0f0a24e298
Summary:
Add an option for arena block size, default value 4096 bytes. Arena will allocate blocks with such size.
I am not sure about passing parameter to skiplist in the new virtualized framework, though I talked to Jim a bit. So add Jim as reviewer.
Test Plan:
new unit test, I am running db_test.
For passing paramter from configured option to Arena, I tried tests like:
TEST(DBTest, Arena_Option) {
std::string dbname = test::TmpDir() + "/db_arena_option_test";
DestroyDB(dbname, Options());
DB* db = nullptr;
Options opts;
opts.create_if_missing = true;
opts.arena_block_size = 1000000; // tested 99, 999999
Status s = DB::Open(opts, dbname, &db);
db->Put(WriteOptions(), "a", "123");
}
and printed some debug info. The results look good. Any suggestion for such a unit-test?
Reviewers: haobo, dhruba, emayanke, jpaton
Reviewed By: dhruba
CC: leveldb, zshao
Differential Revision: https://reviews.facebook.net/D11799
103 lines
2.7 KiB
C++
103 lines
2.7 KiB
C++
#ifndef STORAGE_LEVELDB_DB_SKIPLISTREP_H_
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#define STORAGE_LEVELDB_DB_SKIPLISTREP_H_
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#include "leveldb/memtablerep.h"
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#include "db/memtable.h"
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#include "db/skiplist.h"
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namespace leveldb {
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class Arena;
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class SkipListRep : public MemTableRep {
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SkipList<const char*, MemTableRep::KeyComparator&> skip_list_;
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public:
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explicit SkipListRep(MemTableRep::KeyComparator& compare, Arena* arena)
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: skip_list_(compare, arena) {
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}
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// Insert key into the list.
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// REQUIRES: nothing that compares equal to key is currently in the list.
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virtual void Insert(const char* key) {
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skip_list_.Insert(key);
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}
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// Returns true iff an entry that compares equal to key is in the list.
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virtual bool Contains(const char* key) const {
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return skip_list_.Contains(key);
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}
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virtual ~SkipListRep() { }
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// Iteration over the contents of a skip list
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class Iterator : public MemTableRep::Iterator {
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SkipList<const char*, MemTableRep::KeyComparator&>::Iterator iter_;
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public:
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// Initialize an iterator over the specified list.
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// The returned iterator is not valid.
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explicit Iterator(
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const SkipList<const char*, MemTableRep::KeyComparator&>* list
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) : iter_(list) { }
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virtual ~Iterator() { }
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// Returns true iff the iterator is positioned at a valid node.
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virtual bool Valid() const {
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return iter_.Valid();
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}
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// Returns the key at the current position.
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// REQUIRES: Valid()
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virtual const char* key() const {
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return iter_.key();
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}
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// Advances to the next position.
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// REQUIRES: Valid()
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virtual void Next() {
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iter_.Next();
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}
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// Advances to the previous position.
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// REQUIRES: Valid()
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virtual void Prev() {
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iter_.Prev();
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}
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// Advance to the first entry with a key >= target
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virtual void Seek(const char* target) {
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iter_.Seek(target);
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}
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// Position at the first entry in list.
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// Final state of iterator is Valid() iff list is not empty.
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virtual void SeekToFirst() {
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iter_.SeekToFirst();
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}
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// Position at the last entry in list.
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// Final state of iterator is Valid() iff list is not empty.
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virtual void SeekToLast() {
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iter_.SeekToLast();
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}
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};
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virtual std::shared_ptr<MemTableRep::Iterator> GetIterator() {
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return std::shared_ptr<MemTableRep::Iterator>(
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new SkipListRep::Iterator(&skip_list_)
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);
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}
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};
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class SkipListFactory : public MemTableRepFactory {
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public:
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virtual std::shared_ptr<MemTableRep> CreateMemTableRep (
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MemTableRep::KeyComparator& compare, Arena* arena) {
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return std::shared_ptr<MemTableRep>(new SkipListRep(compare, arena));
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}
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};
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}
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#endif // STORAGE_LEVELDB_DB_SKIPLISTREP_H_
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