AK: Make encode_base64 take a ByteBuffer and return a String

That makes the interface symmetric with decode_base64 and it's
what all current callers want (except for one, which is buggy).

AK/Base64.cpp

@@ -25,6 +25,8 @@
  */
 
 #include <AK/ByteBuffer.h>
+#include <AK/String.h>
+#include <AK/StringBuilder.h>
 #include <AK/StringView.h>
 #include <AK/Types.h>
 #include <AK/Vector.h>
@@ -84,20 +86,20 @@ ByteBuffer decode_base64(const StringView& input)
  return ByteBuffer::copy(output.data(), output.size());
 }
 
-ByteBuffer encode_base64(const StringView& input)
+String encode_base64(const ByteBuffer& input)
 {
- Vector<u8> output;
+ StringBuilder output;
 
  auto get = [&](size_t offset, bool* need_padding = nullptr) -> u8 {
- if (offset >= input.length()) {
+ if (offset >= input.size()) {
  if (need_padding)
  *need_padding = true;
  return 0;
  }
- return (u8)input[offset];
+ return input[offset];
  };
 
- for (size_t i = 0; i < input.length(); i += 3) {
+ for (size_t i = 0; i < input.size(); i += 3) {
  bool is_8bit = false;
  bool is_16bit = false;
 
@@ -121,7 +123,7 @@ ByteBuffer encode_base64(const StringView& input)
  output.append(out3);
  }
 
- return ByteBuffer::copy(output.data(), output.size());
+ return output.to_string();
 }
 
 }

AK/Base64.h

@@ -32,7 +32,7 @@ namespace AK {
 
 ByteBuffer decode_base64(const StringView&);
 
-ByteBuffer encode_base64(const StringView&);
+String encode_base64(const ByteBuffer&);
 
 }
 

AK/Tests/TestBase64.cpp

@@ -49,8 +49,8 @@ TEST_CASE(test_decode)
 TEST_CASE(test_encode)
 {
  auto encode_equal = [&](const char* input, const char* expected) {
- auto encoded = encode_base64(StringView(input));
- EXPECT(String::copy(encoded) == String(expected));
+ auto encoded = encode_base64(ByteBuffer::wrap(input, strlen(input)));
+ EXPECT(encoded == String(expected));
  };
 
  encode_equal("", "");

Libraries/LibWeb/Bindings/WindowObject.cpp

@@ -267,8 +267,8 @@ JS_DEFINE_NATIVE_FUNCTION(WindowObject::btoa)
  if (interpreter.exception())
  return {};
  // FIXME: This should convert string to a non-UTF-8 byte string first.
- auto encoded = encode_base64(StringView(string));
- return JS::js_string(interpreter, String::copy(encoded));
+ auto encoded = encode_base64(ByteBuffer::wrap(string.characters(), string.length()));
+ return JS::js_string(interpreter, move(encoded));
 }
 
 JS_DEFINE_NATIVE_GETTER(WindowObject::document_getter)

Userland/base64.cpp

@@ -75,6 +75,6 @@ int main(int argc, char** argv)
  return 0;
  }
 
- auto encoded = encode_base64(StringView(buffer));
- printf("%s\n", String::copy(encoded).characters());
+ auto encoded = encode_base64(buffer);
+ printf("%s\n", encoded.characters());
 }