platform_build_soong/cmd/diff_target_files/compare.go

134 lines
3.6 KiB
Go

// 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, allowLists []allowList, 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 applyAllowLists(diff, allowLists)
}
// 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
}