55 lines
1.2 KiB
Go
55 lines
1.2 KiB
Go
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package mydb
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import (
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"fmt"
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"sync"
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)
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var (
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adapterMap = make(map[string]Adapter)
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adapterMapMu sync.RWMutex
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)
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// Adapter interface defines an adapter
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type Adapter interface {
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Open(ConnectionURL) (Session, error)
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}
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type missingAdapter struct {
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name string
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}
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func (ma *missingAdapter) Open(ConnectionURL) (Session, error) {
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return nil, fmt.Errorf("mydb: Missing adapter %q, did you forget to import it?", ma.name)
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}
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// RegisterAdapter registers a generic database adapter.
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func RegisterAdapter(name string, adapter Adapter) {
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adapterMapMu.Lock()
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defer adapterMapMu.Unlock()
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if name == "" {
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panic(`Missing adapter name`)
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}
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if _, ok := adapterMap[name]; ok {
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panic(`db.RegisterAdapter() called twice for adapter: ` + name)
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}
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adapterMap[name] = adapter
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}
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// LookupAdapter returns a previously registered adapter by name.
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func LookupAdapter(name string) Adapter {
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adapterMapMu.RLock()
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defer adapterMapMu.RUnlock()
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if adapter, ok := adapterMap[name]; ok {
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return adapter
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}
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return &missingAdapter{name: name}
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}
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// Open attempts to stablish a connection with a database.
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func Open(adapterName string, settings ConnectionURL) (Session, error) {
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return LookupAdapter(adapterName).Open(settings)
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}
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