Skip to content

Commit

Permalink
feat: add dynamic routing header generation (#887)
Browse files Browse the repository at this point in the history 
* feat: add dynamic routing header generation

* refactor

* refactor

* undo change to file

* remove empty header and update test
  • Loading branch information
@alicejli
alicejli authored Feb 17, 2022
1 parent 10b611a commit e2520c7
Show file tree
Hide file tree
Showing 14 changed files with 612 additions and 50 deletions.
2 changes: 1 addition & 1 deletion cmd/protoc-gen-go_cli/test.sh
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,7 @@ mkdir -p "$OUT/showcase"
# make test proto directories
mkdir -p $SHOW_PROTOS

SHOWCASE_VERSION=0.9.0
SHOWCASE_VERSION=0.19.0

# download gapic-showcase proto descriptor set
curl -L -O https://github.com/googleapis/gapic-showcase/releases/download/v$SHOWCASE_VERSION/gapic-showcase-$SHOWCASE_VERSION.desc
Expand Down
174 changes: 129 additions & 45 deletions internal/gengapic/gengapic.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -243,12 +243,49 @@ func (g *generator) deadline(s, m string) {
g.imports[pbinfo.ImportSpec{Path: "time"}] = true
}

func (g *generator) insertMetadata(m *descriptor.MethodDescriptorProto) error {
headers, err := parseRequestHeaders(m)
func (g *generator) getFormattedValue(m *descriptor.MethodDescriptorProto, field string, accessor string) (string, error) {
f := g.lookupField(m.GetInputType(), field)
value := ""
// TODO(noahdietz): need to handle []byte for TYPE_BYTES.
switch f.GetType() {
case descriptor.FieldDescriptorProto_TYPE_STRING:
value = fmt.Sprintf("url.QueryEscape(%s)", accessor)
case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
// Double and float are handled the same way.
fallthrough
case descriptor.FieldDescriptorProto_TYPE_FLOAT:
// Format the floating point value with mode 'g' to allow for
// exponent formatting when necessary, and decimal when adequate.
// QueryEscape the resulting string in case there is a '+' in the
// exponent.
// See golang.org/pkg/fmt for more information on formatting.
value = fmt.Sprintf(`url.QueryEscape(fmt.Sprintf("%%g", %s))`, accessor)
case descriptor.FieldDescriptorProto_TYPE_ENUM:
en := g.descInfo.Type[f.GetTypeName()]

n, imp, err := g.descInfo.NameSpec(en)
if err != nil {
return "", err
}
g.imports[imp] = true

// protobuf Go generates a mapping from number to string
// representation of an enum, in UPPER_SNAKE_CASE form. The map
// is named with the enum name and the _name suffix. If it is a
// nested enum, the name is prefixed with the parent message name.
// For example, Severity_name or Error_Severity_name.
value = fmt.Sprintf("%s.%s_name[int32(%s)]", imp.Name, n, accessor)
default:
value = accessor
}
return value, nil
}

func (g *generator) insertImplicitRequestHeaders(m *descriptor.MethodDescriptorProto) error {
headers, err := parseImplicitRequestHeaders(m)
if err != nil {
return err
}

if len(headers) > 0 {
seen := map[string]bool{}
var formats, values strings.Builder
Expand All @@ -259,62 +296,82 @@ func (g *generator) insertMetadata(m *descriptor.MethodDescriptorProto) error {
continue
}
seen[field] = true

accessor := fmt.Sprintf("req%s", fieldGetter(field))
f := g.lookupField(m.GetInputType(), field)

// TODO(noahdietz): need to handle []byte for TYPE_BYTES.
switch f.GetType() {
case descriptor.FieldDescriptorProto_TYPE_STRING:
accessor = fmt.Sprintf("url.QueryEscape(%s)", accessor)
case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
// Double and float are handled the same way.
fallthrough
case descriptor.FieldDescriptorProto_TYPE_FLOAT:
// Format the floating point value with mode 'g' to allow for
// exponent formatting when necessary, and decimal when adequate.
// QueryEscape the resulting string in case there is a '+' in the
// exponent.
// See golang.org/pkg/fmt for more information on formatting.
accessor = fmt.Sprintf(`url.QueryEscape(fmt.Sprintf("%%g", %s))`, accessor)
case descriptor.FieldDescriptorProto_TYPE_ENUM:
en := g.descInfo.Type[f.GetTypeName()]

n, imp, err := g.descInfo.NameSpec(en)
if err != nil {
return err
}
g.imports[imp] = true

// protobuf Go generates a mapping from number to string
// representation of an enum, in UPPER_SNAKE_CASE form. The map
// is named with the enum name and the _name suffix. If it is a
// nested enum, the name is prefixed with the parent message name.
// For example, Severity_name or Error_Severity_name.
accessor = fmt.Sprintf("%s.%s_name[int32(%s)]", imp.Name, n, accessor)
accessor, err = g.getFormattedValue(m, field, accessor)
if err != nil {
return err
}

// URL encode key & values separately per aip.dev/4222.
// Encode the key ahead of time to reduce clutter
// and because it will likely never be necessary
fmt.Fprintf(&values, " %q, %s,", url.QueryEscape(field), accessor)
formats.WriteString("%s=%v&")
}
// Trim the trailing comma and ampersand symbols.
f := formats.String()[:formats.Len()-1]
v := values.String()[:values.Len()-1]

g.printf("md := metadata.Pairs(\"x-goog-request-params\", fmt.Sprintf(%q,%s))", f, v)
g.printf("ctx = insertMetadata(ctx, c.xGoogMetadata, md)")
}
return nil
}

func (g *generator) insertDynamicRequestHeaders(m *descriptor.MethodDescriptorProto) error {
headers, err := parseDynamicRequestHeaders(m)
if err != nil {
return err
}
if len(headers) > 0 {
g.printf(`routingHeaders := ""`)
g.printf("routingHeadersMap := make(map[string]string)")
for i := range headers {
namedCaptureRegex := headers[i][0]
field := headers[i][1]
headerName := headers[i][2]
accessor := fmt.Sprintf("req%s", fieldGetter(field))
regexHelper := fmt.Sprintf("reg.FindStringSubmatch(%s)[1]", accessor)
regexHelper, err = g.getFormattedValue(m, field, regexHelper)
if err != nil {
return err
}
// There could be an edge case where the request field is empty and the path template is a wildcard. In that case, we still don't want to send an empty header name.
g.printf("if reg := regexp.MustCompile(%q); reg.MatchString(%s) && len(%s) > 0 {", namedCaptureRegex, accessor, regexHelper)
g.printf(" routingHeadersMap[%q] = %s", headerName, regexHelper)
g.printf("}")
}
g.printf("for headerName, headerValue := range routingHeadersMap {")
g.printf(` routingHeaders = fmt.Sprintf("%%s%%s=%%s&", routingHeaders, headerName, headerValue)`)
g.printf("}")
g.printf(`routingHeaders = strings.TrimSuffix(routingHeaders, "&")`)
g.imports[pbinfo.ImportSpec{Path: "strings"}] = true
g.printf("md := metadata.Pairs(\"x-goog-request-params\", routingHeaders)")
g.imports[pbinfo.ImportSpec{Path: "regexp"}] = true
}
return nil
}

func (g *generator) insertMetadata(m *descriptor.MethodDescriptorProto) error {
headers, err := parseImplicitRequestHeaders(m)
if err != nil {
return err
}
// If dynamic routing annotation exists, it supercedes and replaces other request headers.
if dynamicRequestHeadersExist(m) {
headers, err = parseDynamicRequestHeaders(m)
if err != nil {
return err
}
}

if len(headers) > 0 {
insertHeaders := g.insertImplicitRequestHeaders
if dynamicRequestHeadersExist(m) {
insertHeaders = g.insertDynamicRequestHeaders
}
insertHeaders(m)
g.printf("")
g.printf("ctx = insertMetadata(ctx, c.xGoogMetadata, md)")
g.imports[pbinfo.ImportSpec{Path: "fmt"}] = true
g.imports[pbinfo.ImportSpec{Path: "net/url"}] = true

return nil
}

g.printf("ctx = insertMetadata(ctx, c.xGoogMetadata)")

return nil
}

Expand Down Expand Up @@ -498,7 +555,7 @@ func (g *generator) returnType(m *descriptor.MethodDescriptorProto) (string, err
return retTyp, nil
}

func parseRequestHeaders(m *descriptor.MethodDescriptorProto) ([][]string, error) {
func parseImplicitRequestHeaders(m *descriptor.MethodDescriptorProto) ([][]string, error) {
var matches [][]string

eHTTP := proto.GetExtension(m.GetOptions(), annotations.E_Http)
Expand Down Expand Up @@ -531,3 +588,30 @@ func parseRequestHeaders(m *descriptor.MethodDescriptorProto) ([][]string, error

return matches, nil
}

// Determine whether routing annotation exists
func dynamicRequestHeadersExist(m *descriptor.MethodDescriptorProto) bool {
return proto.HasExtension(m.GetOptions(), annotations.E_Routing)
}

// Parse routing annotations to be used as request headers
func parseDynamicRequestHeaders(m *descriptor.MethodDescriptorProto) ([][]string, error) {
var matches [][]string

reqHeaders := proto.GetExtension(m.GetOptions(), annotations.E_Routing)
routingRule := reqHeaders.(*annotations.RoutingRule)
routingParameter := routingRule.GetRoutingParameters()

for _, param := range routingParameter {
pathTemplateRegex := convertPathTemplateToRegex(param.GetPathTemplate())
fieldReq := param.Field
headerName := getHeaderName(param.GetPathTemplate())
if len(headerName) < 1 {
headerName = fieldReq
}
paramSlice := []string{pathTemplateRegex, fieldReq, headerName}
matches = append(matches, paramSlice)
}

return matches, nil
}
Loading

0 comments on commit e2520c7

Please sign in to comment.