[PATCH] Reordering of thread authors to list matching authors first

[Dirk Hohndel <hohndel@infradead.org>]

When displaying threads as result of a search it makes sense to list those
authors first who match the search. The matching authors are separated from the
non-matching ones with a '|' instead of a ','

Imagine the default "+inbox" query. Those mails in the thread that
match the query are actually "new" (whatever that means). And some
people seem to think that it would be much better to see those author
names first. For example, imagine a long and drawn out thread that once
was started by me; you have long read the older part of the thread and
removed the inbox tag. Whenever a new email comes in on this thread,
prior to this patch the author column in the search display will first show
"Dirk Hohndel" - I think it should first show the actual author(s) of the new
mail(s).

Signed-off-by: Dirk Hohndel <hohndel@infradead.org>
---
 lib/message.cc |   16 ++++++++++++
 lib/notmuch.h  |   11 ++++++++
 lib/thread.cc  |   74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 101 insertions(+), 0 deletions(-)

diff --git a/lib/message.cc b/lib/message.cc
index 721c9a6..ac0afd9 100644
--- a/lib/message.cc
+++ b/lib/message.cc
@@ -35,6 +35,7 @@ struct _notmuch_message {
     char *thread_id;
     char *in_reply_to;
     char *filename;
+    char *author;
     notmuch_message_file_t *message_file;
     notmuch_message_list_t *replies;
     unsigned long flags;
@@ -110,6 +111,7 @@ _notmuch_message_create (const void *talloc_owner,
     message->in_reply_to = NULL;
     message->filename = NULL;
     message->message_file = NULL;
+    message->author = NULL;
 
     message->replies = _notmuch_message_list_create (message);
     if (unlikely (message->replies == NULL)) {
@@ -533,6 +535,20 @@ notmuch_message_get_tags (notmuch_message_t *message)
     return _notmuch_convert_tags(message, i, end);
 }
 
+const char *
+notmuch_message_get_author (notmuch_message_t *message)
+{
+    return message->author;
+}
+
+void
+notmuch_message_set_author (notmuch_message_t *message,
+			    const char *author)
+{
+    message->author = talloc_strdup(message, author);
+    return;
+}
+
 void
 _notmuch_message_set_date (notmuch_message_t *message,
 			   const char *date)
diff --git a/lib/notmuch.h b/lib/notmuch.h
index bae48a6..769f747 100644
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -773,6 +773,17 @@ notmuch_message_set_flag (notmuch_message_t *message,
 time_t
 notmuch_message_get_date  (notmuch_message_t *message);
 
+/* Set the author member of 'message' - this is the representation used
+ * when displaying the message
+ */
+void
+notmuch_message_set_author (notmuch_message_t *message, const char *author);
+
+/* Get the author member of 'message'
+ */
+const char *
+notmuch_message_get_author (notmuch_message_t *message);
+
 /* Get the value of the specified header from 'message'.
  *
  * The value will be read from the actual message file, not from the
diff --git a/lib/thread.cc b/lib/thread.cc
index e514bf8..baa0d7f 100644
--- a/lib/thread.cc
+++ b/lib/thread.cc
@@ -32,6 +32,7 @@ struct _notmuch_thread {
     char *subject;
     GHashTable *authors_hash;
     char *authors;
+    char *nonmatched_authors;
     GHashTable *tags;
 
     notmuch_message_list_t *message_list;
@@ -73,6 +74,76 @@ _thread_add_author (notmuch_thread_t *thread,
 	thread->authors = talloc_strdup (thread, author);
 }
 
+/*
+ * move authors of matched messages in the thread to 
+ * the front of the authors list, but keep them in
+ * existing order within their group
+ */
+static void
+_thread_move_matched_author (notmuch_thread_t *thread,
+			     const char *author)
+{
+    char *authorscopy;
+    char *currentauthor;
+    char *lastpipe,*nextpipe;
+    int idx,nmstart,author_len,authors_len;
+
+    if (thread->authors == NULL || author == NULL)
+	return;
+    if (thread->nonmatched_authors == NULL)
+	thread->nonmatched_authors = thread->authors;
+    author_len = strlen(author);
+    authors_len = strlen(thread->authors);
+    if (author_len == authors_len) {
+	/* just one author */
+	thread->nonmatched_authors += author_len;
+	return;
+    }
+    currentauthor = strcasestr(thread->authors, author);
+    if (currentauthor == NULL)
+	return;
+    /* how far inside the nonmatched authors is our author? */
+    idx = currentauthor - thread->nonmatched_authors;
+    if (idx < 0) {
+	/* already among matched authors */
+	return;
+    }
+    /* are there any authors in the list after our author? */
+    if (thread->nonmatched_authors + author_len < thread->authors + authors_len) {
+	/* we have to make changes, so let's get a temp copy */
+	authorscopy = xstrdup(thread->authors);
+	/* nmstart is the offset into where the non-matched authors start */
+	nmstart = thread->nonmatched_authors - thread->authors;
+	/* copy this author and add the "| " - the if clause above tells us there's more */
+	strncpy(thread->nonmatched_authors,author,author_len);
+	strncpy(thread->nonmatched_authors+author_len,"| ",2);
+	thread->nonmatched_authors += author_len+2;	
+	if (idx > 0) {
+	  /* we are actually moving authors around, not just changing the separator
+	   * first copy the authors that came BEFORE our author */
+	  strncpy(thread->nonmatched_authors, authorscopy+nmstart, idx-2);
+	  /* finally, if there are authors AFTER our author, copy those */
+	  if(author_len+nmstart+idx < authors_len) {
+	    strncpy(thread->nonmatched_authors + idx - 2,", ",2);
+	    strncpy(thread->nonmatched_authors + idx, authorscopy+nmstart + idx + author_len + 2, 
+		    authors_len - (nmstart + idx + author_len + 2));
+	  }
+	}
+	free(authorscopy);
+	/* finally let's make sure there's just one '|' in the authors string */
+	lastpipe = strchr(thread->authors,'|');
+	while (lastpipe) {
+	    nextpipe = strchr(lastpipe+1,'|');
+	    if (nextpipe)
+		*lastpipe = ',';
+	    lastpipe = nextpipe;
+	}
+    } else {
+	thread->nonmatched_authors += author_len;
+    }
+    return;
+}
+
 /* Add 'message' as a message that belongs to 'thread'.
  *
  * The 'thread' will talloc_steal the 'message' and hold onto a
@@ -108,6 +179,7 @@ _thread_add_message (notmuch_thread_t *thread,
 		author = internet_address_mailbox_get_addr (mailbox);
 	    }
 	    _thread_add_author (thread, author);
+	    notmuch_message_set_author (message, author);
 	}
 	g_object_unref (G_OBJECT (list));
     }
@@ -162,6 +234,7 @@ _thread_add_matched_message (notmuch_thread_t *thread,
 	notmuch_message_set_flag (hashed_message,
 				  NOTMUCH_MESSAGE_FLAG_MATCH, 1);
     }
+    _thread_move_matched_author (thread,notmuch_message_get_author(hashed_message));
 }
 
 static void
@@ -283,6 +356,7 @@ _notmuch_thread_create (void *ctx,
     thread->authors_hash = g_hash_table_new_full (g_str_hash, g_str_equal,
 						  free, NULL);
     thread->authors = NULL;
+    thread->nonmatched_authors = NULL;
     thread->tags = g_hash_table_new_full (g_str_hash, g_str_equal,
 					  free, NULL);
 
-- 
1.6.6.1


-- 
Dirk Hohndel
Intel Open Source Technology Center