warcprox/warcprox/dedup.py

'''
warcprox/dedup.py - identical payload digest deduplication using sqlite db

Copyright (C) 2013-2017 Internet Archive

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
USA.
'''

from __future__ import absolute_import

import logging
import os
import json
from hanzo import warctools
import warcprox
import sqlite3
import requests
import doublethink
import rethinkdb as r
import datetime

class DedupDb(object):
    logger = logging.getLogger("warcprox.dedup.DedupDb")

    def __init__(
            self, file='./warcprox.sqlite', options=warcprox.Options()):
        self.file = file
        self.options = options

    def start(self):
        if os.path.exists(self.file):
            self.logger.info(
                    'opening existing deduplication database %s',
                    self.file)
        else:
            self.logger.info(
                    'creating new deduplication database %s', self.file)

        conn = sqlite3.connect(self.file)
        conn.execute(
                'create table if not exists dedup ('
                '  key varchar(300) primary key,'
                '  value varchar(4000)'
                ');')
        conn.commit()
        conn.close()

    def save(self, digest_key, response_record, bucket=""):
        record_id = response_record.get_header(warctools.WarcRecord.ID).decode('latin1')
        url = response_record.get_header(warctools.WarcRecord.URL).decode('latin1')
        date = response_record.get_header(warctools.WarcRecord.DATE).decode('latin1')

        key = digest_key.decode('utf-8') + "|" + bucket

        py_value = {'id':record_id, 'url':url, 'date':date}
        json_value = json.dumps(py_value, separators=(',',':'))

        conn = sqlite3.connect(self.file)
        conn.execute(
                'insert or replace into dedup (key, value) values (?, ?)',
                (key, json_value))
        conn.commit()
        conn.close()
        self.logger.debug('dedup db saved %s:%s', key, json_value)

    def lookup(self, digest_key, bucket=""):
        result = None
        key = digest_key.decode('utf-8') + '|' + bucket
        conn = sqlite3.connect(self.file)
        cursor = conn.execute('select value from dedup where key = ?', (key,))
        result_tuple = cursor.fetchone()
        conn.close()
        if result_tuple:
            result = json.loads(result_tuple[0])
            result['id'] = result['id'].encode('latin1')
            result['url'] = result['url'].encode('latin1')
            result['date'] = result['date'].encode('latin1')
        self.logger.debug('dedup db lookup of key=%s returning %s', key, result)
        return result

    def notify(self, recorded_url, records):
        if (records[0].get_header(warctools.WarcRecord.TYPE) == warctools.WarcRecord.RESPONSE
                and recorded_url.response_recorder.payload_size() > 0):
            digest_key = warcprox.digest_str(
                    recorded_url.response_recorder.payload_digest,
                    self.options.base32)
            if recorded_url.warcprox_meta and "captures-bucket" in recorded_url.warcprox_meta:
                self.save(
                        digest_key, records[0],
                        bucket=recorded_url.warcprox_meta["captures-bucket"])
            else:
                self.save(digest_key, records[0])


def decorate_with_dedup_info(dedup_db, recorded_url, base32=False):
    if (recorded_url.response_recorder
            and recorded_url.response_recorder.payload_digest
            and recorded_url.response_recorder.payload_size() > 0):
        digest_key = warcprox.digest_str(recorded_url.response_recorder.payload_digest, base32)
        if recorded_url.warcprox_meta and "captures-bucket" in recorded_url.warcprox_meta:
            recorded_url.dedup_info = dedup_db.lookup(digest_key, recorded_url.warcprox_meta["captures-bucket"])
        else:
            recorded_url.dedup_info = dedup_db.lookup(digest_key)

class RethinkDedupDb:
    logger = logging.getLogger("warcprox.dedup.RethinkDedupDb")

    def __init__(self, options=warcprox.Options()):
        parsed = doublethink.parse_rethinkdb_url(options.rethinkdb_dedup_url)
        self.rr = doublethink.Rethinker(
                servers=parsed.hosts, db=parsed.database)
        self.table = parsed.table
        self._ensure_db_table()
        self.options = options

    def _ensure_db_table(self):
        dbs = self.rr.db_list().run()
        if not self.rr.dbname in dbs:
            self.logger.info("creating rethinkdb database %r", self.rr.dbname)
            self.rr.db_create(self.rr.dbname).run()
        tables = self.rr.table_list().run()
        if not self.table in tables:
            self.logger.info(
                    "creating rethinkdb table %r in database %r shards=%r "
                    "replicas=%r", self.table, self.rr.dbname,
                    len(self.rr.servers), min(3, len(self.rr.servers)))
            self.rr.table_create(
                    self.table, primary_key="key", shards=len(self.rr.servers),
                    replicas=min(3, len(self.rr.servers))).run()

    def start(self):
        pass

    def save(self, digest_key, response_record, bucket=""):
        k = digest_key.decode("utf-8") if isinstance(digest_key, bytes) else digest_key
        k = "{}|{}".format(k, bucket)
        record_id = response_record.get_header(warctools.WarcRecord.ID).decode('latin1')
        url = response_record.get_header(warctools.WarcRecord.URL).decode('latin1')
        date = response_record.get_header(warctools.WarcRecord.DATE).decode('latin1')
        record = {'key':k,'url':url,'date':date,'id':record_id}
        result = self.rr.table(self.table).insert(
                record, conflict="replace").run()
        if sorted(result.values()) != [0,0,0,0,0,1] and [result["deleted"],result["skipped"],result["errors"]] != [0,0,0]:
            raise Exception("unexpected result %s saving %s", result, record)
        self.logger.debug('dedup db saved %s:%s', k, record)

    def lookup(self, digest_key, bucket=""):
        k = digest_key.decode("utf-8") if isinstance(digest_key, bytes) else digest_key
        k = "{}|{}".format(k, bucket)
        result = self.rr.table(self.table).get(k).run()
        if result:
            for x in result:
                result[x] = result[x].encode("utf-8")
        self.logger.debug('dedup db lookup of key=%s returning %s', k, result)
        return result

    def notify(self, recorded_url, records):
        if (records[0].get_header(warctools.WarcRecord.TYPE) == warctools.WarcRecord.RESPONSE
                and recorded_url.response_recorder.payload_size() > 0):
            digest_key = warcprox.digest_str(recorded_url.response_recorder.payload_digest,
                    self.options.base32)
            if recorded_url.warcprox_meta and "captures-bucket" in recorded_url.warcprox_meta:
                self.save(digest_key, records[0], bucket=recorded_url.warcprox_meta["captures-bucket"])
            else:
                self.save(digest_key, records[0])

class TroughDedupDb(object):
    '''
    https://github.com/jkafader/trough
    '''
    logger = logging.getLogger("warcprox.dedup.TroughDedupDb")

    def __init__(self, options=warcprox.Options()):
        parsed = doublethink.parse_rethinkdb_url(
                options.rethinkdb_trough_db_url)
        self.rr = doublethink.Rethinker(
                servers=parsed.hosts, db=parsed.database)
        self.svcreg = doublethink.ServiceRegistry(self.rr)
        self.options = options

    def start(self):
        pass

    def stop(self):
        pass

    def _write_url(self, bucket):
        segment_id = 'warcprox-trough-%s' % bucket
        master_node = self.svcreg.unique_service('trough-sync-master')
        response = requests.post(master_node['url'], segment_id)
        response.raise_for_status()
        write_url = response.text.strip()
        return write_url

    def _read_url(self, bucket):
        segment_id = 'warcprox-trough-%s' % bucket
        reql = self.rr.table('services').get_all(
                segment_id, index='segment').filter(
                        {'role':'trough-read'}).filter(
                                lambda svc: r.now().sub(
                                    svc['last_heartbeat']).lt(svc['ttl'])
                                ).order_by('load')
        logging.debug('querying rethinkdb: %r', reql)
        results = reql.run()
        if results:
            return results[0]['url']
        else:
            return None

    def sql_value(self, x):
        if x is None:
            return 'null'
        elif isinstance(x, datetime.datetime):
            return 'datetime(%r)' % x.isoformat()
        elif isinstance(x, bool):
            return int(x)
        elif isinstance(x, str) or isinstance(x, bytes):
            # py3: repr(u'abc') => 'abc'
            #      repr(b'abc') => b'abc'
            # py2: repr(u'abc') => u'abc'
            #      repr(b'abc') => 'abc'
            # Repr gives us a prefix we don't want in different situations
            # depending on whether this is py2 or py3. Chop it off either way.
            r = repr(x)
            if r[:1] == "'":
                return r
            else:
                return r[1:]
        else:
            raise Exception("don't know how to make an sql value from %r" % x)

    def save(self, digest_key, response_record, bucket='__unspecified__'):
        write_url = self._write_url(bucket)
        record_id = response_record.get_header(warctools.WarcRecord.ID)
        url = response_record.get_header(warctools.WarcRecord.URL)
        warc_date = response_record.get_header(warctools.WarcRecord.DATE)

        # XXX create table statement here is a temporary hack,
        # see https://webarchive.jira.com/browse/AITFIVE-1465
        sql = ('create table if not exists dedup (\n'
               '    digest_key varchar(100) primary key,\n'
               '    url varchar(2100) not null,\n'
               '    date datetime not null,\n'
               '    id varchar(100));\n' # warc record id
               'insert into dedup (digest_key, url, date, id) '
               'values (%s, %s, %s, %s);') % (
                       self.sql_value(digest_key), self.sql_value(url),
                       self.sql_value(warc_date), self.sql_value(record_id))
        response = requests.post(write_url, sql)
        if response.status_code != 200:
            logging.warn(
                    'unexpected response %r %r %r to sql=%r',
                    response.status_code, response.reason, response.text, sql)

    def lookup(self, digest_key, bucket='__unspecified__'):
        read_url = self._read_url(bucket)
        if not read_url:
            return None
        sql = 'select * from dedup where digest_key=%s;' % (
                self.sql_value(digest_key))
        response = requests.post(read_url, sql)
        if response.status_code != 200:
            logging.warn(
                    'unexpected response %r %r %r to sql=%r',
                    response.status_code, response.reason, response.text, sql)
            return None
        logging.debug('got %r from query %r', response.text, sql)
        results = json.loads(response.text)
        assert len(results) <= 1  # sanity check (digest_key is primary key)
        if results:
            result = results[0]
            result['id'] = result['id'].encode('ascii')
            result['url'] = result['url'].encode('ascii')
            result['date'] = result['date'].encode('ascii')
            self.logger.debug(
                    'trough lookup of key=%r returning %r', digest_key, result)
            return result
        else:
            return None

    def notify(self, recorded_url, records):
        if (records[0].get_header(warctools.WarcRecord.TYPE) == warctools.WarcRecord.RESPONSE
                and recorded_url.response_recorder.payload_size() > 0):
            digest_key = warcprox.digest_str(
                    recorded_url.response_recorder.payload_digest,
                    self.options.base32)
            if recorded_url.warcprox_meta and 'captures-bucket' in recorded_url.warcprox_meta:
                self.save(
                        digest_key, records[0],
                        bucket=recorded_url.warcprox_meta['captures-bucket'])
            else:
                self.save(digest_key, records[0])