/*
* Copyright 1999-2101 Alibaba Group.
*
* 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 com.alibaba.fastjson.parser;
import java.io.CharArrayReader;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.lang.ref.SoftReference;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONException;
import com.alibaba.fastjson.util.Base64;
import com.alibaba.fastjson.util.IOUtils;
//这个类，为了性能优化做了很多特别处理，一切都是为了性能！！！
/**
* @author wenshao<szujobs@hotmail.com>
*/
public final class JSONReaderScanner extends JSONLexer {
public final static int BUF_INIT_LEN = 8192;
private final static ThreadLocal<SoftReference<char[]>> BUF_REF_LOCAL = new ThreadLocal<SoftReference<char[]>>();
private Reader reader;
private char[] buf;
private int bufLength;
public JSONReaderScanner(String input){
this(input, JSON.DEFAULT_PARSER_FEATURE);
}
public JSONReaderScanner(String input, int features){
this(new StringReader(input), features);
}
public JSONReaderScanner(char[] input, int inputLength){
this(input, inputLength, JSON.DEFAULT_PARSER_FEATURE);
}
public JSONReaderScanner(Reader reader){
this(reader, JSON.DEFAULT_PARSER_FEATURE);
}
public JSONReaderScanner(Reader reader, int features){
this.reader = reader;
this.features = features;
SoftReference<char[]> bufRef = BUF_REF_LOCAL.get();
if (bufRef != null) {
this.buf = bufRef.get();
BUF_REF_LOCAL.set(null);
}
if (this.buf == null) {
this.buf = new char[BUF_INIT_LEN];
}
try {
bufLength = reader.read(buf);
} catch (IOException e) {
throw new JSONException(e.getMessage(), e);
}
bp = -1;
next();
if (ch == 65279) {
next();
}
}
public JSONReaderScanner(char[] input, int inputLength, int features){
this(new CharArrayReader(input, 0, inputLength), features);
}
public final char charAt(int index) {
if (index >= bufLength) {
if (bufLength == -1) {
if (index < sp) {
return buf[index];
}
return EOI;
}
int rest = bufLength - bp;
if (rest > 0) {
System.arraycopy(buf, bp, buf, 0, rest);
}
try {
bufLength = reader.read(buf, rest, buf.length - rest);
} catch (IOException e) {
throw new JSONException(e.getMessage(), e);
}
if (bufLength == 0) {
throw new JSONException("illegal stat, textLength is zero");
}
if (bufLength == -1) {
return EOI;
}
bufLength += rest;
index -= bp;
np -= bp;
bp = 0;
}
return buf[index];
}
public final int indexOf(char ch, int startIndex) {
int offset = startIndex;
for (;; ++offset) {
if (ch == charAt(offset)) {
return offset;
}
if (ch == EOI) {
return -1;
}
}
}
public final String addSymbol(int offset, int len, int hash, final SymbolTable symbolTable) {
return symbolTable.addSymbol(buf, offset, len, hash);
}
public final char next() {
int index = ++bp;
if (index >= bufLength) {
if (bufLength == -1) {
return EOI;
}
if (sp > 0) {
if (this.token == JSONToken.LITERAL_STRING) {
System.arraycopy(buf, buf.length - sp, buf, 0, sp);
np = -1 + sp;
} else {
System.arraycopy(buf, bufLength - sp, buf, 0, sp);
np = 0;
}
}
index = bp = sp;
try {
int startPos = bp;
int readLength = buf.length - startPos;
bufLength = reader.read(buf, bp, readLength);
} catch (IOException e) {
throw new JSONException(e.getMessage(), e);
}
if (bufLength == 0) {
throw new JSONException("illegal stat, textLength is zero");
}
if (bufLength == -1) {
return ch = EOI;
}
bufLength += bp;
}
return ch = buf[index];
}
protected final void copyTo(int offset, int count, char[] dest) {
System.arraycopy(buf, offset, dest, 0, count);
}
public final boolean charArrayCompare(char[] chars) {
for (int i = 0; i < chars.length; ++i) {
if (charAt(bp + i) != chars[i]) {
return false;
}
}
return true;
}
public byte[] bytesValue() {
return Base64.decodeFast(buf, np + 1, sp);
}
protected final void arrayCopy(int srcPos, char[] dest, int destPos, int length) {
System.arraycopy(buf, srcPos, dest, destPos, length);
}
/**
* The value of a literal token, recorded as a string. For integers, leading 0x and 'l' suffixes are suppressed.
*/
public final String stringVal() {
if (!hasSpecial) {
return new String(buf, np + 1, sp);
// return text.substring(np + 1, np + 1 + sp);
} else {
return new String(sbuf, 0, sp);
}
}
public final String subString(int offset, int count) {
return new String(buf, offset, count);
// return text.substring(offset, offset + count);
}
public final String numberString() {
char chLocal = charAt(np + sp - 1);
int sp = this.sp;
if (chLocal == 'L' || chLocal == 'S' || chLocal == 'B' || chLocal == 'F' || chLocal == 'D') {
sp--;
}
return new String(buf, np, sp);
}
public void close() {
super.close();
BUF_REF_LOCAL.set(new SoftReference<char[]>(buf));
this.buf = null;
IOUtils.close(reader);
}
@Override
public boolean isEOF() {
return bufLength == -1 || bp == buf.length || ch == EOI && bp + 1 == buf.length;
}
}