Import files from compare_target_files for use in diff_target_files
Copied from cl/240594925.
Bug: 121158314
Test: copied unit tests
Change-Id: I2e91126285dcd33171ff8b8dbfcfa5d48501f535
diff --git a/cmd/diff_target_files/compare.go b/cmd/diff_target_files/compare.go
new file mode 100644
index 0000000..00cd9ca
--- /dev/null
+++ b/cmd/diff_target_files/compare.go
@@ -0,0 +1,133 @@
+// Copyright 2019 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 main
+
+import (
+ "bytes"
+ "fmt"
+)
+
+// compareTargetFiles takes two ZipArtifacts and compares the files they contain by examining
+// the path, size, and CRC of each file.
+func compareTargetFiles(priZip, refZip ZipArtifact, artifact string, whitelists []whitelist, filters []string) (zipDiff, error) {
+ priZipFiles, err := priZip.Files()
+ if err != nil {
+ return zipDiff{}, fmt.Errorf("error fetching target file lists from primary zip %v", err)
+ }
+
+ refZipFiles, err := refZip.Files()
+ if err != nil {
+ return zipDiff{}, fmt.Errorf("error fetching target file lists from reference zip %v", err)
+ }
+
+ priZipFiles, err = filterTargetZipFiles(priZipFiles, artifact, filters)
+ if err != nil {
+ return zipDiff{}, err
+ }
+
+ refZipFiles, err = filterTargetZipFiles(refZipFiles, artifact, filters)
+ if err != nil {
+ return zipDiff{}, err
+ }
+
+ // Compare the file lists from both builds
+ diff := diffTargetFilesLists(refZipFiles, priZipFiles)
+
+ return applyWhitelists(diff, whitelists)
+}
+
+// zipDiff contains the list of files that differ between two zip files.
+type zipDiff struct {
+ modified [][2]*ZipArtifactFile
+ onlyInA, onlyInB []*ZipArtifactFile
+}
+
+// String pretty-prints the list of files that differ between two zip files.
+func (d *zipDiff) String() string {
+ buf := &bytes.Buffer{}
+
+ must := func(n int, err error) {
+ if err != nil {
+ panic(err)
+ }
+ }
+
+ var sizeChange int64
+
+ if len(d.modified) > 0 {
+ must(fmt.Fprintln(buf, "files modified:"))
+ for _, f := range d.modified {
+ must(fmt.Fprintf(buf, " %v (%v bytes -> %v bytes)\n", f[0].Name, f[0].UncompressedSize64, f[1].UncompressedSize64))
+ sizeChange += int64(f[1].UncompressedSize64) - int64(f[0].UncompressedSize64)
+ }
+ }
+
+ if len(d.onlyInA) > 0 {
+ must(fmt.Fprintln(buf, "files removed:"))
+ for _, f := range d.onlyInA {
+ must(fmt.Fprintf(buf, " - %v (%v bytes)\n", f.Name, f.UncompressedSize64))
+ sizeChange -= int64(f.UncompressedSize64)
+ }
+ }
+
+ if len(d.onlyInB) > 0 {
+ must(fmt.Fprintln(buf, "files added:"))
+ for _, f := range d.onlyInB {
+ must(fmt.Fprintf(buf, " + %v (%v bytes)\n", f.Name, f.UncompressedSize64))
+ sizeChange += int64(f.UncompressedSize64)
+ }
+ }
+
+ if len(d.modified) > 0 || len(d.onlyInA) > 0 || len(d.onlyInB) > 0 {
+ must(fmt.Fprintf(buf, "total size change: %v bytes\n", sizeChange))
+ }
+
+ return buf.String()
+}
+
+func diffTargetFilesLists(a, b []*ZipArtifactFile) zipDiff {
+ i := 0
+ j := 0
+
+ diff := zipDiff{}
+
+ for i < len(a) && j < len(b) {
+ if a[i].Name == b[j].Name {
+ if a[i].UncompressedSize64 != b[j].UncompressedSize64 || a[i].CRC32 != b[j].CRC32 {
+ diff.modified = append(diff.modified, [2]*ZipArtifactFile{a[i], b[j]})
+ }
+ i++
+ j++
+ } else if a[i].Name < b[j].Name {
+ // a[i] is not present in b
+ diff.onlyInA = append(diff.onlyInA, a[i])
+ i++
+ } else {
+ // b[j] is not present in a
+ diff.onlyInB = append(diff.onlyInB, b[j])
+ j++
+ }
+ }
+ for i < len(a) {
+ diff.onlyInA = append(diff.onlyInA, a[i])
+ i++
+ }
+ for j < len(b) {
+ diff.onlyInB = append(diff.onlyInB, b[j])
+ j++
+ }
+
+ return diff
+}