buffer: add encoding parameter to fill()

Can now call fill() using following parameters if value is a String:

    fill(string[, start[, end]][, encoding])

And with the following if value is a Buffer:

    fill(buffer[, start[, end]])

The encoding is ignored if value is not a String. All other non-Buffer
values are coerced to a uint32.

A multibyte strings will simply be copied into the Buffer until the
number of bytes run out. Meaning partial strings can be left behind:

    Buffer(3).fill('\u0222');
    // returns: <Buffer c8 a2 c8>

In some encoding cases, such as 'hex', fill() will throw if the input
string is not valid.

PR-URL: https://github.com/nodejs/node/pull/4935
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/src/util.cc b/src/util.cc
index 903fbbba13..095e5582db 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -25,4 +25,27 @@ Utf8Value::Utf8Value(v8::Isolate* isolate, v8::Local<v8::Value> value)
   str_[length_] = '\0';
 }
 
+
+TwoByteValue::TwoByteValue(v8::Isolate* isolate, v8::Local<v8::Value> value)
+    : length_(0), str_(str_st_) {
+  if (value.IsEmpty())
+    return;
+
+  v8::Local<v8::String> string = value->ToString(isolate);
+  if (string.IsEmpty())
+    return;
+
+  // Allocate enough space to include the null terminator
+  size_t len = StringBytes::StorageSize(isolate, string, UCS2) + 1;
+  if (len > sizeof(str_st_)) {
+    str_ = static_cast<uint16_t*>(malloc(len));
+    CHECK_NE(str_, nullptr);
+  }
+
+  const int flags =
+      v8::String::NO_NULL_TERMINATION | v8::String::REPLACE_INVALID_UTF8;
+  length_ = string->Write(str_, 0, len, flags);
+  str_[length_] = '\0';
+}
+
 }  // namespace node