Merge pull request #2578 from Shopify/Alex/comment-list-improvements

Fix bad scaling in `rbs_comment_t` tokens

Author: soutaro

include/rbs/parser.h

@@ -27,9 +27,9 @@ typedef struct rbs_comment_t {
     rbs_position_t start;
     rbs_position_t end;
 
-    size_t line_size;
-    size_t line_count;
-    rbs_token_t *tokens;
+    size_t line_tokens_capacity;
+    size_t line_tokens_count;
+    rbs_token_t *line_tokens;
 
     struct rbs_comment_t *next_comment;
 } rbs_comment_t;

src/parser.c

@@ -3182,8 +3182,8 @@ static rbs_ast_comment_t *parse_comment_lines(rbs_parser_t *parser, rbs_comment_
     rbs_buffer_t rbs_buffer;
     rbs_buffer_init(ALLOCATOR(), &rbs_buffer);
 
-    for (size_t i = 0; i < com->line_count; i++) {
-        rbs_token_t tok = com->tokens[i];
+    for (size_t i = 0; i < com->line_tokens_count; i++) {
+        rbs_token_t tok = com->line_tokens[i];
 
         const char *comment_start = parser->rbs_lexer_t->string.start + tok.range.start.byte_pos + hash_bytes;
         size_t comment_bytes = RBS_RANGE_BYTES(tok.range) - hash_bytes;
@@ -3227,42 +3227,43 @@ static rbs_comment_t *comment_get_comment(rbs_comment_t *com, int line) {
 }
 
 static void comment_insert_new_line(rbs_allocator_t *allocator, rbs_comment_t *com, rbs_token_t comment_token) {
-    if (com->line_count == 0) {
-        com->start = comment_token.range.start;
-    }
-
-    if (com->line_count == com->line_size) {
-        com->line_size += 10;
-
-        if (com->tokens) {
-            rbs_token_t *p = com->tokens;
-            com->tokens = rbs_allocator_calloc(allocator, com->line_size, rbs_token_t);
-            memcpy(com->tokens, p, sizeof(rbs_token_t) * com->line_count);
-        } else {
-            com->tokens = rbs_allocator_calloc(allocator, com->line_size, rbs_token_t);
-        }
+    if (com->line_tokens_count == com->line_tokens_capacity) {
+        size_t old_size = com->line_tokens_capacity;
+        size_t new_size = old_size * 2;
+        com->line_tokens_capacity = new_size;
+
+        com->line_tokens = rbs_allocator_realloc(
+            allocator,
+            com->line_tokens,
+            sizeof(rbs_token_t) * old_size,
+            sizeof(rbs_token_t) * new_size,
+            rbs_token_t
+        );
     }
 
-    com->tokens[com->line_count++] = comment_token;
+    com->line_tokens[com->line_tokens_count++] = comment_token;
     com->end = comment_token.range.end;
 }
 
 static rbs_comment_t *alloc_comment(rbs_allocator_t *allocator, rbs_token_t comment_token, rbs_comment_t *last_comment) {
     rbs_comment_t *new_comment = rbs_allocator_alloc(allocator, rbs_comment_t);
 
+    size_t initial_line_capacity = 10;
+
+    rbs_token_t *tokens = rbs_allocator_calloc(allocator, initial_line_capacity, rbs_token_t);
+    tokens[0] = comment_token;
+
     *new_comment = (rbs_comment_t) {
         .start = comment_token.range.start,
         .end = comment_token.range.end,
 
-        .line_size = 0,
-        .line_count = 0,
-        .tokens = NULL,
+        .line_tokens_capacity = initial_line_capacity,
+        .line_tokens_count = 1,
+        .line_tokens = tokens,
 
         .next_comment = last_comment,
     };
 
-    comment_insert_new_line(allocator, new_comment, comment_token);
-
     return new_comment;
 }