AndroidFileSystemCache.java

package com.nutiteq.cache;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import android.content.Context;

import com.nutiteq.log.Log;
import com.nutiteq.utils.IOUtils;

public class AndroidFileSystemCache implements Cache {
  private final String caheName;
  private final File cacheDir;
  private final int cacheSize;
  private final Context ctx;
  private final CacheIndexDatabaseHelper database;

  public AndroidFileSystemCache(final Context ctx, final String caheName, final File cacheDir,
      final int cacheSize) {
    this.ctx = ctx;
    this.caheName = caheName;
    this.cacheDir = cacheDir;
    this.cacheSize = cacheSize;
    database = new CacheIndexDatabaseHelper(ctx, caheName);
  }

  public void cache(final String cacheKey, final byte[] data, final int cacheLevel) {
    if ((cacheLevel & Cache.CACHE_LEVEL_PERSISTENT) == 0) {
      return;
    }
    Log.debug("Cache " + cacheKey + " : " + data.length);

    final String cacheableKey = normalizeKey(cacheKey);
    Log.debug("Cache key would be: " + cacheableKey);
    final File cacheFile = new File(cacheDir, cacheableKey);
    cacheFile.getParentFile().mkdirs();

    FileOutputStream fos = null;
    final List<String> deletedFiles = new ArrayList<String>();
    try {
      fos = new FileOutputStream(cacheFile);
      fos.write(data);
      deletedFiles.addAll(database.addToIndex(cacheKey, cacheableKey, data.length, cacheSize));
      deleteFilesFromFileSystem(deletedFiles);
    } catch (final IOException e) {
      Log.error("Error writing " + cacheableKey);
      Log.printStackTrace(e);
    } finally {
      IOUtils.closeStream(fos);
    }
  }

  private void deleteFilesFromFileSystem(final List<String> deletedFiles) {
    for (final String file : deletedFiles) {
      final File deleted = new File(cacheDir, file);
      Log.debug("Deleting " + deleted.getAbsolutePath());
      if (!deleted.delete()) {
        Log.debug("No success");
      }
    }
  }

  private String normalizeKey(final String cacheKey) {
    return cacheKey.replaceAll("://", "_").replaceAll("[^a-zA-Z\\d/]", "_");
  }

  public boolean contains(final String cacheKey) {
    final boolean containsKey = database.containsKey(cacheKey);
    Log.debug("Contains 1 " + cacheKey + " : " + containsKey);
    return containsKey;
  }

  public boolean contains(final String cacheKey, final int cacheLevel) {
    final boolean contains = cacheLevel == Cache.CACHE_LEVEL_PERSISTENT && contains(cacheKey);
    //Log.debug("Contains 2 " + cacheKey + " : " + contains);
    return contains;
  }

  public void deinitialize() {
    database.close();
  }

  public byte[] get(final String cacheKey) {
    Log.debug("cache load " + cacheKey);
    final String fileName = database.getRespourcePathForKey(cacheKey);

    if ("".equals(fileName)) {
      return null;
    }

    final File resource = new File(cacheDir, fileName);
    FileInputStream fis;
    try {
      fis = new FileInputStream(resource);
      return IOUtils.readFullyAndClose(fis);
    } catch (final FileNotFoundException e) {
      Log.printStackTrace(e);
      Log.debug("Could not load " + cacheKey);
      return null;
    }
  }

  public void initialize() {
    Log.debug("ZZZZZZZZZZZZZZZZZZZZZZZZZ Initialize fs cache");
    database.open();
  }
}