ccf0fcd5c2
- Implemented Get() directly instead of building on top of a full merging iterator stack. This speeds up the "readrandom" benchmark by up to 15-30%. - Fixed an opensource compilation problem. Added --db=<name> flag to control where the database is placed. - Automatically compact a file when we have done enough overlapping seeks to that file. - Fixed a performance bug where we would read from at least one file in a level even if none of the files overlapped the key being read. - Makefile fix for Mac OSX installations that have XCode 4 without XCode 3. - Unified the two occurrences of binary search in a file-list into one routine. - Found and fixed a bug where we would unnecessarily search the last file when looking for a key larger than all data in the level. - A fix to avoid the need for trivial move compactions and therefore gets rid of two out of five syncs in "fillseq". - Removed the MANIFEST file write when switching to a new memtable/log-file for a 10-20% improvement on fill speed on ext4. - Adding a SNAPPY setting in the Makefile for folks who have Snappy installed. Snappy compresses values and speeds up writes. git-svn-id: https://leveldb.googlecode.com/svn/trunk@32 62dab493-f737-651d-591e-8d6aee1b9529
107 lines
3.4 KiB
C++
107 lines
3.4 KiB
C++
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file. See the AUTHORS file for names of contributors.
|
|
|
|
#include <stdio.h>
|
|
#include "db/dbformat.h"
|
|
#include "port/port.h"
|
|
#include "util/coding.h"
|
|
|
|
namespace leveldb {
|
|
|
|
static uint64_t PackSequenceAndType(uint64_t seq, ValueType t) {
|
|
assert(seq <= kMaxSequenceNumber);
|
|
assert(t <= kValueTypeForSeek);
|
|
return (seq << 8) | t;
|
|
}
|
|
|
|
void AppendInternalKey(std::string* result, const ParsedInternalKey& key) {
|
|
result->append(key.user_key.data(), key.user_key.size());
|
|
PutFixed64(result, PackSequenceAndType(key.sequence, key.type));
|
|
}
|
|
|
|
std::string ParsedInternalKey::DebugString() const {
|
|
char buf[50];
|
|
snprintf(buf, sizeof(buf), "' @ %llu : %d",
|
|
(unsigned long long) sequence,
|
|
int(type));
|
|
std::string result = "'";
|
|
result += user_key.ToString();
|
|
result += buf;
|
|
return result;
|
|
}
|
|
|
|
const char* InternalKeyComparator::Name() const {
|
|
return "leveldb.InternalKeyComparator";
|
|
}
|
|
|
|
int InternalKeyComparator::Compare(const Slice& akey, const Slice& bkey) const {
|
|
// Order by:
|
|
// increasing user key (according to user-supplied comparator)
|
|
// decreasing sequence number
|
|
// decreasing type (though sequence# should be enough to disambiguate)
|
|
int r = user_comparator_->Compare(ExtractUserKey(akey), ExtractUserKey(bkey));
|
|
if (r == 0) {
|
|
const uint64_t anum = DecodeFixed64(akey.data() + akey.size() - 8);
|
|
const uint64_t bnum = DecodeFixed64(bkey.data() + bkey.size() - 8);
|
|
if (anum > bnum) {
|
|
r = -1;
|
|
} else if (anum < bnum) {
|
|
r = +1;
|
|
}
|
|
}
|
|
return r;
|
|
}
|
|
|
|
void InternalKeyComparator::FindShortestSeparator(
|
|
std::string* start,
|
|
const Slice& limit) const {
|
|
// Attempt to shorten the user portion of the key
|
|
Slice user_start = ExtractUserKey(*start);
|
|
Slice user_limit = ExtractUserKey(limit);
|
|
std::string tmp(user_start.data(), user_start.size());
|
|
user_comparator_->FindShortestSeparator(&tmp, user_limit);
|
|
if (user_comparator_->Compare(*start, tmp) < 0) {
|
|
// User key has become larger. Tack on the earliest possible
|
|
// number to the shortened user key.
|
|
PutFixed64(&tmp, PackSequenceAndType(kMaxSequenceNumber,kValueTypeForSeek));
|
|
assert(this->Compare(*start, tmp) < 0);
|
|
assert(this->Compare(tmp, limit) < 0);
|
|
start->swap(tmp);
|
|
}
|
|
}
|
|
|
|
void InternalKeyComparator::FindShortSuccessor(std::string* key) const {
|
|
Slice user_key = ExtractUserKey(*key);
|
|
std::string tmp(user_key.data(), user_key.size());
|
|
user_comparator_->FindShortSuccessor(&tmp);
|
|
if (user_comparator_->Compare(user_key, tmp) < 0) {
|
|
// User key has become larger. Tack on the earliest possible
|
|
// number to the shortened user key.
|
|
PutFixed64(&tmp, PackSequenceAndType(kMaxSequenceNumber,kValueTypeForSeek));
|
|
assert(this->Compare(*key, tmp) < 0);
|
|
key->swap(tmp);
|
|
}
|
|
}
|
|
|
|
LookupKey::LookupKey(const Slice& user_key, SequenceNumber s) {
|
|
size_t usize = user_key.size();
|
|
size_t needed = usize + 13; // A conservative estimate
|
|
char* dst;
|
|
if (needed <= sizeof(space_)) {
|
|
dst = space_;
|
|
} else {
|
|
dst = new char[needed];
|
|
}
|
|
start_ = dst;
|
|
dst = EncodeVarint32(dst, usize + 8);
|
|
kstart_ = dst;
|
|
memcpy(dst, user_key.data(), usize);
|
|
dst += usize;
|
|
EncodeFixed64(dst, PackSequenceAndType(s, kValueTypeForSeek));
|
|
dst += 8;
|
|
end_ = dst;
|
|
}
|
|
|
|
}
|