#24 Add WikibaseUri atomic class.

WikiClientLibrary/Wikibase/PropertyType.cs

@@ -72,7 +72,7 @@ public static class PropertyTypes
                 var after = (int) e["after"];
                 var precision = (WikibaseTimePrecision) (int) e["precision"];
                 var calendar = (string) e["calendarmodel"];
-                return new WikibaseTime(time, before, after, timeZone, precision, calendar);
+                return new WikibaseTime(time, before, after, timeZone, precision, WikibaseUri.Get(calendar));
             }, v =>
             {
                 var obj = new JObject
@@ -82,7 +82,7 @@ public static class PropertyTypes
                     {"before", v.Before},
                     {"after", v.After},
                     {"precision", (int) v.Precision},
-                    {"calendarmodel", v.CalendarModel}
+                    {"calendarmodel", v.CalendarModel.Uri}
                 };
                 return obj;
             });

WikiClientLibrary/Wikibase/WikibaseTime.cs

@@ -14,7 +14,7 @@ public struct WikibaseTime : IEquatable<WikibaseTime>
 
         public WikibaseTime(int year, int month, int day, int hour, int minute, int second,
             int before, int after, int timeZone,
-            WikibaseTimePrecision precision, string calendarModel)
+            WikibaseTimePrecision precision, WikibaseUri calendarModel)
         {
             Year = year;
             Month = month;
@@ -33,7 +33,8 @@ public WikibaseTime(int year, int month, int day, int hour, int minute, int seco
         private static readonly Regex ISO8601Matcher =
             new Regex(@"^\s*(?<Y>[\+-]?\d{1,9})-(?<M>\d\d?)-(?<D>\d\d?)T(?<H>\d\d?)-(?<m>\d\d?)-(?<S>\d\d?)(?<K>Z|[\+-]\d\d?:\d\d?)?\s*$");
 
-        public WikibaseTime(string dateTime, int before, int after, int timeZone, WikibaseTimePrecision precision, string calendarModel)
+        public WikibaseTime(string dateTime, int before, int after, int timeZone,
+            WikibaseTimePrecision precision, WikibaseUri calendarModel)
         {
             if (dateTime == null) throw new ArgumentNullException(nameof(dateTime));
             var dateTimeMatch = ISO8601Matcher.Match(dateTime);
@@ -102,7 +103,7 @@ public WikibaseTime(string dateTime, int before, int after, int timeZone, Wikiba
         /// <summary>
         /// URI identifying the calendar model.
         /// </summary>
-        public string CalendarModel { get; }
+        public WikibaseUri CalendarModel { get; }
 
         public string ToIso8601UtcString()
         {

WikiClientLibrary/Wikibase/WikibaseUri.cs

@@ -0,0 +1,111 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+using System.Text;
+using Newtonsoft.Json;
+
+namespace WikiClientLibrary.Wikibase
+{
+    /// <summary>
+    /// An atomic instance of URI used in Wikibase.
+    /// </summary>
+    [JsonObject(ItemConverterType = typeof(WikibaseUriJsonConverter))]
+    public sealed class WikibaseUri : IEquatable<WikibaseUri>
+    {
+
+        private static readonly ConcurrentDictionary<string, WeakReference<WikibaseUri>> cacheDict =
+            new ConcurrentDictionary<string, WeakReference<WikibaseUri>>();
+
+        public static WikibaseUri Get(string uri)
+        {
+            if (uri == null) throw new ArgumentNullException(nameof(uri));
+            WikibaseUri inst = null;
+            // Fast route
+            if (cacheDict.TryGetValue(uri, out var r) && r.TryGetTarget(out inst))
+                return inst;
+            // Slow route
+            cacheDict.AddOrUpdate(uri,
+                u => new WeakReference<WikibaseUri>(inst = new WikibaseUri(u)),
+                (u, r0) =>
+                {
+                    if (!r0.TryGetTarget(out inst))
+                    {
+                        inst = new WikibaseUri(u);
+                        return new WeakReference<WikibaseUri>(inst);
+                    }
+                    return r0;
+                });
+            return inst;
+        }
+
+        private WikibaseUri(string uri)
+        {
+            Uri = uri ?? throw new ArgumentNullException(nameof(uri));
+        }
+
+        public string Uri { get; }
+
+        /// <inheritdoc />
+        public override string ToString() => Uri;
+
+        /// <inheritdoc />
+        public bool Equals(WikibaseUri other)
+        {
+            Debug.Assert(ReferenceEquals(this, other) == (this.Uri == other.Uri));
+            return ReferenceEquals(this, other);
+        }
+
+        /// <inheritdoc />
+        public override bool Equals(object obj)
+        {
+#if DEBUG
+            if (obj is WikibaseUri other)
+                Debug.Assert(ReferenceEquals(this, other) == (this.Uri == other.Uri));
+#endif
+            return ReferenceEquals(this, obj);
+        }
+
+        /// <inheritdoc />
+        public override int GetHashCode()
+        {
+            return Uri.GetHashCode();
+        }
+
+        public static bool operator ==(WikibaseUri left, WikibaseUri right)
+        {
+            return Equals(left, right);
+        }
+
+        public static bool operator !=(WikibaseUri left, WikibaseUri right)
+        {
+            return !Equals(left, right);
+        }
+    }
+
+    internal class WikibaseUriJsonConverter : JsonConverter
+    {
+        /// <inheritdoc />
+        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        {
+            var obj = (WikibaseUri) value;
+            writer.WriteValue(obj.Uri);
+        }
+
+        /// <inheritdoc />
+        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        {
+            if (reader.TokenType != JsonToken.String) throw new JsonException("Expect string value.");
+            var uri = (string) reader.Value;
+            return WikibaseUri.Get(uri);
+        }
+
+        /// <inheritdoc />
+        public override bool CanConvert(Type objectType)
+        {
+            return objectType == typeof(WikibaseUri);
+        }
+    }
+
+}