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Diffstat (limited to 'vendor/google.golang.org/grpc/metadata')
-rw-r--r-- | vendor/google.golang.org/grpc/metadata/metadata.go | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/metadata/metadata.go b/vendor/google.golang.org/grpc/metadata/metadata.go new file mode 100644 index 0000000..52070db --- /dev/null +++ b/vendor/google.golang.org/grpc/metadata/metadata.go @@ -0,0 +1,134 @@ +/* + * + * Copyright 2014, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +// Package metadata define the structure of the metadata supported by gRPC library. +package metadata // import "google.golang.org/grpc/metadata" + +import ( + "encoding/base64" + "fmt" + "strings" + + "golang.org/x/net/context" +) + +const ( + binHdrSuffix = "-bin" +) + +// encodeKeyValue encodes key and value qualified for transmission via gRPC. +// Transmitting binary headers violates HTTP/2 spec. +// TODO(zhaoq): Maybe check if k is ASCII also. +func encodeKeyValue(k, v string) (string, string) { + k = strings.ToLower(k) + if strings.HasSuffix(k, binHdrSuffix) { + val := base64.StdEncoding.EncodeToString([]byte(v)) + v = string(val) + } + return k, v +} + +// DecodeKeyValue returns the original key and value corresponding to the +// encoded data in k, v. +func DecodeKeyValue(k, v string) (string, string, error) { + if !strings.HasSuffix(k, binHdrSuffix) { + return k, v, nil + } + val, err := base64.StdEncoding.DecodeString(v) + if err != nil { + return "", "", err + } + return k, string(val), nil +} + +// MD is a mapping from metadata keys to values. Users should use the following +// two convenience functions New and Pairs to generate MD. +type MD map[string][]string + +// New creates a MD from given key-value map. +func New(m map[string]string) MD { + md := MD{} + for k, v := range m { + key, val := encodeKeyValue(k, v) + md[key] = append(md[key], val) + } + return md +} + +// Pairs returns an MD formed by the mapping of key, value ... +// Pairs panics if len(kv) is odd. +func Pairs(kv ...string) MD { + if len(kv)%2 == 1 { + panic(fmt.Sprintf("metadata: Pairs got the odd number of input pairs for metadata: %d", len(kv))) + } + md := MD{} + var k string + for i, s := range kv { + if i%2 == 0 { + k = s + continue + } + key, val := encodeKeyValue(k, s) + md[key] = append(md[key], val) + } + return md +} + +// Len returns the number of items in md. +func (md MD) Len() int { + return len(md) +} + +// Copy returns a copy of md. +func (md MD) Copy() MD { + out := MD{} + for k, v := range md { + for _, i := range v { + out[k] = append(out[k], i) + } + } + return out +} + +type mdKey struct{} + +// NewContext creates a new context with md attached. +func NewContext(ctx context.Context, md MD) context.Context { + return context.WithValue(ctx, mdKey{}, md) +} + +// FromContext returns the MD in ctx if it exists. +func FromContext(ctx context.Context) (md MD, ok bool) { + md, ok = ctx.Value(mdKey{}).(MD) + return +} |