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

cmd/diff_target_files/target_files.go

@@ -0,0 +1,86 @@
+// 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 (
+	"fmt"
+	"strings"
+)
+
+const targetFilesPattern = "*-target_files-*.zip"
+
+var targetZipPartitions = []string{
+	"BOOT/RAMDISK/",
+	"BOOT/",
+	"DATA/",
+	"ODM/",
+	"OEM/",
+	"PRODUCT/",
+	"PRODUCT_SERVICES/",
+	"ROOT/",
+	"SYSTEM/",
+	"SYSTEM_OTHER/",
+	"VENDOR/",
+}
+
+var targetZipFilter = []string{
+	"IMAGES/",
+	"OTA/",
+	"META/",
+	"PREBUILT_IMAGES/",
+	"RADIO/",
+}
+
+func filterTargetZipFiles(files []*ZipArtifactFile, artifact string, patterns []string) ([]*ZipArtifactFile, error) {
+	var ret []*ZipArtifactFile
+outer:
+	for _, f := range files {
+		if f.FileInfo().IsDir() {
+			continue
+		}
+
+		if artifact == targetFilesPattern {
+			found := false
+			for _, p := range targetZipPartitions {
+				if strings.HasPrefix(f.Name, p) {
+					f.Name = strings.ToLower(p) + strings.TrimPrefix(f.Name, p)
+					found = true
+				}
+			}
+			for _, filter := range targetZipFilter {
+				if strings.HasPrefix(f.Name, filter) {
+					continue outer
+				}
+			}
+
+			if !found {
+				return nil, fmt.Errorf("unmatched prefix for %s", f.Name)
+			}
+		}
+
+		if patterns != nil {
+			for _, pattern := range patterns {
+				match, _ := Match(pattern, f.Name)
+				if match {
+					ret = append(ret, f)
+				}
+			}
+		} else {
+			ret = append(ret, f)
+		}
+	}
+
+	return ret, nil
+}