From f6e760bfad39f36c0c60e0864a8f113ab9c4970c Mon Sep 17 00:00:00 2001
From: Marcus Holland-Moritz <github@mhxnet.de>
Date: Sat, 15 Mar 2025 09:43:21 +0100
Subject: [PATCH] refactor: explicitly handle release_until() return value

---
 include/dwarfs/writer/internal/chunkable.h          | 3 ++-
 include/dwarfs/writer/internal/fragment_chunkable.h | 2 +-
 src/writer/internal/entry.cpp                       | 2 ++
 src/writer/internal/fragment_chunkable.cpp          | 4 ++--
 src/writer/internal/inode_manager.cpp               | 2 ++
 src/writer/segmenter.cpp                            | 5 ++++-
 test/segmenter_benchmark.cpp                        | 2 +-
 7 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/include/dwarfs/writer/internal/chunkable.h b/include/dwarfs/writer/internal/chunkable.h
index 67cf5753..36e7076e 100644
--- a/include/dwarfs/writer/internal/chunkable.h
+++ b/include/dwarfs/writer/internal/chunkable.h
@@ -23,6 +23,7 @@
 
 #include <span>
 #include <string_view>
+#include <system_error>
 
 namespace dwarfs {
 
@@ -39,7 +40,7 @@ class chunkable {
   virtual std::string description() const = 0;
   virtual std::span<uint8_t const> span() const = 0;
   virtual void add_chunk(size_t block, size_t offset, size_t size) = 0;
-  virtual void release_until(size_t offset) = 0;
+  virtual std::error_code release_until(size_t offset) = 0;
 };
 
 } // namespace writer::internal
diff --git a/include/dwarfs/writer/internal/fragment_chunkable.h b/include/dwarfs/writer/internal/fragment_chunkable.h
index 2fcb1c7b..b25a9c94 100644
--- a/include/dwarfs/writer/internal/fragment_chunkable.h
+++ b/include/dwarfs/writer/internal/fragment_chunkable.h
@@ -50,7 +50,7 @@ class fragment_chunkable : public chunkable {
   std::string description() const override;
   std::span<uint8_t const> span() const override;
   void add_chunk(size_t block, size_t offset, size_t size) override;
-  void release_until(size_t offset) override;
+  std::error_code release_until(size_t offset) override;
 
  private:
   inode const& ino_;
diff --git a/src/writer/internal/entry.cpp b/src/writer/internal/entry.cpp
index af48219b..8b912f78 100644
--- a/src/writer/internal/entry.cpp
+++ b/src/writer/internal/entry.cpp
@@ -264,6 +264,8 @@ void file::scan(mmif* mm, progress& prog,
 
       while (s >= chunk_size) {
         cs.update(mm->as<void>(offset), chunk_size);
+        // release_until() is best-effort, we can ignore the return value
+        // NOLINTNEXTLINE(bugprone-unused-return-value)
         mm->release_until(offset);
         offset += chunk_size;
         s -= chunk_size;
diff --git a/src/writer/internal/fragment_chunkable.cpp b/src/writer/internal/fragment_chunkable.cpp
index 620c514d..6a288515 100644
--- a/src/writer/internal/fragment_chunkable.cpp
+++ b/src/writer/internal/fragment_chunkable.cpp
@@ -61,8 +61,8 @@ void fragment_chunkable::add_chunk(size_t block, size_t offset, size_t size) {
   frag_.add_chunk(block, offset, size);
 }
 
-void fragment_chunkable::release_until(size_t offset) {
-  mm_.release_until(offset_ + offset);
+std::error_code fragment_chunkable::release_until(size_t offset) {
+  return mm_.release_until(offset_ + offset);
 }
 
 } // namespace dwarfs::writer::internal
diff --git a/src/writer/internal/inode_manager.cpp b/src/writer/internal/inode_manager.cpp
index 56654ce2..21ed41ad 100644
--- a/src/writer/internal/inode_manager.cpp
+++ b/src/writer/internal/inode_manager.cpp
@@ -385,6 +385,8 @@ class inode_ : public inode {
                   size_t chunk_size, T&& scanner) {
     while (size >= chunk_size) {
       std::forward<T>(scanner)(mm->span(offset, chunk_size));
+      // release_until() is best-effort, we can ignore the return value
+      // NOLINTNEXTLINE(bugprone-unused-return-value)
       mm->release_until(offset);
       offset += chunk_size;
       size -= chunk_size;
diff --git a/src/writer/segmenter.cpp b/src/writer/segmenter.cpp
index cfc5769c..bfaa86ce 100644
--- a/src/writer/segmenter.cpp
+++ b/src/writer/segmenter.cpp
@@ -1071,7 +1071,10 @@ segmenter_<LoggerPolicy, SegmentingPolicy>::append_to_block(
   prog_.filesystem_size += size_in_bytes;
 
   if (block.full()) [[unlikely]] {
-    chkable.release_until(offset_in_bytes + size_in_bytes);
+    if (auto ec = chkable.release_until(offset_in_bytes + size_in_bytes)) {
+      LOG_DEBUG << cfg_.context
+                << "error releasing chunkable: " << ec.message();
+    }
     finish_chunk(chkable);
     block_ready();
   }
diff --git a/test/segmenter_benchmark.cpp b/test/segmenter_benchmark.cpp
index 41eff872..2ff07170 100644
--- a/test/segmenter_benchmark.cpp
+++ b/test/segmenter_benchmark.cpp
@@ -55,7 +55,7 @@ class bench_chunkable : public dwarfs::writer::internal::chunkable {
   void
   add_chunk(size_t /*block*/, size_t /*offset*/, size_t /*size*/) override {}
 
-  void release_until(size_t /*offset*/) override {}
+  std::error_code release_until(size_t /*offset*/) override { return {}; }
 
  private:
   std::vector<uint8_t> data_;