Add zip2zip tool to copy zip entries from one file to another

This doesn't do any decompression / recompression, but just copies over
the already compressed contents. So it's similar to zip -U, but allows
rewriting of the paths.

The first expected usecase is to replace img_from_target_files during
the build, since it does the equivalent of this:

zip2zip -i <target-files.zip> -o <img.zip> OTA/android-info.txt:android-info.txt IMAGES/*:.

Except it decompresses and recompresses the images, which takes over a
minute instead of a few seconds.

Change-Id: I88d0df188635088783223873f78e193272dbdf1c

4 files changed, 239 insertions, 0 deletions

diff --git a/Android.bp b/Android.bp
index e1a66213..523bec16 100644
--- a/Android.bp
+++ b/Android.bp
@@ -10,6 +10,8 @@
 //    2) Build again
 //
 
+subdirs = ["third_party/zip"]
+
 bootstrap_go_binary {
     name: "soong_build",
     deps: [
@@ -195,6 +197,14 @@ bootstrap_go_package {
 }
 
 blueprint_go_binary {
+    name: "zip2zip",
+    deps: ["android-archive-zip"],
+    srcs: [
+        "cmd/zip2zip/zip2zip.go",
+    ],
+}
+
+blueprint_go_binary {
     name: "soong_jar",
     srcs: [
         "cmd/soong_jar/soong_jar.go",
diff --git a/cmd/zip2zip/zip2zip.go b/cmd/zip2zip/zip2zip.go
new file mode 100644
index 00000000..8e7523ff
--- /dev/null
+++ b/cmd/zip2zip/zip2zip.go
@@ -0,0 +1,128 @@
+// Copyright 2016 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 (
+	"flag"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"android/soong/third_party/zip"
+)
+
+var (
+	input  = flag.String("i", "", "zip file to read from")
+	output = flag.String("o", "", "output file")
+)
+
+func usage() {
+	fmt.Fprintln(os.Stderr, "usage: zip2zip -i zipfile -o zipfile [filespec]...")
+	flag.PrintDefaults()
+	fmt.Fprintln(os.Stderr, "  filespec:")
+	fmt.Fprintln(os.Stderr, "    <name>")
+	fmt.Fprintln(os.Stderr, "    <in_name>:<out_name>")
+	fmt.Fprintln(os.Stderr, "    <glob>:<out_dir>/")
+	fmt.Fprintln(os.Stderr, "")
+	fmt.Fprintln(os.Stderr, "Files will be copied with their existing compression from the input zipfile to")
+	fmt.Fprintln(os.Stderr, "the output zipfile, in the order of filespec arguments")
+	os.Exit(2)
+}
+
+func main() {
+	flag.Parse()
+
+	if flag.NArg() == 0 || *input == "" || *output == "" {
+		usage()
+	}
+
+	reader, err := zip.OpenReader(*input)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(3)
+	}
+	defer reader.Close()
+
+	output, err := os.Create(*output)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(4)
+	}
+	defer output.Close()
+
+	writer := zip.NewWriter(output)
+	defer func() {
+		err := writer.Close()
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(5)
+		}
+	}()
+
+	for _, arg := range flag.Args() {
+		var input string
+		var output string
+
+		// Reserve escaping for future implementation, so make sure no
+		// one is using \ and expecting a certain behavior.
+		if strings.Contains(arg, "\\") {
+			fmt.Fprintln(os.Stderr, "\\ characters are not currently supported")
+			os.Exit(6)
+		}
+
+		args := strings.SplitN(arg, ":", 2)
+		input = args[0]
+		if len(args) == 2 {
+			output = args[1]
+		}
+
+		if strings.IndexAny(input, "*?[") >= 0 {
+			for _, file := range reader.File {
+				if match, err := filepath.Match(input, file.Name); err != nil {
+					fmt.Fprintln(os.Stderr, err)
+					os.Exit(7)
+				} else if match {
+					var newFileName string
+					if output == "" {
+						newFileName = file.Name
+					} else {
+						_, name := filepath.Split(file.Name)
+						newFileName = filepath.Join(output, name)
+					}
+					err = writer.CopyFrom(file, newFileName)
+					if err != nil {
+						fmt.Fprintln(os.Stderr, err)
+						os.Exit(8)
+					}
+				}
+			}
+		} else {
+			if output == "" {
+				output = input
+			}
+			for _, file := range reader.File {
+				if input == file.Name {
+					err = writer.CopyFrom(file, output)
+					if err != nil {
+						fmt.Fprintln(os.Stderr, err)
+						os.Exit(8)
+					}
+					break
+				}
+			}
+		}
+	}
+}
diff --git a/third_party/zip/Android.bp b/third_party/zip/Android.bp
new file mode 100644
index 00000000..044e6f8e
--- /dev/null
+++ b/third_party/zip/Android.bp
@@ -0,0 +1,31 @@
+// Copyright 2016 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.
+
+bootstrap_go_package {
+    name: "android-archive-zip",
+    pkgPath: "android/soong/third_party/zip",
+    srcs: [
+        "reader.go",
+        "register.go",
+        "struct.go",
+        "writer.go",
+
+        "android.go",
+    ],
+    testSrcs: [
+        "reader_test.go",
+        "writer_test.go",
+        "zip_test.go",
+    ],
+}
diff --git a/third_party/zip/android.go b/third_party/zip/android.go
new file mode 100644
index 00000000..7a3a2213
--- /dev/null
+++ b/third_party/zip/android.go
@@ -0,0 +1,70 @@
+// Copyright 2016 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 zip
+
+import (
+	"io"
+)
+
+func (w *Writer) CopyFrom(orig *File, newName string) error {
+	if w.last != nil && !w.last.closed {
+		if err := w.last.close(); err != nil {
+			return err
+		}
+		w.last = nil
+	}
+
+	fileHeader := orig.FileHeader
+	fileHeader.Name = newName
+	fh := &fileHeader
+	fh.Flags |= 0x8
+
+	h := &header{
+		FileHeader: fh,
+		offset:     uint64(w.cw.count),
+	}
+	w.dir = append(w.dir, h)
+
+	if err := writeHeader(w.cw, fh); err != nil {
+		return err
+	}
+
+	// Copy data
+	dataOffset, err := orig.DataOffset()
+	if err != nil {
+		return err
+	}
+	io.Copy(w.cw, io.NewSectionReader(orig.zipr, dataOffset, int64(orig.CompressedSize64)))
+
+	// Write data descriptor.
+	var buf []byte
+	if fh.isZip64() {
+		buf = make([]byte, dataDescriptor64Len)
+	} else {
+		buf = make([]byte, dataDescriptorLen)
+	}
+	b := writeBuf(buf)
+	b.uint32(dataDescriptorSignature)
+	b.uint32(fh.CRC32)
+	if fh.isZip64() {
+		b.uint64(fh.CompressedSize64)
+		b.uint64(fh.UncompressedSize64)
+	} else {
+		b.uint32(fh.CompressedSize)
+		b.uint32(fh.UncompressedSize)
+	}
+	_, err = w.cw.Write(buf)
+	return err
+}