46 lines
1.1 KiB
Go
46 lines
1.1 KiB
Go
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package common
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import "database/sql"
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import "github.com/Azareal/Gosora/query_gen"
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var Meta MetaStore
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// MetaStore is a simple key-value store for the system to stash things in when needed
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type MetaStore interface {
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Get(name string) (val string, err error)
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Set(name string, val string) error
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}
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type DefaultMetaStore struct {
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get *sql.Stmt
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set *sql.Stmt
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add *sql.Stmt
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}
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func NewDefaultMetaStore(acc *qgen.Accumulator) (*DefaultMetaStore, error) {
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m := &DefaultMetaStore{
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get: acc.Select("meta").Columns("value").Where("name = ?").Prepare(),
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set: acc.Update("meta").Set("value = ?").Where("name = ?").Prepare(),
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add: acc.Insert("meta").Columns("name,value").Fields("?,''").Prepare(),
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}
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return m, acc.FirstError()
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}
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func (s *DefaultMetaStore) Get(name string) (val string, err error) {
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err = s.get.QueryRow(name).Scan(&val)
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return val, err
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}
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// TODO: Use timestamped rows as a more robust method of ensuring data integrity
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func (s *DefaultMetaStore) Set(name string, val string) error {
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_, err := s.Get(name)
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if err == sql.ErrNoRows {
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_, err := s.add.Exec(name)
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if err != nil {
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return err
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}
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}
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_, err = s.set.Exec(val, name)
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return err
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}
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