Add ResolvePlatform function to info package

Signed-off-by: Evan Lezar <elezar@nvidia.com>

pkg/nvlib/info/api.go

@@ -18,9 +18,15 @@ package info
 
 // Interface provides the API to the info package.
 type Interface interface {
+	PlatformResolver
 	PropertyExtractor
 }
 
+// PlatformResolver defines a function to resolve the current platform.
+type PlatformResolver interface {
+	ResolvePlatform() Platform
+}
+
 // PropertyExtractor provides a set of functions to query capabilities of the
 // system.
 //

pkg/nvlib/info/builder.go

@@ -22,18 +22,30 @@ import (
 	"github.com/NVIDIA/go-nvlib/pkg/nvlib/device"
 )
 
+type infolib struct {
+	PropertyExtractor
+	PlatformResolver
+}
+
 type options struct {
+	logger    basicLogger
 	root      root
 	nvmllib   nvml.Interface
 	devicelib device.Interface
+
+	platform          Platform
+	propertyExtractor PropertyExtractor
 }
 
-// New creates a new instance of the 'info' Interface.
+// New creates a new instance of the 'info' interface.
 func New(opts ...Option) Interface {
 	o := &options{}
 	for _, opt := range opts {
 		opt(o)
 	}
+	if o.logger == nil {
+		o.logger = &nullLogger{}
+	}
 	if o.root == "" {
 		o.root = "/"
 	}
@@ -45,9 +57,22 @@ func New(opts ...Option) Interface {
 	if o.devicelib == nil {
 		o.devicelib = device.New(device.WithNvml(o.nvmllib))
 	}
-	return &propertyExtractor{
-		root:      o.root,
-		nvmllib:   o.nvmllib,
-		devicelib: o.devicelib,
+	if o.platform == "" {
+		o.platform = PlatformAuto
+	}
+	if o.propertyExtractor == nil {
+		o.propertyExtractor = &propertyExtractor{
+			root:      o.root,
+			nvmllib:   o.nvmllib,
+			devicelib: o.devicelib,
+		}
+	}
+	return &infolib{
+		PlatformResolver: &platformResolver{
+			logger:            o.logger,
+			platform:          o.platform,
+			propertyExtractor: o.propertyExtractor,
+		},
+		PropertyExtractor: o.propertyExtractor,
 	}
 }

pkg/nvlib/info/logger.go

@@ -0,0 +1,28 @@
+/**
+# Copyright 2024 NVIDIA CORPORATION
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+**/
+
+package info
+
+type basicLogger interface {
+	Debugf(string, ...interface{})
+	Infof(string, ...interface{})
+}
+
+type nullLogger struct{}
+
+func (n *nullLogger) Debugf(string, ...interface{}) {}
+
+func (n *nullLogger) Infof(string, ...interface{}) {}

pkg/nvlib/info/options.go

@@ -27,15 +27,22 @@ type Option func(*options)
 
 // WithDeviceLib sets the device library for the library.
 func WithDeviceLib(devicelib device.Interface) Option {
-	return func(l *options) {
-		l.devicelib = devicelib
+	return func(i *options) {
+		i.devicelib = devicelib
+	}
+}
+
+// WithLogger sets the logger for the library.
+func WithLogger(logger basicLogger) Option {
+	return func(i *options) {
+		i.logger = logger
 	}
 }
 
 // WithNvmlLib sets the nvml library for the library.
 func WithNvmlLib(nvmllib nvml.Interface) Option {
-	return func(l *options) {
-		l.nvmllib = nvmllib
+	return func(i *options) {
+		i.nvmllib = nvmllib
 	}
 }
 
@@ -45,3 +52,19 @@ func WithRoot(r string) Option {
 		i.root = root(r)
 	}
 }
+
+// WithPropertyExtractor provides an Option to set the PropertyExtractor
+// interface implementation.
+// This is predominantly used for testing.
+func WithPropertyExtractor(propertyExtractor PropertyExtractor) Option {
+	return func(i *options) {
+		i.propertyExtractor = propertyExtractor
+	}
+}
+
+// WithPlatform provides an option to set the platform explicitly.
+func WithPlatform(platform Platform) Option {
+	return func(i *options) {
+		i.platform = platform
+	}
+}

pkg/nvlib/info/property-extractor.go

@@ -32,7 +32,7 @@ type propertyExtractor struct {
 	devicelib device.Interface
 }
 
-var _ Interface = &propertyExtractor{}
+var _ PropertyExtractor = &propertyExtractor{}
 
 // HasDXCore returns true if DXCore is detected on the system.
 func (i *propertyExtractor) HasDXCore() (bool, string) {

pkg/nvlib/info/resolver.go

@@ -0,0 +1,64 @@
+/**
+# Copyright 2024 NVIDIA CORPORATION
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+**/
+
+package info
+
+// Platform represents a supported plaform.
+type Platform string
+
+const (
+	PlatformAuto    = Platform("auto")
+	PlatformNVML    = Platform("nvml")
+	PlatformTegra   = Platform("tegra")
+	PlatformWSL     = Platform("wsl")
+	PlatformUnknown = Platform("unknown")
+)
+
+type platformResolver struct {
+	logger            basicLogger
+	platform          Platform
+	propertyExtractor PropertyExtractor
+}
+
+func (p platformResolver) ResolvePlatform() Platform {
+	if p.platform != PlatformAuto {
+		p.logger.Infof("Using requested platform '%s'", p.platform)
+		return p.platform
+	}
+
+	hasDXCore, reason := p.propertyExtractor.HasDXCore()
+	p.logger.Debugf("Is WSL-based system? %v: %v", hasDXCore, reason)
+
+	hasTegraFiles, reason := p.propertyExtractor.HasTegraFiles()
+	p.logger.Debugf("Is Tegra-based system? %v: %v", hasTegraFiles, reason)
+
+	hasNVML, reason := p.propertyExtractor.HasNvml()
+	p.logger.Debugf("Is NVML-based system? %v: %v", hasNVML, reason)
+
+	usesOnlyNVGPUModule, reason := p.propertyExtractor.UsesOnlyNVGPUModule()
+	p.logger.Debugf("Uses nvgpu kernel module? %v: %v", usesOnlyNVGPUModule, reason)
+
+	switch {
+	case hasDXCore:
+		return PlatformWSL
+	case (hasTegraFiles && !hasNVML), usesOnlyNVGPUModule:
+		return PlatformTegra
+	case hasNVML:
+		return PlatformNVML
+	default:
+		return PlatformUnknown
+	}
+}

pkg/nvlib/info/resolver_test.go

@@ -0,0 +1,110 @@
+/**
+# Copyright (c) NVIDIA CORPORATION.  All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+**/
+
+package info
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestResolvePlatform(t *testing.T) {
+	testCases := []struct {
+		platform            string
+		hasTegraFiles       bool
+		hasDXCore           bool
+		hasNVML             bool
+		usesOnlyNVGPUModule bool
+		expected            string
+	}{
+		{
+			platform:  "auto",
+			hasDXCore: true,
+			expected:  "wsl",
+		},
+		{
+			platform:      "auto",
+			hasDXCore:     false,
+			hasTegraFiles: true,
+			hasNVML:       false,
+			expected:      "tegra",
+		},
+		{
+			platform:      "auto",
+			hasDXCore:     false,
+			hasTegraFiles: false,
+			hasNVML:       false,
+			expected:      "unknown",
+		},
+		{
+			platform:      "auto",
+			hasDXCore:     false,
+			hasTegraFiles: true,
+			hasNVML:       true,
+			expected:      "nvml",
+		},
+		{
+			platform:            "auto",
+			hasDXCore:           false,
+			hasTegraFiles:       true,
+			hasNVML:             true,
+			usesOnlyNVGPUModule: true,
+			expected:            "tegra",
+		},
+		{
+			platform:      "nvml",
+			hasDXCore:     true,
+			hasTegraFiles: true,
+			expected:      "nvml",
+		},
+		{
+			platform:  "wsl",
+			hasDXCore: false,
+			expected:  "wsl",
+		},
+		{
+			platform:  "not-auto",
+			hasDXCore: true,
+			expected:  "not-auto",
+		},
+	}
+
+	for i, tc := range testCases {
+		t.Run(fmt.Sprintf("test case %d", i), func(t *testing.T) {
+			l := New(
+				WithPropertyExtractor(&PropertyExtractorMock{
+					HasDXCoreFunc: func() (bool, string) {
+						return tc.hasDXCore, ""
+					},
+					HasNvmlFunc: func() (bool, string) {
+						return tc.hasNVML, ""
+					},
+					HasTegraFilesFunc: func() (bool, string) {
+						return tc.hasTegraFiles, ""
+					},
+					UsesOnlyNVGPUModuleFunc: func() (bool, string) {
+						return tc.usesOnlyNVGPUModule, ""
+					},
+				}),
+				WithPlatform(Platform(tc.platform)),
+			)
+
+			require.Equal(t, Platform(tc.expected), l.ResolvePlatform())
+		})
+	}
+}