Created
March 30, 2015 16:44
-
-
Save Swoogan/41c3bb1beb3cdfd9f209 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
public struct DocIdLookup | |
{ | |
public List<string> DocIds; | |
public int Index; | |
} | |
public class Indexer | |
{ | |
private readonly Dictionary<string, List<string>> _terms = | |
new Dictionary<string, List<string>>(StringComparer.OrdinalIgnoreCase); | |
private readonly Dictionary<string, List<DocIdLookup>> _docIds = | |
new Dictionary<string, List<DocIdLookup>>(); | |
public void Index(string docId, string text) | |
{ | |
List<DocIdLookup> indexes; | |
if (_docIds.TryGetValue(docId, out indexes)) | |
{ | |
foreach (var index in indexes) | |
index.DocIds.RemoveAt(index.Index); | |
} | |
else | |
{ | |
indexes = new List<DocIdLookup>(); | |
} | |
var words = text.Split(); | |
foreach (var term in words) | |
{ | |
List<string> val; | |
if (_terms.TryGetValue(term, out val) == false) | |
{ | |
val = new List<string>(); | |
_terms[term] = val; | |
} | |
val.Add(docId); | |
indexes.Add(new DocIdLookup | |
{ | |
DocIds = val, | |
Index = val.Count - 1 | |
}); | |
} | |
_docIds[docId] = indexes; | |
} | |
public List<string> Query(string term) | |
{ | |
List<string> val; | |
_terms.TryGetValue(term, out val); | |
return val ?? new List<string>(); | |
} | |
public void Delete(string docId) | |
{ | |
List<DocIdLookup> indexes; | |
if (!_docIds.TryGetValue(docId, out indexes)) | |
return; | |
foreach (var index in indexes) | |
index.DocIds.RemoveAt(index.Index); | |
_docIds.Remove(docId); | |
} | |
} | |
[TestMethod] | |
public void CanIndexAndQuery() | |
{ | |
var index = new Indexer(); | |
index.Index("users/1", "Oren Eini"); | |
index.Index("users/2", "Hibernating Rhinos"); | |
index.Index("users/3", "Oren is Anyende"); | |
Assert.IsTrue(index.Query("eini").Contains("users/1")); | |
Assert.IsTrue(index.Query("rhinos").Contains("users/2")); | |
Assert.IsTrue(index.Query("Oren").Contains("users/1")); | |
Assert.IsTrue(index.Query("Oren").Contains("users/3")); | |
} | |
[TestMethod] | |
public void CanUpdate() | |
{ | |
var index = new Indexer(); | |
index.Index("users/1", "Oren Eini"); | |
//updating | |
index.Index("users/1", "Ayende Rahien"); | |
Assert.IsTrue(index.Query("Rahien").Contains("users/1")); | |
Assert.IsTrue(index.Query("eini").Count == 0); | |
} | |
[TestMethod] | |
public void CanDelete() | |
{ | |
var index = new Indexer(); | |
index.Index("users/1", "Oren Eini"); | |
var query = index.Query("Oren"); | |
Assert.IsTrue(query.Contains("users/1")); | |
// deleting | |
index.Delete("users/1"); | |
Assert.IsTrue(index.Query("Oren").Count == 0); | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment