ref: 3749e92cdb88a157f99c0709a264bd508603be9b
dir: /sys/src/cmd/hg/contrib/hg-relink/
#!/usr/bin/env python # # Copyright (C) 2007 Brendan Cully <[email protected]> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2, incorporated herein by reference. import os, sys class ConfigError(Exception): pass def usage(): print """relink <source> <destination> Recreate hard links between source and destination repositories""" class Config: def __init__(self, args): if len(args) != 3: raise ConfigError("wrong number of arguments") self.src = os.path.abspath(args[1]) self.dst = os.path.abspath(args[2]) for d in (self.src, self.dst): if not os.path.exists(os.path.join(d, '.hg')): raise ConfigError("%s: not a mercurial repository" % d) def collect(src): seplen = len(os.path.sep) candidates = [] for dirpath, dirnames, filenames in os.walk(src): relpath = dirpath[len(src) + seplen:] for filename in filenames: if not filename.endswith('.i'): continue st = os.stat(os.path.join(dirpath, filename)) candidates.append((os.path.join(relpath, filename), st)) return candidates def prune(candidates, dst): def getdatafile(path): if not path.endswith('.i'): return None, None df = path[:-1] + 'd' try: st = os.stat(df) except OSError: return None, None return df, st def linkfilter(dst, st): try: ts = os.stat(dst) except OSError: # Destination doesn't have this file? return False if st.st_ino == ts.st_ino: return False if st.st_dev != ts.st_dev: # No point in continuing raise Exception('Source and destination are on different devices') if st.st_size != ts.st_size: # TODO: compare revlog heads return False return st targets = [] for fn, st in candidates: tgt = os.path.join(dst, fn) ts = linkfilter(tgt, st) if not ts: continue targets.append((fn, ts.st_size)) df, ts = getdatafile(tgt) if df: targets.append((fn[:-1] + 'd', ts.st_size)) return targets def relink(src, dst, files): def relinkfile(src, dst): bak = dst + '.bak' os.rename(dst, bak) try: os.link(src, dst) except OSError: os.rename(bak, dst) raise os.remove(bak) CHUNKLEN = 65536 relinked = 0 savedbytes = 0 for f, sz in files: source = os.path.join(src, f) tgt = os.path.join(dst, f) sfp = file(source) dfp = file(tgt) sin = sfp.read(CHUNKLEN) while sin: din = dfp.read(CHUNKLEN) if sin != din: break sin = sfp.read(CHUNKLEN) if sin: continue try: relinkfile(source, tgt) print 'Relinked %s' % f relinked += 1 savedbytes += sz except OSError, inst: print '%s: %s' % (tgt, str(inst)) print 'Relinked %d files (%d bytes reclaimed)' % (relinked, savedbytes) try: cfg = Config(sys.argv) except ConfigError, inst: print str(inst) usage() sys.exit(1) src = os.path.join(cfg.src, '.hg') dst = os.path.join(cfg.dst, '.hg') candidates = collect(src) targets = prune(candidates, dst) relink(src, dst, targets)