Add new configuration mechanism for CoreCLR.

1 files changed, 125 insertions, 0 deletions

diff --git a/src/utilcode/configuration.cpp b/src/utilcode/configuration.cpp
new file mode 100644
index 0000000000..817bc06e90
--- /dev/null
+++ b/src/utilcode/configuration.cpp
@@ -0,0 +1,125 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+//
+// --------------------------------------------------------------------------------------------------
+// configuration.cpp
+// 
+//
+// Access and update configuration values, falling back on legacy CLRConfig methods where necessary.
+// 
+// --------------------------------------------------------------------------------------------------
+
+#include "stdafx.h"
+
+#include "clrconfig.h"
+#include "configuration.h"
+
+LPCWSTR *knobNames = nullptr;
+LPCWSTR *knobValues = nullptr;
+int numberOfKnobs = 0;
+
+void Configuration::InitializeConfigurationKnobs(int numberOfConfigs, LPCWSTR *names, LPCWSTR *values)
+{
+    numberOfKnobs = numberOfConfigs;
+
+    // Neither should be null, or both should be null
+    _ASSERT(!((names == nullptr) ^ (values == nullptr)));
+
+    knobNames = names;
+    knobValues = values;
+}
+
+static LPCWSTR GetConfigurationValue(LPCWSTR name)
+{
+    _ASSERT(name != nullptr);
+    if (name == nullptr || knobNames == nullptr || knobValues == nullptr)
+    {
+        return nullptr;
+    }
+
+    for (int i = 0; i < numberOfKnobs; ++i)
+    {
+        _ASSERT(knobNames[i] != nullptr);
+        if (wcscmp(name, knobNames[i]) == 0)
+        {
+            return knobValues[i];
+        }
+    }
+
+    return nullptr;
+}
+
+DWORD Configuration::GetKnobDWORDValue(LPCWSTR name, const CLRConfig::ConfigDWORDInfo& dwordInfo)
+{
+    bool returnedDefaultValue;
+    DWORD legacyValue = CLRConfig::GetConfigValue(dwordInfo, true /* acceptExplicitDefaultFromRegutil */, &returnedDefaultValue);
+    if (!returnedDefaultValue)
+    {
+        return legacyValue;
+    }
+
+    LPCWSTR knobValue = GetConfigurationValue(name);
+    if (knobValue != nullptr)
+    {
+        return wcstoul(knobValue, nullptr, 0);
+    }
+
+    return legacyValue;
+}
+
+DWORD Configuration::GetKnobDWORDValue(LPCWSTR name, DWORD defaultValue)
+{
+    LPCWSTR knobValue = GetConfigurationValue(name);
+    if (knobValue != nullptr)
+    {
+        return wcstoul(knobValue, nullptr, 0);
+    }
+
+    return defaultValue;
+}
+
+LPCWSTR Configuration::GetKnobStringValue(LPCWSTR name, const CLRConfig::ConfigStringInfo& stringInfo)
+{
+    LPCWSTR value = CLRConfig::GetConfigValue(stringInfo);
+    if (value == nullptr)
+    {
+        value = GetConfigurationValue(name);
+    }
+
+    return value;
+}
+
+LPCWSTR Configuration::GetKnobStringValue(LPCWSTR name)
+{
+    return GetConfigurationValue(name);
+}
+
+bool Configuration::GetKnobBooleanValue(LPCWSTR name, const CLRConfig::ConfigDWORDInfo& dwordInfo)
+{
+    bool returnedDefaultValue;
+    DWORD legacyValue = CLRConfig::GetConfigValue(dwordInfo, true /* acceptExplicitDefaultFromRegutil */, &returnedDefaultValue);
+    if (!returnedDefaultValue)
+    {
+        return (legacyValue != 0);
+    }
+
+    LPCWSTR knobValue = GetConfigurationValue(name);
+    if (knobValue != nullptr)
+    {
+        return (wcscmp(knobValue, W("true")) == 0);
+    }
+
+    return (legacyValue != 0);
+}
+
+bool Configuration::GetKnobBooleanValue(LPCWSTR name, bool defaultValue)
+{
+    LPCWSTR knobValue = GetConfigurationValue(name);
+    if (knobValue != nullptr)
+    {
+        return (wcscmp(knobValue, W("true")) == 0);
+    }
+
+    return defaultValue;
+}
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