From cd93d59eaf5aa05e0fa55eadd958339b9042155d Mon Sep 17 00:00:00 2001
From: Tyler Staples <tstaples@akimbocreations.com>
Date: Mon, 12 Dec 2016 15:58:44 -0800
Subject: Added a struct to wrap cache entries for the sake of tracking invalid
 lookups. This fixes the issue where a null reference exception would be
 thrown when trying to look up non-existant or non-private members. Added a
 null check to GetPrivateValue and it's overloads to fix the issue where it
 would throw a null reference exception when required was false and the field
 was null.

---
 .../Framework/Reflection/ReflectionHelper.cs       | 49 ++++++++++++++++++----
 1 file changed, 42 insertions(+), 7 deletions(-)

(limited to 'src/StardewModdingAPI/Framework/Reflection')

diff --git a/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs b/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs
index 38b4e357..1d5cf157 100644
--- a/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs
+++ b/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs
@@ -12,6 +12,16 @@ namespace StardewModdingAPI.Framework.Reflection
         /*********
         ** Properties
         *********/
+        /// <summary>MemberInfo wrapper for tracking validity.</summary>
+        internal struct CacheEntry
+        {
+            /// <summary>Is this member valid. Used to avoid unecessary lookups.</summary>
+            public bool IsValid;
+
+            /// <summary>The reflection data for this member. This will be null if IsValid is false.</summary>
+            public MemberInfo MemberInfo;
+        }
+
         /// <summary>The cached fields and methods found via reflection.</summary>
         private readonly MemoryCache Cache = new MemoryCache(typeof(ReflectionHelper).FullName);
 
@@ -67,10 +77,17 @@ namespace StardewModdingAPI.Framework.Reflection
         /// <param name="obj">The object which has the field.</param>
         /// <param name="name">The field name.</param>
         /// <param name="required">Whether to throw an exception if the private field is not found.</param>
-        /// <remarks>This is a shortcut for <see cref="GetPrivateField{TValue}(object,string,bool)"/> followed by <see cref="IPrivateField{TValue}.GetValue"/>.</remarks>
+        /// <returns>The value of the field or the default value of the type if the field is not found.</returns>
+        /// <remarks>
+        /// This is a shortcut for <see cref="GetPrivateField{TValue}(object,string,bool)"/> followed by <see cref="IPrivateField{TValue}.GetValue"/>.
+        /// When <paramref name="required" /> is false, this will return the default value if reflection fails. If you need to check whether the field exists, use <see cref="GetPrivateField{TValue}(object,string,bool)" /> instead.
+        /// </remarks>
         public TValue GetPrivateValue<TValue>(object obj, string name, bool required = true)
         {
-            return this.GetPrivateField<TValue>(obj, name, required).GetValue();
+            IPrivateField<TValue> field = this.GetPrivateField<TValue>(obj, name, required);
+            return (field != null)
+                ? field.GetValue()
+                : default(TValue);
         }
 
         /// <summary>Get the value of a private static field.</summary>
@@ -78,10 +95,17 @@ namespace StardewModdingAPI.Framework.Reflection
         /// <param name="type">The type which has the field.</param>
         /// <param name="name">The field name.</param>
         /// <param name="required">Whether to throw an exception if the private field is not found.</param>
-        /// <remarks>This is a shortcut for <see cref="GetPrivateField{TValue}(Type,string,bool)"/> followed by <see cref="IPrivateField{TValue}.GetValue"/>.</remarks>
+        /// <returns>The value of the field or the default value of the type if the field is not found.</returns>
+        /// <remarks>
+        /// This is a shortcut for <see cref="GetPrivateField{TValue}(Type,string,bool)"/> followed by <see cref="IPrivateField{TValue}.GetValue"/>.
+        /// When <paramref name="required" /> is false, this will return the default value if reflection fails. If you need to check whether the field exists, use <see cref="GetPrivateField{TValue}(Type,string,bool)" /> instead.
+        /// </remarks>
         public TValue GetPrivateValue<TValue>(Type type, string name, bool required = true)
         {
-            return this.GetPrivateField<TValue>(type, name, required).GetValue();
+            IPrivateField<TValue> field = this.GetPrivateField<TValue>(type, name, required);
+            return (field != null)
+                ? field.GetValue()
+                : default(TValue);
         }
 
         /****
@@ -228,11 +252,22 @@ namespace StardewModdingAPI.Framework.Reflection
         {
             // get from cache
             if (this.Cache.Contains(key))
-                return (TMemberInfo)this.Cache[key];
+            {
+                CacheEntry entry = (CacheEntry)this.Cache[key];
+                return entry.IsValid 
+                    ? (TMemberInfo)entry.MemberInfo 
+                    : default(TMemberInfo);
+            }
 
-            // fetch & cache new value
+            // fetch & cache new value, marking if it's valid for future lookups.
             TMemberInfo result = fetch();
-            this.Cache.Add(key, result, new CacheItemPolicy { SlidingExpiration = this.SlidingCacheExpiry });
+            CacheEntry cacheEntry = new CacheEntry()
+            {
+                IsValid = (result != null),
+                MemberInfo = result
+            };
+
+            this.Cache.Add(key, cacheEntry, new CacheItemPolicy { SlidingExpiration = this.SlidingCacheExpiry });
             return result;
         }
     }
-- 
cgit 


From d9e87399bf65d0053ad57d316d0df9e1a631a42b Mon Sep 17 00:00:00 2001
From: Jesse Plamondon-Willard <github@jplamondonw.com>
Date: Sun, 18 Dec 2016 12:27:44 -0500
Subject: format code (#193)

---
 .../Framework/Reflection/CacheEntry.cs             | 30 ++++++++++++++++++++
 .../Framework/Reflection/ReflectionHelper.cs       | 33 ++++++----------------
 src/StardewModdingAPI/StardewModdingAPI.csproj     |  1 +
 3 files changed, 40 insertions(+), 24 deletions(-)
 create mode 100644 src/StardewModdingAPI/Framework/Reflection/CacheEntry.cs

(limited to 'src/StardewModdingAPI/Framework/Reflection')

diff --git a/src/StardewModdingAPI/Framework/Reflection/CacheEntry.cs b/src/StardewModdingAPI/Framework/Reflection/CacheEntry.cs
new file mode 100644
index 00000000..30faca37
--- /dev/null
+++ b/src/StardewModdingAPI/Framework/Reflection/CacheEntry.cs
@@ -0,0 +1,30 @@
+using System.Reflection;
+
+namespace StardewModdingAPI.Framework.Reflection
+{
+    /// <summary>A cached member reflection result.</summary>
+    internal struct CacheEntry
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>Whether the lookup found a valid match.</summary>
+        public bool IsValid;
+
+        /// <summary>The reflection data for this member (or <c>null</c> if invalid).</summary>
+        public MemberInfo MemberInfo;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="isValid">Whether the lookup found a valid match.</param>
+        /// <param name="memberInfo">The reflection data for this member (or <c>null</c> if invalid).</param>
+        public CacheEntry(bool isValid, MemberInfo memberInfo)
+        {
+            this.IsValid = isValid;
+            this.MemberInfo = memberInfo;
+        }
+    }
+}
diff --git a/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs b/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs
index 1d5cf157..edf59b81 100644
--- a/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs
+++ b/src/StardewModdingAPI/Framework/Reflection/ReflectionHelper.cs
@@ -12,16 +12,6 @@ namespace StardewModdingAPI.Framework.Reflection
         /*********
         ** Properties
         *********/
-        /// <summary>MemberInfo wrapper for tracking validity.</summary>
-        internal struct CacheEntry
-        {
-            /// <summary>Is this member valid. Used to avoid unecessary lookups.</summary>
-            public bool IsValid;
-
-            /// <summary>The reflection data for this member. This will be null if IsValid is false.</summary>
-            public MemberInfo MemberInfo;
-        }
-
         /// <summary>The cached fields and methods found via reflection.</summary>
         private readonly MemoryCache Cache = new MemoryCache(typeof(ReflectionHelper).FullName);
 
@@ -77,7 +67,7 @@ namespace StardewModdingAPI.Framework.Reflection
         /// <param name="obj">The object which has the field.</param>
         /// <param name="name">The field name.</param>
         /// <param name="required">Whether to throw an exception if the private field is not found.</param>
-        /// <returns>The value of the field or the default value of the type if the field is not found.</returns>
+        /// <returns>Returns the field value, or the default value for <typeparamref name="TValue"/> if the field wasn't found and <paramref name="required"/> is false.</returns>
         /// <remarks>
         /// This is a shortcut for <see cref="GetPrivateField{TValue}(object,string,bool)"/> followed by <see cref="IPrivateField{TValue}.GetValue"/>.
         /// When <paramref name="required" /> is false, this will return the default value if reflection fails. If you need to check whether the field exists, use <see cref="GetPrivateField{TValue}(object,string,bool)" /> instead.
@@ -85,7 +75,7 @@ namespace StardewModdingAPI.Framework.Reflection
         public TValue GetPrivateValue<TValue>(object obj, string name, bool required = true)
         {
             IPrivateField<TValue> field = this.GetPrivateField<TValue>(obj, name, required);
-            return (field != null)
+            return field != null
                 ? field.GetValue()
                 : default(TValue);
         }
@@ -95,7 +85,7 @@ namespace StardewModdingAPI.Framework.Reflection
         /// <param name="type">The type which has the field.</param>
         /// <param name="name">The field name.</param>
         /// <param name="required">Whether to throw an exception if the private field is not found.</param>
-        /// <returns>The value of the field or the default value of the type if the field is not found.</returns>
+        /// <returns>Returns the field value, or the default value for <typeparamref name="TValue"/> if the field wasn't found and <paramref name="required"/> is false.</returns>
         /// <remarks>
         /// This is a shortcut for <see cref="GetPrivateField{TValue}(Type,string,bool)"/> followed by <see cref="IPrivateField{TValue}.GetValue"/>.
         /// When <paramref name="required" /> is false, this will return the default value if reflection fails. If you need to check whether the field exists, use <see cref="GetPrivateField{TValue}(Type,string,bool)" /> instead.
@@ -103,7 +93,7 @@ namespace StardewModdingAPI.Framework.Reflection
         public TValue GetPrivateValue<TValue>(Type type, string name, bool required = true)
         {
             IPrivateField<TValue> field = this.GetPrivateField<TValue>(type, name, required);
-            return (field != null)
+            return field != null
                 ? field.GetValue()
                 : default(TValue);
         }
@@ -254,21 +244,16 @@ namespace StardewModdingAPI.Framework.Reflection
             if (this.Cache.Contains(key))
             {
                 CacheEntry entry = (CacheEntry)this.Cache[key];
-                return entry.IsValid 
-                    ? (TMemberInfo)entry.MemberInfo 
+                return entry.IsValid
+                    ? (TMemberInfo)entry.MemberInfo
                     : default(TMemberInfo);
             }
 
-            // fetch & cache new value, marking if it's valid for future lookups.
+            // fetch & cache new value
             TMemberInfo result = fetch();
-            CacheEntry cacheEntry = new CacheEntry()
-            {
-                IsValid = (result != null),
-                MemberInfo = result
-            };
-
+            CacheEntry cacheEntry = new CacheEntry(result != null, result);
             this.Cache.Add(key, cacheEntry, new CacheItemPolicy { SlidingExpiration = this.SlidingCacheExpiry });
             return result;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/StardewModdingAPI/StardewModdingAPI.csproj b/src/StardewModdingAPI/StardewModdingAPI.csproj
index 1a31b751..65083e67 100644
--- a/src/StardewModdingAPI/StardewModdingAPI.csproj
+++ b/src/StardewModdingAPI/StardewModdingAPI.csproj
@@ -162,6 +162,7 @@
     <Compile Include="Framework\DeprecationManager.cs" />
     <Compile Include="Framework\InternalExtensions.cs" />
     <Compile Include="Framework\ModAssemblyLoader.cs" />
+    <Compile Include="Framework\Reflection\CacheEntry.cs" />
     <Compile Include="Framework\Reflection\PrivateField.cs" />
     <Compile Include="Framework\Reflection\PrivateMethod.cs" />
     <Compile Include="Framework\Reflection\ReflectionHelper.cs" />
-- 
cgit