import com.datastax.driver.core.Row;
public abstract class Loader<DATA> {
- private int keylimit;
- public Loader(int keylimit) {
- this.keylimit = keylimit;
- }
-
- public int keylimit() {
- return keylimit;
- }
-
- protected abstract DATA load(DATA data, Row row);
- protected abstract void key(DATA data, int idx, Object[] obj);
- protected abstract void body(DATA data, int idx, Object[] obj);
+ private int keylimit;
+ public Loader(int keylimit) {
+ this.keylimit = keylimit;
+ }
+
+ public int keylimit() {
+ return keylimit;
+ }
+
+ protected abstract DATA load(DATA data, Row row);
+ protected abstract void key(DATA data, int idx, Object[] obj);
+ protected abstract void body(DATA data, int idx, Object[] obj);
- public final Object[] extract(DATA data, int size, CassDAOImpl.CRUD type) {
- Object[] rv=null;
- switch(type) {
- case delete:
- rv = new Object[keylimit()];
- key(data,0,rv);
- break;
- case update:
- rv = new Object[size];
- body(data,0,rv);
- int body = size-keylimit();
- if(body>0) {
- key(data,body,rv);
- }
- break;
- default:
- rv = new Object[size];
- key(data,0,rv);
- if(size>keylimit()) {
- body(data,keylimit(),rv);
- }
- break;
- }
- return rv;
- }
-
- public static void writeString(DataOutputStream os, String s) throws IOException {
- if(s==null) {
- os.writeInt(-1);
- } else {
- switch(s.length()) {
- case 0:
- os.writeInt(0);
- break;
- default:
- byte[] bytes = s.getBytes();
- os.writeInt(bytes.length);
- os.write(bytes);
- }
- }
- }
-
-
- /**
- * We use bytes here to set a Maximum
- *
- * @param is
- * @param MAX
- * @return
- * @throws IOException
- */
- public static String readString(DataInputStream is, byte[] _buff) throws IOException {
- int l = is.readInt();
- byte[] buff = _buff;
- switch(l) {
- case -1: return null;
- case 0: return "";
- default:
- // Cover case where there is a large string, without always allocating a large buffer.
- if(l>buff.length) {
- buff = new byte[l];
- }
- is.read(buff,0,l);
- return new String(buff,0,l);
- }
- }
+ public final Object[] extract(DATA data, int size, CassDAOImpl.CRUD type) {
+ Object[] rv=null;
+ switch(type) {
+ case delete:
+ rv = new Object[keylimit()];
+ key(data,0,rv);
+ break;
+ case update:
+ rv = new Object[size];
+ body(data,0,rv);
+ int body = size-keylimit();
+ if(body>0) {
+ key(data,body,rv);
+ }
+ break;
+ default:
+ rv = new Object[size];
+ key(data,0,rv);
+ if(size>keylimit()) {
+ body(data,keylimit(),rv);
+ }
+ break;
+ }
+ return rv;
+ }
+
+ public static void writeString(DataOutputStream os, String s) throws IOException {
+ if(s==null) {
+ os.writeInt(-1);
+ } else {
+ switch(s.length()) {
+ case 0:
+ os.writeInt(0);
+ break;
+ default:
+ byte[] bytes = s.getBytes();
+ os.writeInt(bytes.length);
+ os.write(bytes);
+ }
+ }
+ }
+
+
+ /**
+ * We use bytes here to set a Maximum
+ *
+ * @param is
+ * @param MAX
+ * @return
+ * @throws IOException
+ */
+ public static String readString(DataInputStream is, byte[] _buff) throws IOException {
+ int l = is.readInt();
+ byte[] buff = _buff;
+ switch(l) {
+ case -1: return null;
+ case 0: return "";
+ default:
+ // Cover case where there is a large string, without always allocating a large buffer.
+ if(l>buff.length) {
+ buff = new byte[l];
+ }
+ is.read(buff,0,l);
+ return new String(buff,0,l);
+ }
+ }
- /**
- * Write a set with proper sizing
- *
- * Note: at the moment, this is just String. Probably can develop system where types
- * are supported too... but not now.
- *
- * @param os
- * @param set
- * @throws IOException
- */
- public static void writeStringSet(DataOutputStream os, Collection<String> set) throws IOException {
- if(set==null) {
- os.writeInt(-1);
- } else {
- os.writeInt(set.size());
- for(String s : set) {
- writeString(os, s);
- }
- }
+ /**
+ * Write a set with proper sizing
+ *
+ * Note: at the moment, this is just String. Probably can develop system where types
+ * are supported too... but not now.
+ *
+ * @param os
+ * @param set
+ * @throws IOException
+ */
+ public static void writeStringSet(DataOutputStream os, Collection<String> set) throws IOException {
+ if(set==null) {
+ os.writeInt(-1);
+ } else {
+ os.writeInt(set.size());
+ for(String s : set) {
+ writeString(os, s);
+ }
+ }
- }
-
- public static Set<String> readStringSet(DataInputStream is, byte[] buff) throws IOException {
- int l = is.readInt();
- if(l<0) {
- return null;
- }
- Set<String> set = new HashSet<String>(l);
- for(int i=0;i<l;++i) {
- set.add(readString(is,buff));
- }
- return set;
- }
-
- public static List<String> readStringList(DataInputStream is, byte[] buff) throws IOException {
- int l = is.readInt();
- if(l<0) {
- return null;
- }
- List<String> list = new ArrayList<String>(l);
- for(int i=0;i<l;++i) {
- list.add(Loader.readString(is,buff));
- }
- return list;
- }
+ }
+
+ public static Set<String> readStringSet(DataInputStream is, byte[] buff) throws IOException {
+ int l = is.readInt();
+ if(l<0) {
+ return null;
+ }
+ Set<String> set = new HashSet<>(l);
+ for(int i=0;i<l;++i) {
+ set.add(readString(is,buff));
+ }
+ return set;
+ }
+
+ public static List<String> readStringList(DataInputStream is, byte[] buff) throws IOException {
+ int l = is.readInt();
+ if(l<0) {
+ return null;
+ }
+ List<String> list = new ArrayList<>(l);
+ for(int i=0;i<l;++i) {
+ list.add(Loader.readString(is,buff));
+ }
+ return list;
+ }
- /**
- * Write a map
- * @param os
- * @param map
- * @throws IOException
- */
- public static void writeStringMap(DataOutputStream os, Map<String,String> map) throws IOException {
- if(map==null) {
- os.writeInt(-1);
- } else {
- Set<Entry<String, String>> es = map.entrySet();
- os.writeInt(es.size());
- for(Entry<String,String> e : es) {
- writeString(os, e.getKey());
- writeString(os, e.getValue());
- }
- }
+ /**
+ * Write a map
+ * @param os
+ * @param map
+ * @throws IOException
+ */
+ public static void writeStringMap(DataOutputStream os, Map<String,String> map) throws IOException {
+ if(map==null) {
+ os.writeInt(-1);
+ } else {
+ Set<Entry<String, String>> es = map.entrySet();
+ os.writeInt(es.size());
+ for(Entry<String,String> e : es) {
+ writeString(os, e.getKey());
+ writeString(os, e.getValue());
+ }
+ }
- }
+ }
- public static Map<String,String> readStringMap(DataInputStream is, byte[] buff) throws IOException {
- int l = is.readInt();
- if(l<0) {
- return null;
- }
- Map<String,String> map = new HashMap<String,String>(l);
- for(int i=0;i<l;++i) {
- String key = readString(is,buff);
- map.put(key,readString(is,buff));
- }
- return map;
- }
- public static void writeHeader(DataOutputStream os, int magic, int version) throws IOException {
- os.writeInt(magic);
- os.writeInt(version);
- }
-
- public static int readHeader(DataInputStream is, final int magic, final int version) throws IOException {
- if(is.readInt()!=magic) {
- throw new IOException("Corrupted Data Stream");
- }
- int v = is.readInt();
- if(version<0 || v>version) {
- throw new IOException("Unsupported Data Version: " + v);
- }
- return v;
- }
+ public static Map<String,String> readStringMap(DataInputStream is, byte[] buff) throws IOException {
+ int l = is.readInt();
+ if(l<0) {
+ return null;
+ }
+ Map<String,String> map = new HashMap<>(l);
+ for(int i=0;i<l;++i) {
+ String key = readString(is,buff);
+ map.put(key,readString(is,buff));
+ }
+ return map;
+ }
+ public static void writeHeader(DataOutputStream os, int magic, int version) throws IOException {
+ os.writeInt(magic);
+ os.writeInt(version);
+ }
+
+ public static int readHeader(DataInputStream is, final int magic, final int version) throws IOException {
+ if(is.readInt()!=magic) {
+ throw new IOException("Corrupted Data Stream");
+ }
+ int v = is.readInt();
+ if(version<0 || v>version) {
+ throw new IOException("Unsupported Data Version: " + v);
+ }
+ return v;
+ }
}