/Raven.Database/Server/Controllers/QueriesController.cs

using System.Collections.Generic;

using System.Linq;

using System.Net;

using System.Net.Http;

using System.Threading.Tasks;

using System.Web.Http;

using Raven.Abstractions.Data;

using Raven.Abstractions.Util.Encryptors;

using Raven.Database.Data;

using Raven.Json.Linq;



namespace Raven.Database.Server.Controllers

{

	public class QueriesController : RavenDbApiController

	{

		[HttpGet]

		[Route("queries")]

		[Route("databases/{databaseName}/queries")]

		public Task<HttpResponseMessage> QueriesGet()

		{

			return GetQueriesResponse(true);

		}



		[HttpPost]

		[Route("queries")]

		[Route("databases/{databaseName}/queries")]

		public Task<HttpResponseMessage> QueriesPost()

		{

			return GetQueriesResponse(false);

		}



		private async Task<HttpResponseMessage> GetQueriesResponse(bool isGet)

		{

			RavenJArray itemsToLoad;

		    if (isGet == false)

		    {

		        itemsToLoad = await ReadJsonArrayAsync();

                AddRequestTraceInfo(sb =>

                {

                    foreach (var item in itemsToLoad)

                    {

                        sb.Append("\t").Append(item).AppendLine();

                    }

                });

		    }

		    else

		    {

		        itemsToLoad = new RavenJArray(GetQueryStringValues("id").Cast<object>());

		    }



			var result = new MultiLoadResult();

			var loadedIds = new HashSet<string>();

            var includedIds = new HashSet<string>();

			var includes = GetQueryStringValues("include") ?? new string[0];

			var transformer = GetQueryStringValue("transformer") ?? GetQueryStringValue("resultTransformer");

			var transformerParameters = this.ExtractTransformerParameters();

			var transactionInformation = GetRequestTransaction();

			var includedEtags = new List<byte>();



		    if (string.IsNullOrEmpty(transformer) == false)

		    {

                var transformerDef = Database.IndexDefinitionStorage.GetTransformer(transformer);

		        if (transformerDef == null)

		            return GetMessageWithObject(new {Error = "No such transformer: " + transformer}, HttpStatusCode.BadRequest);

                includedEtags.AddRange(transformerDef.GetHashCodeBytes());



		    }



			Database.TransactionalStorage.Batch(actions =>

			{

				foreach (RavenJToken item in itemsToLoad)

				{

					var value = item.Value<string>();

					if (loadedIds.Add(value) == false)

						continue;

					var documentByKey = string.IsNullOrEmpty(transformer)

										? Database.Documents.Get(value, transactionInformation)

                                        : Database.Documents.GetWithTransformer(value, transformer, transactionInformation, transformerParameters, out includedIds);

				    if (documentByKey == null)

				    {

                        if(ClientIsV3OrHigher)

                            result.Results.Add(null); 

                        continue;

				    }

					result.Results.Add(documentByKey.ToJson());



					if (documentByKey.Etag != null)

						includedEtags.AddRange(documentByKey.Etag.ToByteArray());



					includedEtags.Add((documentByKey.NonAuthoritativeInformation ?? false) ? (byte)0 : (byte)1);

				}



				var addIncludesCommand = new AddIncludesCommand(Database, transactionInformation, (etag, includedDoc) =>

				{

					includedEtags.AddRange(etag.ToByteArray());

					result.Includes.Add(includedDoc);

				}, includes, loadedIds);



				foreach (var item in result.Results.Where(item => item != null))

				{

					addIncludesCommand.Execute(item);

				}

			});





			foreach (var includedId in includedIds)

		    {

		        var doc = Database.Documents.Get(includedId, transactionInformation);

		        if (doc == null)

		        {

                    continue;

		        }

                includedEtags.AddRange(doc.Etag.ToByteArray());

		        result.Includes.Add(doc.ToJson());

		    }



            var computeHash = Encryptor.Current.Hash.Compute16(includedEtags.ToArray());

            Etag computedEtag = Etag.Parse(computeHash);



			if (MatchEtag(computedEtag))

			{

				return GetEmptyMessage(HttpStatusCode.NotModified);

			}



			var msg = GetMessageWithObject(result);

			WriteETag(computedEtag, msg);



			AddRequestTraceInfo(sb => sb.Append("Results count: {0}, includes count: {1}", result.Results.Count, result.Includes.Count).AppendLine());



			return msg;

		}

        

	}

}