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/*
* This file is part of Go Responsiveness.
*
* Go Responsiveness is free software: you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by the Free Software Foundation,
* either version 2 of the License, or (at your option) any later version.
* Go Responsiveness is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with Go Responsiveness. If not, see <https://www.gnu.org/licenses/>.
*/
package datalogger
import (
"fmt"
"io"
"os"
"reflect"
"sync"
"github.com/network-quality/goresponsiveness/utilities"
)
type DataLogger[T any] interface {
LogRecord(record T)
Export() bool
Close() bool
}
type CSVDataLogger[T any] struct {
mut *sync.Mutex
recordCount int
data []T
isOpen bool
destination io.WriteCloser
}
type NullDataLogger[T any] struct{}
func CreateNullDataLogger[T any]() DataLogger[T] {
return &NullDataLogger[T]{}
}
func (_ *NullDataLogger[T]) LogRecord(_ T) {}
func (_ *NullDataLogger[T]) Export() bool { return true }
func (_ *NullDataLogger[T]) Close() bool { return true }
func CreateCSVDataLogger[T any](filename string) (DataLogger[T], error) {
data := make([]T, 0)
destination, err := os.Create(filename)
if err != nil {
return &CSVDataLogger[T]{&sync.Mutex{}, 0, data, true, destination}, err
}
result := CSVDataLogger[T]{&sync.Mutex{}, 0, data, true, destination}
return &result, nil
}
func (logger *CSVDataLogger[T]) LogRecord(record T) {
logger.mut.Lock()
defer logger.mut.Unlock()
logger.recordCount += 1
logger.data = append(logger.data, record)
}
func doCustomFormatting(value reflect.Value, tag reflect.StructTag) (string, error) {
if utilities.IsInterfaceNil(value) {
return "", fmt.Errorf("Cannot format an empty interface value")
}
formatMethodName, success := tag.Lookup("Formatter")
if !success {
return "", fmt.Errorf("Could not find the formatter name")
}
formatMethodArgument, success := tag.Lookup("FormatterArgument")
if !success {
formatMethodArgument = ""
}
formatMethod := value.MethodByName(formatMethodName)
if formatMethod == reflect.ValueOf(0) {
return "", fmt.Errorf(
"Type %v does not support a method named %v",
value.Type(),
formatMethodName,
)
}
var formatMethodArgumentUsable []reflect.Value = make([]reflect.Value, 0)
if formatMethodArgument != "" {
formatMethodArgumentUsable = append(
formatMethodArgumentUsable,
reflect.ValueOf(formatMethodArgument),
)
}
result := formatMethod.Call(formatMethodArgumentUsable)
if len(result) == 1 {
return fmt.Sprintf("%v", result[0]), nil
}
return "", fmt.Errorf("Too many results returned by the format method's invocation.")
}
func (logger *CSVDataLogger[T]) Export() bool {
logger.mut.Lock()
defer logger.mut.Unlock()
if !logger.isOpen {
return false
}
toOmit := make([]int, 0)
visibleFields := reflect.VisibleFields(reflect.TypeOf((*T)(nil)).Elem())
for i, v := range visibleFields {
description, success := v.Tag.Lookup("Description")
columnName := v.Name
if success {
if description == "[OMIT]" {
toOmit = append(toOmit, i)
continue
}
columnName = description
}
logger.destination.Write([]byte(fmt.Sprintf("%s, ", columnName)))
}
logger.destination.Write([]byte("\n"))
// Remove the Omitted fields
for _, i := range toOmit {
visibleFields = append(visibleFields[:i], visibleFields[i+1:]...)
}
for _, d := range logger.data {
for _, v := range visibleFields {
data := reflect.ValueOf(d)
toWrite := data.FieldByIndex(v.Index)
if formattedToWrite, err := doCustomFormatting(toWrite, v.Tag); err == nil {
logger.destination.Write([]byte(fmt.Sprintf("%s,", formattedToWrite)))
} else {
logger.destination.Write([]byte(fmt.Sprintf("%v, ", toWrite)))
}
}
logger.destination.Write([]byte("\n"))
}
return true
}
func (logger *CSVDataLogger[T]) Close() bool {
logger.mut.Lock()
defer logger.mut.Unlock()
if !logger.isOpen {
return false
}
logger.destination.Close()
logger.isOpen = false
return true
}
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