Initial open source release

internal/store/postgres/counter_source.go

@@ -0,0 +1,78 @@
+package postgres
+
+import (
+	"context"
+	"fmt"
+
+	"telesrv/internal/store/postgres/sqlcgen"
+)
+
+// MessageBoxCounterSource 从 message_boxes durable log 恢复某 owner 的当前最大 box_id。
+type MessageBoxCounterSource struct {
+	q *sqlcgen.Queries
+}
+
+// NewMessageBoxCounterSource 创建 Redis BoxIDAllocator 的 PG 恢复源。
+func NewMessageBoxCounterSource(db sqlcgen.DBTX) *MessageBoxCounterSource {
+	return &MessageBoxCounterSource{q: sqlcgen.New(db)}
+}
+
+func (s *MessageBoxCounterSource) Current(ctx context.Context, userID int64) (int, error) {
+	v, err := s.q.MaxMessageBoxID(ctx, userID)
+	if err != nil {
+		return 0, fmt.Errorf("max message box id: %w", err)
+	}
+	return int(v), nil
+}
+
+// ChannelIDCounterSource 从 channels durable 表恢复全局 channel id。
+type ChannelIDCounterSource struct {
+	db sqlcgen.DBTX
+}
+
+// NewChannelIDCounterSource 创建 Redis ChannelIDAllocator 的 PG 恢复源。
+func NewChannelIDCounterSource(db sqlcgen.DBTX) *ChannelIDCounterSource {
+	return &ChannelIDCounterSource{db: db}
+}
+
+func (s *ChannelIDCounterSource) Current(ctx context.Context, _ int64) (int, error) {
+	var id int
+	if err := s.db.QueryRow(ctx, `SELECT COALESCE(MAX(id), 0) FROM channels`).Scan(&id); err != nil {
+		return 0, fmt.Errorf("max channel id: %w", err)
+	}
+	return id, nil
+}
+
+// ChannelPtsCounterSource 从 channel_update_events 恢复某 channel 的当前最大 pts。
+type ChannelPtsCounterSource struct {
+	db sqlcgen.DBTX
+}
+
+func NewChannelPtsCounterSource(db sqlcgen.DBTX) *ChannelPtsCounterSource {
+	return &ChannelPtsCounterSource{db: db}
+}
+
+func (s *ChannelPtsCounterSource) Current(ctx context.Context, channelID int64) (int, error) {
+	var pts int
+	if err := s.db.QueryRow(ctx, `SELECT COALESCE(MAX(pts), 0) FROM channel_update_events WHERE channel_id = $1`, channelID).Scan(&pts); err != nil {
+		return 0, fmt.Errorf("max channel pts: %w", err)
+	}
+	return pts, nil
+}
+
+// ChannelMessageIDCounterSource 从 channel_messages 恢复某 channel 的当前最大 message id。
+type ChannelMessageIDCounterSource struct {
+	db sqlcgen.DBTX
+}
+
+func NewChannelMessageIDCounterSource(db sqlcgen.DBTX) *ChannelMessageIDCounterSource {
+	return &ChannelMessageIDCounterSource{db: db}
+}
+
+func (s *ChannelMessageIDCounterSource) Current(ctx context.Context, channelID int64) (int, error) {
+	var id int
+	if err := s.db.QueryRow(ctx, `SELECT COALESCE(MAX(id), 0) FROM channel_messages WHERE channel_id = $1`, channelID).Scan(&id); err != nil {
+		return 0, fmt.Errorf("max channel message id: %w", err)
+	}
+	return id, nil
+}