modtimes

#!/usr/bin/env python
"""
(c) William Stein, 2013

The modification times are stored under git in the file .salvus/mtimes.json
"""

import json, os

FILENAME = '.salvus/modtimes.json'
dir, file = os.path.split(FILENAME)

def save_obj(mtimes, commit):
    if not os.path.exists(dir):
        os.makedirs(dir)

    open(FILENAME, 'w').write(json.dumps(mtimes, separators=(',\n',':')))
    if commit:
        cmd = "git add %s; git commit %s -m 'Save file modification times.'"%(FILENAME, FILENAME)
        print cmd
        os.system(cmd)

def load_obj():
    try:
        return json.loads(open(FILENAME).read())
    except Exception, msg:
        # important that this be non-fatal, in case user deleted this file or something... since mtime is not that critical of info.
        print msg
        print "NON-FATAL ERROR: Unable to restore modification; leaving as they are."
        return {}

def compute_mtimes(path='.', obj=None):
    if obj is None:
        obj = []
    if os.path.split(path)[1] == '.git':
        return obj
    for X in os.listdir(path):
        if X == file:  # don't bother storing modtimes of cache file, so that if nothing changed, we don't have a pointless commit.
            continue
        fullpath = os.path.join(path, X)
        if fullpath.endswith('.git'):
            continue
        obj.append([fullpath, os.path.getmtime(fullpath)])
        if os.path.isdir(fullpath):
            compute_mtimes(fullpath, obj)
    return obj

def set_mtimes(obj):
    for fullpath, mtime in obj:
        try:
            os.utime(fullpath, (-1, mtime))
        except Exception, msg:
            print "non-fatal", msg

if __name__ == "__main__":
    import argparse
    parser = argparse.ArgumentParser(description="modtimes -- save or restore modification times of all files/directories under this path")
    parser.add_argument('--save', help='save modification times', action='store_true')
    parser.add_argument('--restore', help='restore modification times', action='store_true')
    parser.add_argument('--commit', help='if specified, then git add cache file and do git commit.', action='store_true')
    parser.add_argument('path', nargs='?', help='save or restore modification times of all files/directories under this path')

    args = parser.parse_args()
    if isinstance(args.path, list):
        args.path = args.path[0]

    if args.path is None:
        args.path = os.path.abspath('.')

    os.chdir(args.path)

    if args.save:
        save_obj(compute_mtimes(), args.commit)

    if args.restore:
        set_mtimes(load_obj())