* fills, it is doubled.
 */
@Suppress("NAME_SHADOWING")
object Hpack {
  private const val PREFIX_4_BITS = 0x0f
  private const val PREFIX_5_BITS = 0x1f
  private const val PREFIX_6_BITS = 0x3f
  private const val PREFIX_7_BITS = 0x7f

  private const val SETTINGS_HEADER_TABLE_SIZE = 4_096

  /**
   * The decoder has ultimate control of the maximum size of the dynamic table but we can choose

0x2d, 0x69, 0x6e, 0x6c, 0x69, 0x6e, 0x65, 0x2d, 0x64, 0x61, 0x74, 0x61, 0xc4, 0x4, 0x74, 0x72, 0x75, 0x65, 0xa7, 0x4d, 0x65, 0x74, 0x61, 0x55, 0x73, 0x72, 0x82, 0xac, 0x63, 0x6f, 0x6e, 0x74, 0x65, 0x6e, 0x74, 0x2d, 0x74, 0x79, 0x70, 0x65, 0xb8, 0x61, 0x70, 0x70, 0x6c, 0x69, 0x63, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x2f, 0x6f, 0x63, 0x74, 0x65, 0x74, 0x2d, 0x73, 0x74, 0x72, 0x65, 0x61, 0x6d, 0xa4, 0x65, 0x74, 0x61, 0x67, 0xd9, 0x20, 0x36, 0x64, 0x31, 0x31, 0x61, 0x34, 0x35, 0x31, 0x62, 0x30, 0x62, 0x32, 0x34,...

    testDecodes(base64(), "Zg====", "f");
  }

  public void testBase64InvalidDecodings() {
    // These contain bytes not in the decodabet.
    assertFailsToDecode(base64(), "A\u007f", "Unrecognized character: 0x7f");
    assertFailsToDecode(base64(), "Wf2!", "Unrecognized character: !");
    // This sentence just isn't base64() encoded.
    assertFailsToDecode(base64(), "let's not talk of love or chains!");

		0x8a, 0x45, 0x78, 0xc1, 0x64, 0x28, 0x85, 0x57, 0x89, 0xf7, 0xa2, 0x49, 0xe3,
		0x84, 0xcb, 0x2d, 0x9f, 0xae, 0x2d, 0x67, 0xfd, 0x96, 0xfb, 0x92, 0x6c, 0x19,
		0x8e, 0x7, 0x73, 0x99, 0xfd, 0xc8, 0x15, 0xc0, 0xaf, 0x9, 0x7d, 0xde, 0x5a,
		0xad, 0xef, 0xf4, 0x4d, 0xe7, 0xe, 0x82, 0x7f, 0x48, 0x78, 0x43, 0x24, 0x39,
		0xbf, 0xee, 0xb9, 0x60, 0x68, 0xd0, 0x47, 0x4f, 0xc5, 0xd, 0x6d, 0x90, 0xbf,

    assertBytes(
      // Dynamic table size update (size = 2048).
      0x3F, 0xE1, 0xF,
      0x40, 3, 'f'.code, 'o'.code, 'o'.code, 3, 'b'.code, 'a'.code, 'r'.code,
    )
    hpackWriter!!.resizeHeaderTable(8192)
    hpackWriter!!.writeHeaders(listOf(Header("bar", "foo")))
    assertBytes(
      // Dynamic table size update (size = 8192).
      0x3F, 0xE1, 0x3F,
      0x40, 3, 'b'.code, 'a'.code, 'r'.code, 3, 'f'.code, 'o'.code, 'o'.code,

        key8[0] = (byte) ( ( key7[0] >> 1) & 0xff);
        key8[1] = (byte)(( ((key7[0] & 0x01) << 6) | (((key7[1] & 0xff)>>2) & 0xff)) & 0xff );
        key8[2] = (byte)(( ((key7[1] & 0x03) << 5) | (((key7[2] & 0xff)>>3) & 0xff)) & 0xff );
        key8[3] = (byte)(( ((key7[2] & 0x07) << 4) | (((key7[3] & 0xff)>>4) & 0xff)) & 0xff );
        key8[4] = (byte)(( ((key7[3] & 0x0F) << 3) | (((key7[4] & 0xff)>>5) & 0xff)) & 0xff );

    testDecodes(base64(), "Zg====", "f");
  }

  public void testBase64InvalidDecodings() {
    // These contain bytes not in the decodabet.
    assertFailsToDecode(base64(), "A\u007f", "Unrecognized character: 0x7f");
    assertFailsToDecode(base64(), "Wf2!", "Unrecognized character: !");
    // This sentence just isn't base64() encoded.
    assertFailsToDecode(base64(), "let's not talk of love or chains!");

      encodings[ 0x1c] = encoding // File Separator
      encodings[ 0x1d] = encoding // Group Separator
      encodings[ 0x1e] = encoding // Record Separator
      encodings[ 0x1f] = encoding // Unit Separator
      encodings[ 0x7f] = encoding // Delete
    }

  fun nonAscii(encoding: Encoding) =
    apply {
      encodings[UNICODE_2] = encoding
      encodings[UNICODE_3] = encoding

import com.google.common.annotations.GwtCompatible;
import java.nio.charset.StandardCharsets;

/**
 * Static methods pertaining to ASCII characters (those in the range of values {@code 0x00} through
 * {@code 0x7F}), and to strings containing such characters.
 *
 * <p>ASCII utilities also exist in other classes of this package:
 *
 * <ul>
 *   <!-- TODO(kevinb): how can we make this not produce a warning when building gwt javadoc? -->

            char ch = str.charAt(i);
            // handle unicode
            if (ch > 0xfff) {
                out.append("\\u").append(hex(ch));
            } else if (ch > 0xff) {
                out.append("\\u0").append(hex(ch));
            } else if (ch > 0x7f) {
                out.append("\\u00").append(hex(ch));
            } else if (ch < 32) {
                switch (ch) {
                    case '\b':