Mercurial > hg
view tests/f @ 27475:a2e2a8fa5fd1
revlog: avoid string slice when decompressing u* chunks
Revlog chunks can be stored uncompressed. If the first byte of the
raw data is \0, we store the data as is. Else we prefix it with 'u'.
Before, we performed a string slice to strip out the 'u' prefix.
With this patch, we use a buffer to avoid an extra memory copy and
associated garbage collection overhead.
I was unable to verify any performance impact of this patch. For both
mozilla-central and the hg repos, the number of manifest revisions
with 'u' prefixes is very small - under 1%. So this change likely
isn't called enough to have an impact on manifest reading. However,
the reasoning behind this change is solid, so it should be safe.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 20 Dec 2015 16:00:27 -0800 |
parents | 6686ae524f94 |
children | e4f70e79a65f |
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#!/usr/bin/env python """ Utility for inspecting files in various ways. This tool is like the collection of tools found in a unix environment but are cross platform and stable and suitable for our needs in the test suite. This can be used instead of tools like: [ dd find head hexdump ls md5sum readlink sha1sum stat tail test readlink.py md5sum.py """ import sys, os, errno, re, glob, optparse def visit(opts, filenames, outfile): """Process filenames in the way specified in opts, writing output to outfile.""" for f in sorted(filenames): isstdin = f == '-' if not isstdin and not os.path.lexists(f): outfile.write('%s: file not found\n' % f) continue quiet = opts.quiet and not opts.recurse or isstdin isdir = os.path.isdir(f) islink = os.path.islink(f) isfile = os.path.isfile(f) and not islink dirfiles = None content = None facts = [] if isfile: if opts.type: facts.append('file') if opts.hexdump or opts.dump or opts.md5: content = file(f, 'rb').read() elif islink: if opts.type: facts.append('link') content = os.readlink(f) elif isstdin: content = sys.stdin.read() if opts.size: facts.append('size=%s' % len(content)) elif isdir: if opts.recurse or opts.type: dirfiles = glob.glob(f + '/*') facts.append('directory with %s files' % len(dirfiles)) elif opts.type: facts.append('type unknown') if not isstdin: stat = os.lstat(f) if opts.size and not isdir: facts.append('size=%s' % stat.st_size) if opts.mode and not islink: facts.append('mode=%o' % (stat.st_mode & 0777)) if opts.links: facts.append('links=%s' % stat.st_nlink) if opts.newer: # mtime might be in whole seconds so newer file might be same if stat.st_mtime >= os.stat(opts.newer).st_mtime: facts.append('newer than %s' % opts.newer) else: facts.append('older than %s' % opts.newer) if opts.md5 and content is not None: try: from hashlib import md5 except ImportError: from md5 import md5 facts.append('md5=%s' % md5(content).hexdigest()[:opts.bytes]) if opts.sha1 and content is not None: try: from hashlib import sha1 except ImportError: from sha import sha as sha1 facts.append('sha1=%s' % sha1(content).hexdigest()[:opts.bytes]) if isstdin: outfile.write(', '.join(facts) + '\n') elif facts: outfile.write('%s: %s\n' % (f, ', '.join(facts))) elif not quiet: outfile.write('%s:\n' % f) if content is not None: chunk = content if not islink: if opts.lines: if opts.lines >= 0: chunk = ''.join(chunk.splitlines(True)[:opts.lines]) else: chunk = ''.join(chunk.splitlines(True)[opts.lines:]) if opts.bytes: if opts.bytes >= 0: chunk = chunk[:opts.bytes] else: chunk = chunk[opts.bytes:] if opts.hexdump: for i in range(0, len(chunk), 16): s = chunk[i:i+16] outfile.write('%04x: %-47s |%s|\n' % (i, ' '.join('%02x' % ord(c) for c in s), re.sub('[^ -~]', '.', s))) if opts.dump: if not quiet: outfile.write('>>>\n') outfile.write(chunk) if not quiet: if chunk.endswith('\n'): outfile.write('<<<\n') else: outfile.write('\n<<< no trailing newline\n') if opts.recurse and dirfiles: assert not isstdin visit(opts, dirfiles, outfile) if __name__ == "__main__": parser = optparse.OptionParser("%prog [options] [filenames]") parser.add_option("-t", "--type", action="store_true", help="show file type (file or directory)") parser.add_option("-m", "--mode", action="store_true", help="show file mode") parser.add_option("-l", "--links", action="store_true", help="show number of links") parser.add_option("-s", "--size", action="store_true", help="show size of file") parser.add_option("-n", "--newer", action="store", help="check if file is newer (or same)") parser.add_option("-r", "--recurse", action="store_true", help="recurse into directories") parser.add_option("-S", "--sha1", action="store_true", help="show sha1 hash of the content") parser.add_option("-M", "--md5", action="store_true", help="show md5 hash of the content") parser.add_option("-D", "--dump", action="store_true", help="dump file content") parser.add_option("-H", "--hexdump", action="store_true", help="hexdump file content") parser.add_option("-B", "--bytes", type="int", help="number of characters to dump") parser.add_option("-L", "--lines", type="int", help="number of lines to dump") parser.add_option("-q", "--quiet", action="store_true", help="no default output") (opts, filenames) = parser.parse_args(sys.argv[1:]) if not filenames: filenames = ['-'] visit(opts, filenames, sys.stdout)