/**
* Returns the first non-static cell in the ColumnFamily. This is necessary to avoid recording a
* static column as the "last" cell seen in a reversed query. Because we will always query static
* columns alongside the normal data for a page, they are not a good indicator of where paging
* should resume. When we begin the next page, we need to start from the last non-static cell.
*/
protected Column firstNonStaticColumn(ColumnFamily cf) {
for (Column column : cf) {
ColumnDefinition def = cfm.getColumnDefinitionFromColumnName(column.name());
if (def == null || def.type != ColumnDefinition.Type.STATIC) return column;
}
return null;
}
private int discardHead(
ColumnFamily cf,
int toDiscard,
ColumnFamily copy,
Iterator<Column> iter,
DeletionInfo.InOrderTester tester) {
ColumnCounter counter = columnCounter();
List<Column> staticColumns = new ArrayList<>(cfm.staticColumns().size());
// Discard the first 'toDiscard' live, non-static columns
while (iter.hasNext()) {
Column c = iter.next();
// if it's a static column, don't count it and save it to add to the trimmed results
ColumnDefinition columnDef = cfm.getColumnDefinitionFromColumnName(c.name());
if (columnDef != null && columnDef.type == ColumnDefinition.Type.STATIC) {
staticColumns.add(c);
continue;
}
counter.count(c, tester);
// once we've discarded the required amount, add the rest
if (counter.live() > toDiscard) {
for (Column staticColumn : staticColumns) copy.addColumn(staticColumn);
copy.addColumn(c);
while (iter.hasNext()) copy.addColumn(iter.next());
}
}
return Math.min(counter.live(), toDiscard);
}
public IndexedEntry decodeEntry(DecoratedKey indexedValue, Column indexEntry) {
int ckCount = baseCfs.metadata.clusteringKeyColumns().size();
ByteBuffer[] components = getIndexComparator().split(indexEntry.name());
ColumnNameBuilder builder = getBaseComparator().builder();
for (int i = 0; i < ckCount; i++) builder.add(components[i + 1]);
return new IndexedEntry(
indexedValue, indexEntry.name(), indexEntry.timestamp(), components[0], builder);
}
public RowMutation toSchema(long timestamp) {
RowMutation rm = new RowMutation(Table.SYSTEM_TABLE, SystemTable.getSchemaKSKey(name));
ColumnFamily cf = rm.addOrGet(SystemTable.SCHEMA_KEYSPACES_CF);
cf.addColumn(Column.create(name, timestamp, "name"));
cf.addColumn(Column.create(durableWrites, timestamp, "durable_writes"));
cf.addColumn(Column.create(strategyClass.getName(), timestamp, "strategy_class"));
cf.addColumn(Column.create(json(strategyOptions), timestamp, "strategy_options"));
for (CFMetaData cfm : cfMetaData.values()) cfm.toSchema(rm, timestamp);
return rm;
}
public Column reconcile(Column left, Column right) {
ClockRelationship cr = left.clock().compare(right.clock());
switch (cr) {
case EQUAL:
// tombstones take precedence. (if both are tombstones, then it doesn't matter which one we
// use.)
if (left.isMarkedForDelete()) return left;
if (right.isMarkedForDelete()) return right;
// break ties by comparing values.
return FBUtilities.compareByteArrays(left.value(), right.value()) < 0 ? right : left;
case GREATER_THAN:
return left;
case LESS_THAN:
return right;
default:
throw new IllegalArgumentException(
"Timestamp clocks must either be equal, greater then or less than: " + cr);
}
}
