| 0,0 → 1,191 |
|---|
| import java.io.*; |
| |
| public class XmlParser2 |
| { |
| public static void main(String[] args) |
| throws Exception |
| { |
| if(args.length < 1) { |
| System.err.println("Need file name as parameter"); |
| return; |
| } |
| |
| FileInputStream in = new FileInputStream(args[0]); |
| |
| try { |
| XmlBuffer buf = new XmlBuffer(in); |
| |
| for(int i = 0; !buf.isEnd(); ++i) { |
| byte c = buf.cur(); |
| //System.out.print((char)c); |
| buf.toNext(); |
| if(i == 8 || i == 40) { |
| buf.mark(); |
| } |
| else if(i == 14 || i == 42) { |
| buf.reset(); |
| } |
| } |
| } |
| finally { |
| in.close(); |
| } |
| } |
| } |
| |
| class XmlBuffer |
| { |
| private InputStream in; |
| private byte[][] bufs = new byte[2][10]; |
| private int[] lens = new int[bufs.length]; // lengthes of valid data in buffers |
| private int bufCur = -1; |
| private int bufNext = -1; |
| private int bufPrev = -1; |
| private int lenCur = 0; // length of valid data in current buffer |
| private int pos = 0; // position in buffers, 0 means begin of current one |
| private boolean end = false; // no more data in the input stream |
| private long offset = 0; // offset in input for begin of current buffer |
| |
| private long markedOffset = -1; |
| private int markedPos = 0; |
| |
| public XmlBuffer(InputStream in) |
| throws IOException |
| { |
| this.in = in; |
| |
| loadNextBuffer(); |
| bufCur = bufNext; |
| lenCur = lens[bufCur]; |
| bufNext = -1; |
| } |
| |
| public byte cur() |
| throws IOException |
| { |
| if(pos >= lenCur) { |
| return at(0); |
| } |
| |
| System.out.println("cur " + offset + "+" + pos + " [" + (char)bufs[bufCur][pos] + "]"); |
| return bufs[bufCur][pos]; |
| } |
| |
| public byte at(int n) |
| throws IOException |
| { |
| int p = pos + n; |
| byte[] buf; |
| |
| if(p >= lenCur) { |
| //System.out.println("at p1 " + p + " " + lenCur); |
| if(!loadNextBuffer()) return 0; // no more data |
| |
| p -= lenCur; |
| buf = bufs[bufNext]; |
| |
| if(p > lens[bufNext]) { |
| return 0; |
| } |
| //System.out.println("at p2 " + p + " " + bufNext); |
| } |
| else { |
| //System.out.println("at p3 " + p + " " + lenCur + " " + bufCur); |
| buf = bufs[bufCur]; |
| } |
| |
| System.out.println("at " + offset + "+" + pos + "+" + p + " [" + (char)buf[p] + "]"); |
| return buf[p]; |
| } |
| |
| public void toNext() |
| throws IOException |
| { |
| ++pos; |
| |
| if(pos >= lenCur) { |
| System.out.println("toNext " + pos + " " + lenCur); |
| if(bufNext < 0) { |
| if(!loadNextBuffer()) return; |
| } |
| |
| pos -= lenCur; |
| offset += lenCur; |
| bufPrev = bufCur; |
| bufCur = bufNext; |
| lenCur = lens[bufCur]; |
| bufNext = -1; |
| } |
| } |
| |
| public boolean isEnd() |
| { |
| return (end && pos >= lenCur); |
| } |
| |
| public void mark() |
| { |
| System.out.println("mark " + offset + "+" + pos + " " + bufPrev + " " + bufCur + " " + bufNext); |
| markedOffset = offset; |
| markedPos = pos; |
| } |
| |
| public void reset() |
| throws IOException |
| { |
| if(markedOffset < 0) { |
| throw new IOException("no mark"); |
| } |
| |
| System.out.println("reset p1 " + offset + "+" + pos + " " + bufPrev + " " + bufCur + " " + bufNext); |
| int diff = (int)(offset - markedOffset); |
| if(diff > bufs[0].length) { |
| throw new IOException("mark too old"); |
| } |
| else if(diff > 0) { // moved to next buffer after the 'mark' |
| bufNext = bufCur; |
| bufCur = bufPrev; |
| offset = markedOffset; |
| } |
| // else still the same buffer |
| |
| pos = markedPos; |
| lenCur = lens[bufCur]; |
| |
| markedOffset = -1; |
| System.out.println("reset p2 " + offset + "+" + pos + " " + bufPrev + " " + bufCur + " " + bufNext); |
| } |
| |
| private boolean loadNextBuffer() |
| throws IOException |
| { |
| System.out.println("loadNextBuffer p1"); |
| if(end) return false; |
| |
| bufNext = (bufCur + 1); |
| if(bufNext >= bufs.length) bufNext = 0; |
| if(bufNext == bufPrev) bufPrev = -1; |
| |
| lens[bufNext] = in.read(bufs[bufNext]); |
| System.out.println("loadNextBuffer p2 " + bufNext + " " + lens[bufNext]); |
| if(lens[bufNext] < 0) { |
| end = true; |
| |
| return false; |
| } |
| |
| System.out.println("loadNextBuffer p3"); |
| return true; |
| } |
| |
| public long getPosition() |
| { |
| return (offset + pos); |
| } |
| |
| public String toString(long begin, int length) |
| { |
| |
| } |
| } |
| |