diff options
Diffstat (limited to 'server/src/request_handler.py')
| -rw-r--r-- | server/src/request_handler.py | 205 |
1 files changed, 180 insertions, 25 deletions
diff --git a/server/src/request_handler.py b/server/src/request_handler.py index 9d820e4..458c554 100644 --- a/server/src/request_handler.py +++ b/server/src/request_handler.py @@ -1,5 +1,7 @@ """RequestHandler.""" +import bisect +import difflib import log from users_text_manager import AUTHORITY @@ -10,19 +12,145 @@ class JSON_TOKEN: # pylint:disable=W0232 """Enumeration the Ttken strings for json object.""" BYE = 'bye' # Resets the user and do nothong. CURSORS = 'cursors' # other users' cursor position + DIFF = 'diff' # Difference between this time and last time. ERROR = 'error' # error string IDENTITY = 'identity' # identity of myself INIT = 'init' # initialize connect flag MODE = 'mode' # vim mode. NICKNAME = 'nickname' # nick name of the user. OTHERS = 'others' # other users info. - TEXT = 'text' # text content in the buffer + + +def apply_patch(orig_lines, patch_info): + """Applies a patch. + + Args: + orig_lines: Original lines of the text. + patch_info: A list of replacing information. + + Return: + A list of text. + """ + new_lines, done_len = [], 0 + for beg, end, lines in patch_info: + new_lines += orig_lines[done_len : beg] + new_lines += lines + done_len = end + return new_lines + orig_lines[done_len : ] + + +def _squash_patch(patch_info): + """Squash list of replacing information to a smaller mount of information. + + Args: + patch_info: Information of patches. + + Return: + A list of replacing information. + """ + ret, index = [], 0 + while index < len(patch_info): + lines = patch_info[index][2] + index2 = index + 1 + while index2 < len(patch_info) and \ + patch_info[index2 - 1][1] >= patch_info[index2][0]: + lines += patch_info[index2][2] + index2 += 1 + ret.append((patch_info[index][0], patch_info[index2 - 1][1], lines)) + index = index2 + return ret + + +def gen_patch(orig_lines, new_lines): + """Creates a patch from two lines text. + + Args: + orig_lines: Original lines of the text. + new_lines: New lines of the text. + + Return: + A list of replacing information. + """ + diff_result = list(difflib.Differ().compare(orig_lines, new_lines)) + orig_index, ret = 0, [] + for line in diff_result: + if line.startswith(' '): + orig_index += 1 + elif line.startswith('+ '): + ret.append((orig_index, orig_index, [line[2 : ]])) + elif line.startswith('- '): + ret.append((orig_index, orig_index + 1, [])) + orig_index += 1 + return _squash_patch(ret) + + +class _CursorTransformer(object): + """Transformer for format of the cursor position. + + In vim, it use (row, col) to represent an cursor's position. + In UsersTextManager, it use numerical notation (byte distance between the + first byte in the text). + + Attributes: + _sum_len: Sum of each row. + """ + def __init__(self): + """Constructor.""" + self._sum_len = [0] + + def update_lines(self, lines): + """Update lines of text. + + Args: + lines: Lines of text. + """ + self._sum_len = [0] + for line in lines: + delta = len(line) + 1 # "+ 1" is for newline char + self._sum_len.append(self._sum_len[-1] + delta) + + def rcs_to_nums(self, rcs): + """Transform row-col format's cursor position to numerical type. + + Args: + lines: List of line text. + rcs: List of tuple of row-col format cursor postions + + Return: + A list of numerical cursor positions. + """ + ret = [] + for rc in rcs: + base = self._sum_len[min(rc[0], len(self._sum_len) - 1)] + ret.append(min(base + rc[1], self._sum_len[-1])) + return ret + + + def nums_to_rcs(self, nums): + """Transform numerical format's cursor position to row-col format. + + Args: + lines: List of line text. + nums: A list of numerical cursor positions. + + Return: + List of tuple of row-col format cursor postions + """ + ans, rmin = {}, 0 + for num in sorted(nums): + row = bisect.bisect(self._sum_len, num, lo=rmin) - 1 + col = (num - self._sum_len[row]) if row < len(self._sum_len) else 0 + rmin = row + 1 + ans[num] = (row, col) + return [ans[num] for num in nums] + class RequestHandler(object): """Handles all kinds of request. Attributes: _users_text_manager: An instance of UsersTextManager. + _cursor_transformer: An instance of _CursorTransformer. """ def __init__(self, users_text_manager): """Constructor. @@ -32,6 +160,7 @@ class RequestHandler(object): """ super(RequestHandler, self).__init__() self._users_text_manager = users_text_manager + self._cursor_transformer = _CursorTransformer() def handle(self, request): """Handles the request and returns the response. @@ -74,41 +203,68 @@ class RequestHandler(object): identity: The identity of that user. request: The request from that user. """ - if all(key in request for key in [JSON_TOKEN.INIT, - JSON_TOKEN.TEXT, - JSON_TOKEN.MODE, - JSON_TOKEN.CURSORS]): + if all(key in request for key in [JSON_TOKEN.INIT, JSON_TOKEN.DIFF, + JSON_TOKEN.MODE, JSON_TOKEN.CURSORS]): log.info('handle sync-request from %r\n' % identity) self._check_init(identity, request) self._check_authority(identity, request) + lines = apply_patch( + self._users_text_manager.get_user_text(identity).split('\n'), + request[JSON_TOKEN.DIFF]) + self._cursor_transformer.update_lines(lines) + cursors = dict(zip(request[JSON_TOKEN.CURSORS].keys(), + self._cursor_transformer.rcs_to_nums( + request[JSON_TOKEN.CURSORS].values()))) new_user_info, new_text = self._users_text_manager.update_user_text( identity, - UserInfo(mode=request[JSON_TOKEN.MODE], - cursors=request[JSON_TOKEN.CURSORS]), - request[JSON_TOKEN.TEXT]) - return self._pack_sync_response(identity, new_user_info, new_text) + UserInfo(mode=request[JSON_TOKEN.MODE], cursors=cursors), + '\n'.join(lines)) + return self._pack_sync_response( + identity, new_user_info, new_text.split('\n'), lines) - def _pack_sync_response(self, identity, user_info, text): + def _pack_sync_response(self, identity, user_info, lines, old_lines): """Packs the response for the sync request by the result from manager. Args: identity: Identity of that user. user_info: Informations of that user. - text: New text. + lines: New lines of text. + old_lines: Old lines of text. + + Return: + The response json object. + """ + self._cursor_transformer.update_lines(lines) + return { + JSON_TOKEN.DIFF : gen_patch(old_lines, lines), + JSON_TOKEN.CURSORS : dict(zip( + user_info.cursors.keys(), + self._cursor_transformer.nums_to_rcs( + user_info.cursors.values()))), + JSON_TOKEN.MODE : user_info.mode, + JSON_TOKEN.OTHERS : self._pack_sync_others_response(identity) + } + + def _pack_sync_others_response(self, identity): + """Packs the response information for other users. + + Args: + identity: Identity of that user. Return: The response json object. """ - return {JSON_TOKEN.TEXT : text, - JSON_TOKEN.CURSORS : user_info.cursors, - JSON_TOKEN.MODE : user_info.mode, - JSON_TOKEN.OTHERS : [ - {JSON_TOKEN.NICKNAME : other.nick_name, - JSON_TOKEN.MODE : other.mode, - JSON_TOKEN.CURSORS: other.cursors} - for iden, other in self._users_text_manager.get_users_info( - without=[identity], must_online=True).items() - ]} + return [ + { + JSON_TOKEN.NICKNAME : other.nick_name, + JSON_TOKEN.MODE : other.mode, + JSON_TOKEN.CURSORS: dict(zip( + other.cursors.keys(), + self._cursor_transformer.nums_to_rcs( + other.cursors.values()))) + } for iden, other in self._users_text_manager.get_users_info( + without=[identity], must_online=True).items() + ] def _check_init(self, identity, request): """Checks whether that user should be initialize or not. @@ -122,9 +278,9 @@ class RequestHandler(object): if request[JSON_TOKEN.INIT]: log.info('Init the user %r\n' % identity) self._users_text_manager.reset_user(identity) - request[JSON_TOKEN.TEXT] = '' + request[JSON_TOKEN.DIFF] = [] for mark in request.get(JSON_TOKEN.CURSORS, []): - request[JSON_TOKEN.CURSORS][mark] = 0 + request[JSON_TOKEN.CURSORS][mark] = (0, 0) def _check_authority(self, identity, request): """Checks the authroity and updates the request. @@ -138,5 +294,4 @@ class RequestHandler(object): """ auth = self._users_text_manager.get_users_info()[identity].authority if auth < AUTHORITY.READWRITE: - old_text = self._users_text_manager.get_user_text(identity) - request[JSON_TOKEN.TEXT] = old_text + request[JSON_TOKEN.DIFF] = [] |