Microsoft.Extensions.Caching.Postgres 1.2.2

Microsoft.Extensions.Caching.Postgres

A distributed cache implementation using PostgreSQL for .NET applications.

Installation

Install the NuGet package:

dotnet add package Microsoft.Extensions.Caching.Postgres

Configuration

1. Configure appsettings.json

Add the following configuration sections to your appsettings.json file. It's also recommended to configure your connection string to use connection pooling:

 "ConnectionStrings": {
 "PostgresCache": "Host=localhost;Port=5432;Username=postgres;Password=yourpassword;Database=yourdatabase;Pooling=true;MinPoolSize=0;MaxPoolSize=100;Timeout=15;"
 },
 "PostgresCache": {
 "SchemaName": "public",
 "TableName": "cache",
 "CreateIfNotExists": true,
 "UseWAL": false,
 "ExpiredItemsDeletionInterval": "00:30:00",
 "DefaultSlidingExpiration": "00:20:00"
 }

Configuration Options

2. Register the Service

Using Configuration Binding

using Microsoft.Extensions.DependencyInjection;

var builder = WebApplication.CreateBuilder(args);

// Register Postgres distributed cache
builder.Services.AddDistributedPostgresCache(options => {
 options.ConnectionString = builder.Configuration.GetConnectionString("PostgresCache");
 options.SchemaName = builder.Configuration.GetValue<string>("PostgresCache:SchemaName", "public");
 options.TableName = builder.Configuration.GetValue<string>("PostgresCache:TableName", "cache");
 options.CreateIfNotExists = builder.Configuration.GetValue<bool>("PostgresCache:CreateIfNotExists", true);
 options.UseWAL = builder.Configuration.GetValue<bool>("PostgresCache:UseWAL", false);
 
 // Optional: Configure expiration settings

 var expirationInterval = builder.Configuration.GetValue<string>("PostgresCache:ExpiredItemsDeletionInterval");
 if (!string.IsNullOrEmpty(expirationInterval) && TimeSpan.TryParse(expirationInterval, out var interval)) {
 options.ExpiredItemsDeletionInterval = interval;
 }
 
 var slidingExpiration = builder.Configuration.GetValue<string>("PostgresCache:DefaultSlidingExpiration");
 if (!string.IsNullOrEmpty(slidingExpiration) && TimeSpan.TryParse(slidingExpiration, out var sliding)) {
 options.DefaultSlidingExpiration = sliding;
 }
});

var app = builder.Build();

3. Using the Cache

Once configured, you can inject and use IDistributedCache in your services: using Microsoft.Extensions.Caching.Distributed;

public class MyService {
 private readonly IDistributedCache _cache; 

 public MyService(IDistributedCache cache) {
 _cache = cache;
 }

 public async Task<string> GetDataAsync(string key) {
 var cachedData = await _cache.GetStringAsync(key);
 
 if (cachedData == null) {
 // Fetch data from source
 var data = await FetchDataFromSource();
 
 // Cache the data with options
 var options = new DistributedCacheEntryOptions {
 AbsoluteExpirationRelativeToNow = TimeSpan.FromMinutes(30),
 SlidingExpiration = TimeSpan.FromMinutes(5)
 };
 
 await _cache.SetStringAsync(key, data, options);
 return data;
 }
 
 return cachedData;
 }
}

Environment Variables

You can also configure the cache using environment variables with the prefix PostgresCache__:

PostgresCache__ConnectionString="Host=localhost;Port=5432;Username=postgres;Password=yourpassword;Database=yourdatabase"
PostgresCache__SchemaName="public"
PostgresCache__TableName="cache"
PostgresCache__CreateIfNotExists="true"