AAPT2: Define and Implement AAPT Container Format

AAPT Container Format (.apc) is a simple container that
enumerates the various intermediate files that AAPT2 generates
during the compile phase.

The format is defined in formats.md.

For now, continue using the .flat extension for the container file,
and keep making use of the .flata zip for storing multiple files.
This will allow easier integration with existing build systems and allow
the evolution of the APC format to better handle arbitrarily large
files.

Test: make aapt2_tests
Change-Id: Id7216e5b76316bdd683f0fa4eaf2d2da273ba815

tools/aapt2/Android.bp

@@ -84,17 +84,18 @@ cc_library_host_static {
         "filter/AbiFilter.cpp",
         "filter/ConfigFilter.cpp",
         "format/Archive.cpp",
+        "format/Container.cpp",
         "format/binary/BinaryResourceParser.cpp",
         "format/binary/ResChunkPullParser.cpp",
         "format/binary/TableFlattener.cpp",
         "format/binary/XmlFlattener.cpp",
         "format/proto/ProtoDeserialize.cpp",
         "format/proto/ProtoSerialize.cpp",
-        "io/BigBufferStreams.cpp",
+        "io/BigBufferStream.cpp",
         "io/File.cpp",
-        "io/FileInputStream.cpp",
+        "io/FileStream.cpp",
         "io/FileSystem.cpp",
-        "io/StringInputStream.cpp",
+        "io/StringStream.cpp",
         "io/Util.cpp",
         "io/ZipArchive.cpp",
         "link/AutoVersioner.cpp",

tools/aapt2/LoadedApk.cpp

@@ -21,7 +21,7 @@
 #include "format/Archive.h"
 #include "format/binary/TableFlattener.h"
 #include "format/binary/XmlFlattener.h"
-#include "io/BigBufferInputStream.h"
+#include "io/BigBufferStream.h"
 #include "io/Util.h"
 #include "xml/XmlDom.h"
 

tools/aapt2/Resource.h

@@ -157,12 +157,22 @@ struct SourcedResourceName {
 };
 
 struct ResourceFile {
+  enum class Type {
+    kUnknown,
+    kPng,
+    kBinaryXml,
+    kProtoXml,
+  };
+
   // Name
   ResourceName name;
 
   // Configuration
   ConfigDescription config;
 
+  // Type
+  Type type;
+
   // Source
   Source source;
 

tools/aapt2/ResourceParser_test.cpp

@@ -22,7 +22,7 @@
 #include "ResourceTable.h"
 #include "ResourceUtils.h"
 #include "ResourceValues.h"
-#include "io/StringInputStream.h"
+#include "io/StringStream.h"
 #include "test/Test.h"
 #include "xml/XmlPullParser.h"
 

tools/aapt2/ResourceValues.cpp

@@ -292,6 +292,7 @@ bool FileReference::Flatten(android::Res_value* out_value) const {
 FileReference* FileReference::Clone(StringPool* new_pool) const {
   FileReference* fr = new FileReference(new_pool->MakeRef(*path));
   fr->file = file;
+  fr->type = type;
   fr->comment_ = comment_;
   fr->source_ = source_;
   return fr;

tools/aapt2/ResourceValues.h

@@ -249,6 +249,10 @@ struct FileReference : public BaseItem<FileReference> {
   // This field is NOT persisted in any format. It is transient.
   io::IFile* file = nullptr;
 
+  // FileType of the file pointed to by `file`. This is used to know how to inflate the file,
+  // or if to inflate at all (just copy).
+  ResourceFile::Type type = ResourceFile::Type::kUnknown;
+
   FileReference() = default;
   explicit FileReference(const StringPool::Ref& path);
 

tools/aapt2/ResourcesInternal.proto

@@ -41,13 +41,22 @@ message CompiledFile {
   // The configuration for which the resource is defined.
   aapt.pb.Configuration config = 2;
 
+  enum Type {
+    UNKNOWN = 0;
+    PNG = 1;
+    BINARY_XML = 2;
+    PROTO_XML = 3;
+  }
+
+  Type type = 3;
+
   // The filesystem path to where the source file originated.
   // Mainly used to display helpful error messages.
-  string source_path = 3;
+  string source_path = 4;
 
   // Any symbols this file auto-generates/exports (eg. @+id/foo in an XML file).
-  repeated Symbol exported_symbol = 4;
+  repeated Symbol exported_symbol = 5;
 
   // If this is a compiled XML file, this is the root node.
-  aapt.pb.XmlNode xml_root = 5;
+  aapt.pb.XmlNode xml_root = 6;
 }