[runtime] Implement encodeURI as single runtime function.

src/runtime/runtime-strings.cc

Index: src/runtime/runtime-strings.cc
diff --git a/src/runtime/runtime-strings.cc b/src/runtime/runtime-strings.cc
index 2477eb70b9026a5256563b19c9bed124643a44c8..2923c0416123c90e608e5916b5a863e2c0407f89 100644
--- a/src/runtime/runtime-strings.cc
+++ b/src/runtime/runtime-strings.cc
@@ -5,6 +5,7 @@
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
+#include "src/char-predicates-inl.h"
 #include "src/regexp/jsregexp-inl.h"
 #include "src/string-builder.h"
 #include "src/string-search.h"
@@ -1151,6 +1152,132 @@ RUNTIME_FUNCTION(Runtime_NewString) {
   return *result;
 }
 
+// anonymous namespace for URIEncode helper functions
+namespace {
+
+bool IsUnescapePredicateInUriComponent(uc16 c) {
+  if (IsAlphaNumeric(c)) {
+    return true;
+  }
+
+  switch (c) {
+    case '!':
+    case '\'':
+    case '(':
+    case ')':
+    case '*':
+    case '-':
+    case '.':
+    case '_':
+    case '~':
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool IsUriSeparator(uc16 c) {
+  switch (c) {
+    case '#':
+    case ':':
+    case ';':
+    case '/':
+    case '?':
+    case '$':
+    case '&':
+    case '+':
+    case ',':
+    case '@':
+    case '=':
+      return true;
+    default:
+      return false;
+  }
+}
+
+void AddHexEncodedToBuffer(uint8_t octet, List<uint8_t>* buffer) {
+  buffer->Add('%');
+  buffer->Add(HexCharOfValue(octet >> 4));
+  buffer->Add(HexCharOfValue(octet & 0x0F));
+}
+
+void EncodeSingle(uc16 c, List<uint8_t>* buffer) {
+  uint8_t x = (c >> 12) & 0xF;
+  uint8_t y = (c >> 6) & 63;
+  uint8_t z = c & 63;
+  if (c <= 0x007F) {
+    AddHexEncodedToBuffer(c, buffer);
+  } else if (c <= 0x07FF) {
+    AddHexEncodedToBuffer(y + 192, buffer);
+    AddHexEncodedToBuffer(z + 128, buffer);
+  } else {
+    AddHexEncodedToBuffer(x + 224, buffer);
+    AddHexEncodedToBuffer(y + 128, buffer);
+    AddHexEncodedToBuffer(z + 128, buffer);
+  }
+}
+
+void EncodePair(uc16 cc1, uc16 cc2, List<uint8_t>* buffer) {
+  uint8_t u = ((cc1 >> 6) & 0xF) + 1;
+  uint8_t w = (cc1 >> 2) & 0xF;
+  uint8_t x = cc1 & 3;
+  uint8_t y = (cc2 >> 6) & 0xF;
+  uint8_t z = cc2 & 63;
+  AddHexEncodedToBuffer((u >> 2) + 240, buffer);
+  AddHexEncodedToBuffer((((u & 3) << 4) | w) + 128, buffer);
+  AddHexEncodedToBuffer(((x << 4) | y) + 128, buffer);
+  AddHexEncodedToBuffer(z + 128, buffer);
+}
+
+}  // anonymous namespace
+
+RUNTIME_FUNCTION(Runtime_URIEncode) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(String, uri, 0);
+  CONVERT_BOOLEAN_ARG_CHECKED(is_uri, 1);
+
+  uri = String::Flatten(uri);
+  int uri_length = uri->length();
+  List<uint8_t> buffer(uri_length);
+
+  {
+    DisallowHeapAllocation no_gc;
+    String::FlatContent uri_content = uri->GetFlatContent();
+
+    for (int k = 0; k < uri_length; k++) {
+      uc16 cc1 = uri_content.Get(k);
+      if (unibrow::Utf16::IsLeadSurrogate(cc1)) {
+        k++;
+        if (k < uri_length) {
+          uc16 cc2 = uri->Get(k);
+          if (unibrow::Utf16::IsTrailSurrogate(cc2)) {
+            EncodePair(cc1, cc2, &buffer);
+            continue;
+          }
+        }
+      } else if (!unibrow::Utf16::IsTrailSurrogate(cc1)) {
+        if (IsUnescapePredicateInUriComponent(cc1) ||
+            (is_uri && IsUriSeparator(cc1))) {
+          buffer.Add(cc1);
+        } else {
+          EncodeSingle(cc1, &buffer);
+        }
+        continue;
+      }
+
+      AllowHeapAllocation allocate_error_and_return;
+      THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewURIError());
+    }
+  }
+
+  Handle<String> result;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, result,
+      isolate->factory()->NewStringFromOneByte(buffer.ToConstVector()));
+  return *result;
+}
+
 RUNTIME_FUNCTION(Runtime_StringLessThan) {
   HandleScope handle_scope(isolate);
   DCHECK_EQ(2, args.length());