worker_config.go

package ocrworker

import (
	"flag"
	"fmt"
)

// WorkerConfig will be passed to ocr engines and is used to establish connection to a message  broker
type WorkerConfig struct {
	AmqpURI           string
	Exchange          string
	ExchangeType      string
	RoutingKey        string
	Reliable          bool
	AmqpAPIURI        string
	APIPathQueue      string
	APIQueueName      string
	APIPathStats      string
	SaveFiles         bool
	Debug             bool
	Tiff2pdfConverter string
	NumParallelJobs   uint
	FlgVersion        bool
}

// DefaultWorkerConfig will set the default set of worker parameters which are needed for testing and connecting to a broker
func DefaultWorkerConfig() WorkerConfig {
	// Reliable: false due to major issues that would completely
	// wedge the rpc worker.  Setting the buffered channels length
	// higher would delay the problem, but then it would still happen later.

	workerConfig := WorkerConfig{
		AmqpURI:           "amqp://guest:guest@localhost:5672/",
		Exchange:          "open-ocr-exchange",
		ExchangeType:      "direct",
		RoutingKey:        "decode-ocr",
		Reliable:          false, // setting to false because of observed issues
		AmqpAPIURI:        "http://guest:guest@localhost:15672",
		APIPathQueue:      "/api/queues/%2f/",
		APIQueueName:      "decode-ocr",
		APIPathStats:      "/api/nodes",
		SaveFiles:         false,
		Debug:             false,
		Tiff2pdfConverter: "convert",
		NumParallelJobs:   1,
		FlgVersion:        false,
	}
	return workerConfig
}

// FlagFunctionWorker will be used as argument type for DefaultConfigFlagsWorkerOverride
type FlagFunctionWorker func()

// NoOpFlagFunctionWorker will return an empty set of cli parameters.
// In this case default parameter will be used
func NoOpFlagFunctionWorker() FlagFunctionWorker {
	return func() {}
}

func DefaultConfigFlagsWorkerOverride(flagFunction FlagFunctionWorker) (WorkerConfig, error) {
	workerConfig := DefaultWorkerConfig()

	flagFunction()
	var (
		amqpURI           string
		saveFiles         bool
		debug             bool
		tiff2pdfConverter string
		flgVersion        bool
		numParJobs        uint
	)
	flag.StringVar(
		&amqpURI,
		"amqp_uri",
		"",
		"The Amqp URI, eg: amqp://guest:guest@localhost:5672/",
	)
	flag.BoolVar(
		&saveFiles,
		"save_files",
		false,
		"if set there will be no clean up of temporary files",
	)
	flag.BoolVar(
		&debug,
		"debug",
		false,
		"sets debug flag, program will print more messages",
	)
	flag.StringVar(
		&tiff2pdfConverter,
		"image_converter",
		"convert",
		"use convert or tiff2pdf for converting incoming tiff files, e.g. -image_converter {convert,tiff2pdf},"+
			"tools must be installed on system",
	)
	flag.UintVar(
		&numParJobs,
		"num_parallel_jobs",
		1,
		"how many messages will be preloaded from a message broker. Can be used to saturate the load"+
			" Set the value to 1 for round robbin distribution of messages across workers.",
	)

	flag.BoolVar(
		&flgVersion,
		"version",
		false,
		"show version and exit",
	)

	flag.Parse()

	workerConfig.FlgVersion = flgVersion
	if len(amqpURI) > 0 {
		workerConfig.AmqpURI = amqpURI
	}
	if len(tiff2pdfConverter) > 0 {
		workerConfig.Tiff2pdfConverter = tiff2pdfConverter
		if tiff2pdfConverter != "convert" && tiff2pdfConverter != "tiff2pdf" {
			return workerConfig, fmt.Errorf("please choose convert of tiff2pdf as image converter")
		}
	}
	workerConfig.SaveFiles = saveFiles
	workerConfig.Debug = debug
	workerConfig.NumParallelJobs = numParJobs
	return workerConfig, nil
}