#!/usr/bin/env python
#
# Public Domain 2014-present MongoDB, Inc.
# Public Domain 2008-2014 WiredTiger, Inc.
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import time
from helper import copy_wiredtiger_home
import wiredtiger, wttest
from wtdataset import SimpleDataSet
from wiredtiger import stat
from wtscenario import make_scenarios
from test_rollback_to_stable01 import test_rollback_to_stable_base

# test_rollback_to_stable03.py
# Test that rollback to stable clears the history store updates from reconciled pages.
class test_rollback_to_stable01(test_rollback_to_stable_base):
    session_config = 'isolation=snapshot'

    key_format_values = [
        ('column', dict(key_format='r')),
        ('integer_row', dict(key_format='i')),
    ]

    in_memory_values = [
        ('no_inmem', dict(in_memory=False)),
        ('inmem', dict(in_memory=True))
    ]

    prepare_values = [
        ('no_prepare', dict(prepare=False)),
        ('prepare', dict(prepare=True))
    ]

    scenarios = make_scenarios(key_format_values, in_memory_values, prepare_values)

    def conn_config(self):
        config = 'cache_size=4GB,statistics=(all)'
        if self.in_memory:
            config += ',in_memory=true'
        else:
            config += ',log=(enabled),in_memory=false'
        return config

    def test_rollback_to_stable(self):
        nrows = 1000

        # Create a table without logging.
        uri = "table:rollback_to_stable03"
        ds = SimpleDataSet(
            self, uri, 0, key_format=self.key_format, value_format="S", config='log=(enabled=false)')
        ds.populate()

        # Pin oldest and stable to timestamp 1.
        self.conn.set_timestamp('oldest_timestamp=' + self.timestamp_str(1) +
            ',stable_timestamp=' + self.timestamp_str(1))

        valuea = "aaaaa" * 100
        valueb = "bbbbb" * 100
        valuec = "ccccc" * 100
        self.large_updates(uri, valuea, ds, nrows, self.prepare, 10)
        # Check that all updates are seen.
        self.check(valuea, uri, nrows, 10)

        self.large_updates(uri, valueb, ds, nrows, self.prepare, 20)
        # Check that all updates are seen.
        self.check(valueb, uri, nrows, 20)

        self.large_updates(uri, valuec, ds, nrows, self.prepare, 30)
        # Check that all updates are seen.
        self.check(valuec, uri, nrows, 30)

        # Pin stable to timestamp 30 if prepare otherwise 20.
        if self.prepare:
            self.conn.set_timestamp('stable_timestamp=' + self.timestamp_str(30))
        else:
            self.conn.set_timestamp('stable_timestamp=' + self.timestamp_str(20))
        # Checkpoint to ensure that all the updates are flushed to disk.
        if not self.in_memory:
            self.session.checkpoint()

        self.conn.rollback_to_stable()
        # Check that the old updates are only seen even with the update timestamp.
        self.check(valueb, uri, nrows, 20)
        self.check(valuea, uri, nrows, 10)

        stat_cursor = self.session.open_cursor('statistics:', None, None)
        calls = stat_cursor[stat.conn.txn_rts][2]
        hs_removed = stat_cursor[stat.conn.txn_rts_hs_removed][2]
        keys_removed = stat_cursor[stat.conn.txn_rts_keys_removed][2]
        keys_restored = stat_cursor[stat.conn.txn_rts_keys_restored][2]
        pages_visited = stat_cursor[stat.conn.txn_rts_pages_visited][2]
        upd_aborted = stat_cursor[stat.conn.txn_rts_upd_aborted][2]
        stat_cursor.close()

        self.assertEqual(calls, 1)
        self.assertEqual(keys_removed, 0)
        self.assertEqual(keys_restored, 0)
        if self.in_memory:
            self.assertEqual(upd_aborted, nrows)
            self.assertEqual(hs_removed, 0)
        else:
            self.assertGreaterEqual(upd_aborted + hs_removed, nrows)
        self.assertGreater(pages_visited, 0)

if __name__ == '__main__':
    wttest.run()