package storage

import (
	"sync"
	"time"

	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
)

// inmemoryPart represents in-memory partition.
type inmemoryPart struct {
	ph partHeader

	timestampsData bytesutil.ByteBuffer
	valuesData     bytesutil.ByteBuffer
	indexData      bytesutil.ByteBuffer
	metaindexData  bytesutil.ByteBuffer

	creationTime time.Time
}

// Reset resets mp.
func (mp *inmemoryPart) Reset() {
	mp.ph.Reset()

	mp.timestampsData.Reset()
	mp.valuesData.Reset()
	mp.indexData.Reset()
	mp.metaindexData.Reset()

	mp.creationTime = time.Time{}
}

// InitFromRows initializes mp from the given rows.
func (mp *inmemoryPart) InitFromRows(rows []rawRow) {
	if len(rows) == 0 {
		logger.Panicf("BUG: Inmemory.InitFromRows must accept at least one row")
	}

	mp.Reset()
	rrm := getRawRowsMarshaler()
	rrm.marshalToInmemoryPart(mp, rows)
	putRawRowsMarshaler(rrm)
	mp.creationTime = time.Now()
}

// NewPart creates new part from mp.
//
// It is safe calling NewPart multiple times.
// It is unsafe re-using mp while the returned part is in use.
func (mp *inmemoryPart) NewPart() (*part, error) {
	ph := mp.ph
	size := uint64(len(mp.timestampsData.B) + len(mp.valuesData.B) + len(mp.indexData.B) + len(mp.metaindexData.B))
	return newPart(&ph, "", size, mp.metaindexData.NewReader(), &mp.timestampsData, &mp.valuesData, &mp.indexData)
}

func getInmemoryPart() *inmemoryPart {
	v := mpPool.Get()
	if v == nil {
		return &inmemoryPart{}
	}
	return v.(*inmemoryPart)
}

func putInmemoryPart(mp *inmemoryPart) {
	mp.Reset()
	mpPool.Put(mp)
}

var mpPool sync.Pool