diff --git a/swh/fetcher/googlecode/loader.py b/swh/fetcher/googlecode/loader.py index fbd2568..48713ba 100644 --- a/swh/fetcher/googlecode/loader.py +++ b/swh/fetcher/googlecode/loader.py @@ -1,162 +1,179 @@ # Copyright (C) 2015-2016 The Software Heritage developers # See the AUTHORS file at the top-level directory of this distribution # License: GNU General Public License version 3, or any later version # See top-level LICENSE file for more information +import hashlib import logging import os import requests from swh.core import config, hashutil from .utils import transform from .hashutil import md5_hash, md5_from_b64 class SWHGoogleFetcher(config.SWHConfig): """A swh data fetcher loader. This fetcher will: - retrieve the archive metadata and write it to disk. - download the archive to retrieve and write it to disk. - check that size and checksums (md5, crc32c) match those describe in the metadata. """ def __init__(self): self.log = logging.getLogger('swh.fetcher.google.SWHGoogleFetcher') l = logging.getLogger('requests.packages.urllib3.connectionpool') l.setLevel(logging.WARN) def load_meta(self, filepath): """Try and load the metadata from the given filepath. - It is assumed that the code is called after checking the file exists. + It is assumed that the code is called after checking the file + exists. """ import json try: with open(filepath, 'r') as f: return json.loads(f.read()) except: return None def retrieve_source_meta(self, url_meta, filepath_meta): if os.path.exists(filepath_meta): meta = self.load_meta(filepath_meta) if meta: # some meta could be corrupted, so we try to load them return meta # and if we fail, we try to fetch them again meta = {} try: r = requests.get(url_meta) except Exception as e: msg = 'Problem when fetching metadata %s.' % url_meta self.log.error(msg) raise ValueError(msg, e) else: meta = r.json() with open(filepath_meta, 'w') as f: f.write(r.text) return meta - def retrieve_source(self, url, filepath): + def write_and_check(self, filepath, response, md5h): + """Write the response's stream content to filepath. + Compute the hash at the same time and ensure the md5h is the same. + + Returns: + True if everything is ok and the md5 computed match the content. + False otherwise + """ + h = hashlib.md5() + with open(filepath, 'wb') as f: + for chunk in response.iter_content(hashutil.HASH_BLOCK_SIZE): + f.write(chunk) + h.update(chunk) + + return md5h == h.digest() + + def retrieve_source(self, meta, filepath): + url = meta['mediaLink'] if not os.path.exists(filepath): self.log.debug('Fetching %s\' raw data.' % url) try: r = requests.get(url, stream=True) except Exception as e: msg = 'Problem when fetching file %s.' % url self.log.error(msg) raise ValueError(msg, e) else: if not r.ok: msg = 'Problem when fetching file %s.' % url self.log.error(msg) raise ValueError(msg) - else: - with open(filepath, 'wb') as f: - for chunk in r.iter_content(hashutil.HASH_BLOCK_SIZE): - f.write(chunk) - - def check_source(self, meta, filepath): - expected = { - 'md5': md5_from_b64(meta['md5Hash']), - 'size': int(meta['size']) - } - - error = False + + return self.write_and_check(filepath, + r, + md5_from_b64(meta['md5Hash'])) + + def check_source_ok(self, meta, filepath, with_md5=False): + expected_size = int(meta['size']) + ok = True actual_size = os.path.getsize(filepath) - if actual_size != expected['size']: + if actual_size != expected_size: msg = 'Bad size. Expected: %s. Got: %s' % ( - expected['size'], actual_size) + expected_size, actual_size) self.log.error(msg) - error = True - - self.log.debug('Checking %s\' raw data checksums and size.' % - filepath) - # Last, check the metadata are ok - with open(filepath, 'rb') as f: - md5_h = md5_hash(f) - if md5_h != expected['md5']: - msg = 'Bad md5 signature. Expected: %s. Got: %s' % ( - expected['md5'], md5_h) - self.log.error(msg) - error = True + ok = False + + if with_md5: + expected_md5 = md5_from_b64(meta['md5Hash']) + self.log.debug('Checking %s\' raw data checksums and size.' % + filepath) + # Last, check the metadata are ok + with open(filepath, 'rb') as f: + md5_h = md5_hash(f) + if md5_h != expected_md5: + msg = 'Bad md5 signature. Expected: %s. Got: %s' % ( + expected_md5, md5_h) + self.log.error(msg) + ok = False - return error + return ok def process(self, archive_gs, destination_rootpath): self.log.info('Fetch %s\'s metadata' % archive_gs) # First retrieve the archive gs's metadata parent_dir, filename, url_meta, url_content = transform( archive_gs) parent_dir = os.path.join(destination_rootpath, parent_dir) os.makedirs(parent_dir, exist_ok=True) project_name = os.path.basename(parent_dir) filename = project_name + '-' + filename filename_meta = filename + '.json' filepath = os.path.join(parent_dir, filename) filepath_meta = os.path.join(parent_dir, filename_meta) meta = self.retrieve_source_meta(url_meta, filepath_meta) if not meta: raise ValueError('Fail to download metadata, stop.') # check existence of the file if os.path.exists(filepath): # it already exists, check it's ok - errors = self.check_source(meta, filepath) - if errors: - if os.path.exists(filepath): - self.log.error('Clean corrupted file %s' % filepath) - os.remove(filepath) - else: # it's ok, we are done! - self.log.info('Archive %s already fetched!' % archive_gs) - return + checks_ok = self.check_source_ok(meta, filepath, with_md5=True) + if checks_ok: # it's ok, we are done + self.log.info('Archive %s already fetched!' % archive_gs) + return + + self.log.error('Clean corrupted file %s' % filepath) + os.remove(filepath) # the file does not exist, we retrieve it - self.retrieve_source(meta['mediaLink'], filepath) + checks_ok = self.retrieve_source(meta, filepath) # Third - Check the retrieved source - errors = self.check_source(meta, filepath) - if errors: - if os.path.exists(filepath): - filepath_corrupted = filepath + '.corrupted' - self.log.error('Rename corrupted file %s to %s' % ( - os.path.basename(filepath), - os.path.basename(filepath_corrupted))) - os.rename(filepath, filepath_corrupted) - else: + if checks_ok and self.check_source_ok(meta, filepath): self.log.info('Archive %s fetched.' % archive_gs) + return + + # Trouble, we rename the corrupted file + if os.path.exists(filepath): + filepath_corrupted = filepath + '.corrupted' + self.log.error('Rename corrupted file %s to %s' % ( + os.path.basename(filepath), + os.path.basename(filepath_corrupted))) + os.rename(filepath, filepath_corrupted)