me.lightspeed7.mongofs.CountingInputStream Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of mongoFS Show documentation

An extension to the MongoDB Java Driver library that goes beyond what the GridFS feature supports. Compressed file storage, zip files, temporary files

There is a newer version: 0.10.0

Show newest version

package me.lightspeed7.mongofs;

import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;

public class CountingInputStream extends FilterInputStream {

    private long count = 0;
    private long mark = -1;

    private MongoFile file;

    public CountingInputStream(final MongoFile file, final InputStream given) {

        super(given);
        this.file = file;

    }

    @Override
    public int read() throws IOException {

        int result = in.read();
        if (result != -1) {
            count++;
        }
        return result;
    }

    @Override
    public int read(final byte[] b, final int off, final int len) throws IOException {

        int result = in.read(b, off, len);
        if (result != -1) {
            count += result;
        }
        return result;
    }

    @Override
    public long skip(final long n) throws IOException {
        long result = in.skip(n);
        count += result;
        return result;
    }

    @Override
    public synchronized void mark(final int readlimit) {
        in.mark(readlimit);
        mark = count;
        // it's okay to mark even if mark isn't supported, as reset won't work
    }

    @Override
    public synchronized void reset() throws IOException {
        if (!in.markSupported()) {
            throw new IOException("Mark not supported");
        }
        if (mark == -1) {
            throw new IOException("Mark not set");
        }

        in.reset();
        count = mark;
    }

    public final long getCount() {

        return count;
    }

    @Override
    public void close() throws IOException {
        super.close();

        // check for full file read
        long expected = file.getLength();
        if (file.isCompressed()) {
            if (file.containsKey(MongoFileConstants.storage.name())) {
                expected = file.getLong(MongoFileConstants.storage);
            }
            else if (file.containsKey(MongoFileConstants.compressedLength.name())) {
                expected = file.getLong(MongoFileConstants.compressedLength);
            }
            else {
                throw new IllegalStateException("No compressed length stored on object");
            }
        }

        if (expected != count) {
            throw new IOException("File Length mismatch");
        }

    }
}