public KNNVectorFieldMapper build()

in src/main/java/org/opensearch/knn/index/KNNVectorFieldMapper.java [203:266]
45 lines of code
6 McCabe index (conditional complexity)

        public KNNVectorFieldMapper build(BuilderContext context) {
            // Originally, a user would use index settings to set the spaceType, efConstruction and m hnsw
            // parameters. Upon further review, it makes sense to set these parameters in the mapping of a
            // particular field. However, because users migrating from older versions will still use the index
            // settings to set these parameters, we will need to provide backwards compatibilty. In order to
            // handle this, we first check if the mapping is set, and, if so use it. If not, we check if the model is
            // set. If not, we fall back to the parameters set in the index settings. This means that if a user sets
            // the mappings, setting the index settings will have no impact.

            KNNMethodContext knnMethodContext = this.knnMethodContext.getValue();
            if (knnMethodContext != null) {
                return new MethodFieldMapper(name,
                        new KNNVectorFieldType(buildFullName(context), meta.getValue(), dimension.getValue()),
                        multiFieldsBuilder.build(this, context),
                        copyTo.build(),
                        ignoreMalformed(context),
                        stored.get(),
                        hasDocValues.get(),
                        knnMethodContext);
            }

            String modelIdAsString = this.modelId.get();
            if (modelIdAsString != null) {
                // Because model information is stored in cluster metadata, we are unable to get it here. This is
                // because to get the cluster metadata, you need access to the cluster state. Because this code is
                // sometimes used to initialize the cluster state/update cluster state, we cannot get the state here
                // safely. So, we are unable to validate the model. The model gets validated during ingestion.

                return new ModelFieldMapper(
                        name,
                        new KNNVectorFieldType(buildFullName(context), meta.getValue(), -1, modelIdAsString),
                        multiFieldsBuilder.build(this, context),
                        copyTo.build(),
                        ignoreMalformed(context),
                        stored.get(),
                        hasDocValues.get(),
                        modelDao,
                        modelIdAsString);
            }

            // Build legacy
            if (this.spaceType == null) {
                this.spaceType = LegacyFieldMapper.getSpaceType(context.indexSettings());
            }

            if (this.m == null) {
                this.m = LegacyFieldMapper.getM(context.indexSettings());
            }

            if (this.efConstruction == null) {
                this.efConstruction = LegacyFieldMapper.getEfConstruction(context.indexSettings());
            }

            return new LegacyFieldMapper(name,
                    new KNNVectorFieldType(buildFullName(context), meta.getValue(), dimension.getValue()),
                    multiFieldsBuilder.build(this, context),
                    copyTo.build(),
                    ignoreMalformed(context),
                    stored.get(),
                    hasDocValues.get(),
                    spaceType,
                    m,
                    efConstruction);
        }