tools/skqp/download_model

#! /usr/bin/env python

# Copyright 2018 Google Inc.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import hashlib
import os
import shutil
import sys
import threading
import tempfile
import urllib2

def checksum(path):
    if not os.path.exists(path):
        return None
    m = hashlib.md5()
    with open(path, 'rb') as f:
        while True:
            buf = f.read(4096)
            if 0 == len(buf):
                return m.hexdigest()
            m.update(buf)

def download(md5, path):
    if not md5 == checksum(path):
        dirname = os.path.dirname(path)
        if dirname and not os.path.exists(dirname):
            try:
                os.makedirs(dirname)
            except:
                # ignore race condition
                if not os.path.exists(dirname):
                    raise
        url = 'https://storage.googleapis.com/skia-skqp-assets/' + md5
        with open(path, 'wb') as o:
            shutil.copyfileobj(urllib2.urlopen(url), o)

def tmp(prefix):
    fd, path = tempfile.mkstemp(prefix=prefix)
    os.close(fd)
    return path

def main():
    os.chdir(os.path.join(os.path.dirname(__file__), os.pardir, os.pardir,
                         'platform_tools', 'android', 'apps', 'skqp', 'src',
                         'main', 'assets'))
    sys.stderr.write('\n    0 / ????   ')
    file_list_file = tmp('files_')
    with open('files.checksum', 'r') as f:
        md5 = f.read().strip()
        assert(len(md5) == 32)
        download(md5, file_list_file)
    with open(file_list_file, 'r') as f:
        records = []
        for line in f:
            md5, path = line.strip().split(';', 1)
            records.append((md5, path))
    threads = set()
    sys.stderr.write('\r    0 / %d   ' % len(records))
    for i, record in enumerate(records):
        t = threading.Thread(target=download, args=record)
        t.start()
        threads.add(t)
    left = -1
    while left != 0:
        count = sum(1 for t in threading.enumerate() if t in threads)
        if left != count:
            left = count
            sys.stderr.write('\r %4d / %d   ' % (len(records) - left, len(records)))
    sys.stderr.write('\n')

if __name__ == '__main__':
    main()