80 lines
1.4 KiB
Go
80 lines
1.4 KiB
Go
package database
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import (
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"context"
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"fmt"
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"sync"
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"git.yetaga.in/alazyreader/library/media"
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)
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type Memory struct {
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lock sync.Mutex
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shelf []media.Book
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}
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func (m *Memory) GetAllBooks(_ context.Context) ([]media.Book, error) {
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m.lock.Lock()
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defer m.lock.Unlock()
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if m.shelf == nil {
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m.shelf = []media.Book{}
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}
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return m.shelf, nil
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}
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func (m *Memory) AddBook(_ context.Context, b *media.Book) error {
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m.lock.Lock()
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defer m.lock.Unlock()
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if m.shelf == nil {
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m.shelf = []media.Book{}
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}
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m.shelf = append(m.shelf, *b)
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return nil
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}
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func (m *Memory) UpdateBook(_ context.Context, old, new *media.Book) error {
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m.lock.Lock()
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defer m.lock.Unlock()
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if m.shelf == nil {
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m.shelf = []media.Book{}
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return fmt.Errorf("book does not exist")
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}
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if old.ID != new.ID {
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return fmt.Errorf("cannot change book ID")
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}
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for i := range m.shelf {
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if m.shelf[i].ID == old.ID {
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m.shelf[i] = *new
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return nil
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}
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}
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return fmt.Errorf("book does not exist")
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}
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func (m *Memory) DeleteBook(_ context.Context, b *media.Book) error {
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m.lock.Lock()
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defer m.lock.Unlock()
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if m.shelf == nil {
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m.shelf = []media.Book{}
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return fmt.Errorf("book does not exist")
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}
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for i := range m.shelf {
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if m.shelf[i].ID == b.ID {
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// reorder slice to remove book quickly
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m.shelf[i] = m.shelf[len(m.shelf)-1]
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m.shelf = m.shelf[:len(m.shelf)-1]
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return nil
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}
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}
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return fmt.Errorf("book does not exist")
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}
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