protected void parseCreateField()

in src/main/java/org/opensearch/knn/index/KNNVectorFieldMapper.java [389:459]
57 lines of code
14 McCabe index (conditional complexity)

    protected void parseCreateField(ParseContext context, int dimension) throws IOException {

        if (!KNNSettings.isKNNPluginEnabled()) {
            throw new IllegalStateException("KNN plugin is disabled. To enable " +
                    "update knn.plugin.enabled setting to true");
        }

        if (KNNSettings.isCircuitBreakerTriggered()) {
            throw new IllegalStateException("Indexing knn vector fields is rejected as circuit breaker triggered." +
                    " Check _opendistro/_knn/stats for detailed state");
        }

        context.path().add(simpleName());

        ArrayList<Float> vector = new ArrayList<>();
        XContentParser.Token token = context.parser().currentToken();
        float value;
        if (token == XContentParser.Token.START_ARRAY) {
            token = context.parser().nextToken();
            while (token != XContentParser.Token.END_ARRAY) {
                value = context.parser().floatValue();

                if (Float.isNaN(value)) {
                    throw new IllegalArgumentException("KNN vector values cannot be NaN");
                }

                if (Float.isInfinite(value)) {
                    throw new IllegalArgumentException("KNN vector values cannot be infinity");
                }

                vector.add(value);
                token = context.parser().nextToken();
            }
        } else if (token == XContentParser.Token.VALUE_NUMBER) {
            value = context.parser().floatValue();

            if (Float.isNaN(value)) {
                throw new IllegalArgumentException("KNN vector values cannot be NaN");
            }

            if (Float.isInfinite(value)) {
                throw new IllegalArgumentException("KNN vector values cannot be infinity");
            }

            vector.add(value);
            context.parser().nextToken();
        } else if (token == XContentParser.Token.VALUE_NULL) {
            context.path().remove();
            return;
        }

        if (dimension != vector.size()) {
            String errorMessage = String.format("Vector dimension mismatch. Expected: %d, Given: %d", dimension,
                    vector.size());
            throw new IllegalArgumentException(errorMessage);
        }

        float[] array = new float[vector.size()];
        int i = 0;
        for (Float f : vector) {
            array[i++] = f;
        }

        VectorField point = new VectorField(name(), array, fieldType);

        context.doc().add(point);
        if (fieldType.stored()) {
            context.doc().add(new StoredField(name(), point.toString()));
        }
        context.path().remove();
    }