Store and expose time a blog post was received

This is useful when sorting blog posts in the combined feed. It ensures
you do not miss older posts that were just synced to you.

briar-api/src/org/briarproject/api/blogs/BlogConstants.java

@@ -32,6 +32,7 @@ public interface BlogConstants {
 	String KEY_DESCRIPTION = "description";
 	String KEY_TITLE = "title";
 	String KEY_TIMESTAMP = "timestamp";
+	String KEY_TIME_RECEIVED = "timeReceived";
 	String KEY_PARENT = "parent";
 	String KEY_AUTHOR_ID = "id";
 	String KEY_AUTHOR_NAME = "name";

briar-api/src/org/briarproject/api/blogs/BlogPostHeader.java

@@ -11,18 +11,25 @@ public class BlogPostHeader extends PostHeader {
 
 	@Nullable
 	private final String title;
+	private final long timeReceived;
 
 	public BlogPostHeader(@Nullable String title, @NotNull MessageId id,
-			@Nullable MessageId parentId, long timestamp,
+			@Nullable MessageId parentId, long timestamp, long timeReceived,
 			@NotNull Author author,	@NotNull Status authorStatus,
 			@NotNull String contentType, boolean read) {
 		super(id, parentId, timestamp, author, authorStatus, contentType, read);
 
 		this.title = title;
+		this.timeReceived = timeReceived;
 	}
 
 	@Nullable
 	public String getTitle() {
 		return title;
 	}
+
+	public long getTimeReceived() {
+		return timeReceived;
+	}
+
 }

briar-core/src/org/briarproject/blogs/BlogManagerImpl.java

@@ -55,6 +55,7 @@ import static org.briarproject.api.blogs.BlogConstants.KEY_PARENT;
 import static org.briarproject.api.blogs.BlogConstants.KEY_PUBLIC_KEY;
 import static org.briarproject.api.blogs.BlogConstants.KEY_READ;
 import static org.briarproject.api.blogs.BlogConstants.KEY_TIMESTAMP;
+import static org.briarproject.api.blogs.BlogConstants.KEY_TIME_RECEIVED;
 import static org.briarproject.api.blogs.BlogConstants.KEY_TITLE;
 import static org.briarproject.api.contact.ContactManager.AddContactHook;
 import static org.briarproject.api.contact.ContactManager.RemoveContactHook;
@@ -376,6 +377,7 @@ class BlogManagerImpl extends BdfIncomingMessageHook implements BlogManager,
 
 		String title = meta.getOptionalString(KEY_TITLE);
 		long timestamp = meta.getLong(KEY_TIMESTAMP);
+		long timeReceived = meta.getLong(KEY_TIME_RECEIVED, timestamp);
 		MessageId parentId = null;
 		if (meta.containsKey(KEY_PARENT))
 			parentId = new MessageId(meta.getRaw(KEY_PARENT));
@@ -394,7 +396,7 @@ class BlogManagerImpl extends BdfIncomingMessageHook implements BlogManager,
 
 		String contentType = meta.getString(KEY_CONTENT_TYPE);
 		boolean read = meta.getBoolean(KEY_READ);
-		return new BlogPostHeader(title, id, parentId, timestamp, author,
-				authorStatus, contentType, read);
+		return new BlogPostHeader(title, id, parentId, timestamp, timeReceived,
+				author, authorStatus, contentType, read);
 	}
 }

briar-core/src/org/briarproject/blogs/BlogPostValidator.java

@@ -34,6 +34,7 @@ import static org.briarproject.api.blogs.BlogConstants.KEY_PARENT;
 import static org.briarproject.api.blogs.BlogConstants.KEY_PUBLIC_KEY;
 import static org.briarproject.api.blogs.BlogConstants.KEY_READ;
 import static org.briarproject.api.blogs.BlogConstants.KEY_TIMESTAMP;
+import static org.briarproject.api.blogs.BlogConstants.KEY_TIME_RECEIVED;
 import static org.briarproject.api.blogs.BlogConstants.KEY_TITLE;
 import static org.briarproject.api.blogs.BlogConstants.MAX_BLOG_POST_BODY_LENGTH;
 import static org.briarproject.api.blogs.BlogConstants.MAX_BLOG_POST_TITLE_LENGTH;
@@ -119,6 +120,7 @@ class BlogPostValidator extends BdfMessageValidator {
 		);
 		meta.put(KEY_AUTHOR, author);
 		meta.put(KEY_TIMESTAMP, m.getTimestamp());
+		meta.put(KEY_TIME_RECEIVED, clock.currentTimeMillis());
 		if (parent != null) {
 			meta.put(KEY_PARENT, parent);
 			dependencies = Collections.singletonList(new MessageId(parent));