1 files changed, 90 insertions, 0 deletions
diff --git a/src/rocksdb/db/blob/blob_contents.cc b/src/rocksdb/db/blob/blob_contents.cc
new file mode 100644
index 000000000..9015609e7
--- /dev/null
+++ b/src/rocksdb/db/blob/blob_contents.cc
@@ -0,0 +1,90 @@
+//  Copyright (c) Meta Platforms, Inc. and affiliates.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "db/blob/blob_contents.h"
+
+#include <cassert>
+
+#include "cache/cache_entry_roles.h"
+#include "cache/cache_helpers.h"
+#include "port/malloc.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+std::unique_ptr<BlobContents> BlobContents::Create(
+    CacheAllocationPtr&& allocation, size_t size) {
+  return std::unique_ptr<BlobContents>(
+      new BlobContents(std::move(allocation), size));
+}
+
+size_t BlobContents::ApproximateMemoryUsage() const {
+  size_t usage = 0;
+
+  if (allocation_) {
+    MemoryAllocator* const allocator = allocation_.get_deleter().allocator;
+
+    if (allocator) {
+      usage += allocator->UsableSize(allocation_.get(), data_.size());
+    } else {
+#ifdef ROCKSDB_MALLOC_USABLE_SIZE
+      usage += malloc_usable_size(allocation_.get());
+#else
+      usage += data_.size();
+#endif
+    }
+  }
+
+#ifdef ROCKSDB_MALLOC_USABLE_SIZE
+  usage += malloc_usable_size(const_cast<BlobContents*>(this));
+#else
+  usage += sizeof(*this);
+#endif
+
+  return usage;
+}
+
+size_t BlobContents::SizeCallback(void* obj) {
+  assert(obj);
+
+  return static_cast<const BlobContents*>(obj)->size();
+}
+
+Status BlobContents::SaveToCallback(void* from_obj, size_t from_offset,
+                                    size_t length, void* out) {
+  assert(from_obj);
+
+  const BlobContents* buf = static_cast<const BlobContents*>(from_obj);
+  assert(buf->size() >= from_offset + length);
+
+  memcpy(out, buf->data().data() + from_offset, length);
+
+  return Status::OK();
+}
+
+Cache::CacheItemHelper* BlobContents::GetCacheItemHelper() {
+  static Cache::CacheItemHelper cache_helper(
+      &SizeCallback, &SaveToCallback,
+      GetCacheEntryDeleterForRole<BlobContents, CacheEntryRole::kBlobValue>());
+
+  return &cache_helper;
+}
+
+Status BlobContents::CreateCallback(CacheAllocationPtr&& allocation,
+                                    const void* buf, size_t size,
+                                    void** out_obj, size_t* charge) {
+  assert(allocation);
+
+  memcpy(allocation.get(), buf, size);
+
+  std::unique_ptr<BlobContents> obj = Create(std::move(allocation), size);
+  BlobContents* const contents = obj.release();
+
+  *out_obj = contents;
+  *charge = contents->ApproximateMemoryUsage();
+
+  return Status::OK();
+}
+
+}  // namespace ROCKSDB_NAMESPACE