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mirror of https://github.com/webrecorder/pywb.git synced 2025-03-23 06:32:24 +01:00
pywb/recorder/warcrecorder.py
Ilya Kreymer b64be0dff1 recorder: add tests for single file writer, including file locking
dedup policy: support customizable dedup/skip/write policy plugins and add tests
2016-03-18 15:28:24 -07:00

309 lines
9.4 KiB
Python

import tempfile
import uuid
import base64
import hashlib
import datetime
import zlib
import sys
import os
import six
import traceback
from collections import OrderedDict
from socket import gethostname
import fcntl
from pywb.utils.loaders import LimitReader, to_native_str
from pywb.utils.bufferedreaders import BufferedReader
from pywb.utils.timeutils import timestamp20_now
from webagg.utils import ParamFormatter
from recorder.filters import ExcludeNone
# ============================================================================
class BaseWARCRecorder(object):
WARC_RECORDS = {'warcinfo': 'application/warc-fields',
'response': 'application/http; msgtype=response',
'revisit': 'application/http; msgtype=response',
'request': 'application/http; msgtype=request',
'metadata': 'application/warc-fields',
}
REVISIT_PROFILE = 'http://netpreserve.org/warc/1.0/revisit/uri-agnostic-identical-payload-digest'
BUFF_SIZE = 8192
def __init__(self, gzip=True, dedup_index=None, name='recorder',
header_filter=ExcludeNone()):
self.gzip = gzip
self.dedup_index = dedup_index
self.rec_source_name = name
self.header_filter = header_filter
def ensure_digest(self, record):
block_digest = record.rec_headers.get('WARC-Block-Digest')
payload_digest = record.rec_headers.get('WARC-Payload-Digest')
if block_digest and payload_digest:
return
block_digester = self._create_digester()
payload_digester = self._create_digester()
pos = record.stream.tell()
block_digester.update(record.status_headers.headers_buff)
while True:
buf = record.stream.read(self.BUFF_SIZE)
if not buf:
break
block_digester.update(buf)
payload_digester.update(buf)
record.stream.seek(pos)
record.rec_headers['WARC-Block-Digest'] = str(block_digester)
record.rec_headers['WARC-Payload-Digest'] = str(payload_digester)
def _create_digester(self):
return Digester('sha1')
def _set_header_buff(self, record):
exclude_list = self.header_filter(record)
buff = record.status_headers.to_bytes(exclude_list)
record.status_headers.headers_buff = buff
def write_req_resp(self, req, resp, params):
url = resp.rec_headers.get('WARC-Target-Uri')
dt = resp.rec_headers.get('WARC-Date')
if not req.rec_headers.get('WARC-Record-ID'):
req.rec_headers['WARC-Record-ID'] = self._make_warc_id()
req.rec_headers['WARC-Target-Uri'] = url
req.rec_headers['WARC-Date'] = dt
req.rec_headers['WARC-Type'] = 'request'
req.rec_headers['Content-Type'] = req.content_type
resp_id = resp.rec_headers.get('WARC-Record-ID')
if resp_id:
req.rec_headers['WARC-Concurrent-To'] = resp_id
self._set_header_buff(req)
self._set_header_buff(resp)
self.ensure_digest(resp)
resp = self._check_revisit(resp, params)
if not resp:
print('Skipping due to dedup')
return
formatter = ParamFormatter(params, name=self.rec_source_name)
self._do_write_req_resp(req, resp, params, formatter)
def _check_revisit(self, record, params):
if not self.dedup_index:
return record
try:
url = record.rec_headers.get('WARC-Target-Uri')
digest = record.rec_headers.get('WARC-Payload-Digest')
iso_dt = record.rec_headers.get('WARC-Date')
result = self.dedup_index.lookup_revisit(params, digest, url, iso_dt)
except Exception as e:
traceback.print_exc()
result = None
if result == 'skip':
return None
if isinstance(result, tuple) and result[0] == 'revisit':
record.rec_headers['WARC-Type'] = 'revisit'
record.rec_headers['WARC-Profile'] = self.REVISIT_PROFILE
record.rec_headers['WARC-Refers-To-Target-URI'] = result[1]
record.rec_headers['WARC-Refers-To-Date'] = result[2]
return record
def _write_warc_record(self, out, record):
if self.gzip:
out = GzippingWriter(out)
self._line(out, b'WARC/1.0')
for n, v in six.iteritems(record.rec_headers):
self._header(out, n, v)
content_type = record.content_type
if not content_type:
content_type = self.WARC_RECORDS[record.rec_headers['WARC-Type']]
self._header(out, 'Content-Type', record.content_type)
if record.rec_headers['WARC-Type'] == 'revisit':
http_headers_only = True
else:
http_headers_only = False
if record.length:
actual_len = len(record.status_headers.headers_buff)
if not http_headers_only:
diff = record.stream.tell() - actual_len
actual_len = record.length - diff
self._header(out, 'Content-Length', str(actual_len))
# add empty line
self._line(out, b'')
# write headers and buffer
out.write(record.status_headers.headers_buff)
if not http_headers_only:
out.write(record.stream.read())
# add two lines
self._line(out, b'\r\n')
else:
# add three lines (1 for end of header, 2 for end of record)
self._line(out, b'Content-Length: 0\r\n\r\n')
out.flush()
def _header(self, out, name, value):
if not value:
return
self._line(out, (name + ': ' + str(value)).encode('latin-1'))
def _line(self, out, line):
out.write(line + b'\r\n')
@staticmethod
def _make_warc_id(id_=None):
if not id_:
id_ = uuid.uuid1()
return '<urn:uuid:{0}>'.format(id_)
# ============================================================================
class GzippingWriter(object):
def __init__(self, out):
self.compressor = zlib.compressobj(9, zlib.DEFLATED, zlib.MAX_WBITS + 16)
self.out = out
def write(self, buff):
#if isinstance(buff, str):
# buff = buff.encode('utf-8')
buff = self.compressor.compress(buff)
self.out.write(buff)
def flush(self):
buff = self.compressor.flush()
self.out.write(buff)
self.out.flush()
# ============================================================================
class Digester(object):
def __init__(self, type_='sha1'):
self.type_ = type_
self.digester = hashlib.new(type_)
def update(self, buff):
self.digester.update(buff)
def __str__(self):
return self.type_ + ':' + to_native_str(base64.b32encode(self.digester.digest()))
# ============================================================================
class SingleFileWARCRecorder(BaseWARCRecorder):
def __init__(self, filename, *args, **kwargs):
super(SingleFileWARCRecorder, self).__init__(*args, **kwargs)
self.filename = filename.format(timestamp=timestamp20_now(),
host=gethostname())
try:
os.makedirs(os.path.dirname(self.filename))
except:
pass
self._fh = open(self.filename, 'a+b')
fcntl.flock(self._fh, fcntl.LOCK_EX | fcntl.LOCK_NB)
def _do_write_req_resp(self, req, resp, params, formatter):
url = resp.rec_headers.get('WARC-Target-Uri')
print('Writing {0} to {1} '.format(url, self.filename))
out = self._fh
if not out:
raise IOError('Already closed')
start = out.tell()
self._write_warc_record(out, resp)
self._write_warc_record(out, req)
out.flush()
out.seek(start)
if self.dedup_index:
self.dedup_index.index_records(out, params, filename=self.filename)
def close(self):
if not self._fh:
return None
fcntl.flock(self._fh, fcntl.LOCK_UN)
self._fh.close()
self._fh = None
# ============================================================================
class PerRecordWARCRecorder(BaseWARCRecorder):
def __init__(self, warcdir, *args, **kwargs):
super(PerRecordWARCRecorder, self).__init__(*args, **kwargs)
self.warcdir = warcdir
def _do_write_req_resp(self, req, resp, params, formatter):
resp_uuid = resp.rec_headers['WARC-Record-ID'].split(':')[-1].strip('<> ')
req_uuid = req.rec_headers['WARC-Record-ID'].split(':')[-1].strip('<> ')
full_dir = formatter.format(self.warcdir)
try:
os.makedirs(full_dir)
except:
pass
resp_filename = os.path.join(full_dir, resp_uuid + '.warc.gz')
req_filename = os.path.join(full_dir, req_uuid + '.warc.gz')
url = resp.rec_headers.get('WARC-Target-Uri')
print('Writing request for {0} to {1}'.format(url, req_filename))
print('Writing response for {0} to {1}'.format(url, resp_filename))
self._write_and_index(resp_filename, resp, params, True)
self._write_and_index(req_filename, req, params, False)
def _write_and_index(self, filename, rec, params, index=False):
with open(filename, 'w+b') as out:
self._write_warc_record(out, rec)
if index and self.dedup_index:
out.seek(0)
self.dedup_index.index_records(out, params, filename=filename)