/// <summary>
/// Sets prunable backups in set.
/// </summary>
/// <param name="set">The set of backups for a given database.</param>
/// <returns></returns>
public void FlagPrunableBackupsInSet(IEnumerable <BakModel> set)
{
// Ignore set with 0 or 1 entries
if (set.Count() < 2)
{
foreach (var backup in set)
{
backup.Prunable = false;
}
return;
}
// Make sure the set is ordered (and most recent first)
set = set.OrderByDescending(x => x.Created);
var mostRecentBackupDate = set.First().Created;
var startOfWeek = mostRecentBackupDate.Date.StartOfWeek(DayOfWeek.Sunday);
var twoWeeksFromStart = mostRecentBackupDate.AddDays(-2 * 7).Date;
var eightWeeksFromStart = startOfWeek.AddDays(-2 * 4 * 7).Date;
var fiftyTwoWeeksFromStart = startOfWeek.AddDays(-52 * 7).Date;
var keepOneDaily = new List <BakModel>();
var keepFirstSundayWeekly = new List <BakModel>();
var keepFirstAndThridSundayMonthly = new List <BakModel>();
var keepFirstSundayYearly = new List <BakModel>();
string databaseName = null;
foreach (var backup in set)
{
// Make sure there is only one database
if (databaseName != backup.DatabaseName)
{
if (databaseName != null && databaseName != backup.DatabaseName)
{
throw new ArgumentException("More than one database name in the set", "set");
}
databaseName = backup.DatabaseName;
}
if (backup.Created.Date >= twoWeeksFromStart)
{
keepOneDaily.Add(backup);
}
else if (backup.Created.Date >= eightWeeksFromStart && backup.Created.Date >= fiftyTwoWeeksFromStart)
{
keepFirstSundayWeekly.Add(backup);
}
else if (backup.Created.Date >= fiftyTwoWeeksFromStart.Date)
{
keepFirstAndThridSundayMonthly.Add(backup);
}
else
{
keepFirstSundayYearly.Add(backup);
}
}
// Keep all backups made in the last 7 days
foreach (var backup in keepOneDaily)
{
backup.Prunable = false;
}
var calendar = new JulianCalendar();
// Keep Sundays for a month
var weekGrouping =
keepFirstSundayWeekly.GroupBy(
x =>
new
{
x.Created.Year,
WeekNumber = calendar.GetWeekOfYear(x.Created, CalendarWeekRule.FirstDay, DayOfWeek.Sunday)
});
foreach (var week in weekGrouping)
{
if (week.Count() > 1)
{
KeepDayOccurences(week, DayOfWeek.Sunday, 0);
}
else
{
week.First().Prunable = false;
}
}
// Keep first and third Sunday of month
var monthGrouping = keepFirstAndThridSundayMonthly.GroupBy(x => new { x.Created.Year, x.Created.Month });
foreach (var month in monthGrouping)
{
if (month.Count() > 1)
{
KeepDayOccurences(month, DayOfWeek.Sunday, new[] { 0, 2 });
}
else
{
month.First().Prunable = false;
}
}
// Keep first backup of each year
var yearGrouping = keepFirstSundayYearly.GroupBy(x => new { x.Created.Year });
foreach (var year in yearGrouping)
{
if (year.Count() > 1)
{
// Order year set ascending
KeepDayOccurences(year, DayOfWeek.Sunday, 0);
}
else
{
// Last of ordered by DESC = first
year.Last().Prunable = false;
}
}
// Make sure only the most recent backup of 'Keeper' days is kept.
KeepOnePerDay(set);
}