72 lines
2.5 KiB
Go
72 lines
2.5 KiB
Go
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// Package queue implements the message-plane business logic from
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// design.md §2b/§3: SendMessage/ReceiveMessage/DeleteMessage/
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// ChangeMessageVisibility, FIFO gating, and shard-aware routing.
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package queue
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import (
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"context"
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"fmt"
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goredis "github.com/redis/go-redis/v9"
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"github.com/rockliang/kafka-management-service/internal/kafka"
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kmsvcredis "github.com/rockliang/kafka-management-service/internal/redis"
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)
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// ShardRouter resolves a routing key to a shard by reading the cached shard
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// map the queue-operator writes (design.md §4 `kmsvc:shardmap:`). It is the
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// only piece of core logic that needs to know shards exist — everything
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// downstream operates against a resolved (shard, topic) pair exactly as it
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// would against a single topic.
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//
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// In-process caching of the shard map (design.md §4's stated optimization)
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// is intentionally not implemented in v1: a direct Redis read per call is
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// simpler and still cheap relative to a Kafka round trip, and can be added
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// later without changing this type's interface.
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type ShardRouter struct {
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Redis *goredis.Client
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}
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// RouteForSend returns the Active shard a new message with the given
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// routing key (MessageGroupId for FIFO, a random UUID for standard queues)
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// should be produced to.
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func (r *ShardRouter) RouteForSend(ctx context.Context, queueName, routingKey string) (kafka.Shard, error) {
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shards, err := r.shards(ctx, queueName)
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if err != nil {
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return kafka.Shard{}, err
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}
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shard, found := kafka.SelectShard(kafka.ActiveShards(shards), routingKey)
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if !found {
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return kafka.Shard{}, fmt.Errorf("no active shard covers the routing key for queue %s", queueName)
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}
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return shard, nil
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}
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// ConsumableShards returns every shard a consumer should be subscribed to:
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// Active (write+read) and Closing (read-only, draining) — everything except
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// Closed, whose topic has already been deleted.
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func (r *ShardRouter) ConsumableShards(ctx context.Context, queueName string) ([]kafka.Shard, error) {
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shards, err := r.shards(ctx, queueName)
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if err != nil {
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return nil, err
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}
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out := make([]kafka.Shard, 0, len(shards))
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for _, s := range shards {
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if s.Phase != "Closed" {
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out = append(out, s)
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}
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}
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return out, nil
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}
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func (r *ShardRouter) shards(ctx context.Context, queueName string) ([]kafka.Shard, error) {
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shards, ok, err := kmsvcredis.GetShardMap(ctx, r.Redis, queueName)
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if err != nil {
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return nil, fmt.Errorf("read shard map %s: %w", queueName, err)
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}
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if !ok || len(shards) == 0 {
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return nil, fmt.Errorf("queue %s has no shard map yet (not reconciled)", queueName)
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}
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return shards, nil
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}
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