From 85be0e7e753841b9159084250d5da24d5b3987a3 Mon Sep 17 00:00:00 2001 From: Max Brunsfeld Date: Fri, 4 Aug 2017 14:50:50 -0700 Subject: [PATCH] Ensure that no backtracking occurs during tree-comparison --- src/runtime/get_changed_ranges.c | 103 ++++++++++++++----------------- 1 file changed, 48 insertions(+), 55 deletions(-) diff --git a/src/runtime/get_changed_ranges.c b/src/runtime/get_changed_ranges.c index a045b69f..af45a8cc 100644 --- a/src/runtime/get_changed_ranges.c +++ b/src/runtime/get_changed_ranges.c @@ -3,12 +3,6 @@ #include "runtime/language.h" #include "runtime/error_costs.h" -typedef struct { - TreePath path; - const TSLanguage *language; - unsigned visible_depth; -} Iterator; - typedef Array(TSRange) RangeArray; static void range_array_add(RangeArray *results, TSPoint start, TSPoint end) { @@ -26,6 +20,12 @@ static void range_array_add(RangeArray *results, TSPoint start, TSPoint end) { } } +typedef struct { + TreePath path; + const TSLanguage *language; + unsigned visible_depth; +} Iterator; + static bool iterator_tree_is_visible(const Iterator *self) { TreePathEntry entry = *array_back(&self->path); if (entry.tree->visible) return true; @@ -41,32 +41,6 @@ static bool iterator_done(Iterator *self) { return self->path.size == 0; } -static void iterator_check(Iterator *self) { - unsigned visible_depth = 0; - - if (self->path.size > 0 && self->path.contents[0].tree->visible) visible_depth++; - for (unsigned i = 1; i < self->path.size; i++) { - TreePathEntry entry = self->path.contents[i]; - if (entry.tree->visible) { - visible_depth++; - } else { - Tree *parent = self->path.contents[i - 1].tree; - const TSSymbol *alias_sequence = ts_language_alias_sequence(self->language, parent->alias_sequence_id); - if (alias_sequence && alias_sequence[entry.structural_child_index] != 0) visible_depth++; - } - } - - assert(visible_depth == self->visible_depth); -} - -static void iterator_print_state(Iterator *self) { - TreePathEntry entry = *array_back(&self->path); - TSPoint start = point_add(entry.position.extent, entry.tree->padding.extent); - TSPoint end = point_add(start, entry.tree->size.extent); - const char *name = ts_language_symbol_name(self->language, entry.tree->symbol); - printf("(%-25s\t depth:%u [%u, %u] - [%u, %u])", name, self->visible_depth, start.row, start.column, end.row, end.column); -} - static void iterator_ascend(Iterator *self) { bool did_ascend = false; for (;;) { @@ -76,7 +50,7 @@ static void iterator_ascend(Iterator *self) { did_ascend = true; self->visible_depth--; } - array_pop(&self->path); + self->path.size--; } } @@ -111,7 +85,7 @@ static bool iterator_descend(Iterator *self, Length position) { break; } - array_pop(&self->path); + self->path.size--; } child_left = child_right; @@ -123,13 +97,13 @@ static bool iterator_descend(Iterator *self, Length position) { return false; } -static void iterator_advance(Iterator *self) { - if (iterator_done(self)) return; +static bool iterator_advance(Iterator *self) { + if (iterator_done(self)) return false; for (;;) { if (iterator_tree_is_visible(self)) self->visible_depth--; TreePathEntry entry = array_pop(&self->path); - if (iterator_done(self)) break; + if (iterator_done(self)) return false; Tree *parent = array_back(&self->path)->tree; Length position = length_add(entry.position, ts_tree_total_size(entry.tree)); @@ -147,19 +121,19 @@ static void iterator_advance(Iterator *self) { if (iterator_tree_is_visible(self)) { self->visible_depth++; - return; + return true; } if (next_child->visible_child_count > 0) { iterator_descend(self, length_zero()); - return; + return true; } if (next_child->child_count == 0) { - return; + return true; } - array_pop(&self->path); + self->path.size--; position = length_add(position, ts_tree_total_size(next_child)); if (!next_child->extra) structural_child_index++; } @@ -262,29 +236,30 @@ IteratorComparison iterator_compare(const Iterator *self, const Iterator *other) return IteratorDiffers; } +static void iterator_print_state(Iterator *self) { + TreePathEntry entry = *array_back(&self->path); + TSPoint start = point_add(entry.position.extent, entry.tree->padding.extent); + TSPoint end = point_add(start, entry.tree->size.extent); + const char *name = ts_language_symbol_name(self->language, entry.tree->symbol); + printf("(%-25s\t depth:%u [%u, %u] - [%u, %u])", name, self->visible_depth, start.row, start.column, end.row, end.column); +} + unsigned ts_tree_get_changed_ranges(Tree *old_tree, Tree *new_tree, TreePath *path1, TreePath *path2, const TSLanguage *language, TSRange **ranges) { Iterator old_iter = iterator_new(path1, old_tree, language); Iterator new_iter = iterator_new(path2, new_tree, language); - Length position = length_zero(); RangeArray results = array_new(); + Length position = length_zero(); while (!iterator_done(&old_iter) && !iterator_done(&new_iter)) { bool is_changed = false; Length next_position = position; - Length old_start = iterator_start_position(&old_iter); Length new_start = iterator_start_position(&new_iter); Length old_end = iterator_end_position(&old_iter); Length new_end = iterator_end_position(&new_iter); - // printf("At [%-2u, %-2u] Compare ", position.extent.row, position.extent.column); - // iterator_print_state(&old_iter); - // printf("\tvs\t"); - // iterator_print_state(&new_iter); - // printf("\n"); - if (position.bytes < old_start.bytes) { if (position.bytes < new_start.bytes) { next_position = length_min(old_start, new_start); @@ -296,6 +271,12 @@ unsigned ts_tree_get_changed_ranges(Tree *old_tree, Tree *new_tree, is_changed = true; next_position = new_start; } else { + // printf("At [%-2u, %-2u] Compare ", position.extent.row, position.extent.column); + // iterator_print_state(&old_iter); + // printf("\tvs\t"); + // iterator_print_state(&new_iter); + // printf("\n"); + switch (iterator_compare(&old_iter, &new_iter)) { case IteratorMatches: next_position = old_end; @@ -317,23 +298,35 @@ unsigned ts_tree_get_changed_ranges(Tree *old_tree, Tree *new_tree, break; case IteratorDiffers: - is_changed = true; next_position = length_min(old_end, new_end); + is_changed = true; break; } } - if (old_end.bytes <= next_position.bytes) iterator_advance(&old_iter); - if (new_end.bytes <= next_position.bytes) iterator_advance(&new_iter); - while (old_iter.visible_depth > new_iter.visible_depth) iterator_ascend(&old_iter); - while (new_iter.visible_depth > old_iter.visible_depth) iterator_ascend(&new_iter); + while (old_end.bytes <= next_position.bytes && iterator_advance(&old_iter)) { + old_end = iterator_end_position(&old_iter); + } + + while (new_end.bytes <= next_position.bytes && iterator_advance(&new_iter)) { + new_end = iterator_end_position(&new_iter); + } + + while (old_iter.visible_depth > new_iter.visible_depth) { + iterator_ascend(&old_iter); + } + + while (new_iter.visible_depth > old_iter.visible_depth) { + iterator_ascend(&new_iter); + } if (is_changed) { // printf( - // "add range [[%u, %u] - [%u, %u]]\n", + // " changed range: [[%u, %u] - [%u, %u]]\n", // position.extent.row, position.extent.column, // next_position.extent.row, next_position.extent.column // ); + range_array_add(&results, position.extent, next_position.extent); }