idmap2: initial code drop

idmap2 is a reboot of the idmap project. The project aims to

  - use modern C++
  - greatly improve test and debug support
  - interface towards AssetManager2 (instead of AssetManager)
  - provide a solid foundation to add support for new features

To make it easier to verify correctness, this first version of idmap2 is
feature equivalent to idmap. Later versions will add support for new
features such as <overlayable>.

Bug: 78815803
Test: make idmap2_tests
Change-Id: I1d806dc875a493e730ab55d2fdb027618e586d16
diff --git a/cmds/idmap2/libidmap2/ZipFile.cpp b/cmds/idmap2/libidmap2/ZipFile.cpp
new file mode 100644
index 0000000..3f2079a
--- /dev/null
+++ b/cmds/idmap2/libidmap2/ZipFile.cpp
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#include <memory>
+#include <string>
+#include <utility>
+
+#include "idmap2/ZipFile.h"
+
+namespace android {
+namespace idmap2 {
+
+std::unique_ptr<MemoryChunk> MemoryChunk::Allocate(size_t size) {
+  void* ptr = ::operator new(sizeof(MemoryChunk) + size);
+  std::unique_ptr<MemoryChunk> chunk(reinterpret_cast<MemoryChunk*>(ptr));
+  chunk->size = size;
+  return chunk;
+}
+
+std::unique_ptr<const ZipFile> ZipFile::Open(const std::string& path) {
+  ::ZipArchiveHandle handle;
+  int32_t status = ::OpenArchive(path.c_str(), &handle);
+  if (status != 0) {
+    return nullptr;
+  }
+  return std::unique_ptr<ZipFile>(new ZipFile(handle));
+}
+
+ZipFile::~ZipFile() {
+  ::CloseArchive(handle_);
+}
+
+std::unique_ptr<const MemoryChunk> ZipFile::Uncompress(const std::string& entryPath) const {
+  ::ZipEntry entry;
+  int32_t status = ::FindEntry(handle_, ::ZipString(entryPath.c_str()), &entry);
+  if (status != 0) {
+    return nullptr;
+  }
+  std::unique_ptr<MemoryChunk> chunk = MemoryChunk::Allocate(entry.uncompressed_length);
+  status = ::ExtractToMemory(handle_, &entry, chunk->buf, chunk->size);
+  if (status != 0) {
+    return nullptr;
+  }
+  return chunk;
+}
+
+std::pair<bool, uint32_t> ZipFile::Crc(const std::string& entryPath) const {
+  ::ZipEntry entry;
+  int32_t status = ::FindEntry(handle_, ::ZipString(entryPath.c_str()), &entry);
+  return std::make_pair(status == 0, entry.crc32);
+}
+
+}  // namespace idmap2
+}  // namespace android