memtable.cc: Refactory & minor bugfix

db/memtable.cc

@@ -36,6 +36,7 @@
 #include "util/memory_usage.h"
 #include "util/murmurhash.h"
 #include "util/mutexlock.h"
+#include "util/util.h"
 
 namespace rocksdb {
 
@@ -117,10 +118,10 @@ MemTableRep* MemTableRepFactory::CreateMemTableRep(
     const MemTableRep::KeyComparator& key_cmp, Allocator* allocator,
     const ImmutableCFOptions& ioptions,
     const MutableCFOptions& mutable_cf_options,
-    uint32_t /* column_family_id */) {
+    uint32_t column_family_id) {
   return CreateMemTableRep(key_cmp, allocator,
                            mutable_cf_options.prefix_extractor.get(),
-                           ioptions.info_log);
+                           ioptions.info_log, column_family_id);
 }
 
 MemTable::~MemTable() {
@@ -679,7 +680,7 @@ static bool SaveValue(void* arg, const MemTableRep::KeyValuePair* pair) {
           *(s->found_final_value) = true;
           return false;
         }
-      // intentional fallthrough
+      FALLTHROUGH_INTENDED;
       case kTypeValue: {
         if (s->inplace_update_support) {
           s->mem->GetLock(s->key->user_key())->ReadLock();
@@ -819,7 +820,8 @@ bool MemTable::Get(const LookupKey& key, std::string* value, Status* s,
   return found_final_value;
 }
 
-void MemTable::Update(SequenceNumber seq, const Slice& key,
+void MemTable::Update(SequenceNumber seq,
+                      const Slice& key,
                       const Slice& value) {
   LookupKey lkey(key, seq);
   Slice mem_key = lkey.memtable_key();
@@ -831,8 +833,8 @@ void MemTable::Update(SequenceNumber seq, const Slice& key,
   if (iter->Valid()) {
     // sequence number since the Seek() call above should have skipped
     // all entries with overly large sequence numbers.
-    Slice internal_key, prev_value;
-    std::tie(internal_key, prev_value) = iter->GetKeyValue();
+    Slice internal_key, old_value;
+    std::tie(internal_key, old_value) = iter->GetKeyValue();
     if (comparator_.comparator.user_comparator()->Equal(
             ExtractUserKey(internal_key), lkey.user_key())) {
       // Correct user key
@@ -842,13 +844,13 @@ void MemTable::Update(SequenceNumber seq, const Slice& key,
       SequenceNumber unused;
       UnPackSequenceAndType(tag, &unused, &type);
       if (type == kTypeValue) {
-        uint32_t prev_size = static_cast<uint32_t>(prev_value.size());
+        uint32_t old_size = static_cast<uint32_t>(old_value.size());
         uint32_t new_size = static_cast<uint32_t>(value.size());
 
-        // Update value, if new value size <= previous value size
-        if (new_size <= prev_size) {
+        // Update value, if new value size <= old value size
+        if (new_size <= old_size) {
           char* p =
-              const_cast<char*>(prev_value.data()) - VarintLength(prev_size);
+              const_cast<char*>(old_value.data()) - VarintLength(old_size);
           p = EncodeVarint32(p, new_size);
           WriteLock wl(GetLock(lkey.user_key()));
           memcpy(p, value.data(), value.size());
@@ -863,7 +865,8 @@ void MemTable::Update(SequenceNumber seq, const Slice& key,
   Add(seq, kTypeValue, key, value);
 }
 
-bool MemTable::UpdateCallback(SequenceNumber seq, const Slice& key,
+bool MemTable::UpdateCallback(SequenceNumber seq,
+                              const Slice& key,
                               const Slice& delta) {
   LookupKey lkey(key, seq);
   Slice memkey = lkey.memtable_key();
@@ -876,8 +879,8 @@ bool MemTable::UpdateCallback(SequenceNumber seq, const Slice& key,
     // Check that it belongs to same user key.  We do not check the
     // sequence number since the Seek() call above should have skipped
     // all entries with overly large sequence numbers.
-    Slice internal_key, prev_value;
-    std::tie(internal_key, prev_value) = iter->GetKeyValue();
+    Slice internal_key, old_value;
+    std::tie(internal_key, old_value) = iter->GetKeyValue();
     if (comparator_.comparator.user_comparator()->Equal(
             ExtractUserKey(internal_key), lkey.user_key())) {
       // Correct user key
@@ -888,33 +891,33 @@ bool MemTable::UpdateCallback(SequenceNumber seq, const Slice& key,
       UnPackSequenceAndType(tag, &unused, &type);
       switch (type) {
         case kTypeValue: {
-          uint32_t prev_size = static_cast<uint32_t>(prev_value.size());
+          uint32_t old_size = static_cast<uint32_t>(old_value.size());
 
-          char* prev_buffer = const_cast<char*>(prev_value.data());
-          uint32_t new_prev_size = prev_size;
+          char* old_buffer = const_cast<char*>(old_value.data());
+          uint32_t new_inplace_size = old_size;
 
-          std::string str_value;
+          std::string merged_value;
           WriteLock wl(GetLock(lkey.user_key()));
-          auto status = moptions_.inplace_callback(prev_buffer, &new_prev_size,
-                                                   delta, &str_value);
+          auto status = moptions_.inplace_callback(old_buffer, &new_inplace_size,
+                                                   delta, &merged_value);
           if (status == UpdateStatus::UPDATED_INPLACE) {
             // Value already updated by callback.
-            assert(new_prev_size <= prev_size);
-            if (new_prev_size < prev_size) {
-              // overwrite the new prev_size
+            assert(new_inplace_size <= old_size);
+            if (new_inplace_size < old_size) {
+              // overwrite the new inplace size
               char* p =
-                const_cast<char*>(prev_value.data()) - VarintLength(prev_size);
-              p = EncodeVarint32(p, new_prev_size);
-              if (p < prev_buffer) {
+                const_cast<char*>(old_value.data()) - VarintLength(old_size);
+              p = EncodeVarint32(p, new_inplace_size);
+              if (p < old_buffer) {
                 // shift the value buffer as well.
-                memmove(p, prev_buffer, new_prev_size);
+                memmove(p, old_buffer, new_inplace_size);
               }
             }
             RecordTick(moptions_.statistics, NUMBER_KEYS_UPDATED);
             UpdateFlushState();
             return true;
           } else if (status == UpdateStatus::UPDATED) {
-            Add(seq, kTypeValue, key, Slice(str_value));
+            Add(seq, kTypeValue, key, Slice(merged_value));
             RecordTick(moptions_.statistics, NUMBER_KEYS_WRITTEN);
             UpdateFlushState();
             return true;