From 1cb36d300e3366d000086a0b2cac06c8187d34cb Mon Sep 17 00:00:00 2001
From: Daniel Zheng <zhengdaniel@google.com>
Date: Tue, 8 Aug 2023 08:51:48 -0700
Subject: [PATCH] Adding struct to hold compresion parameters

Since we're adding compression levels should consolidate this
information into one structure.  Adding in CowCompression struct
to hold this information and refactoring code to work off this struct

Test: ota
Change-Id: I969a3ae19ec80fd964bcfb76b39f42f8dd31a56d
---
 .../include/libsnapshot/cow_format.h           |  4 ++++
 fs_mgr/libsnapshot/libsnapshot_cow/test_v2.cpp |  3 ++-
 .../libsnapshot/libsnapshot_cow/writer_v2.cpp  | 18 +++++++++---------
 fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.h |  2 +-
 4 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/fs_mgr/libsnapshot/include/libsnapshot/cow_format.h b/fs_mgr/libsnapshot/include/libsnapshot/cow_format.h
index 3a81f6384..c9a4dee3a 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/cow_format.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/cow_format.h
@@ -161,6 +161,10 @@ enum CowCompressionAlgorithm : uint8_t {
     kCowCompressLz4 = 3,
     kCowCompressZstd = 4,
 };
+struct CowCompression {
+    CowCompressionAlgorithm algorithm = kCowCompressNone;
+    uint32_t compression_level = 0;
+};
 
 static constexpr uint8_t kCowReadAheadNotStarted = 0;
 static constexpr uint8_t kCowReadAheadInProgress = 1;
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/test_v2.cpp b/fs_mgr/libsnapshot/libsnapshot_cow/test_v2.cpp
index 31b9a5840..ab275d4eb 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/test_v2.cpp
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/test_v2.cpp
@@ -472,9 +472,10 @@ TEST_P(CompressionTest, HorribleStream) {
     if (strcmp(GetParam(), "none") == 0) {
         GTEST_SKIP();
     }
-
+    CowCompression compression;
     auto algorithm = CompressionAlgorithmFromString(GetParam());
     ASSERT_TRUE(algorithm.has_value());
+    compression.algorithm = algorithm.value();
 
     std::string expected = "The quick brown fox jumps over the lazy dog.";
     expected.resize(4096, '\0');
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.cpp b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.cpp
index c54996972..cbd7569d2 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.cpp
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.cpp
@@ -124,7 +124,7 @@ bool CowWriterV2::ParseOptions() {
         LOG(ERROR) << "unrecognized compression: " << options_.compression;
         return false;
     }
-    compression_ = *algorithm;
+    compression_.algorithm = *algorithm;
 
     if (options_.cluster_ops == 1) {
         LOG(ERROR) << "Clusters must contain at least two operations to function.";
@@ -165,7 +165,7 @@ void CowWriterV2::InitWorkers() {
         return;
     }
     for (int i = 0; i < num_compress_threads_; i++) {
-        auto wt = std::make_unique<CompressWorker>(compression_, header_.block_size);
+        auto wt = std::make_unique<CompressWorker>(compression_.algorithm, header_.block_size);
         threads_.emplace_back(std::async(std::launch::async, &CompressWorker::RunThread, wt.get()));
         compress_threads_.push_back(std::move(wt));
     }
@@ -320,8 +320,8 @@ bool CowWriterV2::CompressBlocks(size_t num_blocks, const void* data) {
     const uint8_t* iter = reinterpret_cast<const uint8_t*>(data);
     compressed_buf_.clear();
     if (num_threads <= 1) {
-        return CompressWorker::CompressBlocks(compression_, options_.block_size, data, num_blocks,
-                                              &compressed_buf_);
+        return CompressWorker::CompressBlocks(compression_.algorithm, options_.block_size, data,
+                                              num_blocks, &compressed_buf_);
     }
 
     // Submit the blocks per thread. The retrieval of
@@ -366,7 +366,7 @@ bool CowWriterV2::EmitBlocks(uint64_t new_block_start, const void* data, size_t
     while (num_blocks) {
         size_t pending_blocks = (std::min(kProcessingBlocks, num_blocks));
 
-        if (compression_ && num_compress_threads_ > 1) {
+        if (compression_.algorithm && num_compress_threads_ > 1) {
             if (!CompressBlocks(pending_blocks, iter)) {
                 return false;
             }
@@ -386,19 +386,19 @@ bool CowWriterV2::EmitBlocks(uint64_t new_block_start, const void* data, size_t
                 op.source = next_data_pos_;
             }
 
-            if (compression_) {
+            if (compression_.algorithm) {
                 auto data = [&, this]() {
                     if (num_compress_threads_ > 1) {
                         auto data = std::move(*buf_iter_);
                         buf_iter_++;
                         return data;
                     } else {
-                        auto data =
-                                CompressWorker::Compress(compression_, iter, header_.block_size);
+                        auto data = CompressWorker::Compress(compression_.algorithm, iter,
+                                                             header_.block_size);
                         return data;
                     }
                 }();
-                op.compression = compression_;
+                op.compression = compression_.algorithm;
                 op.data_length = static_cast<uint16_t>(data.size());
 
                 if (!WriteOperation(op, data.data(), data.size())) {
diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.h b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.h
index 809ae5747..1aa851872 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.h
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v2.h
@@ -63,7 +63,7 @@ class CowWriterV2 : public CowWriterBase {
 
   private:
     CowFooter footer_{};
-    CowCompressionAlgorithm compression_ = kCowCompressNone;
+    CowCompression compression_;
     uint64_t current_op_pos_ = 0;
     uint64_t next_op_pos_ = 0;
     uint64_t next_data_pos_ = 0;