Examples with ProcessContextParameter org.apache.beam.sdk.transforms.reflect.DoFnSignature.Parameter.ProcessContextParameter used on opensource projects

Example 1 with ProcessContextParameter

use of org.apache.beam.sdk.transforms.reflect.DoFnSignature.Parameter.ProcessContextParameter in project beam by apache.

the class ParDo method getDoFnSchemaInformation.

/**
 * Extract information on how the DoFn uses schemas. In particular, if the schema of an element
 * parameter does not match the input PCollection's schema, convert.
 */
@Internal
public static DoFnSchemaInformation getDoFnSchemaInformation(DoFn<?, ?> fn, PCollection<?> input) {
    DoFnSignature signature = DoFnSignatures.getSignature(fn.getClass());
    DoFnSignature.ProcessElementMethod processElementMethod = signature.processElement();
    if (!processElementMethod.getSchemaElementParameters().isEmpty()) {
        if (!input.hasSchema()) {
            throw new IllegalArgumentException("Type of @Element must match the DoFn type" + input);
        }
    }
    SchemaRegistry schemaRegistry = input.getPipeline().getSchemaRegistry();
    DoFnSchemaInformation doFnSchemaInformation = DoFnSchemaInformation.create();
    for (SchemaElementParameter parameter : processElementMethod.getSchemaElementParameters()) {
        TypeDescriptor<?> elementT = parameter.elementT();
        FieldAccessDescriptor accessDescriptor = getFieldAccessDescriptorFromParameter(parameter.fieldAccessString(), input.getSchema(), signature.fieldAccessDeclarations(), fn);
        doFnSchemaInformation = doFnSchemaInformation.withFieldAccessDescriptor(accessDescriptor);
        Schema selectedSchema = SelectHelpers.getOutputSchema(input.getSchema(), accessDescriptor);
        ConvertHelpers.ConvertedSchemaInformation converted = ConvertHelpers.getConvertedSchemaInformation(selectedSchema, elementT, schemaRegistry);
        if (converted.outputSchemaCoder != null) {
            doFnSchemaInformation = doFnSchemaInformation.withSelectFromSchemaParameter((SchemaCoder<?>) input.getCoder(), accessDescriptor, selectedSchema, converted.outputSchemaCoder, converted.unboxedType != null);
        } else {
            // If the selected schema is a Row containing a single primitive type (which is the output
            // of Select when selecting a primitive), attempt to unbox it and match against the
            // parameter.
            checkArgument(converted.unboxedType != null);
            doFnSchemaInformation = doFnSchemaInformation.withUnboxPrimitiveParameter((SchemaCoder<?>) input.getCoder(), accessDescriptor, selectedSchema, elementT);
        }
    }
    for (DoFnSignature.Parameter p : processElementMethod.extraParameters()) {
        if (p instanceof ProcessContextParameter || p instanceof ElementParameter) {
            doFnSchemaInformation = doFnSchemaInformation.withFieldAccessDescriptor(FieldAccessDescriptor.withAllFields());
            break;
        }
    }
    return doFnSchemaInformation;
}