docker api

vendor/github.com/docker/distribution/registry/api/errcode/register.go

@@ -0,0 +1,138 @@
+package errcode
+
+import (
+	"fmt"
+	"net/http"
+	"sort"
+	"sync"
+)
+
+var (
+	errorCodeToDescriptors = map[ErrorCode]ErrorDescriptor{}
+	idToDescriptors        = map[string]ErrorDescriptor{}
+	groupToDescriptors     = map[string][]ErrorDescriptor{}
+)
+
+var (
+	// ErrorCodeUnknown is a generic error that can be used as a last
+	// resort if there is no situation-specific error message that can be used
+	ErrorCodeUnknown = Register("errcode", ErrorDescriptor{
+		Value:   "UNKNOWN",
+		Message: "unknown error",
+		Description: `Generic error returned when the error does not have an
+			                                            API classification.`,
+		HTTPStatusCode: http.StatusInternalServerError,
+	})
+
+	// ErrorCodeUnsupported is returned when an operation is not supported.
+	ErrorCodeUnsupported = Register("errcode", ErrorDescriptor{
+		Value:   "UNSUPPORTED",
+		Message: "The operation is unsupported.",
+		Description: `The operation was unsupported due to a missing
+		implementation or invalid set of parameters.`,
+		HTTPStatusCode: http.StatusMethodNotAllowed,
+	})
+
+	// ErrorCodeUnauthorized is returned if a request requires
+	// authentication.
+	ErrorCodeUnauthorized = Register("errcode", ErrorDescriptor{
+		Value:   "UNAUTHORIZED",
+		Message: "authentication required",
+		Description: `The access controller was unable to authenticate
+		the client. Often this will be accompanied by a
+		Www-Authenticate HTTP response header indicating how to
+		authenticate.`,
+		HTTPStatusCode: http.StatusUnauthorized,
+	})
+
+	// ErrorCodeDenied is returned if a client does not have sufficient
+	// permission to perform an action.
+	ErrorCodeDenied = Register("errcode", ErrorDescriptor{
+		Value:   "DENIED",
+		Message: "requested access to the resource is denied",
+		Description: `The access controller denied access for the
+		operation on a resource.`,
+		HTTPStatusCode: http.StatusForbidden,
+	})
+
+	// ErrorCodeUnavailable provides a common error to report unavailability
+	// of a service or endpoint.
+	ErrorCodeUnavailable = Register("errcode", ErrorDescriptor{
+		Value:          "UNAVAILABLE",
+		Message:        "service unavailable",
+		Description:    "Returned when a service is not available",
+		HTTPStatusCode: http.StatusServiceUnavailable,
+	})
+
+	// ErrorCodeTooManyRequests is returned if a client attempts too many
+	// times to contact a service endpoint.
+	ErrorCodeTooManyRequests = Register("errcode", ErrorDescriptor{
+		Value:   "TOOMANYREQUESTS",
+		Message: "too many requests",
+		Description: `Returned when a client attempts to contact a
+		service too many times`,
+		HTTPStatusCode: http.StatusTooManyRequests,
+	})
+)
+
+var nextCode = 1000
+var registerLock sync.Mutex
+
+// Register will make the passed-in error known to the environment and
+// return a new ErrorCode
+func Register(group string, descriptor ErrorDescriptor) ErrorCode {
+	registerLock.Lock()
+	defer registerLock.Unlock()
+
+	descriptor.Code = ErrorCode(nextCode)
+
+	if _, ok := idToDescriptors[descriptor.Value]; ok {
+		panic(fmt.Sprintf("ErrorValue %q is already registered", descriptor.Value))
+	}
+	if _, ok := errorCodeToDescriptors[descriptor.Code]; ok {
+		panic(fmt.Sprintf("ErrorCode %v is already registered", descriptor.Code))
+	}
+
+	groupToDescriptors[group] = append(groupToDescriptors[group], descriptor)
+	errorCodeToDescriptors[descriptor.Code] = descriptor
+	idToDescriptors[descriptor.Value] = descriptor
+
+	nextCode++
+	return descriptor.Code
+}
+
+type byValue []ErrorDescriptor
+
+func (a byValue) Len() int           { return len(a) }
+func (a byValue) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a byValue) Less(i, j int) bool { return a[i].Value < a[j].Value }
+
+// GetGroupNames returns the list of Error group names that are registered
+func GetGroupNames() []string {
+	keys := []string{}
+
+	for k := range groupToDescriptors {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	return keys
+}
+
+// GetErrorCodeGroup returns the named group of error descriptors
+func GetErrorCodeGroup(name string) []ErrorDescriptor {
+	desc := groupToDescriptors[name]
+	sort.Sort(byValue(desc))
+	return desc
+}
+
+// GetErrorAllDescriptors returns a slice of all ErrorDescriptors that are
+// registered, irrespective of what group they're in
+func GetErrorAllDescriptors() []ErrorDescriptor {
+	result := []ErrorDescriptor{}
+
+	for _, group := range GetGroupNames() {
+		result = append(result, GetErrorCodeGroup(group)...)
+	}
+	sort.Sort(byValue(result))
+	return result
+}