11// Licensed to the .NET Foundation under one or more agreements.
22// The .NET Foundation licenses this file to you under the MIT license.
33
4- using System . Collections ;
5- using System . Collections . Generic ;
6- using System . Diagnostics ;
74using System . Diagnostics . CodeAnalysis ;
8- using System . Runtime . InteropServices ;
95using System . Runtime ;
10- using System . Text ;
116using System . Threading ;
127
138namespace System
@@ -16,157 +11,9 @@ public static partial class Environment
1611 {
1712 internal static int CurrentNativeThreadId => ManagedThreadId . Current ;
1813
19- private static Dictionary < string , string > s_environment ;
20-
21- private static string ? GetEnvironmentVariableCore ( string variable )
22- {
23- Debug . Assert ( variable != null ) ;
24-
25- if ( s_environment == null )
26- {
27- return Marshal . PtrToStringUTF8 ( Interop . Sys . GetEnv ( variable ) ) ;
28- }
29-
30- lock ( s_environment )
31- {
32- variable = TrimStringOnFirstZero ( variable ) ;
33- s_environment . TryGetValue ( variable , out string ? value ) ;
34- return value ;
35- }
36- }
37-
38- private static void SetEnvironmentVariableCore ( string variable , string ? value )
39- {
40- Debug . Assert ( variable != null ) ;
41-
42- EnsureEnvironmentCached ( ) ;
43- lock ( s_environment )
44- {
45- variable = TrimStringOnFirstZero ( variable ) ;
46- value = value == null ? null : TrimStringOnFirstZero ( value ) ;
47- if ( string . IsNullOrEmpty ( value ) )
48- {
49- s_environment . Remove ( variable ) ;
50- }
51- else
52- {
53- s_environment [ variable ] = value ;
54- }
55- }
56- }
57-
58- public static IDictionary GetEnvironmentVariables ( )
59- {
60- var results = new Hashtable ( ) ;
61-
62- EnsureEnvironmentCached ( ) ;
63- lock ( s_environment )
64- {
65- foreach ( var keyValuePair in s_environment )
66- {
67- results . Add ( keyValuePair . Key , keyValuePair . Value ) ;
68- }
69- }
70-
71- return results ;
72- }
73-
74- private static string TrimStringOnFirstZero ( string value )
75- {
76- int index = value . IndexOf ( '\0 ' ) ;
77- if ( index >= 0 )
78- {
79- return value . Substring ( 0 , index ) ;
80- }
81- return value ;
82- }
83-
84- private static void EnsureEnvironmentCached ( )
85- {
86- if ( s_environment == null )
87- {
88- Interlocked . CompareExchange ( ref s_environment , GetSystemEnvironmentVariables ( ) , null ) ;
89- }
90- }
91-
92- private static Dictionary < string , string > GetSystemEnvironmentVariables ( )
93- {
94- var results = new Dictionary < string , string > ( ) ;
95-
96- IntPtr block = Interop . Sys . GetEnviron ( ) ;
97- if ( block != IntPtr . Zero )
98- {
99- try
100- {
101- IntPtr blockIterator = block ;
102-
103- // Per man page, environment variables come back as an array of pointers to strings
104- // Parse each pointer of strings individually
105- while ( ParseEntry ( blockIterator , out string ? key , out string ? value ) )
106- {
107- if ( key != null && value != null )
108- {
109- try
110- {
111- // Add may throw if the environment block was corrupted leading to duplicate entries.
112- // We allow such throws and eat them (rather than proactively checking for duplication)
113- // to provide a non-fatal notification about the corruption.
114- results . Add ( key , value ) ;
115- }
116- catch ( ArgumentException ) { }
117- }
118-
119- // Increment to next environment variable entry
120- blockIterator += IntPtr . Size ;
121- }
122- }
123- finally
124- {
125- Interop . Sys . FreeEnviron ( block ) ;
126- }
127- }
128-
129- return results ;
130-
131- // Use a local, unsafe function since we cannot use `yield return` inside of an `unsafe` block
132- static unsafe bool ParseEntry ( IntPtr current , out string ? key , out string ? value )
133- {
134- // Setup
135- key = null ;
136- value = null ;
137-
138- // Point to current entry
139- byte * entry = * ( byte * * ) current ;
140-
141- // Per man page, "The last pointer in this array has the value NULL"
142- // Therefore, if entry is null then we're at the end and can bail
143- if ( entry == null )
144- return false ;
145-
146- // Parse each byte of the entry until we hit either the separator '=' or '\0'.
147- // This finds the split point for creating key/value strings below.
148- // On some old OS, the environment block can be corrupted.
149- // Some will not have '=', so we need to check for '\0'.
150- byte * splitpoint = entry ;
151- while ( * splitpoint != '=' && * splitpoint != '\0 ' )
152- splitpoint ++ ;
153-
154- // Skip over entries starting with '=' and entries with no value (just a null-terminating char '\0')
155- if ( splitpoint == entry || * splitpoint == '\0 ' )
156- return true ;
157-
158- // The key is the bytes from start (0) until our splitpoint
159- key = new string ( ( sbyte * ) entry , 0 , checked ( ( int ) ( splitpoint - entry ) ) ) ;
160- // The value is the rest of the bytes starting after the splitpoint
161- value = new string ( ( sbyte * ) ( splitpoint + 1 ) ) ;
162-
163- return true ;
164- }
165- }
14+ public static long TickCount64 => ( long ) RuntimeImports . RhpGetTickCount64 ( ) ;
16615
16716 [ DoesNotReturn ]
16817 private static void ExitRaw ( ) => Interop . Sys . Exit ( s_latchedExitCode ) ;
169-
170- public static long TickCount64 => ( long ) RuntimeImports . RhpGetTickCount64 ( ) ;
17118 }
17219}
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