github.com/zntrio/harp/v2@v2.0.9/pkg/sdk/value/signature/registry.go (about)

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     2  // license agreements. See the NOTICE file distributed with
     3  // this work for additional information regarding copyright
     4  // ownership. Elasticsearch B.V. licenses this file to you under
     5  // the Apache License, Version 2.0 (the "License"); you may
     6  // not use this file except in compliance with the License.
     7  // You may obtain a copy of the License at
     8  //
     9  //     http://www.apache.org/licenses/LICENSE-2.0
    10  //
    11  // Unless required by applicable law or agreed to in writing,
    12  // software distributed under the License is distributed on an
    13  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    14  // KIND, either express or implied.  See the License for the
    15  // specific language governing permissions and limitations
    16  // under the License.
    17  
    18  package signature
    19  
    20  import (
    21  	"fmt"
    22  
    23  	"github.com/zntrio/harp/v2/pkg/sdk/value"
    24  )
    25  
    26  // TransformerFactoryFunc is used for transformer building for signature.
    27  type TransformerFactoryFunc func(string) (value.Transformer, error)
    28  
    29  var registry map[string]TransformerFactoryFunc
    30  
    31  // Register a transformer with the given prefix.
    32  func Register(prefix string, factory TransformerFactoryFunc) {
    33  	// Lazy initialization
    34  	if registry == nil {
    35  		registry = map[string]TransformerFactoryFunc{}
    36  	}
    37  
    38  	// Check if not already registered
    39  	if _, ok := registry[prefix]; ok {
    40  		panic(fmt.Errorf("signature transformer already registered fro %q prefix", prefix))
    41  	}
    42  
    43  	// Register the transformer
    44  	registry[prefix] = factory
    45  }