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-rw-r--r--Lib/lib-old/cmpcache.py64
1 files changed, 0 insertions, 64 deletions
diff --git a/Lib/lib-old/cmpcache.py b/Lib/lib-old/cmpcache.py
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index 11540f8..0000000
--- a/Lib/lib-old/cmpcache.py
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@@ -1,64 +0,0 @@
-"""Efficiently compare files, boolean outcome only (equal / not equal).
-
-Tricks (used in this order):
- - Use the statcache module to avoid statting files more than once
- - Files with identical type, size & mtime are assumed to be clones
- - Files with different type or size cannot be identical
- - We keep a cache of outcomes of earlier comparisons
- - We don't fork a process to run 'cmp' but read the files ourselves
-"""
-
-import os
-from stat import *
-import statcache
-
-
-# The cache.
-#
-cache = {}
-
-
-def cmp(f1, f2, shallow=1):
- """Compare two files, use the cache if possible.
- May raise os.error if a stat or open of either fails.
- Return 1 for identical files, 0 for different.
- Raise exceptions if either file could not be statted, read, etc."""
- s1, s2 = sig(statcache.stat(f1)), sig(statcache.stat(f2))
- if not S_ISREG(s1[0]) or not S_ISREG(s2[0]):
- # Either is a not a plain file -- always report as different
- return 0
- if shallow and s1 == s2:
- # type, size & mtime match -- report same
- return 1
- if s1[:2] != s2[:2]: # Types or sizes differ, don't bother
- # types or sizes differ -- report different
- return 0
- # same type and size -- look in the cache
- key = f1 + ' ' + f2
- if cache.has_key(key):
- cs1, cs2, outcome = cache[key]
- # cache hit
- if s1 == cs1 and s2 == cs2:
- # cached signatures match
- return outcome
- # stale cached signature(s)
- # really compare
- outcome = do_cmp(f1, f2)
- cache[key] = s1, s2, outcome
- return outcome
-
-def sig(st):
- """Return signature (i.e., type, size, mtime) from raw stat data."""
- return S_IFMT(st[ST_MODE]), st[ST_SIZE], st[ST_MTIME]
-
-def do_cmp(f1, f2):
- """Compare two files, really."""
- #print ' cmp', f1, f2 # XXX remove when debugged
- bufsize = 8*1024 # Could be tuned
- fp1 = open(f1, 'rb')
- fp2 = open(f2, 'rb')
- while 1:
- b1 = fp1.read(bufsize)
- b2 = fp2.read(bufsize)
- if b1 != b2: return 0
- if not b1: return 1