import org.apache.cassandra.cql.CQLStatement; //导入依赖的package包/类
public PreparationContext(ThriftClientState clientState, String queryString, CQLStatement statement)
{
    this.clientState = clientState;
    this.queryString = queryString;
    this.statement = statement;
}
 

import org.apache.cassandra.cql.CQLStatement; //导入依赖的package包/类
protected boolean removeEldestEntry(Map.Entry<Integer, CQLStatement> eldest)
{
    return size() > MAX_CACHE_PREPARED;
}
 

import org.apache.cassandra.cql.CQLStatement; //导入依赖的package包/类
public Map<Integer, CQLStatement> getPrepared()
{
    return prepared;
}
 

import org.apache.cassandra.cql.CQLStatement; //导入依赖的package包/类
protected boolean removeEldestEntry(Map.Entry<Integer, CQLStatement> eldest) {
    return size() > MAX_CACHE_PREPARED;
}
 

import org.apache.cassandra.cql.CQLStatement; //导入依赖的package包/类
/**
 * Called in QueryProcessor, once a CQL statement has been prepared.
 *
 * @param statement the statement to perform additional processing on
 * @param context preparation context containing additional info
 *                about the operation and statement
 * @throws RequestValidationException
 */
void processStatement(CQLStatement statement, PreparationContext context) throws RequestValidationException;
 

import org.apache.cassandra.cql.CQLStatement; //导入依赖的package包/类
/**
 * Perform pre-processing on a CQL statement prior to it being
 * executed by the QueryProcessor. If required, implementations
 * may modify the statement as the returned instance is what
 * is actually executed.
 *
 * @param statement the statement to perform pre-processing on
 * @param context execution context containing additional info
 *                about the operation and statement
 * @return the actual statement that will be executed, possibly
 *         a modification of the initial statement
 * @throws RequestExecutionException, RequestValidationException
 */
CQLStatement processStatement(CQLStatement statement, ExecutionContext context) throws RequestExecutionException, RequestValidationException;