grpc-swift/Packages/gRPC/Sources/Metadata.swift

/*
 *
 * Copyright 2016, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 */
#if SWIFT_PACKAGE
  import CgRPC
#endif
import Foundation // for String.Encoding

/// An item of metadata
public struct MetadataPair {
  public var key: String
  public var value: String
  public init(key:String, value:String) {
    self.key = key
    self.value = value
  }
}

/// Metadata sent with gRPC messages
public class Metadata {

  /// Pointer to underlying C representation
  var array: UnsafeMutableRawPointer

  init(array: UnsafeMutableRawPointer) {
    self.array = array
  }

  public init() {
    self.array = cgrpc_metadata_array_create();
  }

  public init(pairs: [MetadataPair]) {
    self.array = cgrpc_metadata_array_create();
    for pair in pairs {
      self.add(key:pair.key, value:pair.value)
    }
  }

  deinit {
    cgrpc_metadata_array_destroy(array);
  }

  public func count() -> Int {
    return cgrpc_metadata_array_get_count(array);
  }

  public func key(index: Int) -> (String) {
    return String(cString:cgrpc_metadata_array_get_key_at_index(array, index),
                  encoding:String.Encoding.utf8)!;
  }

  public func value(index: Int) -> (String) {
    return String(cString:cgrpc_metadata_array_get_value_at_index(array, index),
                  encoding:String.Encoding.utf8)!;
  }

  public func add(key:String, value:String) {
    cgrpc_metadata_array_append_metadata(array, key, value)
  }
}