~launchpad-pqm/launchpad/devel

# Copyright 2011 Canonical Ltd.  This software is licensed under the
# GNU Affero General Public License version 3 (see the file LICENSE).

"""Populate `DistroSeriesDifference` table.

This script creates `DistroSeriesDifference` entries for the package
version differences between a derived `DistroSeries` and its parent.

The entries will still need to be processed by the cron job that works
out the exact differences.  Any pre-existing `DistroSeriesDifference`
entries remain untouched.
"""

__metaclass__ = type
__all__ = [
    'PopulateDistroSeriesDiff',
    ]

from collections import defaultdict
from optparse import (
    Option,
    OptionValueError,
    )

from storm.locals import ClassAlias
import transaction
from zope.component import getUtility

from canonical.database.sqlbase import (
    quote,
    quote_identifier,
    )
from canonical.launchpad.interfaces.lpstorm import IStore
from canonical.launchpad.utilities.looptuner import TunableLoop
from lp.registry.enum import (
    DistroSeriesDifferenceStatus,
    DistroSeriesDifferenceType,
    )
from lp.registry.interfaces.distribution import IDistributionSet
from lp.registry.interfaces.distroseriesparent import IDistroSeriesParentSet
from lp.registry.interfaces.pocket import PackagePublishingPocket
from lp.registry.model.distroseries import DistroSeries
from lp.registry.model.distroseriesdifference import DistroSeriesDifference
from lp.registry.model.distroseriesparent import DistroSeriesParent
from lp.services.scripts.base import LaunchpadScript
from lp.soyuz.interfaces.publishing import active_publishing_status


def compose_sql_find_latest_source_package_releases(distroseries):
    """Produce SQL that gets the last-published `SourcePackageRelease`s.

    Within `distroseries`, looks for the `SourcePackageRelease`
    belonging to each respective `SourcePackageName`'s respective latest
    `SourcePackagePublishingHistory`.

    For each of those, it produces a tuple consisting of:
     * `SourcePackageName` id: sourcepackagename
     * `SourcePackageRelease` id: sourcepackagerelease
     * Source package version: version.

    :return: SQL query, as a string.
    """
    parameters = {
        'active_status': quote(active_publishing_status),
        'distroseries': quote(distroseries),
        'main_archive': quote(distroseries.distribution.main_archive),
        'release_pocket': quote(PackagePublishingPocket.RELEASE),
    }
    return """
        SELECT DISTINCT ON (SPR.sourcepackagename)
            SPR.sourcepackagename,
            SPR.id As sourcepackagerelease,
            SPR.version
        FROM SourcePackagePublishingHistory AS SPPH
        JOIN SourcePackageRelease AS SPR ON SPR.id = SPPH.sourcepackagerelease
        WHERE
            SPPH.distroseries = %(distroseries)s AND
            SPPH.archive = %(main_archive)s AND
            SPPH.pocket = %(release_pocket)s AND
            SPPH.status IN %(active_status)s
        ORDER BY SPR.sourcepackagename, SPPH.id DESC
        """ % parameters


def compose_sql_find_differences(derived_series, parent_series):
    """Produce SQL that finds differences for a `DistroSeries`.

    The query compares `derived_distroseries` and its `previous_series`
    and for each package whose latest `SourcePackageRelease`s in the
    respective series differ, produces a tuple of:
     * `SourcePackageName` id: sourcepackagename
     * Source package version in derived series: source_version
     * Source package version in parent series: parent_source_version.

    :return: SQL query, as a string.
    """
    parameters = {
        'derived_query': compose_sql_find_latest_source_package_releases(
            derived_series),
        'parent_query': compose_sql_find_latest_source_package_releases(
            parent_series),
    }
    return """
        SELECT DISTINCT
            COALESCE(
                parent.sourcepackagename,
                derived.sourcepackagename) AS sourcepackagename,
            derived.version AS source_version,
            parent.version AS parent_source_version
        FROM (%(parent_query)s) AS parent
        FULL OUTER JOIN (%(derived_query)s) AS derived
        ON derived.sourcepackagename = parent.sourcepackagename
        WHERE derived.version IS DISTINCT FROM parent.version
        """ % parameters


def compose_sql_difference_type():
    """Produce SQL to compute a difference's `DistroSeriesDifferenceType`.

    Works with the parent_source_version and source_version fields as
    produced by the SQL from `compose_sql_find_differences`.

    :return: SQL query, as a string.
    """
    parameters = {
        'unique_to_derived_series': quote(
            DistroSeriesDifferenceType.UNIQUE_TO_DERIVED_SERIES),
        'missing_from_derived_series': quote(
            DistroSeriesDifferenceType.MISSING_FROM_DERIVED_SERIES),
        'different_versions': quote(
            DistroSeriesDifferenceType.DIFFERENT_VERSIONS),
    }
    return """
        CASE
            WHEN parent_source_version IS NULL THEN
                %(unique_to_derived_series)s
            WHEN source_version IS NULL THEN
                %(missing_from_derived_series)s
            ELSE %(different_versions)s
        END
        """ % parameters


def compose_sql_populate_distroseriesdiff(derived_series, parent_series,
                                          temp_table):
    """Create `DistroSeriesDifference` rows based on found differences.

    Uses field values that describe the difference, as produced by the
    SQL from `compose_sql_find_differences`:
     * sourcepackagename
     * source_version
     * parent_source_version

    Existing `DistroSeriesDifference` rows are not affected.

    :param derived_distroseries: A derived `DistroSeries`.
    :param temp_table: The name of a table to select the input fields
        from.
    :return: SQL query, as a string.
    """
    parameters = {
        'derived_series': quote(derived_series),
        'parent_series': quote(parent_series),
        'difference_type_expression': compose_sql_difference_type(),
        'needs_attention': quote(
            DistroSeriesDifferenceStatus.NEEDS_ATTENTION),
        'temp_table': quote_identifier(temp_table),
    }
    return """
        INSERT INTO DistroSeriesDifference (
            derived_series,
            parent_series,
            source_package_name,
            status,
            difference_type,
            source_version,
            parent_source_version)
        SELECT
            %(derived_series)s,
            %(parent_series)s,
            sourcepackagename,
            %(needs_attention)s,
            %(difference_type_expression)s,
            source_version,
            parent_source_version
        FROM %(temp_table)s
        WHERE sourcepackagename NOT IN (
            SELECT source_package_name
            FROM DistroSeriesDifference
            WHERE derived_series = %(derived_series)s)
        """ % parameters


def drop_table(store, table):
    """Drop `table`, if it exists."""
    store.execute("DROP TABLE IF EXISTS %s" % quote_identifier(table))


def populate_distroseriesdiff(logger, derived_series, parent_series):
    """Compare `derived_distroseries` to parent, and register differences.

    The differences are registered by creating `DistroSeriesDifference`
    records, insofar as they do not yet exist.
    """
    temp_table = "temp_potentialdistroseriesdiff"

    store = IStore(derived_series)
    drop_table(store, temp_table)
    quoted_temp_table = quote_identifier(temp_table)
    store.execute("""
        CREATE TEMP TABLE %s(
            sourcepackagename INTEGER,
            source_version debversion,
            parent_source_version debversion)
            ON COMMIT DROP
        """ % (
        quoted_temp_table))
    store.execute("INSERT INTO %s %s" % (
        quoted_temp_table,
        compose_sql_find_differences(derived_series, parent_series)))
    logger.info(
        "Found %d potential difference(s).",
        store.execute("SELECT count(*) FROM %s" % temp_table).get_one()[0])
    store.execute(
        compose_sql_populate_distroseriesdiff(
            derived_series, parent_series, temp_table))


def find_derived_series():
    """Find all derived `DistroSeries`."""
    Child = ClassAlias(DistroSeries, "Child")
    Parent = ClassAlias(DistroSeries, "Parent")
    relations = IStore(DistroSeries).find(
        (Child, Parent),
        DistroSeriesParent.derived_series_id == Child.id,
        DistroSeriesParent.parent_series_id == Parent.id)
    collated = defaultdict(list)
    for child, parent in relations:
        collated[child].append(parent)
    return collated


class DSDUpdater(TunableLoop):
    """Call `DistroSeriesDifference.update()` where appropriate.

    The `DistroSeriesDifference` records we create don't have their
    details filled out, such as base version or their diffs.

    Since this is likely to be much, much slower than the rest of the
    work of creating and initializing `DistroSeriesDifference`s, it is
    done in a `DBLoopTuner`.
    """

    def __init__(self, log, store, commit, ids):
        """See `TunableLoop`.

        :param log: A logger.
        :param store: Database store to work on.
        :param commit: A commit function to call after each batch.
        :param ids: Sequence of `DistroSeriesDifference` ids to fix.
        """
        super(DSDUpdater, self).__init__(log)
        self.minimum_chunk_size = 2
        self.maximum_chunk_size = 1000
        self.store = store
        self.commit = commit
        self.ids = sorted(ids, reverse=True)

    def isDone(self):
        """See `ITunableLoop`."""
        return len(self.ids) == 0

    def _cutChunk(self, chunk_size):
        """Cut a chunk of up to `chunk_size` items from the remaining work.

        Removes the items to be processed in this chunk from the list of
        remaining work, and returns those.
        """
        todo = self.ids[-chunk_size:]
        self.ids = self.ids[:-chunk_size]
        return todo

    def _getBatch(self, ids):
        """Retrieve a batch of `DistroSeriesDifference`s with given ids."""
        return self.store.find(
            DistroSeriesDifference, DistroSeriesDifference.id.is_in(ids))

    def __call__(self, chunk_size):
        """See `ITunableLoop`."""
        for dsd in self._getBatch(self._cutChunk(int(chunk_size))):
            dsd.update()
        self.commit()


class PopulateDistroSeriesDiff(LaunchpadScript):
    """Populate `DistroSeriesDifference` for pre-existing differences."""

    def add_my_options(self):
        """Register options specific to this script."""
        self.parser.add_options([
            Option(
                '-a', '--all', dest='all', action='store_true', default=False,
                help="Populate all derived distribution series."),
            Option(
                '-d', '--distribution', dest='distribution', default=None,
                help="Derived distribution."),
            Option(
                '-l', '--list', dest='list', action='store_true',
                default=False, help="List derived distroseries, then exit."),
            Option(
                '-s', '--series', dest='series', default=None,
                help="Derived distribution series."),
            Option(
                '-x', '--dry-run', dest='dry_run', action='store_true',
                default=False, help="Pretend; don't commit changes.")])

    def getDistroSeries(self):
        """Return the `DistroSeries` that are to be processed."""
        if self.options.all:
            return find_derived_series()
        else:
            distro = getUtility(IDistributionSet).getByName(
                self.options.distribution)
            series = distro.getSeries(self.options.series)
            augmented_series = defaultdict(list)
            if series is None:
                raise OptionValueError(
                    "Could not find %s series %s." % (
                        self.options.distribution, self.options.series))
            dsp = getUtility(IDistroSeriesParentSet).getByDerivedSeries(
                series)
            for rel in dsp:
                augmented_series[rel.derived_series].append(
                    rel.parent_series)
            if len(augmented_series) == 0:
                raise OptionValueError(
                    "%s series %s is not derived." % (
                        self.options.distribution, self.options.series))
            return augmented_series

    def processDistroSeries(self, distroseries, parent):
        """Generate `DistroSeriesDifference`s for `distroseries`."""
        self.logger.info(
            "Looking for differences in %s with regards to %s.",
            distroseries, parent)
        populate_distroseriesdiff(self.logger, distroseries, parent)
        self.commit()
        self.logger.info("Updating base_versions.")
        self.update(distroseries)
        self.commit()
        self.logger.info("Done with %s.", distroseries)

    def commit(self):
        """Commit (or if doing a dry run, abort instead)."""
        if self.options.dry_run:
            transaction.abort()
        else:
            transaction.commit()

    def listDerivedSeries(self):
        """Log all `DistroSeries` that the --all option would cover."""
        relationships = self.getDistroSeries()
        for child in relationships:
            for parent in relationships[child]:
               self.logger.info(
                    "%s %s with a parent of %s %s", child.distribution.name,
                    child.name, parent.distribution.name, parent.name)

    def checkOptions(self):
        """Verify command-line options."""
        if self.options.list:
            return
        specified_distro = (self.options.distribution is not None)
        specified_series = (self.options.series is not None)
        if specified_distro != specified_series:
            raise OptionValueError(
                "Specify both a distribution and a series, or use --all.")
        if specified_distro == self.options.all:
            raise OptionValueError(
                "Either specify a distribution and series, or use --all.")

    def main(self):
        """Do the script's work."""
        self.checkOptions()

        if self.options.list:
            self.options.all = True
            self.listDerivedSeries()
            return

        if self.options.dry_run:
            self.logger.info("Dry run requested.  Not committing changes.")

        relationships = self.getDistroSeries()
        for child in relationships.keys():
            for parent in relationships[child]:
                self.processDistroSeries(child, parent)

    def update(self, distroseries):
        """Call `DistroSeriesDifference.update()` where appropriate.

        The `DistroSeriesDifference` records we create don't have their
        details filled out, such as base version or their diffs.

        Only instances where the source package is published in both the
        parent series and the derived series need to have this done.
        """
        self.logger.info(
            "Updating DSDs for %s.", distroseries.title)
        store = IStore(distroseries)
        dsd_ids = store.find(
            DistroSeriesDifference.id,
            DistroSeriesDifference.derived_series == distroseries,
            DistroSeriesDifference.status ==
                DistroSeriesDifferenceStatus.NEEDS_ATTENTION,
            DistroSeriesDifference.difference_type ==
                DistroSeriesDifferenceType.DIFFERENT_VERSIONS,
            DistroSeriesDifference.base_version == None)
        DSDUpdater(self.logger, store, self.commit, dsd_ids).run()