/**
* Used by subclasses to resolve deferred values on demand. This is useful when a certain value
* comes from a generated key of another master object.
*/
protected Object getValue(Map<String, Object> valueMap, DbAttribute attribute) {
Object value = valueMap.get(attribute.getName());
// if a value is a Factory, resolve it here...
// slight chance that a normal value will implement Factory interface???
if (value instanceof Factory) {
value = ((Factory) value).create();
valueMap.put(attribute.getName(), value);
// update replacement id
if (attribute.isPrimaryKey()) {
// sanity check
if (value == null) {
String name = attribute.getEntity() != null ? attribute.getEntity().getName() : "<null>";
throw new CayenneRuntimeException(
"Failed to generate PK: " + name + "." + attribute.getName());
}
ObjectId id = getObjectId();
if (id != null) {
// always override with fresh value as this is what's in the
// DB
id.getReplacementIdMap().put(attribute.getName(), value);
}
}
}
return value;
}
/**
* Generates a unique and non-repeating primary key for specified dbEntity.
*
* <p>This implementation is naive since it does not lock the database rows when executing select
* and subsequent update. Adapter-specific implementations are more robust.
*
* @since 3.0
*/
public Object generatePk(DataNode node, DbAttribute pk) throws Exception {
DbEntity entity = (DbEntity) pk.getEntity();
switch (pk.getType()) {
case Types.BINARY:
case Types.VARBINARY:
return IDUtil.pseudoUniqueSecureByteSequence(pk.getMaxLength());
}
DbKeyGenerator pkGenerator = entity.getPrimaryKeyGenerator();
long cacheSize;
if (pkGenerator != null && pkGenerator.getKeyCacheSize() != null)
cacheSize = pkGenerator.getKeyCacheSize().intValue();
else cacheSize = pkCacheSize;
long value;
// if no caching, always generate fresh
if (cacheSize <= 1) {
value = longPkFromDatabase(node, entity);
} else {
synchronized (pkCache) {
LongPkRange r = pkCache.get(entity.getName());
if (r == null) {
// created exhausted LongPkRange
r = new LongPkRange(1l, 0l);
pkCache.put(entity.getName(), r);
}
if (r.isExhausted()) {
long val = longPkFromDatabase(node, entity);
r.reset(val, val + cacheSize - 1);
}
value = r.getNextPrimaryKey();
}
}
if (pk.getType() == Types.BIGINT) {
return Long.valueOf(value);
} else {
// leaving it up to the user to ensure that PK does not exceed max int...
return Integer.valueOf((int) value);
}
}