portal/db/models/tus_lock.go

89 lines
2.3 KiB
Go

package models
import (
"context"
"errors"
"gorm.io/gorm"
"gorm.io/gorm/clause"
"time"
)
var (
ErrTusLockBusy = errors.New("lock is currently held by another process")
)
type TusLock struct {
gorm.Model
LockId string `gorm:"index:idx_lock_id,unique"`
HolderPID int `gorm:"index"`
AcquiredAt time.Time
ExpiresAt time.Time
ReleaseRequested bool
DeletedAt gorm.DeletedAt `gorm:"index:idx_lock_id,unique"`
}
func (t *TusLock) TryLock(db *gorm.DB, ctx context.Context) error {
return db.Transaction(func(tx *gorm.DB) error {
var existingLock TusLock
if err := tx.WithContext(ctx).Clauses(clause.Locking{Strength: "UPDATE"}).Where("lock_id = ?", t.LockId).First(&existingLock).Error; err != nil {
if errors.Is(err, gorm.ErrRecordNotFound) {
// Insert new lock record
err := tx.WithContext(ctx).Create(t).Error
if err != nil {
return err
}
t = &existingLock
return nil
}
return err
}
// Check if existing lock is expired
if existingLock.ExpiresAt.Before(time.Now()) || existingLock.ReleaseRequested {
err := tx.Model(&existingLock).Updates(t).Error
if err != nil {
return err
}
t = &existingLock
return nil
}
// Lock is currently held by another process
return ErrTusLockBusy
})
}
func (t *TusLock) RequestRelease(db *gorm.DB) error {
return db.Transaction(func(tx *gorm.DB) error {
// Update the ReleaseRequested flag in the database for the specific lock
return tx.Model(t).Where("lock_id = ?", t.LockId).Update("release_requested", true).Error
})
}
func (t *TusLock) Released(db *gorm.DB) error {
return db.Transaction(func(tx *gorm.DB) error {
// Update the ReleaseRequested flag in the database for the specific lock
return tx.Model(t).Where("lock_id = ?", t.LockId).Update("release_requested", false).Error
})
}
func (t *TusLock) IsReleaseRequested(db *gorm.DB) (bool, error) {
var count int64
err := db.Model(&TusLock{}).Where(&TusLock{LockId: t.LockId, ReleaseRequested: true}).Count(&count).Error
if err != nil {
if errors.Is(err, gorm.ErrRecordNotFound) {
return true, nil
}
return false, err
}
return count > 0, nil
}
func (t *TusLock) Delete(db *gorm.DB) error {
return db.Where("lock_id = ?", t.LockId).Delete(&TusLock{}).Error
}