

class Abort(Exception):
    """Raised if a command needs to print an error and exit."""

def always(fn): return True
def never(fn): return False

def globre(pat, head = '^', tail = '$'):
    "convert a glob pattern into a regexp"
    i, n = 0, len(pat)
    res = ''
    group = False
    def peek(): return i < n and pat[i]
    while i < n:
        c = pat[i]
        i = i+1
        if c == '*':
            if peek() == '*':
                i += 1
                res += '.*'
            else:
                res += '[^/]*'
        elif c == '?':
            res += '.'
        elif c == '[':
            j = i
            if j < n and pat[j] in '!]':
                j += 1
            while j < n and pat[j] != ']':
                j += 1
            if j >= n:
                res += '\\['
            else:
                stuff = pat[i:j].replace('\\','\\\\')
                i = j + 1
                if stuff[0] == '!':
                    stuff = '^' + stuff[1:]
                elif stuff[0] == '^':
                    stuff = '\\' + stuff
                res = '%s[%s]' % (res, stuff)
        elif c == '{':
            group = True
            res += '(?:'
        elif c == '}' and group:
            res += ')'
            group = False
        elif c == ',' and group:
            res += '|'
        else:
            res += re.escape(c)
    return head + res + tail

_globchars = {'[': 1, '{': 1, '*': 1, '?': 1}

def pathto(n1, n2):
    '''return the relative path from one place to another'''
    if not n1: return n2
    a, b = n1.split(os.sep), n2.split(os.sep)
    a.reverse(), b.reverse()
    while a and b and a[-1] == b[-1]:
        a.pop(), b.pop()
    b.reverse()
    return os.sep.join((['..'] * len(a)) + b)

def canonpath(repo, cwd, myname):
    rootsep = repo.root + os.sep
    name = myname
    if not name.startswith(os.sep):
        name = os.path.join(repo.root, cwd, name)
    name = os.path.normpath(name)
    if name.startswith(rootsep):
        return name[len(rootsep):]
    elif name == repo.root:
        return ''
    else:
        raise Abort('%s not under repository root' % myname)
    
def matcher(repo, cwd, names, inc, exc, head = ''):
    def patkind(name):
        for prefix in 're:', 'glob:', 'path:':
            if name.startswith(prefix): return name.split(':', 1)
        for c in name:
            if c in _globchars: return 'glob', name
        return 'relpath', name

    def regex(name, tail):
        '''convert a pattern into a regular expression'''
        kind, name = patkind(name)
        if kind == 're':
            return name
        elif kind == 'path':
            return '^' + re.escape(name) + '$'
        return head + globre(name, '', tail)

    def matchfn(pats, tail):
        """build a matching function from a set of patterns"""
        if pats:
            pat = '(?:%s)' % '|'.join([regex(p, tail) for p in pats])
            return re.compile(pat).match

    def globprefix(pat):
        '''return the non-glob prefix of a path, e.g. foo/* -> foo'''
        root = []
        for p in pat.split(os.sep):
            if patkind(p)[0] == 'glob': break
            root.append(p)
        return os.sep.join(root)

    pats = []
    files = []
    roots = []
    for kind, name in map(patkind, names):
        if kind in ('glob', 'relpath'):
            name = canonpath(repo, cwd, name)
            if name == '':
                kind, name = 'glob', '**'
        if kind in ('glob', 're'):
            pats.append(name)
        if kind == 'glob':
            root = globprefix(name)
            if root: roots.append(root)
        elif kind == 'relpath':
            files.append(name)
            roots.append(name)
        
    patmatch = matchfn(pats, '$') or always
    filematch = matchfn(files, '(?:/|$)') or always
    incmatch = matchfn(inc, '(?:/|$)') or always
    excmatch = matchfn(exc, '(?:/|$)') or (lambda fn: False)

    return roots, lambda fn: (incmatch(fn) and not excmatch(fn) and
                              (fn.endswith('/') or
                               (not pats and not files) or
                               (pats and patmatch(fn)) or
                               (files and filematch(fn))))

def system(cmd, errprefix=None):
    """execute a shell command that must succeed"""
    rc = os.system(cmd)
    if rc:
        errmsg = "%s %s" % (os.path.basename(cmd.split(None, 1)[0]),
                            explain_exit(rc)[0])
        if errprefix:
            errmsg = "%s: %s" % (errprefix, errmsg)
        raise Abort(errmsg)

def rename(src, dst):
    try:
        os.rename(src, dst)
    except:
        os.unlink(dst)
        os.rename(src, dst)

def copytree(src, dst, copyfile):
    """Copy a directory tree, files are copied using 'copyfile'."""
    names = os.listdir(src)
    os.mkdir(dst)

    for name in names:
        srcname = os.path.join(src, name)
        dstname = os.path.join(dst, name)
        if os.path.isdir(srcname):
            copytree(srcname, dstname, copyfile)
        elif os.path.isfile(srcname):
            copyfile(srcname, dstname)
        else:
            raise IOError("Not a regular file: %r" % srcname)

def _makelock_file(info, pathname):
    ld = os.open(pathname, os.O_CREAT | os.O_WRONLY | os.O_EXCL)
    os.write(ld, info)
    os.close(ld)

def _readlock_file(pathname):
    return file(pathname).read()

# Platfor specific varients
if os.name == 'nt':
    nulldev = 'NUL:'

    def is_exec(f, last):
        return last

    def set_exec(f, mode):
        pass

    def pconvert(path):
        return path.replace("\\", "/")

    makelock = _makelock_file
    readlock = _readlock_file

    def explain_exit(code):
        return "exited with status %d" % code, code

else:
    nulldev = '/dev/null'

    def is_exec(f, last):
        return (os.stat(f).st_mode & 0100 != 0)

    def set_exec(f, mode):
        s = os.stat(f).st_mode
        if (s & 0100 != 0) == mode:
            return
        if mode:
            # Turn on +x for every +r bit when making a file executable
            # and obey umask.
            umask = os.umask(0)
            os.umask(umask)
            os.chmod(f, s | (s & 0444) >> 2 & ~umask)
        else:
            os.chmod(f, s & 0666)

    def pconvert(path):
        return path

    def makelock(info, pathname):
        try:
            os.symlink(info, pathname)
        except OSError, why:
            if why.errno == errno.EEXIST:
                raise
            else:
                _makelock_file(info, pathname)

    def readlock(pathname):
        try:
            return os.readlink(pathname)
        except OSError, why:
            if why.errno == errno.EINVAL:
                return _readlock_file(pathname)
            else:
                raise

    def explain_exit(code):
        """return a 2-tuple (desc, code) describing a process's status"""
        if os.WIFEXITED(code):
            val = os.WEXITSTATUS(code)
            return "exited with status %d" % val, val
        elif os.WIFSIGNALED(code):
            val = os.WTERMSIG(code)
            return "killed by signal %d" % val, val
        elif os.WIFSTOPPED(code):
            val = os.STOPSIG(code)
            return "stopped by signal %d" % val, val
        raise ValueError("invalid exit code")