/**
* Puts bitmap into the cache.
*
* @param key the key for the bitmap.
* @param bitmap the bitmap.
* @return true if successful; false otherwise.
*/
private boolean put(String key, Bitmap bitmap) {
boolean isSuccessful = true;
// Get unique filename based on key.
final String filename = StorageHelper.generateValidFilename(key);
if (TextHelper.isValid(filename)) {
final File file = new File(mDiskCacheDir, filename);
// Store PNG in disk cache.
try {
final OutputStream outputStream = new BufferedOutputStream(new FileOutputStream(file));
isSuccessful = ImageHelper.writePng(bitmap, outputStream);
outputStream.flush();
outputStream.close();
} catch (FileNotFoundException e) {
isSuccessful = false;
} catch (IOException e) {
isSuccessful = false;
}
if (isSuccessful) {
// Read PNG from disk cache and put bitmap in memory cache.
Bitmap storedBitmap = BitmapFactory.decodeFile(file.getAbsolutePath());
if (storedBitmap != null) {
mMemCache.put(key, storedBitmap);
} else {
isSuccessful = false;
}
}
}
return isSuccessful;
}
/**
* Removes bitmap from the cache.
*
* @param key the key for the bitmap.
* @return true if successful; false otherwise.
*/
private boolean remove(String key) {
boolean isSuccessful = true;
// Get unique filename based on key.
final String filename = StorageHelper.generateValidFilename(key);
if (TextHelper.isValid(filename)) {
// Remove PNG from disk cache.
final File file = new File(mDiskCacheDir, filename);
isSuccessful = file.delete();
// Remove bitmap from memory cache.
mMemCache.remove(key);
}
return isSuccessful;
}
/**
* Gets bitmap from the cache.
*
* @param key the key for the bitmap.
* @return the bitmap; or null if failed.
*/
private Bitmap get(String key) {
// Try to get bitmap from memory cache.
Bitmap bitmap = mMemCache.get(key);
// Try to get PNG from disk cache if bitmap not found in memory cache.
if (bitmap == null) {
// Get unique filename based on key.
String filename = StorageHelper.generateValidFilename(key);
if (TextHelper.isValid(filename)) {
final File file = new File(mDiskCacheDir, filename);
bitmap = BitmapFactory.decodeFile(file.getAbsolutePath());
if (bitmap != null) {
// Put bitmap in memory cache.
mMemCache.put(key, bitmap);
}
}
}
return bitmap;
}
