commit dccf1b6e39d60675bc3a4518b50692a72d0abebe
author Daniel Zheng <zhengdaniel@google.com> Thu Feb 08 12:35:33 2024 -0800
committer Daniel Zheng <zhengdaniel@google.com> Wed Feb 21 09:22:07 2024 -0800
tree 8e1ed53d5626cea92d5b60b6ee4c4e02d3b371a8
parent 18744c17c13ac4c8e66d760778678fb1ed89e3f8

libsnapshot: update opcountcheck

Since variable block compresses blocks and there is no longer a 1:1
mapping between ops to blocks, we need to update this check in
EmitBlocks to the actual number of compressed blocks written.

Since single threaded + multi threaded + no compression invoke different
code paths. Ensure that that blocks written are still equivalent to
blocks.size(). Adding two test cases to cover these situations.

Test: th
Change-Id: If81eccf74333292a114268862dde0fe49681ef35

fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp

diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp b/fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp
index 3c5b394..2021348 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/test_v3.cpp
@@ -109,6 +109,40 @@
     ASSERT_EQ(reader.header_v3().op_count, 20);
 }
 
+TEST_F(CowTestV3, MaxOpSingleThreadCompression) {
+    CowOptions options;
+    options.op_count_max = 20;
+    options.num_compress_threads = 1;
+    options.compression_factor = 4096 * 8;
+    options.compression = "lz4";
+
+    auto writer = CreateCowWriter(3, options, GetCowFd());
+    ASSERT_TRUE(writer->AddZeroBlocks(1, 20));
+    std::string data = "This is some data, believe it";
+    data.resize(options.block_size, '\0');
+
+    ASSERT_FALSE(writer->AddRawBlocks(5, data.data(), data.size()));
+
+    ASSERT_TRUE(writer->Finalize());
+}
+
+TEST_F(CowTestV3, MaxOpMultiThreadCompression) {
+    CowOptions options;
+    options.op_count_max = 20;
+    options.num_compress_threads = 2;
+    options.compression_factor = 4096 * 8;
+    options.compression = "lz4";
+
+    auto writer = CreateCowWriter(3, options, GetCowFd());
+    ASSERT_TRUE(writer->AddZeroBlocks(1, 20));
+    std::string data = "This is some data, believe it";
+    data.resize(options.block_size, '\0');
+
+    ASSERT_FALSE(writer->AddRawBlocks(5, data.data(), data.size()));
+
+    ASSERT_TRUE(writer->Finalize());
+}
+
 TEST_F(CowTestV3, ZeroOp) {
     CowOptions options;
     options.op_count_max = 20;

fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp

diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp
index 22e6f2c..1e3fee7 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp
@@ -356,6 +356,9 @@
                    << ", actual number of blocks received from compressor " << blocks.size();
         return false;
     }
+    if (!CheckOpCount(blocks.size())) {
+        return false;
+    }
     size_t blocks_written = 0;
     for (size_t blk_index = 0; blk_index < blocks.size(); blk_index++) {
         CowOperation& op = cached_ops_.emplace_back();
@@ -395,9 +398,6 @@
     }
     const auto bytes = reinterpret_cast<const uint8_t*>(data);
     const size_t num_blocks = (size / header_.block_size);
-    if (!CheckOpCount(num_blocks)) {
-        return false;
-    }
     for (size_t i = 0; i < num_blocks;) {
         const size_t blocks_to_write =
                 std::min<size_t>(batch_size_ - cached_data_.size(), num_blocks - i);