private void checkDatabaseSize() throws IOException, LimitedSpaceException {
long size = 0;
for (int chunk = 0; chunk < DB_CHUNKS; chunk++) {
InputStream sizeInput = context.getAssets().open(getFileName(DB_NAME, chunk));
byte[] ibuffer = new byte[1024];
int length;
while ((length = sizeInput.read(ibuffer)) > 0) {
size += length;
}
sizeInput.close();
}
long buffer = (long) (size * 0.1);
long free = AvailableSpaceHandler.getAvailableSpaceInBytes(DB_PATH);
if (size + buffer > free) {
throw new LimitedSpaceException("Not enough free space.", size + buffer);
}
}
/**
* Determines an appropriate location for the reference database.
*
* <p>1. Is external storage available (mounted) 2. if so, does the db already exist? 3. if not,
* is there space for the database here? 4. failing the availability of external storage, sort out
* the location for internal storage 5. if the database is destined for external storage, but
* exists internally, delete internal copy
*
* @return file pointing to where the database is destined to exist
*/
private File manageDatabase() {
File tmpFile, retFile = null;
long dbSize, free;
// Look for old databases that may still exist, delete them in found
tmpFile = new File(OLD_DB_PATH, DB_NAME);
if (tmpFile.exists()) {
tmpFile.delete();
}
// see if external storage is mounted
try {
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
tmpFile = new File(context.getExternalFilesDir(null), DB_NAME);
if (tmpFile != null) {
if (tmpFile.exists()) {
// db already exists
retFile = tmpFile;
} else {
// see if there is enough space to hold the db on
// external storage
free = AvailableSpaceHandler.getAvailableSpaceInBytes(tmpFile.getParent());
try {
dbSize = calcDatabaseSize();
} catch (IOException e) {
// unable to calculate database size
// proper exception handling for this will take
// place
// when
// the db is created
dbSize = 0;
}
if (dbSize < free) {
retFile = tmpFile;
}
}
}
}
} catch (Exception e) {
// Trying SD broke, move to using internal
ErrorReporter.getInstance().putCustomData("Situation", "Failed to write to SD");
ErrorReporter.getInstance().handleException(e);
}
// check internal storage
tmpFile = new File(context.getFilesDir().getAbsolutePath(), DB_NAME);
// see if the db exists on internal storage
if (tmpFile.exists()) {
if (null != retFile) {
// if the db is on internal *and* external storage, delete the
// internal storage copy
tmpFile.delete();
}
}
// if we got this far with retFile undefined, there either isn't
// external storage
// or insufficient space there. default to internal storage
if (null == retFile) {
retFile = tmpFile;
}
return retFile;
}