@Override
public int commit() {
int updated = findDifference();
for (String key : changes.keySet()) {
cache.put(key, changes.get(key));
}
changes.clear();
for (String key : cache.keySet()) {
changes.put(key, cache.get(key));
}
boolean isClosed = true;
DataInputStream[][] inputStreams = new DataInputStream[partsNumber][partsNumber];
DataOutputStream[][] outputStreams = new DataOutputStream[partsNumber][partsNumber];
try {
for (int i = 0; i < partsNumber; i++) {
if (!directoriesList[i].exists()) {
if (!directoriesList[i].mkdir()) {
throw new IOException(directoriesList[i].getPath() + ": couldn't create directory");
}
}
for (int j = 0; j < partsNumber; j++) {
if (!filesList[i][j].exists()) {
if (!filesList[i][j].createNewFile()) {
throw new IOException(filesList[i][j].getAbsolutePath() + ": couldn't create file");
}
}
if (!filesList[i][j].renameTo(new File(filesList[i][j].getPath() + "~"))) {
throw new IOException(filesList[i][j].getAbsolutePath() + ": couldn't rename file");
}
inputStreams[i][j] =
new DataInputStream(new FileInputStream(filesList[i][j].getPath() + "~"));
outputStreams[i][j] = new DataOutputStream(new FileOutputStream(filesList[i][j]));
DataInputStream inputStream = inputStreams[i][j];
DataOutputStream outputStream = outputStreams[i][j];
String nextKey;
String nextValue;
String[] pair;
while ((pair = readNextPair(inputStream)) != null) {
nextKey = pair[0];
nextValue = pair[1];
if (changes.containsKey(nextKey)) {
nextValue = changes.get(nextKey);
changes.remove(nextKey);
}
if (nextValue != null) {
writeNextPair(outputStream, nextKey, nextValue);
}
}
}
}
Set<Map.Entry<String, String>> entries = changes.entrySet();
for (Map.Entry<String, String> entry : entries) {
if (entry.getValue() != null) {
byte firstByte = getFirstByte(entry.getKey());
DataOutputStream outputStream =
outputStreams[firstByte % partsNumber][(firstByte / partsNumber) % partsNumber];
try {
writeNextPair(outputStream, entry.getKey(), entry.getValue());
} catch (IOException e) {
throw new IllegalStateException(e.getMessage());
}
}
}
for (int i = 0; i < partsNumber; i++) {
for (int j = 0; j < partsNumber; j++) {
inputStreams[i][j].close();
outputStreams[i][j].close();
if (!(new File(filesList[i][j].getPath() + "~")).delete()) {
throw new IllegalStateException(filesList[i][j].getPath() + "~: couldn't delete file");
}
if (filesList[i][j].length() == 0) {
if (!filesList[i][j].delete()) {
throw new IllegalStateException(filesList[i][j].getPath() + ": couldn't delete file");
}
}
}
}
changes.clear();
oldRecordNumber = recordNumber;
for (File directory : directoriesList) {
if (directory.list().length == 0) {
if (!directory.delete()) {
throw new IllegalStateException(
directory.getAbsolutePath() + ": couldn't delete directory");
}
}
}
} catch (IOException e) {
throw new IllegalStateException(e.getMessage());
} finally {
for (int i = 0; i < partsNumber; i++) {
for (int j = 0; j < partsNumber; j++) {
try {
if (inputStreams[i][j] != null) {
inputStreams[i][j].close();
}
} catch (Exception e) {
isClosed = false;
}
try {
if (outputStreams[i][j] != null) {
outputStreams[i][j].close();
}
} catch (Exception e) {
isClosed = false;
}
}
}
}
if (!isClosed) {
throw new IllegalStateException("couldn't close some files");
}
return updated;
}
