Made pipeline preprocessing synchronous.

Instead of having the asynchronous preprocessor concept with different
pipelines for new/modify/delete we have a single pipeline with
synchronous preprocessors that act upon new/modify/delete.
This keeps the code simpler due to lack of asynchronity and keeps the
new/modify/delete operations together (which at least for the indexing
makes a lot of sense).
Not supporting asynchronity is ok because the tasks done in
preprocessing are not cpu intensive (if they were we had a problem
since they are directly involved in the round-trip time), and the main
cost comes from i/o, meaning we don't gain much by doing multithreading.
Costly tasks (such as full-text indexing) should rather be implemented
as post-processing, since that doesn't increase the round-trip time directly,
and eventually consistent is typically good enough for that.

1 files changed, 3 insertions, 4 deletions

diff --git a/common/domain/mail.cpp b/common/domain/mail.cpp
index d40dde9..ffe322e 100644
--- a/common/domain/mail.cpp
+++ b/common/domain/mail.cpp
@@ -50,12 +50,11 @@ ResultSet TypeImplementation<Mail>::queryIndexes(const Akonadi2::Query &query, c
     return ResultSet(keys);
 }
 
-void TypeImplementation<Mail>::index(const Mail &type, Akonadi2::Storage::Transaction &transaction)
+void TypeImplementation<Mail>::index(const QByteArray &identifier, const BufferAdaptor &bufferAdaptor, Akonadi2::Storage::Transaction &transaction)
 {
-    const auto uid = type.getProperty("uid");
+    const auto uid = bufferAdaptor.getProperty("uid");
     if (uid.isValid()) {
-        Index uidIndex("mail.index.uid", transaction);
-        uidIndex.add(uid.toByteArray(), type.identifier());
+        Index("mail.index.uid", transaction).add(uid.toByteArray(), identifier);
     }
 }