dev@241: /**
dev@241:  * Created by lucast on 26/04/2017.
dev@241:  */
dev@241: import {StreamingResponse} from 'piper/StreamingService';
dev@241: import {Feature} from 'piper/Feature';
dev@241: import {SampleType} from 'piper';
dev@241: 
dev@241: export const arrayReducer = <T>(acc: T[], val: T[]): T[] => {
dev@241:   acc.push.apply(acc, val);
dev@241:   return acc;
dev@241: };
dev@241: 
dev@241: export const typedArrayReducer = (acc: Float32Array,
dev@241:                                   val: Float32Array): Float32Array => {
dev@241:   return Float32Array.of(...acc, ...val);
dev@241: };
dev@241: 
dev@241: const inPlaceTypedArrayReducer = (acc: Float32Array,
dev@241:                                   val: Float32Array,
dev@241:                                   i: number): Float32Array => {
dev@241:   acc.set(val, i);
dev@241:   return acc;
dev@241: };
dev@241: 
dev@241: export const streamingResponseReducer = (acc: StreamingResponse,
dev@241:                                          val: StreamingResponse,
dev@241:                                          i: number): StreamingResponse => {
dev@241:   acc.processedBlockCount = val.processedBlockCount;
dev@241:   if (acc.features.data instanceof Array &&
dev@241:     val.features.data instanceof Array) {
dev@241:     acc.features.data = arrayReducer<Feature>(
dev@241:       acc.features.data,
dev@241:       val.features.data
dev@241:     );
dev@241:   } else if (acc.features.data instanceof Float32Array &&
dev@241:     val.features.data instanceof Float32Array) {
dev@241:     const isOneSamplePerStep = acc.outputDescriptor.configured.sampleType ===
dev@241:       SampleType.OneSamplePerStep;
dev@241:     if (isOneSamplePerStep) {
dev@241:       // for one sample per step vectors we know there will be totalBlockCount
dev@241:       // number of samples - so pre-allocate the Float32Array when we know
dev@241:       // the totalBlockCount (after receiving the first feature)
dev@241:       if ( i === 1  ) {
dev@241:         const newBlock = new Float32Array(acc.totalBlockCount);
dev@241:         newBlock[0] = acc.features.data[0];
dev@241:         acc.features.data = newBlock;
dev@241:       }
dev@241:       acc.features.data = inPlaceTypedArrayReducer(
dev@241:         acc.features.data,
dev@241:         val.features.data,
dev@241:         i
dev@241:       );
dev@241:     } else { // if not OneSamplePerStep we have to make a new array each time
dev@241:       acc.features.data = typedArrayReducer(
dev@241:         acc.features.data,
dev@241:         val.features.data
dev@241:       );
dev@241:     }
dev@241:   } else {
dev@241:     throw new Error('Invalid feature output. Aborting');
dev@241:   }
dev@241:   return acc;
dev@241: };