Implement a file content storage

Level: intermediate

Example

Create a class that implements the IFileContentStorage interface to create a content storage in the file system.

Implement a file content storage

namespace Terrasoft.Configuration {
    using System.IO;
    using System.Threading.Tasks;
    using Terrasoft.File.Abstractions;
    using Terrasoft.File.Abstractions.Content;
    using Terrasoft.File.Abstractions.Metadata;
    using Terrasoft.File.Metadata;

    /// <summary>
    /// Content storage in the file system.
    /// </summary>
    public class FsFileBlobStorage: IFileContentStorage {

        // A root path to the storage.
        private
        const string BaseFsPath = "C:\\FsStore\\";

        private static string GetPath(FileMetadata fileMetadata) {
            var md = (EntityFileMetadata) fileMetadata;
            string key = $ "{md.EntitySchemaName}\\{md.RecordId}_{fileMetadata.Name}";
            return Path.Combine(BaseFsPath, key);
        }

        public Task <Stream> ReadAsync(IFileContentReadContext context) {
            string filePath = GetPath(context.FileMetadata);
            Stream stream = System.IO.File.OpenRead(filePath);
            return Task.FromResult(stream);
        }

        public async Task WriteAsync(IFileContentWriteContext context) {
            string filePath = GetPath(context.FileMetadata);
            FileMode flags = context.WriteOptions != FileWriteOptions.SinglePart ?
                FileMode.Append :
                FileMode.OpenOrCreate;
            string dirPath = Path.GetDirectoryName(filePath);
            if (!Directory.Exists(dirPath)) {
                Directory.CreateDirectory(dirPath);
            }
            using(var fileStream = System.IO.File.Open(filePath, flags)) {
                context.Stream.CopyToAsync(fileStream);
            }
        }

        public Task DeleteAsync(IFileContentDeleteContext context) {
            string filePath = GetPath(context.FileMetadata);
            System.IO.File.Delete(filePath);
            return Task.CompletedTask;
        }

        public Task CopyAsync(IFileContentCopyMoveContext context) {
            string sourceFilePath = GetPath(context.SourceMetadata);
            string targetFilePath = GetPath(context.TargetMetadata);
            System.IO.File.Copy(sourceFilePath, targetFilePath);
            return Task.CompletedTask;
        }

        public Task MoveAsync(IFileContentCopyMoveContext context) {
            string sourceFilePath = GetPath(context.SourceMetadata);
            string targetFilePath = GetPath(context.TargetMetadata);
            System.IO.File.Move(sourceFilePath, targetFilePath);
            return Task.CompletedTask;
        }
    }
}