io.nats.client.support.Token Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jnats Show documentation
Client library for working with the NATS messaging system.
There is a newer version: 2.20.5
// Copyright 2020 The NATS Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at:
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package io.nats.client.support;

import static io.nats.client.support.NatsConstants.*;
import static java.nio.charset.StandardCharsets.US_ASCII;

public class Token {
    private final byte[] serialized;
    private final TokenType type;
    private final int start;
    private int end;
    private boolean hasValue;

    public Token(byte[] serialized, int len, Token prev, TokenType required) {
        this(serialized, len, prev.end + (prev.type == TokenType.KEY ? 2 : 1), required);
    }

    public Token(byte[] serialized, int len, int cur, TokenType required) {
        this.serialized = serialized;

        if (cur >= len) {
            throw new IllegalArgumentException(INVALID_HEADER_COMPOSITION);
        }
        if (serialized[cur] == SP) {
            type = TokenType.SPACE;
            start = cur;
            end = cur;
            while (serialized[++cur] == SP) {
                end = cur;
            }
        } else if (serialized[cur] == CR) {
            mustBeCrlf(len, cur);
            type = TokenType.CRLF;
            start = cur;
            end = cur + 1;
        } else if (required == TokenType.CRLF || required == TokenType.SPACE) {
            throw new IllegalArgumentException(INVALID_HEADER_COMPOSITION);
        } else {
            byte ender1 = CR;
            byte ender2 = CR;
            if (required == null || required == TokenType.TEXT) {
                type = TokenType.TEXT;
            } else if (required == TokenType.WORD) {
                ender1 = SP;
                ender2 = CR;
                type = TokenType.WORD;
            } else { // KEY is all that's left if (required == TokenType.KEY) {
                ender1 = COLON;
                ender2 = COLON;
                type = TokenType.KEY;
            }
            start = cur;
            end = cur;
            while (++cur < len && serialized[cur] != ender1 && serialized[cur] != ender2) {
                end = cur;
            }
            if (cur >= len) {
                throw new IllegalArgumentException(INVALID_HEADER_COMPOSITION);
            }
            if (serialized[cur] == CR) {
                mustBeCrlf(len, cur);
            }
            hasValue = true;
        }
    }

    private void mustBeCrlf(int len, int cur) {
        if ((cur + 1) >= len || serialized[cur + 1] != LF) {
            throw new IllegalArgumentException(INVALID_HEADER_COMPOSITION);
        }
    }

    public void mustBe(TokenType expected) {
        if (type != expected) {
            throw new IllegalArgumentException(INVALID_HEADER_COMPOSITION);
        }
    }

    public boolean isType(TokenType expected) {
        return type == expected;
    }

    public boolean hasValue() {
        return hasValue;
    }

    public String getValue() {
        return hasValue ? new String(serialized, start, end - start + 1, US_ASCII).trim() : EMPTY;
    }

    public boolean samePoint(Token token) {
        return start == token.start
                && end == token.end
                && type == token.type;
    }
}