forked from twitchtv/twirp
/
command_line.go
84 lines (75 loc) · 2.98 KB
/
command_line.go
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// Copyright 2018 Twitch Interactive, Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License"). You may not
// use this file except in compliance with the License. A copy of the License is
// located at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// or in the "license" file accompanying this file. This file 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 main
import (
"fmt"
"strings"
)
type commandLineParams struct {
importMap map[string]string // Mapping from .proto file name to import path.
paths string // paths flag, used to control file output directory.
module string // module flag, Go import path prefix that is removed from the output filename.
importPrefix string // prefix added to imported package file names.
}
// parseCommandLineParams breaks the comma-separated list of key=value pairs
// in the parameter (a member of the request protobuf) into a key/value map.
// It then sets command line parameter mappings defined by those entries.
func parseCommandLineParams(parameter string) (*commandLineParams, error) {
ps := make(map[string]string)
for _, p := range strings.Split(parameter, ",") {
if p == "" {
continue
}
i := strings.Index(p, "=")
if i < 0 {
return nil, fmt.Errorf("invalid parameter %q: expected format of parameter to be k=v", p)
}
k := p[0:i]
v := p[i+1:]
if v == "" {
return nil, fmt.Errorf("invalid parameter %q: expected format of parameter to be k=v", k)
}
ps[k] = v
}
clp := &commandLineParams{
importMap: make(map[string]string),
}
for k, v := range ps {
switch {
// Support import map 'M' prefix: https://developers.google.com/protocol-buffers/docs/reference/go-generated
case len(k) > 0 && k[0] == 'M':
clp.importMap[k[1:]] = v // 1 is the length of 'M'.
case len(k) > 0 && strings.HasPrefix(k, "go_import_mapping@"): // twirp specific version of M parameters
clp.importMap[k[18:]] = v // 18 is the length of 'go_import_mapping@'.
case k == "paths":
switch v {
case "import":
// this is the default behavior; the output file is placed in a directory named after the option go_package
case "source_relative":
// the directory prefix on the option go_package is removed from the output filename (only the last part is used)
clp.paths = "source_relative"
default:
return nil, fmt.Errorf("invalid command line flag %s=%s", k, v)
}
// If the module={PREFIX} flag is specified, the prefix is removed from the option go_package on the output filename
case k == "module":
clp.module = v
// Deprecated, but may still be useful when working with old versions of protoc-gen-go
case k == "import_prefix":
clp.importPrefix = v
default:
return nil, fmt.Errorf("invalid command line flag %s=%s", k, v)
}
}
return clp, nil
}