Faceted search SO example

gistfile1.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Linq.Expressions;
using Raven.Abstractions.Data;
using Raven.Abstractions.Indexing;
using Raven.Client;
using Raven.Client.Linq;

namespace Raven.Tests.Faceted
{
	public class StackoverflowFacetedIndex  : RavenTest
	{
		private readonly List<Facet> _facets;

		public StackoverflowFacetedIndex()
		{
			_facets = new List<Facet> { new Facet {Name = "Tag"} };
		}

		public void StackoverflowTest()
		{
			using (var store = NewDocumentStore())
			{
				ExecuteTest(store);				
			}
		}    

		private void ExecuteTest(IDocumentStore store)
		{
			using (var s = store.OpenSession())
			{
				s.Store(new FacetSetup { Id = "facets/TagFacets", Facets = _facets });
				s.SaveChanges();

				store.DatabaseCommands.PutIndex("QuestionTags",
												new IndexDefinition
												{
													Map = 
@"from question in docs
from tag in question.Tags
select new 
{ 
	question.CreatedOn, 
	Tag = tag
}"
												});

				var counter = 0;
				var sampleData = GetSampleData();
				foreach (var qu in sampleData)
				{
					s.Store(qu);
					counter++;

					if (counter % 1024 == 0)
						s.SaveChanges();
				}
				s.SaveChanges();

				// Issue a query to make sure the index isn't stale
				var result = s.Query<Question>("QuestionTags")					
					.Customize(x => x.WaitForNonStaleResults())
					.ToList();

				//WaitForUserToContinueTheTest(store as EmbeddableDocumentStore);

				var expressions = new Expression<Func<Question, bool>>[]
				{
					//Matches all docs
					x => x.CreatedOn >= new DateTime(1900, 1, 1),
					//Only matches 2 questions (hence tag count should be different)
					x => x.CreatedOn >= new DateTime(2008, 5, 7),
					//Only matches 1 question 
					x => x.CreatedOn >= new DateTime(2008, 5, 20),
				};

				foreach (var exp in expressions)
				{
					Console.WriteLine("Query: " + exp);

					var facetQueryTimer = Stopwatch.StartNew();
					var facetResults = s.Query<Question>("QuestionTags")
						.Where(exp)
						.ToFacets("facets/TagFacets");
					facetQueryTimer.Stop();
					//Console.WriteLine("Took {0:0.00} msecs", facetQueryTimer.ElapsedMilliseconds);
					
					var filteredData = sampleData
											.Where(exp.Compile())
											.SelectMany(x => x.Tags)
											.GroupBy(tag => tag)
											.Select(grp => new { Tag = grp.Key, Count = grp.Count()})
											.ToList();

					foreach (var tagCount in filteredData)
					{
						var matchingTag = tagCount.Tag.ToLowerInvariant();
						var match = facetResults["Tag"].FirstOrDefault(x => x.Range == matchingTag);
						if (match == null || match.Count != tagCount.Count)
						{
							Console.WriteLine("Tag {0}, expected {1}, got {2}",
											  tagCount.Tag, tagCount.Count, match == null ? "<null>" : match.Count.ToString());
						}
					}
					var facetList = facetResults["Tag"].Select(x => String.Format("{0} - {1}", x.Range, x.Count));
					Console.WriteLine("Results: {0}\n", String.Join(", ", facetList));
				}
			}
		}

		private static IEnumerable<Question> GetSampleData()
		{
			yield return new Question
							 {
								 Subject = "Pew Pew",
								 CreatedOn = new DateTime(2008, 5, 12),
								 UserId = "Users/Justin",
								 Tags = new[] {"C#", ".NET", "Regex"}
							 };

			yield return new Question
							 {
								 Subject = " RuRoh :( ",
								 CreatedOn = new DateTime(2008, 5, 3),
								 UserId = "Users/Ayende",
								 Tags = new[] {"C#", ".NET"}
							 };

			yield return new Question
							 {
								 Subject = "How do I get the codeZ??",
								 CreatedOn = new DateTime(2008, 5, 20),
								 UserId = "Users/Matt",
								 Tags = new[] {"Ruby"}
							 };
		}
	}

	public class User
	{
		public string Id { get; set; }
		public string DisplayName { get; set; }
	}

	public class Question
	{
		public string Id { get; set; }
		public string UserId { get; set; } // Reference to User.Id 
		public string Subject { get; set; }
		public DateTime CreatedOn { get; set; } // Utc of course :) 
		public IList<string> Tags { get; set; } // Tag Id's. (eg. tags/1 tags/2 ...) 
	} 

	public class Tag 
	{ 
		public string Id { get; set; } 
		public string Name { get; set; } 
		public IList<string> Aliases { get; set; } 
	} 	
}