README.md

OS X Yosemite Messages database merger

Early betas of OS X Yosemite had a bug where the library of old messages wasn't migrated. Instead a new library was created and all old messages were gone.

The bug has been fixed, but if you were affected, you still have two separate libraries. This script merged them for me. Use it at your own risk! You might end up worse than before. Backup everything beforehand. Twice.

This is what your ~/Library/Messages folder will look like if you're affected:

• chat.db
• chat.db-shm
• chat.db-wal
• chat.db.incompatible.v7006.sqlitedb
• chat.db.incompatible.v7006.sqlitedb-shm
• chat.db.incompatible.v7006.sqlitedb-wal

After you backed these files up, rename the first three to new.db, new.db-shm and new.db-wal, and rename the other three to look like the first three did. You have new restored your original library. Reboot!

When you start Messages, it will try to migrate the old messages again. Hopefully it will be successful this time. (If not I can't help you!). If you open Messages, you should see all (and only) the messages you saw before upgrading to Yosemite. Both databases now have the new format.

Next, run the merge.py migration script in that folder. It should merge the newer messages into your original database. Reboot and then delete new.*.

Again, this comes with no guarantees and might make things worse. Even if it appears to work, it might cause damage to your database. I have no idea, but the result looked good to me.

merge.py

#!/bin/env python

import sqlite3, os, sys

if os.popen("uname -sr").read() != "Darwin 14.0.0\n":
    print("This is not for your OS X version")
    sys.exit(1)

def verify_format(cursor, name):
    tables = old.execute("SELECT name FROM sqlite_master WHERE type='table'").fetchall()
    if tables != [(u'_SqliteDatabaseProperties',), (u'chat',), (u'sqlite_sequence',), (u'attachment',), (u'handle',), (u'chat_handle_join',), (u'message',), (u'chat_message_join',), (u'message_attachment_join',)]:
        print("Unexpected database format (%s). Didn't iMessage convert it?" % name)
        sys.exit(1)

def fetch(cursor, table):
    cursor.execute("SELECT * FROM " + table + " ORDER BY ROWID")
    return cursor.fetchall()

def max_row_id(cursor, table):
    cursor.execute("SELECT Max(ROWID) FROM " + table)
    return cursor.fetchone()[0]

def set_tuple_index(tup, index, value):
    return tuple(tup[0:index]) + (value,) + tuple(tup[index+1:])

def tuple_where(tuples, id_func, o):
    matches = filter(lambda x: id_func(x) == id_func(o), tuples)
    return matches[0][0] if len(matches) > 0 else None

def merge(old_cursor, new_cursor, table, id_func):
    old = fetch(old_cursor, table)
    new = fetch(new_cursor, table)
    additional = []
    row_map = {}
    next_row = max_row_id(old_cursor, table) + 1
    for row in new:
        rowid = row[0]
        mapped_row = tuple_where(old, id_func, row)
        if not mapped_row:
            mapped_row = next_row
            next_row += 1
            additional = additional + [set_tuple_index(row, 0, mapped_row)]
            print("Adding %s row %d" % (table, mapped_row))
        else:
            print("Mapping %s row %d->%d" % (table, rowid, mapped_row))
        row_map[rowid] = mapped_row
    return (row_map, additional)

def apply_map_to_tuple_index(tuples, index, m):
    return map(lambda t: set_tuple_index(t, index, m[t[index]]), tuples)

def merge_joins(old, new, table, map1, map2):
    print(table + ":")
    new_rows = fetch(new, table)
    old_rows = fetch(old, table)
    mapped = apply_map_to_join(new_rows, map1, map2)
    return filter(lambda x: x not in old_rows, mapped)

def apply_map_to_join(tuples, map1, map2):
    for t in tuples:
        print("Mapping %d/%d->%d/%d" % (t[0], t[1], map1[t[0]], map2[t[1]]))
    return map(lambda t: (map1[t[0]], map2[t[1]]), tuples)

def insert_values(cursor, values, db):
    for row in values:
        placeholder = ", ".join(map(lambda x: "?", list(row)))
        statement = "INSERT INTO %s VALUES (%s)" % (db, placeholder)
        cursor.execute(statement, row)

with sqlite3.connect("chat.db") as old_db, sqlite3.connect("new.db") as new_db:
    old = old_db.cursor()
    new = new_db.cursor()

    verify_format(old, "chat.db")
    verify_format(new, "new.db")

    (attachment_map, attachments) = merge(old, new, "attachment", lambda x: x[1])
    (chat_map, chats) = merge(old, new, "chat", lambda x: x[1])
    (handle_map, handles) = merge(old, new, "handle", lambda x: (x[1], x[3]))
    (message_map, messages) = merge(old, new, "message", lambda x: x[1])
    messages = apply_map_to_tuple_index(messages, 5, handle_map)

    chat_handle_joins = merge_joins(old, new, "chat_handle_join", chat_map, handle_map)
    chat_message_joins = merge_joins(old, new, "chat_message_join", chat_map, message_map)
    message_attachment_joins = merge_joins(old, new, "message_attachment_join", message_map, attachment_map)

    insert_values(old, attachments, "attachment")
    insert_values(old, chats, "chat")
    insert_values(old, handles, "handle")
    insert_values(old, messages, "message")

    insert_values(old, chat_handle_joins, "chat_handle_join")
    insert_values(old, chat_message_joins, "chat_message_join")
    insert_values(old, message_attachment_joins, "message_attachment_join")

    old_db.commit()
    print("OK")