csharp 字典扩展 - GetOrAdd，AddOrUpdate

Posted 2021-05-12

/// Latest version is here: https://gist.github.com/pmunin/28d0ba1acce677736c5e
using System;
using System.Collections;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DictionaryUtils
{
    public static partial class DictionaryGetOrAddExtensions
    {
        static TValue GetOrAdd<TKey, TValue>(IDictionary<TKey, TValue> dictionary, TKey key, Func<TKey, TValue> createValueIfNotExist)
        {
            if(dictionary is ConcurrentDictionary<TKey,TValue> concurrentDictionary)
                return concurrentDictionary.GetOrAdd(key, valueFactory: createValueIfNotExist);

            if (!dictionary.TryGetValue(key, out var res))
                dictionary.Add(key, res = createValueIfNotExist(key));
            return res;
            //System.Collections.Concurrent.ConcurrentDictionary<,>
        }
        public static TResult GetOrAdd<TKey, TValue, TResult>(this IDictionary<TKey, TValue> dictionary, TKey key, Func<TKey, TResult> createResultIfNotExistAs)
            where TResult:TValue
        {
            var res = GetOrAdd<TKey,TValue>(dictionary, key, createValueIfNotExist:k=>createResultIfNotExistAs(k));
            return (TResult)res;
        }
    }
}

/// Latest version is here: https://gist.github.com/pmunin/28d0ba1acce677736c5e
using System;
using System.Collections;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DictionaryUtils
{
    public static partial class DictionaryAddOrUpdateExtensions
    {
        static TValue AddOrUpdate<TKey, TValue>(IDictionary<TKey, TValue> dict, TKey key, TValue addValue, Func<TKey, TValue, TValue> updateValueFactoryExt = null)
        {
            if (updateValueFactoryExt == null)
                updateValueFactoryExt = (k, v) => addValue;
            if (dict is ConcurrentDictionary<TKey, TValue> concDict)
                return concDict.AddOrUpdate(key, addValue, updateValueFactoryExt);

            if (dict.TryGetValue(key, out var res))
                dict[key] = res = updateValueFactoryExt(key, res);
            else
                dict[key] = res = addValue;
            return res;
        }

        static TValue AddOrUpdate<TKey, TValue>(IDictionary<TKey, TValue> dict, TKey key, Func<TKey, TValue> addValueFactory, Func<TKey, TValue, TValue> updateValueFactoryExt = null)
        {
            if (updateValueFactoryExt == null)
                updateValueFactoryExt = (k, v) => addValueFactory(k);
            if (dict is ConcurrentDictionary<TKey, TValue> concDict)
                return concDict.AddOrUpdate(key, addValueFactory, updateValueFactoryExt);

            if (dict.TryGetValue(key, out var res))
                dict[key] = res = updateValueFactoryExt(key, res);
            else
                dict[key] = res = addValueFactory(key);
            return res;
        }

        public static TValue AddOrUpdate<TKey, TValue, TResult>(this IDictionary<TKey, TValue> dict, TKey key, Func<TKey, TResult> addValueFactory, Func<TKey, TResult, TResult> updateValueFactoryExt)
            where TResult : TValue
        {
            return AddOrUpdate<TKey, TValue>(dict, key, k => addValueFactory(k), (k, oldVal) => updateValueFactoryExt(k, (TResult)oldVal));
        }

        public static TValue AddOrUpdate<TKey, TValue, TResult>(this IDictionary<TKey, TValue> dict, TKey key, TResult addValue, Func<TKey, TResult, TResult> updateValueFactoryExt)
    where TResult : TValue
        {
            return AddOrUpdate<TKey, TValue>(dict, key, addValue, (k, oldVal) => updateValueFactoryExt(k, (TResult)oldVal));
        }

    }
}