71 lines
1.4 KiB
Go
71 lines
1.4 KiB
Go
package topic
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import (
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"context"
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"fmt"
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"log"
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"sync"
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"github.com/jackc/pgconn"
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)
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type Database interface {
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Exec(ctx context.Context, query string, args ...interface{}) (pgconn.CommandTag, error)
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}
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type Topic struct {
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CreateTable func(ctx context.Context, db Database) error
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Store func(ctx context.Context, db Database, packet *Packet) error
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}
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var registry = struct {
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topics map[string]*Topic
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lock *sync.Mutex
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}{
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topics: map[string]*Topic{},
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lock: new(sync.Mutex),
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}
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func Register(topic string, handler *Topic) {
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registry.lock.Lock()
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defer registry.lock.Unlock()
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if _, ok := registry.topics[topic]; ok {
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panic(fmt.Sprintf("attempt to register pht '%s' that has already been registered", topic))
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}
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registry.topics[topic] = handler
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}
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type Packet struct {
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Topic string
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Publisher string
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Received int64 // unix timestamp
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Payload []byte
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}
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// Setup ensures all the required tables are created.
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func Setup(ctx context.Context, db Database) error {
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registry.lock.Lock()
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defer registry.lock.Unlock()
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for key, topic := range registry.topics {
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log.Println("running CreateTable for", key)
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err := topic.CreateTable(ctx, db)
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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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return nil
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}
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func Publish(ctx context.Context, db Database, packet *Packet) error {
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topic, ok := registry.topics[packet.Topic]
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if !ok {
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return fmt.Errorf("topic: no handler for topic '%s' [%x]", packet.Topic, packet.Payload)
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}
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return topic.Store(ctx, db, packet)
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}
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