leveldb/db/dbformat.cc
Hans Wennborg 42fb47f6ed Pass system's CFLAGS, remove exit time destructor, sstable bug fix.
- Pass system's values of CFLAGS,LDFLAGS.
  Don't override OPT if it's already set.
  Original patch by Alessio Treglia <alessio@debian.org>:
  http://code.google.com/p/leveldb/issues/detail?id=27#c6

- Remove 1 exit time destructor from leveldb.
  See http://crbug.com/101600

- Fix problem where sstable building code would pass an
  internal key to the user comparator.

(Sync with uptream at 25436817.)
2011-11-14 17:06:16 +00:00

121 lines
3.8 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;
}
std::string InternalKey::DebugString() const {
std::string result;
ParsedInternalKey parsed;
if (ParseInternalKey(rep_, &parsed)) {
result = parsed.DebugString();
} else {
result = "(bad)";
result.append(EscapeString(rep_));
}
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 (tmp.size() < user_start.size() &&
user_comparator_->Compare(user_start, tmp) < 0) {
// User key has become shorter physically, but larger logically.
// 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 (tmp.size() < user_key.size() &&
user_comparator_->Compare(user_key, tmp) < 0) {
// User key has become shorter physically, but larger logically.
// 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;
}
} // namespace leveldb