github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/pkg/sink/codec/avro/schema_manager.go (about)

     1  // Copyright 2023 PingCAP, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package avro
    15  
    16  import (
    17  	"context"
    18  
    19  	"github.com/linkedin/goavro/v2"
    20  )
    21  
    22  // SchemaManager is an interface for schema registry
    23  type SchemaManager interface {
    24  	Register(ctx context.Context, schemaName string, schemaDefinition string) (schemaID, error)
    25  	Lookup(ctx context.Context, schemaName string, schemaID schemaID) (*goavro.Codec, error)
    26  	GetCachedOrRegister(ctx context.Context, topicName string,
    27  		tableVersion uint64, schemaGen SchemaGenerator) (*goavro.Codec, []byte, error)
    28  	RegistryType() string
    29  	ClearRegistry(ctx context.Context, schemaName string) error
    30  }
    31  
    32  // SchemaGenerator represents a function that returns an Avro schema in JSON.
    33  // Used for lazy evaluation
    34  type SchemaGenerator func() (string, error)
    35  
    36  type schemaID struct {
    37  	// confluentSchemaID is the Confluent Schema ID, it represents
    38  	// a unique schema in Confluent Schema Registry
    39  	confluentSchemaID int
    40  	// glueSchemaID is the AWS Glue SchemaVersionID, it represents
    41  	// a unique schema in AWS Glue Schema Registry
    42  	glueSchemaID string
    43  }
    44  
    45  type schemaCacheEntry struct {
    46  	// tableVersion is the table's version which the message associated with.
    47  	// encoder use it as the cache key.
    48  	tableVersion uint64
    49  	// schemaID is the unique identifier of a schema in schema registry.
    50  	// for each message should carry this id to allow the decoder fetch the corresponding schema
    51  	// decoder use it as the cache key.
    52  	schemaID schemaID
    53  	// codec is associated with the schemaID, used to decode the message
    54  	codec  *goavro.Codec
    55  	header []byte
    56  }