Java Panama FFI prototype experiments (DO NOT MERGE)

Makefile

@@ -291,6 +291,9 @@ endif
 export JAVAC_ARGS
 CLEAN_FILES += make_config.mk rocksdb.pc
 
+export JAVA_ARGS
+export JAVADOC_ARGS
+
 ifeq ($(V), 1)
 $(info $(shell uname -a))
 $(info $(shell $(CC) --version))

build_tools/build_detect_platform

@@ -269,7 +269,9 @@ esac
 PLATFORM_CXXFLAGS="$PLATFORM_CXXFLAGS ${CXXFLAGS}"
 JAVA_LDFLAGS="$PLATFORM_LDFLAGS"
 JAVA_STATIC_LDFLAGS="$PLATFORM_LDFLAGS"
-JAVAC_ARGS="-source 8"
+JAVAC_ARGS="-source 19 --enable-preview -Xlint:preview"
+JAVA_ARGS="--enable-preview --enable-native-access=ALL-UNNAMED"
+JAVADOC_ARGS="-source 19 --enable-preview"
 
 if [ "$CROSS_COMPILE" = "true" -o "$FBCODE_BUILD" = "true" ]; then
     # Cross-compiling; do not try any compilation tests.
@@ -867,6 +869,8 @@ echo "JAVA_STATIC_DEPS_CCFLAGS=$JAVA_STATIC_DEPS_CCFLAGS" >> "$OUTPUT"
 echo "JAVA_STATIC_DEPS_CXXFLAGS=$JAVA_STATIC_DEPS_CXXFLAGS" >> "$OUTPUT"
 echo "JAVA_STATIC_DEPS_LDFLAGS=$JAVA_STATIC_DEPS_LDFLAGS" >> "$OUTPUT"
 echo "JAVAC_ARGS=$JAVAC_ARGS" >> "$OUTPUT"
+echo "JAVA_ARGS=$JAVA_ARGS" >> "$OUTPUT"
+echo "JAVADOC_ARGS=$JAVADOC_ARGS" >> "$OUTPUT"
 echo "VALGRIND_VER=$VALGRIND_VER" >> "$OUTPUT"
 echo "PLATFORM_CCFLAGS=$PLATFORM_CCFLAGS" >> "$OUTPUT"
 echo "PLATFORM_CXXFLAGS=$PLATFORM_CXXFLAGS" >> "$OUTPUT"

build_tools/check-sources.sh

@@ -37,7 +37,7 @@ if [ "$?" != "1" ]; then
   BAD=1
 fi
 
-git grep -n -P "[\x80-\xFF]" -- ':!docs' ':!*.md'
+git grep -n -P "[\x80-\xFF]" -- ':!docs' ':!*.md' '!*.png' '!*.pdf'
 if [ "$?" != "1" ]; then
   echo '^^^^ Use only ASCII characters in source files'
   BAD=1

db/c.cc

@@ -5763,7 +5763,7 @@ rocksdb_pinnableslice_t* rocksdb_transaction_get_pinned_for_update(
     const char* key, size_t klen, unsigned char exclusive, char** errptr) {
   rocksdb_pinnableslice_t* v = new (rocksdb_pinnableslice_t);
   Status s = txn->rep->GetForUpdate(options->rep, Slice(key, klen),
-                                    v->rep.GetSelf(), exclusive);
+                                    v->rep.GetSelf()->String(), exclusive);
   v->rep.PinSelf();
   if (!s.ok()) {
     delete (v);

db/db_impl/db_impl.cc

@@ -2109,14 +2109,15 @@ Status DBImpl::GetImpl(const ReadOptions& read_options, const Slice& key,
   if (!skip_memtable) {
     // Get value associated with key
     if (get_impl_options.get_value) {
-      if (sv->mem->Get(
-              lkey,
-              get_impl_options.value ? get_impl_options.value->GetSelf()
-                                     : nullptr,
-              get_impl_options.columns, timestamp, &s, &merge_context,
-              &max_covering_tombstone_seq, read_options,
-              false /* immutable_memtable */, get_impl_options.callback,
-              get_impl_options.is_blob_index)) {
+      if (sv->mem->Get(lkey,
+                       get_impl_options.value
+                           ? get_impl_options.value->GetSelf()->String()
+                           : nullptr,
+                       get_impl_options.columns, timestamp, &s, &merge_context,
+                       &max_covering_tombstone_seq, read_options,
+                       false /* immutable_memtable */,
+                       get_impl_options.callback,
+                       get_impl_options.is_blob_index)) {
         done = true;
 
         if (get_impl_options.value) {
@@ -2127,7 +2128,7 @@ Status DBImpl::GetImpl(const ReadOptions& read_options, const Slice& key,
       } else if ((s.ok() || s.IsMergeInProgress()) &&
                  sv->imm->Get(lkey,
                               get_impl_options.value
-                                  ? get_impl_options.value->GetSelf()
+                                  ? get_impl_options.value->GetSelf()->String()
                                   : nullptr,
                               get_impl_options.columns, timestamp, &s,
                               &merge_context, &max_covering_tombstone_seq,

db/db_impl/db_impl_readonly.cc

@@ -84,7 +84,7 @@ Status DBImplReadOnly::Get(const ReadOptions& read_options,
   SequenceNumber max_covering_tombstone_seq = 0;
   LookupKey lkey(key, snapshot, read_options.timestamp);
   PERF_TIMER_STOP(get_snapshot_time);
-  if (super_version->mem->Get(lkey, pinnable_val->GetSelf(),
+  if (super_version->mem->Get(lkey, pinnable_val->GetSelf()->String(),
                               /*columns=*/nullptr, ts, &s, &merge_context,
                               &max_covering_tombstone_seq, read_options,
                               false /* immutable_memtable */, &read_cb)) {

db/db_impl/db_impl_secondary.cc

@@ -392,7 +392,7 @@ Status DBImplSecondary::GetImpl(const ReadOptions& read_options,
   const Comparator* ucmp = column_family->GetComparator();
   assert(ucmp);
   std::string* ts = ucmp->timestamp_size() > 0 ? timestamp : nullptr;
-  if (super_version->mem->Get(lkey, pinnable_val->GetSelf(),
+  if (super_version->mem->Get(lkey, pinnable_val->GetSelf()->String(),
                               /*columns=*/nullptr, ts, &s, &merge_context,
                               &max_covering_tombstone_seq, read_options,
                               false /* immutable_memtable */, &read_cb)) {
@@ -401,9 +401,9 @@ Status DBImplSecondary::GetImpl(const ReadOptions& read_options,
     RecordTick(stats_, MEMTABLE_HIT);
   } else if ((s.ok() || s.IsMergeInProgress()) &&
              super_version->imm->Get(
-                 lkey, pinnable_val->GetSelf(), /*columns=*/nullptr, ts, &s,
-                 &merge_context, &max_covering_tombstone_seq, read_options,
-                 &read_cb)) {
+                 lkey, pinnable_val->GetSelf()->String(), /*columns=*/nullptr,
+                 ts, &s, &merge_context, &max_covering_tombstone_seq,
+                 read_options, &read_cb)) {
     done = true;
     pinnable_val->PinSelf();
     RecordTick(stats_, MEMTABLE_HIT);

db/memtable.cc

@@ -1455,9 +1455,10 @@ void MemTable::MultiGet(const ReadOptions& read_options, MultiGetRange* range,
     SequenceNumber dummy_seq;
     GetFromTable(*(iter->lkey), iter->max_covering_tombstone_seq, true,
                  callback, &iter->is_blob_index,
-                 iter->value ? iter->value->GetSelf() : nullptr, iter->columns,
-                 iter->timestamp, iter->s, &(iter->merge_context), &dummy_seq,
-                 &found_final_value, &merge_in_progress);
+                 iter->value ? iter->value->GetSelf()->String() : nullptr,
+                 iter->columns, iter->timestamp, iter->s,
+                 &(iter->merge_context), &dummy_seq, &found_final_value,
+                 &merge_in_progress);
 
     if (!found_final_value && merge_in_progress) {
       *(iter->s) = Status::MergeInProgress();

db/version_set.cc

@@ -2440,7 +2440,7 @@ void Version::Get(const ReadOptions& read_options, const LookupKey& k,
           /* op_failure_scope */ nullptr);
       if (status->ok()) {
         if (LIKELY(value != nullptr)) {
-          *(value->GetSelf()) = std::move(result);
+          *(value->GetSelf()->String()) = std::move(result);
           value->PinSelf();
         } else {
           assert(columns != nullptr);
@@ -2690,7 +2690,7 @@ void Version::MultiGet(const ReadOptions& read_options, MultiGetRange* range,
           /* result_operand */ nullptr, /* update_num_ops_stats */ true,
           /* op_failure_scope */ nullptr);
       if (LIKELY(iter->value != nullptr)) {
-        *iter->value->GetSelf() = std::move(result);
+        *iter->value->GetSelf()->String() = std::move(result);
         iter->value->PinSelf();
         range->AddValueSize(iter->value->size());
       } else {

include/rocksdb/slice.h

@@ -129,6 +129,19 @@ class Slice {
   // Intentionally copyable
 };
 
+class SliceBuffer {
+ public:
+  inline std::string* String() { return buf_; }
+  SliceBuffer& operator=(std::string* buf) {
+    this->buf_ = buf;
+    return *this;
+  }
+
+ private:
+  friend class PinnableSlice;
+  std::string* buf_;
+};
+
 /**
  * A Slice that can be pinned with some cleanup tasks, which will be run upon
  * ::Reset() or object destruction, whichever is invoked first. This can be used
@@ -137,8 +150,8 @@ class Slice {
  */
 class PinnableSlice : public Slice, public Cleanable {
  public:
-  PinnableSlice() { buf_ = &self_space_; }
-  explicit PinnableSlice(std::string* buf) { buf_ = buf; }
+  PinnableSlice() { slice_buffer_ = &self_space_; }
+  explicit PinnableSlice(std::string* buf) { slice_buffer_ = buf; }
 
   PinnableSlice(PinnableSlice&& other);
   PinnableSlice& operator=(PinnableSlice&& other);
@@ -170,16 +183,16 @@ class PinnableSlice : public Slice, public Cleanable {
 
   inline void PinSelf(const Slice& slice) {
     assert(!pinned_);
-    buf_->assign(slice.data(), slice.size());
-    data_ = buf_->data();
-    size_ = buf_->size();
+    slice_buffer_.buf_->assign(slice.data(), slice.size());
+    data_ = slice_buffer_.buf_->data();
+    size_ = slice_buffer_.buf_->size();
     assert(!pinned_);
   }
 
   inline void PinSelf() {
     assert(!pinned_);
-    data_ = buf_->data();
-    size_ = buf_->size();
+    data_ = slice_buffer_.buf_->data();
+    size_ = slice_buffer_.buf_->size();
     assert(!pinned_);
   }
 
@@ -188,7 +201,7 @@ class PinnableSlice : public Slice, public Cleanable {
     if (pinned_) {
       size_ -= n;
     } else {
-      buf_->erase(size() - n, n);
+      slice_buffer_.buf_->erase(size() - n, n);
       PinSelf();
     }
   }
@@ -199,7 +212,7 @@ class PinnableSlice : public Slice, public Cleanable {
       data_ += n;
       size_ -= n;
     } else {
-      buf_->erase(0, n);
+      slice_buffer_.buf_->erase(0, n);
       PinSelf();
     }
   }
@@ -210,14 +223,14 @@ class PinnableSlice : public Slice, public Cleanable {
     size_ = 0;
   }
 
-  inline std::string* GetSelf() { return buf_; }
+  inline SliceBuffer* GetSelf() { return &slice_buffer_; }
 
   inline bool IsPinned() const { return pinned_; }
 
  private:
   friend class PinnableSlice4Test;
   std::string self_space_;
-  std::string* buf_;
+  SliceBuffer slice_buffer_;
   bool pinned_ = false;
 };
 

include/rocksdb/utilities/transaction.h

@@ -301,7 +301,8 @@ class Transaction {
                      ColumnFamilyHandle* column_family, const Slice& key,
                      PinnableSlice* pinnable_val) {
     assert(pinnable_val != nullptr);
-    auto s = Get(options, column_family, key, pinnable_val->GetSelf());
+    auto s =
+        Get(options, column_family, key, pinnable_val->GetSelf()->String());
     pinnable_val->PinSelf();
     return s;
   }
@@ -311,7 +312,7 @@ class Transaction {
   virtual Status Get(const ReadOptions& options, const Slice& key,
                      PinnableSlice* pinnable_val) {
     assert(pinnable_val != nullptr);
-    auto s = Get(options, key, pinnable_val->GetSelf());
+    auto s = Get(options, key, pinnable_val->GetSelf()->String());
     pinnable_val->PinSelf();
     return s;
   }
@@ -385,7 +386,8 @@ class Transaction {
                           do_validate);
     } else {
       auto s = GetForUpdate(options, column_family, key,
-                            pinnable_val->GetSelf(), exclusive, do_validate);
+                            pinnable_val->GetSelf()->String(), exclusive,
+                            do_validate);
       pinnable_val->PinSelf();
       return s;
     }

include/rocksdb/wide_columns.h

@@ -139,7 +139,7 @@ inline void PinnableWideColumns::MoveValue(PinnableSlice&& value) {
 }
 
 inline void PinnableWideColumns::MoveValue(std::string&& value) {
-  std::string* const buf = value_.GetSelf();
+  std::string* const buf = value_.GetSelf()->String();
   assert(buf);
 
   *buf = std::move(value);

java/GetBenchmarks.md

@@ -5,31 +5,40 @@ Results associated with [Improve Java API `get()` performance by reducing copies
 ## Build/Run
 
 Mac
-```
+```bash
 make clean jclean
 DEBUG_LEVEL=0 make -j12 rocksdbjava
-(cd java/target; cp rocksdbjni-7.9.0-osx.jar rocksdbjni-7.9.0-SNAPSHOT-osx.jar)
-mvn install:install-file -Dfile=./java/target/rocksdbjni-7.9.0-SNAPSHOT-osx.jar -DgroupId=org.rocksdb -DartifactId=rocksdbjni -Dversion=7.9.0-SNAPSHOT -Dpackaging=jar
+(cd java/target; cp rocksdbjni-7.10.0-osx.jar rocksdbjni-7.10.0-SNAPSHOT-osx.jar)
+mvn install:install-file -Dfile=./java/target/rocksdbjni-7.10.0-SNAPSHOT-osx.jar -DgroupId=org.rocksdb -DartifactId=rocksdbjni -Dversion=7.10.0-SNAPSHOT -Dpackaging=jar
 ```
 
 Linux
-```
+```bash
 make clean jclean
 DEBUG_LEVEL=0 make -j12 rocksdbjava
-(cd java/target; cp rocksdbjni-7.9.0-linux64.jar rocksdbjni-7.9.0-SNAPSHOT-linux64.jar)
-mvn install:install-file -Dfile=./java/target/rocksdbjni-7.9.0-SNAPSHOT-linux64.jar -DgroupId=org.rocksdb -DartifactId=rocksdbjni -Dversion=7.9.0-SNAPSHOT -Dpackaging=jar
+(cd java/target; cp rocksdbjni-7.10.0-linux64.jar rocksdbjni-7.10.0-SNAPSHOT-linux64.jar)
+mvn install:install-file -Dfile=./java/target/rocksdbjni-7.10.0-SNAPSHOT-linux64.jar -DgroupId=org.rocksdb -DartifactId=rocksdbjni -Dversion=7.10.0-SNAPSHOT -Dpackaging=jar
 ```
 
 Build jmh test package, on either platform
-```
+```bash
 pushd java/jmh
 mvn clean package
 ```
 
 A quick test run, just as a sanity check, using a small number of keys, would be
-```
+```bash
 java -jar target/rocksdbjni-jmh-1.0-SNAPSHOT-benchmarks.jar -p keyCount=1000 -p keySize=128 -p valueSize=32768 -p columnFamilyTestType="no_column_family" GetBenchmarks
 ```
+or when we are previewing new features (e.g. Panama FFI in Java 19)
+```bash
+java --enable-preview --enable-native-access=ALL-UNNAMED -jar target/rocksdbjni-jmh-1.0-SNAPSHOT-benchmarks.jar -p keyCount=1000 -p keySize=128 -p valueSize=32768 -p columnFamilyTestType="no_column_family" GetBenchmarks
+```
+to reduce the time to an absolute minimum, append these parameters
+```bash
+-wi 1 -to 1m -i 1
+```
+
 The long performance run (as big as we can make it on our Ubuntu box without filling the disk)
 ```
 java -jar target/rocksdbjni-jmh-1.0-SNAPSHOT-benchmarks.jar -p keyCount=1000,50000 -p keySize=128 -p valueSize=1024,16384 -p columnFamilyTestType="1_column_family","20_column_families" GetBenchmarks.get GetBenchmarks.preallocatedByteBufferGet GetBenchmarks.preallocatedGet