| // Copyright 2019 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package impl |
| |
| import ( |
| "encoding/binary" |
| "encoding/json" |
| "hash/crc32" |
| "math" |
| "reflect" |
| |
| "google.golang.org/protobuf/internal/errors" |
| pref "google.golang.org/protobuf/reflect/protoreflect" |
| piface "google.golang.org/protobuf/runtime/protoiface" |
| ) |
| |
| // These functions exist to support exported APIs in generated protobufs. |
| // While these are deprecated, they cannot be removed for compatibility reasons. |
| |
| // LegacyEnumName returns the name of enums used in legacy code. |
| func (Export) LegacyEnumName(ed pref.EnumDescriptor) string { |
| return legacyEnumName(ed) |
| } |
| |
| // LegacyMessageTypeOf returns the protoreflect.MessageType for m, |
| // with name used as the message name if necessary. |
| func (Export) LegacyMessageTypeOf(m piface.MessageV1, name pref.FullName) pref.MessageType { |
| if mv := (Export{}).protoMessageV2Of(m); mv != nil { |
| return mv.ProtoReflect().Type() |
| } |
| return legacyLoadMessageType(reflect.TypeOf(m), name) |
| } |
| |
| // UnmarshalJSONEnum unmarshals an enum from a JSON-encoded input. |
| // The input can either be a string representing the enum value by name, |
| // or a number representing the enum number itself. |
| func (Export) UnmarshalJSONEnum(ed pref.EnumDescriptor, b []byte) (pref.EnumNumber, error) { |
| if b[0] == '"' { |
| var name pref.Name |
| if err := json.Unmarshal(b, &name); err != nil { |
| return 0, errors.New("invalid input for enum %v: %s", ed.FullName(), b) |
| } |
| ev := ed.Values().ByName(name) |
| if ev == nil { |
| return 0, errors.New("invalid value for enum %v: %s", ed.FullName(), name) |
| } |
| return ev.Number(), nil |
| } else { |
| var num pref.EnumNumber |
| if err := json.Unmarshal(b, &num); err != nil { |
| return 0, errors.New("invalid input for enum %v: %s", ed.FullName(), b) |
| } |
| return num, nil |
| } |
| } |
| |
| // CompressGZIP compresses the input as a GZIP-encoded file. |
| // The current implementation does no compression. |
| func (Export) CompressGZIP(in []byte) (out []byte) { |
| // RFC 1952, section 2.3.1. |
| var gzipHeader = [10]byte{0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff} |
| |
| // RFC 1951, section 3.2.4. |
| var blockHeader [5]byte |
| const maxBlockSize = math.MaxUint16 |
| numBlocks := 1 + len(in)/maxBlockSize |
| |
| // RFC 1952, section 2.3.1. |
| var gzipFooter [8]byte |
| binary.LittleEndian.PutUint32(gzipFooter[0:4], crc32.ChecksumIEEE(in)) |
| binary.LittleEndian.PutUint32(gzipFooter[4:8], uint32(len(in))) |
| |
| // Encode the input without compression using raw DEFLATE blocks. |
| out = make([]byte, 0, len(gzipHeader)+len(blockHeader)*numBlocks+len(in)+len(gzipFooter)) |
| out = append(out, gzipHeader[:]...) |
| for blockHeader[0] == 0 { |
| blockSize := maxBlockSize |
| if blockSize > len(in) { |
| blockHeader[0] = 0x01 // final bit per RFC 1951, section 3.2.3. |
| blockSize = len(in) |
| } |
| binary.LittleEndian.PutUint16(blockHeader[1:3], uint16(blockSize)^0x0000) |
| binary.LittleEndian.PutUint16(blockHeader[3:5], uint16(blockSize)^0xffff) |
| out = append(out, blockHeader[:]...) |
| out = append(out, in[:blockSize]...) |
| in = in[blockSize:] |
| } |
| out = append(out, gzipFooter[:]...) |
| return out |
| } |