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GeezerVison is showing github.com — vscode-python/pythonFiles/parso/python/diff.py at master · wolfedale/vscode-python Expand file tree/ Copy pathdiff.pyMore file actions 594 lines (500 loc) · 22 KB / Copy pathdiff.pyFile metadata and controls594 lines (500 loc) · 22 KB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 """ Basically a contains parser that is faster, because it tries to parse only parts and if anything changes, it only reparses the changed parts. It works with a simple diff in the beginning and will try to reuse old parser fragments. """ import re import difflib from collections import namedtuple import logging from parso.utils import split_lines from parso.python.parser import Parser from parso.python.tree import EndMarker from parso.python.tokenize import (NEWLINE, PythonToken, ERROR_DEDENT, ENDMARKER, INDENT, DEDENT) LOG = logging.getLogger(__name__) def _get_last_line(node_or_leaf): last_leaf = node_or_leaf.get_last_leaf() if _ends_with_newline(last_leaf): return last_leaf.start_pos[0] else: return last_leaf.end_pos[0] def _ends_with_newline(leaf, suffix=''): if leaf.type == 'error_leaf': typ = leaf.original_type else: typ = leaf.type return typ == 'newline' or suffix.endswith('\n') def _flows_finished(pgen_grammar, stack): """ if, while, for and try might not be finished, because another part might still be parsed. """ for dfa, newstate, (symbol_number, nodes) in stack: if pgen_grammar.number2symbol[symbol_number] in ('if_stmt', 'while_stmt', 'for_stmt', 'try_stmt'): return False return True def suite_or_file_input_is_valid(pgen_grammar, stack): if not _flows_finished(pgen_grammar, stack): return False for dfa, newstate, (symbol_number, nodes) in reversed(stack): if pgen_grammar.number2symbol[symbol_number] == 'suite': # If only newline is in the suite, the suite is not valid, yet. return len(nodes) > 1 # Not reaching a suite means that we're dealing with file_input levels # where there's no need for a valid statement in it. It can also be empty. return True def _is_flow_node(node): try: value = node.children[0].value except AttributeError: return False return value in ('if', 'for', 'while', 'try') class _PositionUpdatingFinished(Exception): pass def _update_positions(nodes, line_offset, last_leaf): for node in nodes: try: children = node.children except AttributeError: # Is a leaf node.line += line_offset if node is last_leaf: raise _PositionUpdatingFinished else: _update_positions(children, line_offset, last_leaf) class DiffParser(object): """ An advanced form of parsing a file faster. Unfortunately comes with huge side effects. It changes the given module. """ def __init__(self, pgen_grammar, tokenizer, module): self._pgen_grammar = pgen_grammar self._tokenizer = tokenizer self._module = module def _reset(self): self._copy_count = 0 self._parser_count = 0 self._nodes_stack = _NodesStack(self._module) def update(self, old_lines, new_lines): ''' The algorithm works as follows: Equal: - Assure that the start is a newline, otherwise parse until we get one. - Copy from parsed_until_line + 1 to max(i2 + 1) - Make sure that the indentation is correct (e.g. add DEDENT) - Add old and change positions Insert: - Parse from parsed_until_line + 1 to min(j2 + 1), hopefully not much more. Returns the new module node. ''' LOG.debug('diff parser start') # Reset the used names cache so they get regenerated. self._module._used_names = None self._parser_lines_new = new_lines self._reset() line_length = len(new_lines) sm = difflib.SequenceMatcher(None, old_lines, self._parser_lines_new) opcodes = sm.get_opcodes() LOG.debug('diff parser calculated') LOG.debug('diff: line_lengths old: %s, new: %s' % (len(old_lines), line_length)) for operation, i1, i2, j1, j2 in opcodes: LOG.debug('diff code[%s] old[%s:%s] new[%s:%s]', operation, i1 + 1, i2, j1 + 1, j2) if j2 == line_length and new_lines[-1] == '': # The empty part after the last newline is not relevant. j2 -= 1 if operation == 'equal': line_offset = j1 - i1 self._copy_from_old_parser(line_offset, i2, j2) elif operation == 'replace': self._parse(until_line=j2) elif operation == 'insert': self._parse(until_line=j2) else: assert operation == 'delete' # With this action all change will finally be applied and we have a # changed module. self._nodes_stack.close() last_pos = self._module.end_pos[0] if last_pos != line_length: current_lines = split_lines(self._module.get_code(), keepends=True) diff = difflib.unified_diff(current_lines, new_lines) raise Exception( "There's an issue (%s != %s) with the diff parser. Please report:\n%s" % (last_pos, line_length, ''.join(diff)) ) LOG.debug('diff parser end') return self._module def _enabled_debugging(self, old_lines, lines_new): if self._module.get_code() != ''.join(lines_new): LOG.warning('parser issue:\n%s\n%s', ''.join(old_lines), ''.join(lines_new)) def _copy_from_old_parser(self, line_offset, until_line_old, until_line_new): copied_nodes = [None] last_until_line = -1 while until_line_new > self._nodes_stack.parsed_until_line: parsed_until_line_old = self._nodes_stack.parsed_until_line - line_offset line_stmt = self._get_old_line_stmt(parsed_until_line_old + 1) if line_stmt is None: # Parse 1 line at least. We don't need more, because we just # want to get into a state where the old parser has statements # again that can be copied (e.g. not lines within parentheses). self._parse(self._nodes_stack.parsed_until_line + 1) elif not copied_nodes: # We have copied as much as possible (but definitely not too # much). Therefore we just parse the rest. # We might not reach the end, because there's a statement # that is not finished. self._parse(until_line_new) else: p_children = line_stmt.parent.children index = p_children.index(line_stmt) copied_nodes = self._nodes_stack.copy_nodes( p_children[index:], until_line_old, line_offset ) # Match all the nodes that are in the wanted range. if copied_nodes: self._copy_count += 1 from_ = copied_nodes[0].get_start_pos_of_prefix()[0] + line_offset to = self._nodes_stack.parsed_until_line LOG.debug('diff actually copy %s to %s', from_, to) # Since there are potential bugs that might loop here endlessly, we # just stop here. assert last_until_line != self._nodes_stack.parsed_until_line \ or not copied_nodes, last_until_line last_until_line = self._nodes_stack.parsed_until_line def _get_old_line_stmt(self, old_line): leaf = self._module.get_leaf_for_position((old_line, 0), include_prefixes=True) if _ends_with_newline(leaf): leaf = leaf.get_next_leaf() if leaf.get_start_pos_of_prefix()[0] == old_line: node = leaf while node.parent.type not in ('file_input', 'suite'): node = node.parent return node # Must be on the same line. Otherwise we need to parse that bit. return None def _get_before_insertion_node(self): if self._nodes_stack.is_empty(): return None line = self._nodes_stack.parsed_until_line + 1 node = self._new_module.get_last_leaf() while True: parent = node.parent if parent.type in ('suite', 'file_input'): assert node.end_pos[0] <= line assert node.end_pos[1] == 0 or '\n' in self._prefix return node node = parent def _parse(self, until_line): """ Parses at least until the given line, but might just parse more until a valid state is reached. """ last_until_line = 0 while until_line > self._nodes_stack.parsed_until_line: node = self._try_parse_part(until_line) nodes = node.children self._nodes_stack.add_parsed_nodes(nodes) LOG.debug( 'parse_part from %s to %s (to %s in part parser)', nodes[0].get_start_pos_of_prefix()[0], self._nodes_stack.parsed_until_line, node.end_pos[0] - 1 ) # Since the tokenizer sometimes has bugs, we cannot be sure that # this loop terminates. Therefore assert that there's always a # change. assert last_until_line != self._nodes_stack.parsed_until_line, last_until_line last_until_line = self._nodes_stack.parsed_until_line def _try_parse_part(self, until_line): """ Sets up a normal parser that uses a spezialized tokenizer to only parse until a certain position (or a bit longer if the statement hasn't ended. """ self._parser_count += 1 # TODO speed up, shouldn't copy the whole list all the time. # memoryview? parsed_until_line = self._nodes_stack.parsed_until_line lines_after = self._parser_lines_new[parsed_until_line:] #print('parse_content', parsed_until_line, lines_after, until_line) tokens = self._diff_tokenize( lines_after, until_line, line_offset=parsed_until_line ) self._active_parser = Parser( self._pgen_grammar, error_recovery=True ) return self._active_parser.parse(tokens=tokens) def _diff_tokenize(self, lines, until_line, line_offset=0): is_first_token = True omitted_first_indent = False indents = [] tokens = self._tokenizer(lines, (1, 0)) stack = self._active_parser.pgen_parser.stack for typ, string, start_pos, prefix in tokens: start_pos = start_pos[0] + line_offset, start_pos[1] if typ == INDENT: indents.append(start_pos[1]) if is_first_token: omitted_first_indent = True # We want to get rid of indents that are only here because # we only parse part of the file. These indents would only # get parsed as error leafs, which doesn't make any sense. is_first_token = False continue is_first_token = False # In case of omitted_first_indent, it might not be dedented fully. # However this is a sign for us that a dedent happened. if typ == DEDENT \ or typ == ERROR_DEDENT and omitted_first_indent and len(indents) == 1: indents.pop() if omitted_first_indent and not indents: # We are done here, only thing that can come now is an # endmarker or another dedented code block. typ, string, start_pos, prefix = next(tokens) if '\n' in prefix: prefix = re.sub(r'(<=\n)[^\n]+$', '', prefix) else: prefix = '' yield PythonToken(ENDMARKER, '', (start_pos[0] + line_offset, 0), prefix) break elif typ == NEWLINE and start_pos[0] >= until_line: yield PythonToken(typ, string, start_pos, prefix) # Check if the parser is actually in a valid suite state. if suite_or_file_input_is_valid(self._pgen_grammar, stack): start_pos = start_pos[0] + 1, 0 while len(indents) > int(omitted_first_indent): indents.pop() yield PythonToken(DEDENT, '', start_pos, '') yield PythonToken(ENDMARKER, '', start_pos, '') break else: continue yield PythonToken(typ, string, start_pos, prefix) class _NodesStackNode(object): ChildrenGroup = namedtuple('ChildrenGroup', 'children line_offset last_line_offset_leaf') def __init__(self, tree_node, parent=None): self.tree_node = tree_node self.children_groups = [] self.parent = parent def close(self): children = [] for children_part, line_offset, last_line_offset_leaf in self.children_groups: if line_offset != 0: try: _update_positions( children_part, line_offset, last_line_offset_leaf) except _PositionUpdatingFinished: pass children += children_part self.tree_node.children = children # Reset the parents for node in children: node.parent = self.tree_node def add(self, children, line_offset=0, last_line_offset_leaf=None): group = self.ChildrenGroup(children, line_offset, last_line_offset_leaf) self.children_groups.append(group) def get_last_line(self, suffix): line = 0 if self.children_groups: children_group = self.children_groups[-1] last_leaf = children_group.children[-1].get_last_leaf() line = last_leaf.end_pos[0] # Calculate the line offsets offset = children_group.line_offset if offset: # In case the line_offset is not applied to this specific leaf, # just ignore it. if last_leaf.line <= children_group.last_line_offset_leaf.line: line += children_group.line_offset # Newlines end on the next line, which means that they would cover # the next line. That line is not fully parsed at this point. if _ends_with_newline(last_leaf, suffix): line -= 1 line += suffix.count('\n') if suffix and not suffix.endswith('\n'): # This is the end of a file (that doesn't end with a newline). line += 1 return line class _NodesStack(object): endmarker_type = 'endmarker' def __init__(self, module): # Top of stack self._tos = self._base_node = _NodesStackNode(module) self._module = module self._last_prefix = '' self.prefix = '' def is_empty(self): return not self._base_node.children @property def parsed_until_line(self): return self._tos.get_last_line(self.prefix) def _get_insertion_node(self, indentation_node): indentation = indentation_node.start_pos[1] # find insertion node node = self._tos while True: tree_node = node.tree_node if tree_node.type == 'suite': # A suite starts with NEWLINE, ... node_indentation = tree_node.children[1].start_pos[1] if indentation >= node_indentation: # Not a Dedent # We might be at the most outer layer: modules. We # don't want to depend on the first statement # having the right indentation. return node elif tree_node.type == 'file_input': return node node = self._close_tos() def _close_tos(self): self._tos.close() self._tos = self._tos.parent return self._tos def add_parsed_nodes(self, tree_nodes): tree_nodes = self._remove_endmarker(tree_nodes) if not tree_nodes: return assert tree_nodes[0].type != 'newline' node = self._get_insertion_node(tree_nodes[0]) assert node.tree_node.type in ('suite', 'file_input') node.add(tree_nodes) self._update_tos(tree_nodes[-1]) def _remove_endmarker(self, tree_nodes): """ Helps cleaning up the tree nodes that get inserted. """ last_leaf = tree_nodes[-1].get_last_leaf() is_endmarker = last_leaf.type == self.endmarker_type self._last_prefix = '' if is_endmarker: try: separation = last_leaf.prefix.rindex('\n') + 1 except ValueError: pass else: # Remove the whitespace part of the prefix after a newline. # That is not relevant if parentheses were opened. Always parse # until the end of a line. last_leaf.prefix, self._last_prefix = \ last_leaf.prefix[:separation], last_leaf.prefix[separation:] first_leaf = tree_nodes[0].get_first_leaf() first_leaf.prefix = self.prefix + first_leaf.prefix self.prefix = '' if is_endmarker: self.prefix = last_leaf.prefix tree_nodes = tree_nodes[:-1] return tree_nodes def copy_nodes(self, tree_nodes, until_line, line_offset): """ Copies tree nodes from the old parser tree. Returns the number of tree nodes that were copied. """ tos = self._get_insertion_node(tree_nodes[0]) new_nodes, self._tos = self._copy_nodes(tos, tree_nodes, until_line, line_offset) return new_nodes def _copy_nodes(self, tos, nodes, until_line, line_offset): new_nodes = [] new_tos = tos for node in nodes: if node.start_pos[0] > until_line: break if node.type == 'endmarker': # We basically removed the endmarker, but we are not allowed to # remove the newline at the end of the line, otherwise it's # going to be missing. try: self.prefix = node.prefix[:node.prefix.rindex('\n') + 1] except ValueError: pass # Endmarkers just distort all the checks below. Remove them. break # TODO this check might take a bit of time for large files. We # might want to change this to do more intelligent guessing or # binary search. if _get_last_line(node) > until_line: # We can split up functions and classes later. if node.type in ('classdef', 'funcdef') and node.children[-1].type == 'suite': new_nodes.append(node) break new_nodes.append(node) if not new_nodes: return [], tos last_node = new_nodes[-1] line_offset_index = -1 if last_node.type in ('classdef', 'funcdef'): suite = last_node.children[-1] if suite.type == 'suite': suite_tos = _NodesStackNode(suite) # Don't need to pass line_offset here, it's already done by the # parent. suite_nodes, recursive_tos = self._copy_nodes( suite_tos, suite.children, until_line, line_offset) if len(suite_nodes) < 2: # A suite only with newline is not valid. new_nodes.pop() else: suite_tos.parent = tos new_tos = recursive_tos line_offset_index = -2 elif (new_nodes[-1].type in ('error_leaf', 'error_node') or _is_flow_node(new_nodes[-1])): # Error leafs/nodes don't have a defined start/end. Error # nodes might not end with a newline (e.g. if there's an # open `(`). Therefore ignore all of them unless they are # succeeded with valid parser state. # If we copy flows at the end, they might be continued # after the copy limit (in the new parser). # In this while loop we try to remove until we find a newline. new_nodes.pop() while new_nodes: last_node = new_nodes[-1] if last_node.get_last_leaf().type == 'newline': break new_nodes.pop() if new_nodes: try: last_line_offset_leaf = new_nodes[line_offset_index].get_last_leaf() except IndexError: line_offset = 0 # In this case we don't have to calculate an offset, because # there's no children to be managed. last_line_offset_leaf = None tos.add(new_nodes, line_offset, last_line_offset_leaf) return new_nodes, new_tos def _update_tos(self, tree_node): if tree_node.type in ('suite', 'file_input'): self._tos = _NodesStackNode(tree_node, self._tos) self._tos.add(list(tree_node.children)) self._update_tos(tree_node.children[-1]) elif tree_node.type in ('classdef', 'funcdef'): self._update_tos(tree_node.children[-1]) def close(self): while self._tos is not None: self._close_tos() # Add an endmarker. try: last_leaf = self._module.get_last_leaf() end_pos = list(last_leaf.end_pos) except IndexError: end_pos = [1, 0] lines = split_lines(self.prefix) assert len(lines) > 0 if len(lines) == 1: end_pos[1] += len(lines[0]) else: end_pos[0] += len(lines) - 1 end_pos[1] = len(lines[-1]) endmarker = EndMarker('', tuple(end_pos), self.prefix + self._last_prefix) endmarker.parent = self._module self._module.children.append(endmarker) |
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