io.vertx.core.parsetools.impl.RecordParserImpl Maven / Gradle / Ivy
/*
* Copyright (c) 2011-2013 The original author or authors
* ------------------------------------------------------
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Apache License v2.0 which accompanies this distribution.
*
* The Eclipse Public License is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* The Apache License v2.0 is available at
* http://www.opensource.org/licenses/apache2.0.php
*
* You may elect to redistribute this code under either of these licenses.
*/
package io.vertx.core.parsetools.impl;
import io.vertx.core.Handler;
import io.vertx.core.buffer.Buffer;
import io.vertx.core.impl.Arguments;
import io.vertx.core.parsetools.RecordParser;
import java.util.Objects;
/**
* @author Tim Fox
* @author Lars Timm
*/
public class RecordParserImpl implements RecordParser {
private Buffer buff;
private int pos; // Current position in buffer
private int start; // Position of beginning of current record
private int delimPos; // Position of current match in delimiter array
private boolean reset; // Allows user to toggle mode / change delim when records are emitted
private boolean delimited;
private byte[] delim;
private int recordSize;
private Handler output;
private RecordParserImpl(Handler output) {
this.output = output;
}
public void setOutput(Handler output) {
Objects.requireNonNull(output, "output");
this.output = output;
}
/**
* Helper method to convert a latin-1 String to an array of bytes for use as a delimiter
* Please do not use this for non latin-1 characters
*
* @param str the string
* @return The byte[] form of the string
*/
public static Buffer latin1StringToBytes(String str) {
byte[] bytes = new byte[str.length()];
for (int i = 0; i < str.length(); i++) {
char c = str.charAt(i);
bytes[i] = (byte) (c & 0xFF);
}
return Buffer.buffer(bytes);
}
/**
* Create a new {@code RecordParser} instance, initially in delimited mode, and where the delimiter can be represented
* by the String {@code} delim endcoded in latin-1 . Don't use this if your String contains other than latin-1 characters.
*
* {@code output} Will receive whole records which have been parsed.
*
* @param delim the initial delimiter string
* @param output handler that will receive the output
*/
public static RecordParser newDelimited(String delim, Handler output) {
return newDelimited(latin1StringToBytes(delim), output);
}
/**
* Create a new {@code RecordParser} instance, initially in delimited mode, and where the delimiter can be represented
* by the {@code buffer} delim.
*
* {@code output} Will receive whole records which have been parsed.
*
* @param delim the initial delimiter buffer
* @param output handler that will receive the output
*/
public static RecordParser newDelimited(Buffer delim, Handler output) {
RecordParserImpl ls = new RecordParserImpl(output);
ls.delimitedMode(delim);
return ls;
}
/**
* Create a new {@code RecordParser} instance, initially in fixed size mode, and where the record size is specified
* by the {@code size} parameter.
*
* {@code output} Will receive whole records which have been parsed.
*
* @param size the initial record size
* @param output handler that will receive the output
*/
public static RecordParser newFixed(int size, Handler output) {
Arguments.require(size > 0, "Size must be > 0");
RecordParserImpl ls = new RecordParserImpl(output);
ls.fixedSizeMode(size);
return ls;
}
/**
* Flip the parser into delimited mode, and where the delimiter can be represented
* by the String {@code delim} encoded in latin-1 . Don't use this if your String contains other than latin-1 characters.
*
* This method can be called multiple times with different values of delim while data is being parsed.
*
* @param delim the new delimeter
*/
public void delimitedMode(String delim) {
delimitedMode(latin1StringToBytes(delim));
}
/**
* Flip the parser into delimited mode, and where the delimiter can be represented
* by the delimiter {@code delim}.
*
* This method can be called multiple times with different values of delim while data is being parsed.
*
* @param delim the new delimiter
*/
public void delimitedMode(Buffer delim) {
Objects.requireNonNull(delim, "delim");
delimited = true;
this.delim = delim.getBytes();
delimPos = 0;
reset = true;
}
/**
* Flip the parser into fixed size mode, where the record size is specified by {@code size} in bytes.
*
* This method can be called multiple times with different values of size while data is being parsed.
*
* @param size the new record size
*/
public void fixedSizeMode(int size) {
Arguments.require(size > 0, "Size must be > 0");
delimited = false;
recordSize = size;
reset = true;
}
private void handleParsing() {
int len = buff.length();
do {
reset = false;
if (delimited) {
parseDelimited();
} else {
parseFixed();
}
} while (reset);
if (start == len) {
//Nothing left
buff = null;
pos = 0;
} else {
buff = buff.getBuffer(start, len);
pos = buff.length();
}
start = 0;
}
private void parseDelimited() {
int len = buff.length();
for (; pos < len && !reset; pos++) {
if (buff.getByte(pos) == delim[delimPos]) {
delimPos++;
if (delimPos == delim.length) {
Buffer ret = buff.getBuffer(start, pos - delim.length + 1);
start = pos + 1;
delimPos = 0;
output.handle(ret);
}
} else {
if (delimPos > 0) {
pos -= delimPos;
delimPos = 0;
}
}
}
}
private void parseFixed() {
int len = buff.length();
while (len - start >= recordSize && !reset) {
int end = start + recordSize;
Buffer ret = buff.getBuffer(start, end);
start = end;
pos = start - 1;
output.handle(ret);
}
}
/**
* This method is called to provide the parser with data.
*
* @param buffer a chunk of data
*/
public void handle(Buffer buffer) {
if (buff == null) {
buff = buffer;
} else {
buff.appendBuffer(buffer);
}
handleParsing();
}
}