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author | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
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committer | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
commit | a031b83a09a8628435317a03f199cdc18b78262f (patch) | |
tree | bc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/github.com/docker/distribution/context/context.go | |
parent | 2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff) | |
download | podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.gz podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.bz2 podman-a031b83a09a8628435317a03f199cdc18b78262f.zip |
Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/github.com/docker/distribution/context/context.go')
-rw-r--r-- | vendor/github.com/docker/distribution/context/context.go | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/vendor/github.com/docker/distribution/context/context.go b/vendor/github.com/docker/distribution/context/context.go new file mode 100644 index 000000000..23cbf5b54 --- /dev/null +++ b/vendor/github.com/docker/distribution/context/context.go @@ -0,0 +1,85 @@ +package context + +import ( + "sync" + + "github.com/docker/distribution/uuid" + "golang.org/x/net/context" +) + +// Context is a copy of Context from the golang.org/x/net/context package. +type Context interface { + context.Context +} + +// instanceContext is a context that provides only an instance id. It is +// provided as the main background context. +type instanceContext struct { + Context + id string // id of context, logged as "instance.id" + once sync.Once // once protect generation of the id +} + +func (ic *instanceContext) Value(key interface{}) interface{} { + if key == "instance.id" { + ic.once.Do(func() { + // We want to lazy initialize the UUID such that we don't + // call a random generator from the package initialization + // code. For various reasons random could not be available + // https://github.com/docker/distribution/issues/782 + ic.id = uuid.Generate().String() + }) + return ic.id + } + + return ic.Context.Value(key) +} + +var background = &instanceContext{ + Context: context.Background(), +} + +// Background returns a non-nil, empty Context. The background context +// provides a single key, "instance.id" that is globally unique to the +// process. +func Background() Context { + return background +} + +// WithValue returns a copy of parent in which the value associated with key is +// val. Use context Values only for request-scoped data that transits processes +// and APIs, not for passing optional parameters to functions. +func WithValue(parent Context, key, val interface{}) Context { + return context.WithValue(parent, key, val) +} + +// stringMapContext is a simple context implementation that checks a map for a +// key, falling back to a parent if not present. +type stringMapContext struct { + context.Context + m map[string]interface{} +} + +// WithValues returns a context that proxies lookups through a map. Only +// supports string keys. +func WithValues(ctx context.Context, m map[string]interface{}) context.Context { + mo := make(map[string]interface{}, len(m)) // make our own copy. + for k, v := range m { + mo[k] = v + } + + return stringMapContext{ + Context: ctx, + m: mo, + } +} + +func (smc stringMapContext) Value(key interface{}) interface{} { + if ks, ok := key.(string); ok { + if v, ok := smc.m[ks]; ok { + return v + } + } + + return smc.Context.Value(key) +} |