isValidIpV6AddressOld() — netty Function Reference

Source Code

microbench/src/main/java/io/netty/microbenchmark/common/IsValidIpV6Benchmark.java lines 63–206

    public static boolean isValidIpV6AddressOld(String ipAddress) {
        boolean doubleColon = false;
        int numberOfColons = 0;
        int numberOfPeriods = 0;
        StringBuilder word = new StringBuilder();
        char c = 0;
        char prevChar;
        int startOffset = 0; // offset for [] ip addresses
        int endOffset = ipAddress.length();

        if (endOffset < 2) {
            return false;
        }

        // Strip []
        if (ipAddress.charAt(0) == '[') {
            if (ipAddress.charAt(endOffset - 1) != ']') {
                return false; // must have a close ]
            }

            startOffset = 1;
            endOffset--;
        }

        // Strip the interface name/index after the percent sign.
        int percentIdx = ipAddress.indexOf('%', startOffset);
        if (percentIdx >= 0) {
            endOffset = percentIdx;
        }

        for (int i = startOffset; i < endOffset; i++) {
            prevChar = c;
            c = ipAddress.charAt(i);
            switch (c) {
            // case for the last 32-bits represented as IPv4 x:x:x:x:x:x:d.d.d.d
            case '.':
                numberOfPeriods++;
                if (numberOfPeriods > 3) {
                    return false;
                }
                if (numberOfPeriods == 1) {
                    // Verify this address is of the correct structure to contain an IPv4 address.
                    // It must be IPv4-Mapped or IPv4-Compatible
                    // (see https://tools.ietf.org/html/rfc4291#section-2.5.5).
                    int j = i - word.length() - 2; // index of character before the previous ':'.
                    final int beginColonIndex = ipAddress.lastIndexOf(':', j);
                    if (beginColonIndex == -1) {
                        return false;
                    }
                    char tmpChar = ipAddress.charAt(j);
                    if (isValidIPv4MappedChar(tmpChar)) {
                        if (j - beginColonIndex != 4 ||
                            !isValidIPv4MappedChar(ipAddress.charAt(j - 1)) ||
                            !isValidIPv4MappedChar(ipAddress.charAt(j - 2)) ||
                            !isValidIPv4MappedChar(ipAddress.charAt(j - 3))) {
                            return false;
                        }
                        j -= 5;
                    } else if (tmpChar == '0' || tmpChar == ':') {
                        --j;
                    } else {
                        return false;
                    }

                    // a special case ::1:2:3:4:5:d.d.d.d allows 7 colons with an
                    // IPv4 ending, otherwise 7 :'s is bad
                    if ((numberOfColons != 6 && !doubleColon) || numberOfColons > 7 ||
                        (numberOfColons == 7 && (ipAddress.charAt(startOffset) != ':' ||
                                                 ipAddress.charAt(1 + startOffset) != ':'))) {
                        return false;
                    }

                    for (; j >= startOffset; --j) {
                        tmpChar = ipAddress.charAt(j);
                        if (tmpChar != '0' && tmpChar != ':') {
                            return false;
                        }
                    }
                }

                if (!isValidIp4Word(word.toString())) {