aggregateuse.nc

nesC写的heed算法

// $Id: AggregateUse.nc,v 1.5.4.3 2003/08/26 09:08:14 cssharp Exp $

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/**
 * Author: Eugene Shvets
 *
 * Intention is to make addition of user-defined aggregates easy.
 * Dispatch is based on aggregate id (AggregateID enum is Aggregates.h),
 * which is the first argument for every command in this interface.
 * No in-memory data structures is created to keep aggregate info, therefore
 * we need to pass ParamList argument to each command
 * @author Eugene Shvets
 */

includes Aggregates;
interface AggregateUse {
  /**
   * dest, merge - raw data. each aggregate can cast it to appropriate data structure.
   * Stuff that previosly came as part of expr->ex.tagg is passed in general way as list of params
   */
  command result_t merge(uint8_t id, char *destdata, char *mergedata, ParamList *params, ParamVals *paramValues);

  //we'll probably get rid of this later
  command result_t update(uint8_t id, char *dest, char* value, ParamList *params, ParamVals *paramValues);

  /**
   * Called in the beginning of each epoch
   * @param isFirstTime true if this is the very first call for this aggregate
   */
  command result_t init(uint8_t id, char *data, ParamList *params, ParamVals *paramValues, bool isFirstTime);

  command uint16_t stateSize(uint8_t id, ParamList *params, ParamVals *paramValues);

  command bool hasData(uint8_t id, char *data, ParamList *params, ParamVals *paramValues);

  command TinyDBError finalize(uint8_t id, char *data, char *result_buf, ParamList *params, ParamVals *paramValues);
  
  command AggregateProperties getProperties(uint8_t id);
}