public String readUTF()

in paimon-common/src/main/java/org/apache/paimon/data/AbstractPagedInputView.java [392:481]
79 lines of code
24 McCabe index (conditional complexity)

    public String readUTF() throws IOException {
        final int utflen = readUnsignedShort();

        final byte[] bytearr;
        final char[] chararr;

        if (this.utfByteBuffer == null || this.utfByteBuffer.length < utflen) {
            bytearr = new byte[utflen];
            this.utfByteBuffer = bytearr;
        } else {
            bytearr = this.utfByteBuffer;
        }
        if (this.utfCharBuffer == null || this.utfCharBuffer.length < utflen) {
            chararr = new char[utflen];
            this.utfCharBuffer = chararr;
        } else {
            chararr = this.utfCharBuffer;
        }

        int c, char2, char3;
        int count = 0;
        int chararrCount = 0;

        readFully(bytearr, 0, utflen);

        while (count < utflen) {
            c = (int) bytearr[count] & 0xff;
            if (c > 127) {
                break;
            }
            count++;
            chararr[chararrCount++] = (char) c;
        }

        while (count < utflen) {
            c = (int) bytearr[count] & 0xff;
            switch (c >> 4) {
                case 0:
                case 1:
                case 2:
                case 3:
                case 4:
                case 5:
                case 6:
                case 7:
                    /* 0xxxxxxx */
                    count++;
                    chararr[chararrCount++] = (char) c;
                    break;
                case 12:
                case 13:
                    /* 110x xxxx 10xx xxxx */
                    count += 2;
                    if (count > utflen) {
                        throw new UTFDataFormatException(
                                "malformed input: partial character at end");
                    }
                    char2 = (int) bytearr[count - 1];
                    if ((char2 & 0xC0) != 0x80) {
                        throw new UTFDataFormatException("malformed input around byte " + count);
                    }
                    chararr[chararrCount++] = (char) (((c & 0x1F) << 6) | (char2 & 0x3F));
                    break;
                case 14:
                    /* 1110 xxxx 10xx xxxx 10xx xxxx */
                    count += 3;
                    if (count > utflen) {
                        throw new UTFDataFormatException(
                                "malformed input: partial character at end");
                    }
                    char2 = (int) bytearr[count - 2];
                    char3 = (int) bytearr[count - 1];
                    if (((char2 & 0xC0) != 0x80) || ((char3 & 0xC0) != 0x80)) {
                        throw new UTFDataFormatException(
                                "malformed input around byte " + (count - 1));
                    }
                    chararr[chararrCount++] =
                            (char)
                                    (((c & 0x0F) << 12)
                                            | ((char2 & 0x3F) << 6)
                                            | ((char3 & 0x3F) << 0));
                    break;
                default:
                    /* 10xx xxxx, 1111 xxxx */
                    throw new UTFDataFormatException("malformed input around byte " + count);
            }
        }
        // The number of chars produced may be less than utflen
        return new String(chararr, 0, chararrCount);
    }