Merge pull request #7 from dhohmeyer/LoadLibraryErrorHandling

Load Library Error Handling

Author: olegtarasov

FastText.NetWrapper/FastText.NetWrapper.csproj

@@ -9,8 +9,9 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>FastText.NetWrapper</RootNamespace>
     <AssemblyName>FastText.NetWrapper</AssemblyName>
-    <TargetFrameworkVersion>v4.7</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.7.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
     <DebugSymbols>true</DebugSymbols>

FastText.NetWrapper/FastTextWrapper.LoadLibrary.cs

@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Linq;
 using System.Reflection;
 using System.Runtime.InteropServices;
 using FastText.NetWrapper.Logging;
@@ -39,7 +40,13 @@ private static void LoadLibrary(string path)
         {
             _log.Info($"Directly loading {path}...");
             var result = LoadLibraryEx(path, IntPtr.Zero, LoadLibraryFlags.LOAD_LIBRARY_SEARCH_APPLICATION_DIR | LoadLibraryFlags.LOAD_LIBRARY_SEARCH_DEFAULT_DIRS | LoadLibraryFlags.LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR | LoadLibraryFlags.LOAD_LIBRARY_SEARCH_SYSTEM32 | LoadLibraryFlags.LOAD_LIBRARY_SEARCH_USER_DIRS);
-            _log.Info(result == IntPtr.Zero ? "FAILED!" : "Success");
+            if (result == IntPtr.Zero)
+            {
+                var error = Marshal.GetLastWin32Error();
+                _log.Error($"FAILED! Last Win32 error is: {error}");
+                throw new Exception($"Failed to load library with path \"{path}\"");
+            }
+            _log.Info("Successfully loaded library.");
         }
 
         private static string UnpackResources()
@@ -66,9 +73,46 @@ private static void UnpackFile(string curDir, string fileName, byte[] bytes)
         {
             var path = !string.IsNullOrEmpty(curDir) ? Path.Combine(curDir, fileName) : fileName;
 
-            _log.Info($"Unpacking {fileName}.");
+            try
+            {
+                if (File.Exists(path))
+                {
+                    var existingFileContents = File.ReadAllBytes(path);
+                    if (existingFileContents.Length == bytes.Length)
+                    {
+                        if (existingFileContents.SequenceEqual(bytes))
+                        {
+                            _log.Info($"File {path} already exists and is the same (length and contents)");
+                            return;
+                        }
+                    }
+                }
+            }
+            catch (Exception e)
+            {
+                _log.Warn($"Unable to determine size of existing file, will replace with our version. Message: {e.Message}");
+                try
+                {
+                    File.Delete(path);
+                }
+                catch (Exception deleteException)
+                {
+                    _log.Error($"Unable to delete existing file: {path}. Message: {deleteException.Message}");
+                    return;
+                }
+            }
+
+            _log.Info($"Unpacking {fileName} to path {curDir}.");
 
-            File.WriteAllBytes(path, bytes);
+            try
+            {
+                File.WriteAllBytes(path, bytes);
+            }
+            catch (Exception writeException)
+            {
+                _log.Error($"Unable to write: {path}. Message: {writeException.Message}");
+                throw;
+            }
         }
 
         #region LoadLibraryEx

README.md

@@ -0,0 +1,10 @@
+# FastText.NetWrapper
+
+## Table of contents
+
+* [Requirements](#requirements)
+
+## Requirements
+
+To run on a Windows host (.NET Framework), the host must have VS Runtime Version 140 installed. Visit the MS Downloads page (https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads) and select the appropriate redistributable. 
+

TestUtil/App.config

@@ -1,6 +1,6 @@
-<?xml version="1.0" encoding="utf-8" ?>
+<?xml version="1.0" encoding="utf-8" ?>
 <configuration>
     <startup> 
-        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7" />
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.1"/>
     </startup>
 </configuration>

TestUtil/TestUtil.csproj

@@ -8,9 +8,10 @@
     <OutputType>Exe</OutputType>
     <RootNamespace>TestUtil</RootNamespace>
     <AssemblyName>TestUtil</AssemblyName>
-    <TargetFrameworkVersion>v4.7</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.7.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
     <DebugSymbols>true</DebugSymbols>