/**
* Perform a range scan for a set of records in the database. Each field/value pair from the
* result will be stored in a HashMap.
*
* @param table The name of the table
* @param startkey The record key of the first record to read.
* @param recordcount The number of records to read
* @param fields The list of fields to read, or null for all of them
* @param result A Vector of HashMaps, where each HashMap is a set field/value pairs for one
* record
* @return Zero on success, a non-zero error code on error
*/
public int scan(
String table,
String startkey,
int recordcount,
Set<String> fields,
Vector<HashMap<String, ByteIterator>> result) {
if (!_table.equals(table)) {
try {
client.set_keyspace(table);
_table = table;
} catch (Exception e) {
e.printStackTrace();
e.printStackTrace(System.out);
return Error;
}
}
for (int i = 0; i < OperationRetries; i++) {
try {
SlicePredicate predicate;
if (fields == null) {
predicate =
new SlicePredicate()
.setSlice_range(new SliceRange(emptyByteBuffer, emptyByteBuffer, false, 1000000));
} else {
ArrayList<ByteBuffer> fieldlist = new ArrayList<ByteBuffer>(fields.size());
for (String s : fields) {
fieldlist.add(ByteBuffer.wrap(s.getBytes("UTF-8")));
}
predicate = new SlicePredicate().setColumn_names(fieldlist);
}
KeyRange kr =
new KeyRange()
.setStart_key(startkey.getBytes("UTF-8"))
.setEnd_key(new byte[] {})
.setCount(recordcount);
List<KeySlice> results =
client.get_range_slices(parent, predicate, kr, ConsistencyLevel.ONE);
if (_debug) {
System.out.println("Scanning startkey: " + startkey);
}
HashMap<String, ByteIterator> tuple;
for (KeySlice oneresult : results) {
tuple = new HashMap<String, ByteIterator>();
Column column;
String name;
ByteIterator value;
for (ColumnOrSuperColumn onecol : oneresult.columns) {
column = onecol.column;
name =
new String(
column.name.array(),
column.name.position() + column.name.arrayOffset(),
column.name.remaining());
value =
new ByteArrayByteIterator(
column.value.array(),
column.value.position() + column.value.arrayOffset(),
column.value.remaining());
tuple.put(name, value);
if (_debug) {
System.out.print("(" + name + "=" + value + ")");
}
}
result.add(tuple);
if (_debug) {
System.out.println();
}
}
return Ok;
} catch (Exception e) {
errorexception = e;
}
try {
Thread.sleep(500);
} catch (InterruptedException e) {
}
}
errorexception.printStackTrace();
errorexception.printStackTrace(System.out);
return Error;
}
