[mono] Implement Environment.GetFolderPath for Android #35490

EgorBo · 2020-04-26T19:49:38Z

The following snippet:

var values = Enum.GetValues(typeof(global::System.Environment.SpecialFolder));
foreach (var sf in values)
{
    var path = global::System.Environment.GetFolderPath((global::System.Environment.SpecialFolder)sf);
    if (!string.IsNullOrEmpty(path))
    {
        Console.WriteLine($"{sf} = {path};");
    }
}

doesn't print anything for os=Android (all values are empty).
For reference, here is what current Xamarin.Android returns for my simple app:

Desktop = /data/user/0/com.companyname.Vederko/files/Desktop;
MyDocuments = /data/user/0/com.companyname.Vederko/files;
MyDocuments = /data/user/0/com.companyname.Vederko/files;
MyMusic = /data/user/0/com.companyname.Vederko/files/Music;
MyVideos = /data/user/0/com.companyname.Vederko/files/Videos;
DesktopDirectory = /data/user/0/com.companyname.Vederko/files/Desktop;
Fonts = /data/user/0/com.companyname.Vederko/files/.fonts;
Templates = /data/user/0/com.companyname.Vederko/files/Templates;
ApplicationData = /data/user/0/com.companyname.Vederko/files/.config;
LocalApplicationData = /data/user/0/com.companyname.Vederko/files/.local/share;
CommonApplicationData = /usr/share;
MyPictures = /data/user/0/com.companyname.Vederko/files/Pictures;
UserProfile = /data/user/0/com.companyname.Vederko/files;
CommonTemplates = /usr/share/templates;

MaximLipnin · 2021-07-26T09:38:02Z

When running the following as a functional test

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System;
using System.Globalization;

public static class Program
{
    public static int Main(string[] args)
    {
        int result = 42;

        var values = Enum.GetValues(typeof(global::System.Environment.SpecialFolder));
        Console.WriteLine($"Start logging ==========");
        foreach (var sf in values)
        {
            var path = global::System.Environment.GetFolderPath((global::System.Environment.SpecialFolder)sf);
            if (!string.IsNullOrEmpty(path))
            {
                Console.WriteLine($"{sf} = {path};");
            }
        }

        Console.WriteLine($"Finish logging ==========");
        return result;
    }
}

I get the following output in the log:

07-26 12:22:13.823  7529  7548 I DOTNET  : Start logging ==========
07-26 12:22:13.862  7529  7548 I DOTNET  : MyDocuments = /data/user/0/net.dot.Android.Device_Emulator.EnvironmentGetFolderPath.Test/files;
07-26 12:22:13.862  7529  7548 I DOTNET  : MyDocuments = /data/user/0/net.dot.Android.Device_Emulator.EnvironmentGetFolderPath.Test/files;
07-26 12:22:13.866  7529  7548 I DOTNET  : UserProfile = /data/user/0/net.dot.Android.Device_Emulator.EnvironmentGetFolderPath.Test/files;
07-26 12:22:13.866  7529  7548 I DOTNET  : Finish logging ==========

It seems to be expected behavior.

MaximLipnin · 2021-07-26T12:19:13Z

On the other hand, looking at the entire list of special folder, it still consists mostly of empty values:

07-26 15:13:59.438  8827  8845 I DOTNET  : Start logging ==========
07-26 15:13:59.495  8827  8845 I DOTNET  : Desktop = ;
07-26 15:13:59.495  8827  8845 I DOTNET  : Programs = ;
07-26 15:13:59.495  8827  8845 I DOTNET  : MyDocuments = /data/user/0/net.dot.Android.Device_Emulator.EnvironmentGetFolderPath.Test/files;
07-26 15:13:59.495  8827  8845 I DOTNET  : MyDocuments = /data/user/0/net.dot.Android.Device_Emulator.EnvironmentGetFolderPath.Test/files;
07-26 15:13:59.495  8827  8845 I DOTNET  : Favorites = ;
07-26 15:13:59.495  8827  8845 I DOTNET  : Startup = ;
07-26 15:13:59.495  8827  8845 I DOTNET  : Recent = ;
07-26 15:13:59.495  8827  8845 I DOTNET  : SendTo = ;
07-26 15:13:59.495  8827  8845 I DOTNET  : StartMenu = ;
07-26 15:13:59.495  8827  8845 I DOTNET  : MyMusic = ;
07-26 15:13:59.495  8827  8845 I DOTNET  : MyVideos = ;
07-26 15:13:59.495  8827  8845 I DOTNET  : DesktopDirectory = ;
07-26 15:13:59.496  8827  8845 I DOTNET  : MyComputer = ;
07-26 15:13:59.496  8827  8845 I DOTNET  : NetworkShortcuts = ;
07-26 15:13:59.496  8827  8845 I DOTNET  : Fonts = ;
07-26 15:13:59.496  8827  8845 I DOTNET  : Templates = ;
07-26 15:13:59.496  8827  8845 I DOTNET  : CommonStartMenu = ;
07-26 15:13:59.496  8827  8845 I DOTNET  : CommonPrograms = ;
07-26 15:13:59.496  8827  8845 I DOTNET  : CommonStartup = ;
07-26 15:13:59.496  8827  8845 I DOTNET  : CommonDesktopDirectory = ;
07-26 15:13:59.496  8827  8845 I DOTNET  : ApplicationData = ;
07-26 15:13:59.496  8827  8845 I DOTNET  : PrinterShortcuts = ;
07-26 15:13:59.503  8827  8845 I DOTNET  : LocalApplicationData = ;
07-26 15:13:59.503  8827  8845 I DOTNET  : InternetCache = ;
07-26 15:13:59.503  8827  8845 I DOTNET  : Cookies = ;
07-26 15:13:59.503  8827  8845 I DOTNET  : History = ;
07-26 15:13:59.503  8827  8845 I DOTNET  : CommonApplicationData = ;
07-26 15:13:59.503  8827  8845 I DOTNET  : Windows = ;
07-26 15:13:59.503  8827  8845 I DOTNET  : System = ;
07-26 15:13:59.503  8827  8845 I DOTNET  : ProgramFiles = ;
07-26 15:13:59.503  8827  8845 I DOTNET  : MyPictures = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : UserProfile = /data/user/0/net.dot.Android.Device_Emulator.EnvironmentGetFolderPath.Test/files;
07-26 15:13:59.504  8827  8845 I DOTNET  : SystemX86 = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : ProgramFilesX86 = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : CommonProgramFiles = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : CommonProgramFilesX86 = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : CommonTemplates = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : CommonDocuments = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : CommonAdminTools = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : AdminTools = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : CommonMusic = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : CommonPictures = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : CommonVideos = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : Resources = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : LocalizedResources = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : CommonOemLinks = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : CDBurning = ;
07-26 15:13:59.504  8827  8845 I DOTNET  : Finish logging ==========

EgorBo · 2021-07-26T12:37:33Z

Related PR but for iOS: #34022

directhex · 2021-08-20T21:49:37Z

Is HOME set on Android? It would explain why UserProfile and MyDocuments are set, but nothing else is

filipnavara · 2021-08-21T12:46:59Z

Old Mono had a fallback to getpwuid_r if HOME is not present.

directhex · 2021-08-23T13:21:02Z

It would also explain why CI never caught this - the only SpecialFolders we validate in CI are "is MyDocuments equal to $HOME"

am11 · 2021-08-23T16:03:35Z

Old Mono had a fallback to getpwuid_r if HOME is not present.

Maybe we can use:

runtime/src/libraries/System.Private.CoreLib/src/System/IO/PersistedFiles.Unix.cs

Line 82 in 57bfe47

internal static string? GetHomeDirectory()

rather than reading $HOME env var directly for Android?
it does fallback to getpwuid_r for $HOME-less case:

runtime/src/libraries/System.Private.CoreLib/src/System/IO/PersistedFiles.Unix.cs

Line 125 in 57bfe47

    
           private static unsafe bool TryGetHomeDirectoryFromPasswd(byte* buf, int bufLen, out string? path)

directhex · 2021-08-23T16:12:24Z

As per #35490 (comment) the only case which is already fine is HOME (i.e. MyDocuments and UserProfile share a code path in

runtime/src/libraries/System.Private.CoreLib/src/System/Environment.GetFolderPathCore.Unix.cs

Lines 87 to 89 in 39135a4

    
           case SpecialFolder.UserProfile: 
        
           case SpecialFolder.MyDocuments: // same value as Personal 
        
               return home;

which returns PersistedFiles.GetHomeDirectory();)

HOME is the only case that's already fine, I don't think it matters whether that's fed by $HOME or by getpwuid_r. The issue is CommonApplicationData and friends

am11 · 2021-08-23T16:15:18Z

Aha, okay! I understood that the other cases are broken because $HOME is not set, but apparently it's not the case.

directhex · 2021-08-23T16:18:37Z

Looks like src/libraries/System.Private.CoreLib/src/System/Environment.GetFolderPathCore.Unix.cs is relying on XDG (Linux desktop spec) directory discovery on non-OSX

directhex · 2021-08-23T18:15:53Z

Okay, even with the XDG code paths, there are a few entries which should be specified but aren't on Android, e.g.:

                case SpecialFolder.CommonApplicationData: return "/usr/share";
                case SpecialFolder.CommonTemplates: return "/usr/share/templates";

Which has me thinking the problem is GetFolderPathCore is called, but failing on Android (i.e. because SpecialFolderOption.None is being used, which means in the event that the folder doesn't already exist then return string.Empty)

What is the correct behaviour for Android? Unilaterally create the directories, or simply don't try to validate them? What did Legacy MonoDroid do? @jonpryor/@jonathanpeppers?

jonathanpeppers · 2021-08-23T18:33:12Z

The code sample above, legacy Xamarin.Android prints:

Desktop = /data/user/0/com.companyname.app13/files/Desktop;
MyDocuments = /data/user/0/com.companyname.app13/files;
MyDocuments = /data/user/0/com.companyname.app13/files;
MyMusic = /data/user/0/com.companyname.app13/files/Music;
MyVideos = /data/user/0/com.companyname.app13/files/Videos;
DesktopDirectory = /data/user/0/com.companyname.app13/files/Desktop;
Fonts = /data/user/0/com.companyname.app13/files/.fonts;
Templates = /data/user/0/com.companyname.app13/files/Templates;
ApplicationData = /data/user/0/com.companyname.app13/files/.config;
LocalApplicationData = /data/user/0/com.companyname.app13/files/.local/share;
CommonApplicationData = /usr/share;
MyPictures = /data/user/0/com.companyname.app13/files/Pictures;
UserProfile = /data/user/0/com.companyname.app13/files;
CommonTemplates = /usr/share/templates;

Unilaterally create the directories, or simply don't try to validate them?

I definitely wouldn't try to create the directories. The value for CommonTemplates (/usr/share/templates) does not exist in my running Android emulator.

directhex · 2021-08-23T18:46:07Z

So how about on Android, we switch from SpecialFolderOption.None to SpecialFolderOption.DoNotVerify?

…#58064) This largely mirrors the approach of SpecialFolders handling on iOS, and should give the same output from that structure as legacy Xamarin Fixes: #35490

Dotnet-GitSync-Bot added area-System.Runtime untriaged New issue has not been triaged by the area owner labels Apr 26, 2020

EgorBo added os-android and removed area-System.Runtime labels Apr 26, 2020

EgorBo self-assigned this Apr 26, 2020

jeffschwMSFT added the area-CoreLib-mono label Apr 27, 2020

marek-safar added this to the 6.0.0 milestone Jun 24, 2020

marek-safar removed the untriaged New issue has not been triaged by the area owner label Jun 24, 2020

EgorBo removed their assignment Feb 10, 2021

steveisok assigned MaximLipnin Jul 12, 2021

akoeplinger added the blocking-release label Aug 17, 2021

steveisok assigned directhex and unassigned MaximLipnin Aug 24, 2021

directhex mentioned this issue Aug 24, 2021

Don't blank out SpecialFolders on Android if they don't already exist #58064

Merged

ghost added the in-pr There is an active PR which will close this issue when it is merged label Aug 24, 2021

directhex closed this as completed in #58064 Aug 30, 2021

ghost removed the in-pr There is an active PR which will close this issue when it is merged label Aug 30, 2021

ghost locked as resolved and limited conversation to collaborators Sep 29, 2021

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[mono] Implement Environment.GetFolderPath for Android #35490

[mono] Implement Environment.GetFolderPath for Android #35490

EgorBo commented Apr 26, 2020

MaximLipnin commented Jul 26, 2021

MaximLipnin commented Jul 26, 2021 •

edited

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EgorBo commented Jul 26, 2021

directhex commented Aug 20, 2021

filipnavara commented Aug 21, 2021

directhex commented Aug 23, 2021

am11 commented Aug 23, 2021

directhex commented Aug 23, 2021

am11 commented Aug 23, 2021

directhex commented Aug 23, 2021

directhex commented Aug 23, 2021

jonathanpeppers commented Aug 23, 2021

directhex commented Aug 23, 2021

[mono] Implement Environment.GetFolderPath for Android #35490

[mono] Implement Environment.GetFolderPath for Android #35490

Comments

EgorBo commented Apr 26, 2020

MaximLipnin commented Jul 26, 2021

MaximLipnin commented Jul 26, 2021 • edited Loading

EgorBo commented Jul 26, 2021

directhex commented Aug 20, 2021

filipnavara commented Aug 21, 2021

directhex commented Aug 23, 2021

am11 commented Aug 23, 2021

directhex commented Aug 23, 2021

am11 commented Aug 23, 2021

directhex commented Aug 23, 2021

directhex commented Aug 23, 2021

jonathanpeppers commented Aug 23, 2021

directhex commented Aug 23, 2021

MaximLipnin commented Jul 26, 2021 •

edited

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