1 files changed, 203 insertions, 0 deletions
diff --git a/vendor/github.com/containerd/platforms/compare.go b/vendor/github.com/containerd/platforms/compare.go
new file mode 100644
index 0000000..3913ef6
--- /dev/null
+++ b/vendor/github.com/containerd/platforms/compare.go
@@ -0,0 +1,203 @@
+/*
+   Copyright The containerd Authors.
+
+   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 platforms
+
+import (
+	"strconv"
+	"strings"
+
+	specs "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+// MatchComparer is able to match and compare platforms to
+// filter and sort platforms.
+type MatchComparer interface {
+	Matcher
+
+	Less(specs.Platform, specs.Platform) bool
+}
+
+// platformVector returns an (ordered) vector of appropriate specs.Platform
+// objects to try matching for the given platform object (see platforms.Only).
+func platformVector(platform specs.Platform) []specs.Platform {
+	vector := []specs.Platform{platform}
+
+	switch platform.Architecture {
+	case "amd64":
+		if amd64Version, err := strconv.Atoi(strings.TrimPrefix(platform.Variant, "v")); err == nil && amd64Version > 1 {
+			for amd64Version--; amd64Version >= 1; amd64Version-- {
+				vector = append(vector, specs.Platform{
+					Architecture: platform.Architecture,
+					OS:           platform.OS,
+					OSVersion:    platform.OSVersion,
+					OSFeatures:   platform.OSFeatures,
+					Variant:      "v" + strconv.Itoa(amd64Version),
+				})
+			}
+		}
+		vector = append(vector, specs.Platform{
+			Architecture: "386",
+			OS:           platform.OS,
+			OSVersion:    platform.OSVersion,
+			OSFeatures:   platform.OSFeatures,
+		})
+	case "arm":
+		if armVersion, err := strconv.Atoi(strings.TrimPrefix(platform.Variant, "v")); err == nil && armVersion > 5 {
+			for armVersion--; armVersion >= 5; armVersion-- {
+				vector = append(vector, specs.Platform{
+					Architecture: platform.Architecture,
+					OS:           platform.OS,
+					OSVersion:    platform.OSVersion,
+					OSFeatures:   platform.OSFeatures,
+					Variant:      "v" + strconv.Itoa(armVersion),
+				})
+			}
+		}
+	case "arm64":
+		variant := platform.Variant
+		if variant == "" {
+			variant = "v8"
+		}
+		vector = append(vector, platformVector(specs.Platform{
+			Architecture: "arm",
+			OS:           platform.OS,
+			OSVersion:    platform.OSVersion,
+			OSFeatures:   platform.OSFeatures,
+			Variant:      variant,
+		})...)
+	}
+
+	return vector
+}
+
+// Only returns a match comparer for a single platform
+// using default resolution logic for the platform.
+//
+// For arm/v8, will also match arm/v7, arm/v6 and arm/v5
+// For arm/v7, will also match arm/v6 and arm/v5
+// For arm/v6, will also match arm/v5
+// For amd64, will also match 386
+func Only(platform specs.Platform) MatchComparer {
+	return Ordered(platformVector(Normalize(platform))...)
+}
+
+// OnlyStrict returns a match comparer for a single platform.
+//
+// Unlike Only, OnlyStrict does not match sub platforms.
+// So, "arm/vN" will not match "arm/vM" where M < N,
+// and "amd64" will not also match "386".
+//
+// OnlyStrict matches non-canonical forms.
+// So, "arm64" matches "arm/64/v8".
+func OnlyStrict(platform specs.Platform) MatchComparer {
+	return Ordered(Normalize(platform))
+}
+
+// Ordered returns a platform MatchComparer which matches any of the platforms
+// but orders them in order they are provided.
+func Ordered(platforms ...specs.Platform) MatchComparer {
+	matchers := make([]Matcher, len(platforms))
+	for i := range platforms {
+		matchers[i] = NewMatcher(platforms[i])
+	}
+	return orderedPlatformComparer{
+		matchers: matchers,
+	}
+}
+
+// Any returns a platform MatchComparer which matches any of the platforms
+// with no preference for ordering.
+func Any(platforms ...specs.Platform) MatchComparer {
+	matchers := make([]Matcher, len(platforms))
+	for i := range platforms {
+		matchers[i] = NewMatcher(platforms[i])
+	}
+	return anyPlatformComparer{
+		matchers: matchers,
+	}
+}
+
+// All is a platform MatchComparer which matches all platforms
+// with preference for ordering.
+var All MatchComparer = allPlatformComparer{}
+
+type orderedPlatformComparer struct {
+	matchers []Matcher
+}
+
+func (c orderedPlatformComparer) Match(platform specs.Platform) bool {
+	for _, m := range c.matchers {
+		if m.Match(platform) {
+			return true
+		}
+	}
+	return false
+}
+
+func (c orderedPlatformComparer) Less(p1 specs.Platform, p2 specs.Platform) bool {
+	for _, m := range c.matchers {
+		p1m := m.Match(p1)
+		p2m := m.Match(p2)
+		if p1m && !p2m {
+			return true
+		}
+		if p1m || p2m {
+			return false
+		}
+	}
+	return false
+}
+
+type anyPlatformComparer struct {
+	matchers []Matcher
+}
+
+func (c anyPlatformComparer) Match(platform specs.Platform) bool {
+	for _, m := range c.matchers {
+		if m.Match(platform) {
+			return true
+		}
+	}
+	return false
+}
+
+func (c anyPlatformComparer) Less(p1, p2 specs.Platform) bool {
+	var p1m, p2m bool
+	for _, m := range c.matchers {
+		if !p1m && m.Match(p1) {
+			p1m = true
+		}
+		if !p2m && m.Match(p2) {
+			p2m = true
+		}
+		if p1m && p2m {
+			return false
+		}
+	}
+	// If one matches, and the other does, sort match first
+	return p1m && !p2m
+}
+
+type allPlatformComparer struct{}
+
+func (allPlatformComparer) Match(specs.Platform) bool {
+	return true
+}
+
+func (allPlatformComparer) Less(specs.Platform, specs.Platform) bool {
+	return false
+}