Merge META-INF/services/* files in merge_zips -jar
kotlinx_coroutines_test and kotlinx_coroutine_android each provide a
META-INF/services/kotlinx.coroutines.CoroutineExceptionHandler with
different contents, and the final contents needs to be the combination
of the two files. Implement service merging in merge_zips when the
-jar argument is provided.
Bug: 290933559
Test: TestMergeZips
Change-Id: I69f80d1265c64c671d308ef4cdccfa1564abe056
diff --git a/jar/services.go b/jar/services.go
new file mode 100644
index 0000000..d06a6dc
--- /dev/null
+++ b/jar/services.go
@@ -0,0 +1,128 @@
+// Copyright 2023 Google 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.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License 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 jar
+
+import (
+ "android/soong/third_party/zip"
+ "bufio"
+ "hash/crc32"
+ "sort"
+ "strings"
+)
+
+const servicesPrefix = "META-INF/services/"
+
+// Services is used to collect service files from multiple zip files and produce a list of ServiceFiles containing
+// the unique lines from all the input zip entries with the same name.
+type Services struct {
+ services map[string]*ServiceFile
+}
+
+// ServiceFile contains the combined contents of all input zip entries with a single name.
+type ServiceFile struct {
+ Name string
+ FileHeader *zip.FileHeader
+ Contents []byte
+ Lines []string
+}
+
+// IsServiceFile returns true if the zip entry is in the META-INF/services/ directory.
+func (Services) IsServiceFile(entry *zip.File) bool {
+ return strings.HasPrefix(entry.Name, servicesPrefix)
+}
+
+// AddServiceFile adds a zip entry in the META-INF/services/ directory to the list of service files that need
+// to be combined.
+func (j *Services) AddServiceFile(entry *zip.File) error {
+ if j.services == nil {
+ j.services = map[string]*ServiceFile{}
+ }
+
+ service := entry.Name
+ serviceFile := j.services[service]
+ fh := entry.FileHeader
+ if serviceFile == nil {
+ serviceFile = &ServiceFile{
+ Name: service,
+ FileHeader: &fh,
+ }
+ j.services[service] = serviceFile
+ }
+
+ f, err := entry.Open()
+ if err != nil {
+ return err
+ }
+ defer f.Close()
+
+ scanner := bufio.NewScanner(f)
+ for scanner.Scan() {
+ line := scanner.Text()
+ if line != "" {
+ serviceFile.Lines = append(serviceFile.Lines, line)
+ }
+ }
+
+ if err := scanner.Err(); err != nil {
+ return err
+ }
+
+ return nil
+}
+
+// ServiceFiles returns the list of combined service files, each containing all the unique lines from the
+// corresponding service files in the input zip entries.
+func (j *Services) ServiceFiles() []ServiceFile {
+ services := make([]ServiceFile, 0, len(j.services))
+
+ for _, serviceFile := range j.services {
+ serviceFile.Lines = dedupServicesLines(serviceFile.Lines)
+ serviceFile.Lines = append(serviceFile.Lines, "")
+ serviceFile.Contents = []byte(strings.Join(serviceFile.Lines, "\n"))
+
+ serviceFile.FileHeader.UncompressedSize64 = uint64(len(serviceFile.Contents))
+ serviceFile.FileHeader.CRC32 = crc32.ChecksumIEEE(serviceFile.Contents)
+ if serviceFile.FileHeader.Method == zip.Store {
+ serviceFile.FileHeader.CompressedSize64 = serviceFile.FileHeader.UncompressedSize64
+ }
+
+ services = append(services, *serviceFile)
+ }
+
+ sort.Slice(services, func(i, j int) bool {
+ return services[i].Name < services[j].Name
+ })
+
+ return services
+}
+
+func dedupServicesLines(in []string) []string {
+ writeIndex := 0
+outer:
+ for readIndex := 0; readIndex < len(in); readIndex++ {
+ for compareIndex := 0; compareIndex < writeIndex; compareIndex++ {
+ if interface{}(in[readIndex]) == interface{}(in[compareIndex]) {
+ // The value at readIndex already exists somewhere in the output region
+ // of the slice before writeIndex, skip it.
+ continue outer
+ }
+ }
+ if readIndex != writeIndex {
+ in[writeIndex] = in[readIndex]
+ }
+ writeIndex++
+ }
+ return in[0:writeIndex]
+}