From a12fc1e9760c8927127737c22d57d51bc9a80af6 Mon Sep 17 00:00:00 2001
From: Marc Blank <mblank@google.com>
Date: Fri, 21 May 2010 11:58:42 -0700
Subject: [PATCH] Fix problem w/ sync of large calendars (never syncs)

* While working w/ Microsoft on this issue, we determined that Windows
  Mobile 6.0 does not suffer from this issue; when we compared our
  logs with those from the WM client, we noticed a difference in the
  commands being sent to the server on initial  sync (we send some extra
  options whereas WM doesnot)
* As an experiment, I removed these options from the initial
  sync, and this change solved the problem with a persistently unsyncable
  account (time to receive: 60-70 seconds vs. > 240 seconds).
* The fix is to remove all "options" from the initial sync for a given
  collection (i.e. with SyncKey=0)
* Note that Microsoft's documentation does not generally address the issue
  of what should/should not be sent in an initial sync command

Bug: 2569162
Change-Id: I69642cc0097296956029485abb85ac750303c865
---
 src/com/android/exchange/EasSyncService.java | 57 ++++++++++----------
 1 file changed, 29 insertions(+), 28 deletions(-)

diff --git a/src/com/android/exchange/EasSyncService.java b/src/com/android/exchange/EasSyncService.java
index 694f6b938..82a375f78 100644
--- a/src/com/android/exchange/EasSyncService.java
+++ b/src/com/android/exchange/EasSyncService.java
@@ -1982,43 +1982,44 @@ public class EasSyncService extends AbstractSyncService {
                 .start(Tags.SYNC_COLLECTION)
                 .data(Tags.SYNC_CLASS, className)
                 .data(Tags.SYNC_SYNC_KEY, syncKey)
-                .data(Tags.SYNC_COLLECTION_ID, mailbox.mServerId)
-                .tag(Tags.SYNC_DELETES_AS_MOVES);
+                .data(Tags.SYNC_COLLECTION_ID, mailbox.mServerId);
 
             // Start with the default timeout
             int timeout = COMMAND_TIMEOUT;
             if (!syncKey.equals("0")) {
-                // EAS doesn't like GetChanges if the syncKey is "0"; not documented
+                // EAS doesn't allow GetChanges in an initial sync; sending other options
+                // appears to cause the server to delay its response in some cases, and this delay
+                // can be long enough to result in an IOException and total failure to sync.
+                // Therefore, we don't send any options with the initial sync.
+                s.tag(Tags.SYNC_DELETES_AS_MOVES);
                 s.tag(Tags.SYNC_GET_CHANGES);
+                s.data(Tags.SYNC_WINDOW_SIZE,
+                        className.equals("Email") ? EMAIL_WINDOW_SIZE : PIM_WINDOW_SIZE);
+                // Handle options
+                s.start(Tags.SYNC_OPTIONS);
+                // Set the lookback appropriately (EAS calls this a "filter") for all but Contacts
+                if (className.equals("Email")) {
+                    s.data(Tags.SYNC_FILTER_TYPE, getEmailFilter());
+                } else if (className.equals("Calendar")) {
+                    // TODO Force two weeks for calendar until we can set this!
+                    s.data(Tags.SYNC_FILTER_TYPE, Eas.FILTER_2_WEEKS);
+                }
+                // Set the truncation amount for all classes
+                if (mProtocolVersionDouble >= Eas.SUPPORTED_PROTOCOL_EX2007_DOUBLE) {
+                    s.start(Tags.BASE_BODY_PREFERENCE)
+                    // HTML for email; plain text for everything else
+                    .data(Tags.BASE_TYPE, (className.equals("Email") ? Eas.BODY_PREFERENCE_HTML
+                            : Eas.BODY_PREFERENCE_TEXT))
+                            .data(Tags.BASE_TRUNCATION_SIZE, Eas.EAS12_TRUNCATION_SIZE)
+                            .end();
+                } else {
+                    s.data(Tags.SYNC_TRUNCATION, Eas.EAS2_5_TRUNCATION_SIZE);
+                }
+                s.end();
             } else {
                 // Use enormous timeout for initial sync, which empirically can take a while longer
                 timeout = 120*SECONDS;
             }
-            s.data(Tags.SYNC_WINDOW_SIZE,
-                    className.equals("Email") ? EMAIL_WINDOW_SIZE : PIM_WINDOW_SIZE);
-
-            // Handle options
-            s.start(Tags.SYNC_OPTIONS);
-            // Set the lookback appropriately (EAS calls this a "filter") for all but Contacts
-            if (className.equals("Email")) {
-                s.data(Tags.SYNC_FILTER_TYPE, getEmailFilter());
-            } else if (className.equals("Calendar")) {
-                // TODO Force two weeks for calendar until we can set this!
-                s.data(Tags.SYNC_FILTER_TYPE, Eas.FILTER_2_WEEKS);
-            }
-            // Set the truncation amount for all classes
-            if (mProtocolVersionDouble >= Eas.SUPPORTED_PROTOCOL_EX2007_DOUBLE) {
-                s.start(Tags.BASE_BODY_PREFERENCE)
-                    // HTML for email; plain text for everything else
-                    .data(Tags.BASE_TYPE, (className.equals("Email") ? Eas.BODY_PREFERENCE_HTML
-                        : Eas.BODY_PREFERENCE_TEXT))
-                    .data(Tags.BASE_TRUNCATION_SIZE, Eas.EAS12_TRUNCATION_SIZE)
-                    .end();
-            } else {
-                s.data(Tags.SYNC_TRUNCATION, Eas.EAS2_5_TRUNCATION_SIZE);
-            }
-            s.end();
-
             // Send our changes up to the server
             target.sendLocalChanges(s);