nghttpx: Use BlockAllocator for util::quote_string

src/shrpx_https_upstream.cc

@@ -965,10 +965,10 @@ void write_altsvc(DefaultMemchunks *buf, BlockAllocator &balloc,
   buf->append(
       util::percent_encode_token(balloc, StringRef{altsvc.protocol_id}));
   buf->append("=\"");
-  buf->append(util::quote_string(altsvc.host));
-  buf->append(":");
+  buf->append(util::quote_string(balloc, StringRef{altsvc.host}));
+  buf->append(':');
   buf->append(altsvc.service);
-  buf->append("\"");
+  buf->append('"');
 }
 } // namespace
 

src/util.cc

@@ -167,25 +167,27 @@ uint32_t hex_to_uint(char c) {
   return c;
 }
 
-std::string quote_string(const std::string &target) {
+StringRef quote_string(BlockAllocator &balloc, const StringRef &target) {
   auto cnt = std::count(std::begin(target), std::end(target), '"');
 
   if (cnt == 0) {
-    return target;
+    return make_string_ref(balloc, target);
   }
 
-  std::string res;
-  res.reserve(target.size() + cnt);
+  auto iov = make_byte_ref(balloc, target.size() + cnt + 1);
+  auto p = iov.base;
 
   for (auto c : target) {
     if (c == '"') {
-      res += "\\\"";
+      *p++ = '\\';
+      *p++ = '"';
     } else {
-      res += c;
+      *p++ = c;
     }
   }
+  *p = '\0';
 
-  return res;
+  return StringRef{iov.base, p};
 }
 
 namespace {

src/util.h

@@ -133,7 +133,7 @@ StringRef percent_encode_token(BlockAllocator &balloc, const StringRef &target);
 
 // Returns quotedString version of |target|.  Currently, this function
 // just replace '"' with '\"'.
-std::string quote_string(const std::string &target);
+StringRef quote_string(BlockAllocator &balloc, const StringRef &target);
 
 std::string format_hex(const unsigned char *s, size_t len);
 

src/util_test.cc

@@ -175,9 +175,12 @@ void test_util_percent_decode(void) {
 }
 
 void test_util_quote_string(void) {
-  CU_ASSERT("alpha" == util::quote_string("alpha"));
-  CU_ASSERT("" == util::quote_string(""));
-  CU_ASSERT("\\\"alpha\\\"" == util::quote_string("\"alpha\""));
+  BlockAllocator balloc(4096, 4096);
+  CU_ASSERT("alpha" ==
+            util::quote_string(balloc, StringRef::from_lit("alpha")));
+  CU_ASSERT("" == util::quote_string(balloc, StringRef::from_lit("")));
+  CU_ASSERT("\\\"alpha\\\"" ==
+            util::quote_string(balloc, StringRef::from_lit("\"alpha\"")));
 }
 
 void test_util_utox(void) {