Add functionality to refresh underlying metadata from a stream.

csharp/PhoneNumbers/BuildMetadataFromXml.cs

@@ -80,27 +80,37 @@ public static PhoneMetadataCollection BuildPhoneMetadataCollection(string name,
             => BuildPhoneMetadata(name, null, liteBuild, specialBuild, isShortNumberMetadata, isAlternateFormatsMetadata, nameSuffix: false);
 
         internal static PhoneMetadataCollection BuildPhoneMetadata(string name, Assembly asm = null,
-            bool liteBuild = false, bool specialBuild = false, bool isShortNumberMetadata = false, bool isAlternateFormatsMetadata = false,
+            bool liteBuild = false, bool specialBuild = false, bool isShortNumberMetadata = false,
+            bool isAlternateFormatsMetadata = false,
             bool nameSuffix = true)
         {
-            XDocument document;
 #if NETSTANDARD1_3 || PORTABLE
             asm ??= typeof(PhoneNumberUtil).GetTypeInfo().Assembly;
 #else
             asm ??= typeof(PhoneNumberUtil).Assembly;
 #endif
 
             if (nameSuffix)
-                name = asm.GetManifestResourceNames().FirstOrDefault(n => n.EndsWith(name, StringComparison.Ordinal)) ?? throw new ArgumentException(name + " resource not found");
+                name = asm.GetManifestResourceNames().FirstOrDefault(n => n.EndsWith(name, StringComparison.Ordinal)) ??
+                       throw new ArgumentException(name + " resource not found");
 
             using (var input = asm.GetManifestResourceStream(name))
             {
+                return BuildPhoneMetadataFromStream(input, liteBuild, specialBuild, isShortNumberMetadata,
+                    isAlternateFormatsMetadata);
+            }
+        }
+
+        internal static PhoneMetadataCollection BuildPhoneMetadataFromStream(Stream metadataStream,
+            bool liteBuild = false, bool specialBuild = false, bool isShortNumberMetadata = false,
+            bool isAlternateFormatsMetadata = false)
+        {
 #if NET35
-                document = XDocument.Load(new XmlTextReader(input));
+            var document = XDocument.Load(new XmlTextReader(input));
 #else
-                document = XDocument.Load(input);
+            var document = XDocument.Load(metadataStream);
 #endif
-            }
+
 
             var metadataCollection = new PhoneMetadataCollection.Builder();
             var metadataFilter = GetMetadataFilter(liteBuild, specialBuild);
@@ -114,6 +124,7 @@ internal static PhoneMetadataCollection BuildPhoneMetadata(string name, Assembly
                 metadataFilter.FilterMetadata(metadata);
                 metadataCollection.AddMetadata(metadata);
             }
+
             return metadataCollection.Build();
         }
 

csharp/PhoneNumbers/PhoneNumberUtil.cs

@@ -548,6 +548,25 @@ internal PhoneNumberUtil(string baseFileLocation, Assembly asm = null, Dictionar
             }
             regionToMetadataMap.Remove(REGION_CODE_FOR_NON_GEO_ENTITY);
         }
+
+        internal PhoneNumberUtil(Stream metaDataStream,  Dictionary<int, List<string>> countryCallingCodeToRegionCodeMap = null)
+        {
+            var phoneMetadata = BuildMetadataFromXml.BuildPhoneMetadataFromStream(metaDataStream);
+            this.countryCallingCodeToRegionCodeMap = countryCallingCodeToRegionCodeMap ??= BuildMetadataFromXml.BuildCountryCodeToRegionCodeMap(phoneMetadata);
+
+            foreach (var regionCodes in countryCallingCodeToRegionCodeMap)
+                supportedRegions.UnionWith(regionCodes.Value);
+            supportedRegions.Remove(REGION_CODE_FOR_NON_GEO_ENTITY);
+            if (countryCallingCodeToRegionCodeMap.TryGetValue(NANPA_COUNTRY_CODE, out var regions))
+                nanpaRegions.UnionWith(regions);
+
+            foreach (var m in phoneMetadata.MetadataList)
+            {
+                countryCodeToNonGeographicalMetadataMap[m.CountryCode] = m;
+                regionToMetadataMap[m.Id] = m;
+            }
+            regionToMetadataMap.Remove(REGION_CODE_FOR_NON_GEO_ENTITY);
+        }
 
         /// <summary>
         /// Attempts to extract a possible number from the string passed in. This currently strips all
@@ -908,6 +927,40 @@ public static PhoneNumberUtil GetInstance(string baseFileLocation,
             lock (ThisLock)
                 return instance ??= new PhoneNumberUtil(baseFileLocation, null, countryCallingCodeToRegionCodeMap);
         }
+
+        /// <summary>
+        /// Gets a {@link PhoneNumberUtil} instance to carry out international phone number formatting,
+        /// parsing, or validation. The instance is loaded with all phone number metadata.
+        /// The <see cref="PhoneNumberUtil" /> is implemented as a singleton.Therefore, calling getInstance
+        /// multiple times will only result in one instance being created.
+        /// </summary>
+        /// <returns> a PhoneNumberUtil instance</returns>
+        public static PhoneNumberUtil GetInstance(Stream metadataStream, Dictionary<int, List<string>> countryCallingCodeToRegionCodeMap = null)
+        {
+            lock (ThisLock)
+                return instance ??= new PhoneNumberUtil(metadataStream);
+        }
+
+        /// <summary>
+        /// Re-instantiates the {@link PhoneNumberUtil} singleton with new metadata.
+        /// </summary>
+        /// <param name="metadataStream">Stream of new metadata</param>
+        public static void RefreshMetadata(Stream metadataStream)
+        {
+            lock (ThisLock)
+            {
+                var bak = instance;
+                instance = null;
+                try
+                {
+                    instance = new PhoneNumberUtil(metadataStream,  null);
+                }
+                catch (Exception)
+                {
+                    instance = bak;
+                }
+            }
+        }
 
         /// <summary>
         /// Returns all regions the library has metadata for.