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Diffstat (limited to 'lib/python2.7/filecmp.py')
| -rw-r--r-- | lib/python2.7/filecmp.py | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/lib/python2.7/filecmp.py b/lib/python2.7/filecmp.py new file mode 100644 index 0000000..3a79381 --- /dev/null +++ b/lib/python2.7/filecmp.py @@ -0,0 +1,296 @@ +"""Utilities for comparing files and directories. + +Classes: + dircmp + +Functions: + cmp(f1, f2, shallow=1) -> int + cmpfiles(a, b, common) -> ([], [], []) + +""" + +import os +import stat +from itertools import ifilter, ifilterfalse, imap, izip + +__all__ = ["cmp","dircmp","cmpfiles"] + +_cache = {} +BUFSIZE=8*1024 + +def cmp(f1, f2, shallow=1): + """Compare two files. + + Arguments: + + f1 -- First file name + + f2 -- Second file name + + shallow -- Just check stat signature (do not read the files). + defaults to 1. + + Return value: + + True if the files are the same, False otherwise. + + This function uses a cache for past comparisons and the results, + with a cache invalidation mechanism relying on stale signatures. + + """ + + s1 = _sig(os.stat(f1)) + s2 = _sig(os.stat(f2)) + if s1[0] != stat.S_IFREG or s2[0] != stat.S_IFREG: + return False + if shallow and s1 == s2: + return True + if s1[1] != s2[1]: + return False + + outcome = _cache.get((f1, f2, s1, s2)) + if outcome is None: + outcome = _do_cmp(f1, f2) + if len(_cache) > 100: # limit the maximum size of the cache + _cache.clear() + _cache[f1, f2, s1, s2] = outcome + return outcome + +def _sig(st): + return (stat.S_IFMT(st.st_mode), + st.st_size, + st.st_mtime) + +def _do_cmp(f1, f2): + bufsize = BUFSIZE + with open(f1, 'rb') as fp1, open(f2, 'rb') as fp2: + while True: + b1 = fp1.read(bufsize) + b2 = fp2.read(bufsize) + if b1 != b2: + return False + if not b1: + return True + +# Directory comparison class. +# +class dircmp: + """A class that manages the comparison of 2 directories. + + dircmp(a,b,ignore=None,hide=None) + A and B are directories. + IGNORE is a list of names to ignore, + defaults to ['RCS', 'CVS', 'tags']. + HIDE is a list of names to hide, + defaults to [os.curdir, os.pardir]. + + High level usage: + x = dircmp(dir1, dir2) + x.report() -> prints a report on the differences between dir1 and dir2 + or + x.report_partial_closure() -> prints report on differences between dir1 + and dir2, and reports on common immediate subdirectories. + x.report_full_closure() -> like report_partial_closure, + but fully recursive. + + Attributes: + left_list, right_list: The files in dir1 and dir2, + filtered by hide and ignore. + common: a list of names in both dir1 and dir2. + left_only, right_only: names only in dir1, dir2. + common_dirs: subdirectories in both dir1 and dir2. + common_files: files in both dir1 and dir2. + common_funny: names in both dir1 and dir2 where the type differs between + dir1 and dir2, or the name is not stat-able. + same_files: list of identical files. + diff_files: list of filenames which differ. + funny_files: list of files which could not be compared. + subdirs: a dictionary of dircmp objects, keyed by names in common_dirs. + """ + + def __init__(self, a, b, ignore=None, hide=None): # Initialize + self.left = a + self.right = b + if hide is None: + self.hide = [os.curdir, os.pardir] # Names never to be shown + else: + self.hide = hide + if ignore is None: + self.ignore = ['RCS', 'CVS', 'tags'] # Names ignored in comparison + else: + self.ignore = ignore + + def phase0(self): # Compare everything except common subdirectories + self.left_list = _filter(os.listdir(self.left), + self.hide+self.ignore) + self.right_list = _filter(os.listdir(self.right), + self.hide+self.ignore) + self.left_list.sort() + self.right_list.sort() + + def phase1(self): # Compute common names + a = dict(izip(imap(os.path.normcase, self.left_list), self.left_list)) + b = dict(izip(imap(os.path.normcase, self.right_list), self.right_list)) + self.common = map(a.__getitem__, ifilter(b.__contains__, a)) + self.left_only = map(a.__getitem__, ifilterfalse(b.__contains__, a)) + self.right_only = map(b.__getitem__, ifilterfalse(a.__contains__, b)) + + def phase2(self): # Distinguish files, directories, funnies + self.common_dirs = [] + self.common_files = [] + self.common_funny = [] + + for x in self.common: + a_path = os.path.join(self.left, x) + b_path = os.path.join(self.right, x) + + ok = 1 + try: + a_stat = os.stat(a_path) + except os.error, why: + # print 'Can\'t stat', a_path, ':', why[1] + ok = 0 + try: + b_stat = os.stat(b_path) + except os.error, why: + # print 'Can\'t stat', b_path, ':', why[1] + ok = 0 + + if ok: + a_type = stat.S_IFMT(a_stat.st_mode) + b_type = stat.S_IFMT(b_stat.st_mode) + if a_type != b_type: + self.common_funny.append(x) + elif stat.S_ISDIR(a_type): + self.common_dirs.append(x) + elif stat.S_ISREG(a_type): + self.common_files.append(x) + else: + self.common_funny.append(x) + else: + self.common_funny.append(x) + + def phase3(self): # Find out differences between common files + xx = cmpfiles(self.left, self.right, self.common_files) + self.same_files, self.diff_files, self.funny_files = xx + + def phase4(self): # Find out differences between common subdirectories + # A new dircmp object is created for each common subdirectory, + # these are stored in a dictionary indexed by filename. + # The hide and ignore properties are inherited from the parent + self.subdirs = {} + for x in self.common_dirs: + a_x = os.path.join(self.left, x) + b_x = os.path.join(self.right, x) + self.subdirs[x] = dircmp(a_x, b_x, self.ignore, self.hide) + + def phase4_closure(self): # Recursively call phase4() on subdirectories + self.phase4() + for sd in self.subdirs.itervalues(): + sd.phase4_closure() + + def report(self): # Print a report on the differences between a and b + # Output format is purposely lousy + print 'diff', self.left, self.right + if self.left_only: + self.left_only.sort() + print 'Only in', self.left, ':', self.left_only + if self.right_only: + self.right_only.sort() + print 'Only in', self.right, ':', self.right_only + if self.same_files: + self.same_files.sort() + print 'Identical files :', self.same_files + if self.diff_files: + self.diff_files.sort() + print 'Differing files :', self.diff_files + if self.funny_files: + self.funny_files.sort() + print 'Trouble with common files :', self.funny_files + if self.common_dirs: + self.common_dirs.sort() + print 'Common subdirectories :', self.common_dirs + if self.common_funny: + self.common_funny.sort() + print 'Common funny cases :', self.common_funny + + def report_partial_closure(self): # Print reports on self and on subdirs + self.report() + for sd in self.subdirs.itervalues(): + print + sd.report() + + def report_full_closure(self): # Report on self and subdirs recursively + self.report() + for sd in self.subdirs.itervalues(): + print + sd.report_full_closure() + + methodmap = dict(subdirs=phase4, + same_files=phase3, diff_files=phase3, funny_files=phase3, + common_dirs = phase2, common_files=phase2, common_funny=phase2, + common=phase1, left_only=phase1, right_only=phase1, + left_list=phase0, right_list=phase0) + + def __getattr__(self, attr): + if attr not in self.methodmap: + raise AttributeError, attr + self.methodmap[attr](self) + return getattr(self, attr) + +def cmpfiles(a, b, common, shallow=1): + """Compare common files in two directories. + + a, b -- directory names + common -- list of file names found in both directories + shallow -- if true, do comparison based solely on stat() information + + Returns a tuple of three lists: + files that compare equal + files that are different + filenames that aren't regular files. + + """ + res = ([], [], []) + for x in common: + ax = os.path.join(a, x) + bx = os.path.join(b, x) + res[_cmp(ax, bx, shallow)].append(x) + return res + + +# Compare two files. +# Return: +# 0 for equal +# 1 for different +# 2 for funny cases (can't stat, etc.) +# +def _cmp(a, b, sh, abs=abs, cmp=cmp): + try: + return not abs(cmp(a, b, sh)) + except (os.error, IOError): + return 2 + + +# Return a copy with items that occur in skip removed. +# +def _filter(flist, skip): + return list(ifilterfalse(skip.__contains__, flist)) + + +# Demonstration and testing. +# +def demo(): + import sys + import getopt + options, args = getopt.getopt(sys.argv[1:], 'r') + if len(args) != 2: + raise getopt.GetoptError('need exactly two args', None) + dd = dircmp(args[0], args[1]) + if ('-r', '') in options: + dd.report_full_closure() + else: + dd.report() + +if __name__ == '__main__': + demo() |