/// <summary>
/// Examines the context changes from the ChangeTracker
/// and returns a collection of LuceneIndexChanges
/// </summary>
/// <returns>LuceneIndexChangeset - collection of entity changes converted to LuceneIndexChanges</returns>
private LuceneIndexChangeset GetChangeset()
{
LuceneIndexChangeset changes = new LuceneIndexChangeset();
foreach (var entity in contextInterface.ChangeTracker.Entries().Where(x => x.State != EntityState.Unchanged))
{
Type entityType = entity.Entity.GetType();
bool implementsILuceneIndexable = typeof(ILuceneIndexable).IsAssignableFrom(entityType);
if (implementsILuceneIndexable == true)
{
MethodInfo method = entityType.GetMethod("ToDocument");
if (method != null)
{
LuceneIndexChange change = new LuceneIndexChange(entity.Entity as ILuceneIndexable);
// If the entity doesn't have a guid IndexId, then add one in
if ((change.Entity.IndexId == Guid.Empty || change.Entity.IndexId == null) &&
(change.State == LuceneIndexState.Added || change.State == LuceneIndexState.Updated))
{
change.Entity.IndexId = Guid.NewGuid();
}
switch (entity.State)
{
case EntityState.Added:
change.State = LuceneIndexState.Added;
break;
case EntityState.Deleted:
change.State = LuceneIndexState.Removed;
break;
case EntityState.Modified:
change.State = LuceneIndexState.Updated;
break;
default:
change.State = LuceneIndexState.Unchanged;
break;
}
changes.Entries.Add(change);
}
}
}
return(changes);
}
public async Task <int> SaveChangesAsync(bool index = true)
{
int result = 0;
if (contextInterface.ChangeTracker.HasChanges())
{
// get the chages
LuceneIndexChangeset changes = GetChangeset();
// call the base async SaveChangesAsync method
result = await contextInterface.SaveChangesAsync();
if (changes.HasChanges == true && index == true)
{
indexer.Update(changes);
}
}
return(result);
}
/// <summary>
/// Call the SaveChanges method on the context
/// and index any changes
/// </summary>
/// <returns>Value passed back from the SaveChanges method on the underlying context</returns>
public int SaveChanges(bool index = true)
{
int result = 0;
if (contextInterface.ChangeTracker.HasChanges())
{
// get the Lucene Changeset from the current ChangeTracker
LuceneIndexChangeset changes = GetChangeset();
// Call the base AFTER we have collected out changeset
result = contextInterface.SaveChanges();
// finally, update our lucene with the changes if there are any
if (changes.HasChanges && index == true)
{
indexer.Update(changes);
}
}
return(result);
}
public void Update(LuceneIndexChangeset changeset)
{
using (var writer = new IndexWriter(directory, analyzer, maxFieldLength))
{
foreach (var change in changeset.Entries)
{
switch (change.State)
{
case LuceneIndexState.Added:
writer.AddDocument(change.Entity.ToDocument());
break;
case LuceneIndexState.Removed:
writer.DeleteDocuments(new Term("IndexId", change.Entity.IndexId.ToString()));
break;
case LuceneIndexState.Updated:
writer.UpdateDocument(new Term("IndexId", change.Entity.IndexId.ToString()), change.Entity.ToDocument());
break;
default:
break; // do nothing if the state doesn't involve changing the data
}
}
// only call the optimize if specified in the changeset
// as this can be potentially quite an expensive task
if (changeset.Optimize == true)
{
writer.Optimize();
}
// flush the changes
writer.Flush(true, true, changeset.HasDeletes);
}
}
/// <summary>
/// Update a single LuceneIndexChange
/// </summary>
/// <param name="change">The change to make</param>
/// <param name="optimize">Whether to optimize afterwards</param>
public void Update(LuceneIndexChange change, bool optimize = false)
{
LuceneIndexChangeset changeset = new LuceneIndexChangeset(change, optimize);
Update(changeset);
}
