Add binary to write basic COW
Adding small binary to write a simple COW for version 2. We will then
use updated reader to make sure we can read this version 2 cow. Think it
would be a good idea to keep the binary here to see how exactly we
generated the cow (useful for debugging and if we ever need to recreate
this cow)
Test: m basic_v2_cow_writer
Change-Id: I28435025b7a8280fc5c4574876cc9110b391cb0e
diff --git a/fs_mgr/libsnapshot/tools/Android.bp b/fs_mgr/libsnapshot/tools/Android.bp
index cfa0cef..0f08286 100644
--- a/fs_mgr/libsnapshot/tools/Android.bp
+++ b/fs_mgr/libsnapshot/tools/Android.bp
@@ -20,3 +20,26 @@
cflags: ["-Werror"],
}
+
+
+cc_binary {
+ name: "basic_v2_cow_writer",
+ host_supported: true,
+ defaults: [
+ "fs_mgr_defaults",
+ "libsnapshot_cow_defaults",
+ ],
+
+ srcs: ["basic_v2_cow_writer.cpp"],
+
+ static_libs: [
+ "libsnapshot_cow",
+ ],
+
+ shared_libs: [
+ "libbase",
+ "liblog",
+ ],
+
+ cflags: ["-Werror"],
+}
diff --git a/fs_mgr/libsnapshot/tools/basic_v2_cow_writer.cpp b/fs_mgr/libsnapshot/tools/basic_v2_cow_writer.cpp
new file mode 100644
index 0000000..59d3539
--- /dev/null
+++ b/fs_mgr/libsnapshot/tools/basic_v2_cow_writer.cpp
@@ -0,0 +1,48 @@
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <libsnapshot/cow_compress.h>
+#include <libsnapshot/cow_format.h>
+#include <libsnapshot/cow_writer.h>
+#include <filesystem>
+
+#include "android-base/unique_fd.h"
+
+using namespace android::snapshot;
+
+// This writes a simple cow v2 file in the current directory. This file will serve as testdata for
+// ensuring our v3 cow reader will be able to read a cow file created by the v2 writer.
+//
+// WARNING: We should not be overriding this test file, as it will serve as historic marker for what
+// a device with old writer_v2 will write as a cow.
+void write_cow_v2() {
+ CowOptions options;
+ options.cluster_ops = 5;
+ options.num_merge_ops = 1;
+ std::string data = "This is some data, believe it";
+ data.resize(options.block_size, '\0');
+
+ char cwd_buffer[1024];
+ size_t cwd_buffer_size = sizeof(cwd_buffer);
+
+ // Get the current working directory path.
+ char* err = getcwd(cwd_buffer, cwd_buffer_size);
+ if (!err) {
+ LOG(ERROR) << "Couldn't get current directory";
+ }
+ android::base::unique_fd fd(open(strcat(cwd_buffer, "/cow_v2"), O_CREAT | O_RDWR, 0666));
+ if (fd.get() == -1) {
+ LOG(FATAL) << "couldn't open tmp_cow";
+ }
+ std::unique_ptr<ICowWriter> writer = CreateCowWriter(2, options, std::move(fd));
+ writer->AddCopy(0, 5);
+ writer->AddRawBlocks(2, data.data(), data.size());
+ writer->AddLabel(1);
+ writer->AddXorBlocks(50, data.data(), data.size(), 24, 10);
+ writer->AddZeroBlocks(5, 10);
+ writer->AddLabel(2);
+ writer->Finalize();
+}
+
+int main() {
+ write_cow_v2();
+}
diff --git a/fs_mgr/libsnapshot/tools/testdata/cow_v2 b/fs_mgr/libsnapshot/tools/testdata/cow_v2
new file mode 100644
index 0000000..9f37dfc
--- /dev/null
+++ b/fs_mgr/libsnapshot/tools/testdata/cow_v2
Binary files differ