private async Task HandleMessage(UpdateIndexDto dto)
{
using (var db = new ApplicationDbContext())
{
Farm farm;
switch (dto.UpdateMethod)
{
case EUpdateMethod.Create:
farm =
await db.Farms.Include(f => f.Products).Where(f => f.FarmId == dto.FarmId).FirstAsync();
//good idea but different time zone or system time on different servers do not allow to use a timestamp to filter out old messages
if (farm != null && farm.UpdateDateTime > farm.IndexDateTime) // && farm.UpdateDateTime == dto.UpdateTime)
{
AddFarmToIndex(farm, _indexWriter, db);
await db.SaveChangesAsync();
_indexWriter.Commit();
}
break;
case EUpdateMethod.Update:
farm =
await db.Farms.Include(f => f.Products).Where(f => f.FarmId == dto.FarmId).FirstAsync();
if (farm != null && farm.UpdateDateTime > farm.IndexDateTime) // && farm.UpdateDateTime == dto.UpdateTime)
{
UpdateFarmInIndex(farm, _indexWriter, db);
await db.SaveChangesAsync();
_indexWriter.Commit();
}
break;
case EUpdateMethod.Delete:
farm = await db.Farms.FindAsync(dto.FarmId);
if (farm != null)
{
DeleteFarmFromIndex(farm, _indexWriter, db);
await db.SaveChangesAsync();
_indexWriter.Commit();
}
break;
}
}
}
private static void DeleteFarmFromIndex(Farm farm, IndexWriter indexWriter, ApplicationDbContext db)
{
indexWriter.DeleteDocuments(new Term("id", farm.FarmId.ToString()));
db.Farms.Remove(farm);
}
private async Task CreateIndex(ApplicationDbContext db)
{
var farms = await db.Farms.Include(f => f.Products).ToListAsync();
Parallel.ForEach(farms, farm =>
//foreach (var farm in farms)
{
try
{
if (!farm.DeleteWhenRemovedFromIndex)
{
AddFarmToIndex(farm, _indexWriter, db);
}
else
{
//since it is not yet in the index we can simply remove it from the db
db.Farms.Remove(farm);
}
}
catch (Exception)
{
//TODO error handling. Should certainly not abort the adddition of documents
}
});
await db.SaveChangesAsync();
_indexWriter.Optimize();
_indexWriter.Commit();
}
private static void UpdateFarmInIndex(Farm farm, IndexWriter indexWriter, ApplicationDbContext db)
{
var doc = CreateDocumentFromFarm(farm);
indexWriter.UpdateDocument(new Term("id", farm.FarmId.ToString()), doc);
db.Entry(farm).State = EntityState.Modified;
farm.IndexDateTime = DateTime.Now;
}
private void AddFarmToIndex(Farm farm, IndexWriter indexWriter, ApplicationDbContext db)
{
var doc = CreateDocumentFromFarm(farm);
indexWriter.AddDocument(doc);
db.Entry(farm).State = EntityState.Modified;
farm.IndexDateTime = DateTime.Now;
}
private async Task UpdateIndex(ApplicationDbContext db)
{
var farms = await GetNewAddedQueryable(db).ToListAsync();
Parallel.ForEach(farms, farm =>
{
try
{
AddFarmToIndex(farm, _indexWriter, db);
}
catch (Exception)
{
//TODO error handling. Should certainly not abort the adddition of documents
}
});
farms = await db.Farms.Include(f => f.Products).Where(f => f.UpdateDateTime > f.IndexDateTime && f.IndexDateTime != DateTime.MinValue).ToListAsync();
Parallel.ForEach(farms, farm =>
{
try
{
UpdateFarmInIndex(farm, _indexWriter, db);
}
catch (Exception)
{
//TODO error handling. Should certainly not abort the adddition of documents
}
});
farms = await db.Farms.Where(f => f.DeleteWhenRemovedFromIndex).ToListAsync();
Parallel.ForEach(farms, farm =>
{
try
{
DeleteFarmFromIndex(farm, _indexWriter, db);
}
catch (Exception)
{
//TODO error handling. Should certainly not abort the adddition of documents
}
});
await db.SaveChangesAsync();
_indexWriter.Optimize();
_indexWriter.Commit();
}
private static IQueryable<Farm> GetNewAddedQueryable(ApplicationDbContext db)
{
return db.Farms.Where(f => f.UpdateDateTime > f.IndexDateTime && f.IndexDateTime == DateTime.MinValue && f.DeleteWhenRemovedFromIndex == false);
}
private async Task InitialiseIndex()
{
int totalHits = 0;
try
{
var searcher = new IndexSearcher(_azureDirectory);
var hits = searcher.Search(
new QueryParser(Version.LUCENE_30, "name", new StandardAnalyzer(Version.LUCENE_30)).Parse("*:*"), 1);
totalHits = hits.TotalHits;
}
catch (FileNotFoundException)
{
//that's ok, means no index was created yet
}
using (var db = new ApplicationDbContext())
{
if (totalHits > 0)
{
var farmTotal = await db.Farms.CountAsync();
var totalAdded = await GetNewAddedQueryable(db).CountAsync();
if (farmTotal == totalHits + totalAdded)
{
await UpdateIndex(db);
}
else
{
//Unfortunately not consistent index
_indexWriter.DeleteAll();
await CreateIndex(db);
}
}
else
{
await CreateIndex(db);
}
}
_throttlingCall.LastTimeExecuteWasCalled = DateTime.Now;
await InformWebRolesAboutNewIndex();
}