Merge pull request #1606 from colobot/1605-improve-level-loading-time

Improve level loading time

colobot-base/level/parser/parser.cpp

@@ -36,7 +36,6 @@
 #include <sstream>
 #include <iomanip>
 #include <set>
-#include <regex>
 
 CLevelParser::CLevelParser()
 {
@@ -167,29 +166,11 @@ void CLevelParser::Load()
 
         line = StrUtils::Replace(line, "\t", " "); // replace tab by space
 
-        // ignore comments
-        size_t pos = 0;
-        std::string linesuffix = line;
-        std::regex commentRegex{ R"(("[^"]*")|('[^']*')|(//.*$))" };
-        std::smatch matches;
-        while (std::regex_search(linesuffix, matches, commentRegex))
-        {
-            if (matches[3].matched)
-            {
-                pos += std::distance(linesuffix.cbegin(), matches.prefix().second);
-                line = line.substr(0, pos);
-                linesuffix = "";
-            }
-            else
-            {
-                pos += std::distance(linesuffix.cbegin(), matches.suffix().first);
-                linesuffix = matches.suffix().str();
-            }
-        }
+        StrUtils::RemoveComments(line);
 
         StrUtils::Trim(line);
 
-        pos = line.find_first_of(" \t\n");
+        size_t pos = line.find_first_of(" \t\n");
         std::string command = line.substr(0, pos);
         if (pos != std::string::npos)
         {

colobot-common/src/common/stringutils.cpp

@@ -136,3 +136,40 @@ void StrUtils::Trim(std::string& str)
     TrimLeft(str);
     TrimRight(str);
 }
+
+void StrUtils::RemoveComments(std::string& text)
+{
+    for (size_t i = 0; i < text.size();)
+    {
+        // Skip string literal of form "text"
+        if (size_t start = text.find_first_of('"', i); start != std::string::npos)
+        {
+            size_t end = text.find_first_of('"', start + 1);
+
+            if (end == std::string::npos) break;
+
+            i = end + 1;
+            continue;
+        }
+
+        // Skip string literal of form 'text'
+        if (size_t start = text.find_first_of('\'', i); start != std::string::npos)
+        {
+            size_t end = text.find_first_of('\'', start + 1);
+
+            if (end == std::string::npos) break;
+
+            i = end + 1;
+            continue;
+        }
+
+        // Find and remove comment of form // comment
+        if (size_t start = text.find_first_of("//", i); start != std::string::npos)
+        {
+            text.erase(std::next(text.begin(), start), text.end());
+        }
+
+        // Nothing else to skip or remove
+        break;
+    }
+}

colobot-common/src/common/stringutils.h

@@ -82,6 +82,9 @@ void TrimRight(std::string& str);
 //! Remove whitespace from both ends of the given string (in place)
 void Trim(std::string& str);
 
+//! Removes comments of form // comment
+void RemoveComments(std::string& text);
+
 //! Converts a wide Unicode char to a single UTF-8 encoded char
 std::string UnicodeCharToUtf8(unsigned int ch);
 

test/src/common/stringutils_test.cpp

@@ -54,6 +54,29 @@ TEST(StringUtilTests, ReplaceSameLength)
     EXPECT_EQ(result, expected);
 }
 
+TEST(StringUtilTests, RemoveComments)
+{
+    std::string text = "qwerty";
+    StrUtils::RemoveComments(text);
+    EXPECT_EQ(text, "qwerty");
+
+    text = "qwerty // comment";
+    StrUtils::RemoveComments(text);
+    EXPECT_EQ(text, "qwerty ");
+
+    text = "qwerty 'test' // comment";
+    StrUtils::RemoveComments(text);
+    EXPECT_EQ(text, "qwerty 'test' ");
+
+    text = "qwerty \"test\" // comment";
+    StrUtils::RemoveComments(text);
+    EXPECT_EQ(text, "qwerty \"test\" ");
+
+    text = "qwerty 'test // test'";
+    StrUtils::RemoveComments(text);
+    EXPECT_EQ(text, "qwerty 'test // test'");
+}
+
 TEST(StringUtilTests, SplitSingle)
 {
     std::string text = "CreateObject test value  123";