Android Open Source - Jello Paged File R A F

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Back to project page Jello.

License

The source code is released under:

Apache License

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Java Source Code

package com.atteo.jello.store;
/*from  w w w .j a  v a2  s .com*/
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;

import com.atteo.jello.Jello;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import com.google.inject.name.Named;

@Singleton
public class PagedFileRAF implements PagedFile {
  final File file;

  private boolean readOnly;
  private final int pageSize;
  private int pages;
  private RandomAccessFile raf;

  @Inject
  PagedFileRAF(@Named("pageSize") final short pageSize,
      @Named("fullpath") final String fullpath) {
    this.pageSize = pageSize;

    file = new File(fullpath);
  }

  public int addPages(final int count) {
    pages += count;
    try {
      raf.setLength(pages * pageSize);
    } catch (final IOException e) {
      e.printStackTrace();
    }
    return pages - 1;
  }

  public void close() {
    try {
      raf.close();
    } catch (final IOException e) {
      e.printStackTrace();
    }
  }

  public boolean create() {
    file.getParentFile().mkdirs();
    if (!file.getParentFile().exists())
      return false;
    try {
      file.createNewFile();
    } catch (final IOException e) {
      e.printStackTrace();
      return false;
    }

    return true;
  }

  public boolean exists() {
    return file.exists();
  }

  public long getFileLength() {
    long len = 0;
    try {
      len = raf.length();
    } catch (final IOException e) {
      e.printStackTrace();
    }
    return len;
  }

  public int getPageCount() {
    return pages;
  }

  public boolean isReadOnly() {
    return readOnly;
  }

  public int open() {
    if (!exists())
      return Jello.OPEN_FAILED;

    if (!file.canRead())
      return Jello.OPEN_FAILED;

    readOnly = !file.canWrite();

    String mode;
    if (readOnly)
      mode = "r";
    else
      mode = "rw";

    try {
      raf = new RandomAccessFile(file, mode);
    } catch (final FileNotFoundException e1) {
      e1.printStackTrace();
      return Jello.OPEN_FAILED;

    }

    try {
      pages = (int) (raf.length() / pageSize);
    } catch (final IOException e) {
      e.printStackTrace();
      return Jello.OPEN_FAILED;

    }

    if (readOnly)
      return Jello.OPEN_READONLY;
    else
      return Jello.OPEN_SUCCESS;
  }

  public void readPage(final Page page) {
    try {
      raf.seek(page.getId() * pageSize);
      raf.readFully(page.getData());
    } catch (final IOException e) {
      e.printStackTrace();
    }

  }

  public void remove() {
    file.delete();
  }

  public void removePages(final int count) {
    pages -= count;
    if (pages < 0)
      pages = 0;
    try {
      raf.setLength(pages * pageSize);
    } catch (final IOException e) {
      e.printStackTrace();
    }

  }

  public void syncAll() {

  }

  public void syncPages(final int startPage, final int count) {

  }

  public void writePage(final Page page) {
    try {
      raf.seek(page.getId() * pageSize);
      raf.write(page.getData());
    } catch (final IOException e) {
      e.printStackTrace();
    }
  }

}

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