Permalink
Fetching contributors…
Cannot retrieve contributors at this time
267 lines (240 sloc) 6.78 KB
// 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 "db/version_edit.h"
#include "db/version_set.h"
#include "util/coding.h"
namespace leveldb {
// Tag numbers for serialized VersionEdit. These numbers are written to
// disk and should not be changed.
enum Tag {
kComparator = 1,
kLogNumber = 2,
kNextFileNumber = 3,
kLastSequence = 4,
kCompactPointer = 5,
kDeletedFile = 6,
kNewFile = 7,
// 8 was used for large value refs
kPrevLogNumber = 9
};
void VersionEdit::Clear() {
comparator_.clear();
log_number_ = 0;
prev_log_number_ = 0;
last_sequence_ = 0;
next_file_number_ = 0;
has_comparator_ = false;
has_log_number_ = false;
has_prev_log_number_ = false;
has_next_file_number_ = false;
has_last_sequence_ = false;
deleted_files_.clear();
new_files_.clear();
}
void VersionEdit::EncodeTo(std::string* dst) const {
if (has_comparator_) {
PutVarint32(dst, kComparator);
PutLengthPrefixedSlice(dst, comparator_);
}
if (has_log_number_) {
PutVarint32(dst, kLogNumber);
PutVarint64(dst, log_number_);
}
if (has_prev_log_number_) {
PutVarint32(dst, kPrevLogNumber);
PutVarint64(dst, prev_log_number_);
}
if (has_next_file_number_) {
PutVarint32(dst, kNextFileNumber);
PutVarint64(dst, next_file_number_);
}
if (has_last_sequence_) {
PutVarint32(dst, kLastSequence);
PutVarint64(dst, last_sequence_);
}
for (size_t i = 0; i < compact_pointers_.size(); i++) {
PutVarint32(dst, kCompactPointer);
PutVarint32(dst, compact_pointers_[i].first); // level
PutLengthPrefixedSlice(dst, compact_pointers_[i].second.Encode());
}
for (DeletedFileSet::const_iterator iter = deleted_files_.begin();
iter != deleted_files_.end();
++iter) {
PutVarint32(dst, kDeletedFile);
PutVarint32(dst, iter->first); // level
PutVarint64(dst, iter->second); // file number
}
for (size_t i = 0; i < new_files_.size(); i++) {
const FileMetaData& f = new_files_[i].second;
PutVarint32(dst, kNewFile);
PutVarint32(dst, new_files_[i].first); // level
PutVarint64(dst, f.number);
PutVarint64(dst, f.file_size);
PutLengthPrefixedSlice(dst, f.smallest.Encode());
PutLengthPrefixedSlice(dst, f.largest.Encode());
}
}
static bool GetInternalKey(Slice* input, InternalKey* dst) {
Slice str;
if (GetLengthPrefixedSlice(input, &str)) {
dst->DecodeFrom(str);
return true;
} else {
return false;
}
}
static bool GetLevel(Slice* input, int* level) {
uint32_t v;
if (GetVarint32(input, &v) &&
v < config::kNumLevels) {
*level = v;
return true;
} else {
return false;
}
}
Status VersionEdit::DecodeFrom(const Slice& src) {
Clear();
Slice input = src;
const char* msg = NULL;
uint32_t tag;
// Temporary storage for parsing
int level;
uint64_t number;
FileMetaData f;
Slice str;
InternalKey key;
while (msg == NULL && GetVarint32(&input, &tag)) {
switch (tag) {
case kComparator:
if (GetLengthPrefixedSlice(&input, &str)) {
comparator_ = str.ToString();
has_comparator_ = true;
} else {
msg = "comparator name";
}
break;
case kLogNumber:
if (GetVarint64(&input, &log_number_)) {
has_log_number_ = true;
} else {
msg = "log number";
}
break;
case kPrevLogNumber:
if (GetVarint64(&input, &prev_log_number_)) {
has_prev_log_number_ = true;
} else {
msg = "previous log number";
}
break;
case kNextFileNumber:
if (GetVarint64(&input, &next_file_number_)) {
has_next_file_number_ = true;
} else {
msg = "next file number";
}
break;
case kLastSequence:
if (GetVarint64(&input, &last_sequence_)) {
has_last_sequence_ = true;
} else {
msg = "last sequence number";
}
break;
case kCompactPointer:
if (GetLevel(&input, &level) &&
GetInternalKey(&input, &key)) {
compact_pointers_.push_back(std::make_pair(level, key));
} else {
msg = "compaction pointer";
}
break;
case kDeletedFile:
if (GetLevel(&input, &level) &&
GetVarint64(&input, &number)) {
deleted_files_.insert(std::make_pair(level, number));
} else {
msg = "deleted file";
}
break;
case kNewFile:
if (GetLevel(&input, &level) &&
GetVarint64(&input, &f.number) &&
GetVarint64(&input, &f.file_size) &&
GetInternalKey(&input, &f.smallest) &&
GetInternalKey(&input, &f.largest)) {
new_files_.push_back(std::make_pair(level, f));
} else {
msg = "new-file entry";
}
break;
default:
msg = "unknown tag";
break;
}
}
if (msg == NULL && !input.empty()) {
msg = "invalid tag";
}
Status result;
if (msg != NULL) {
result = Status::Corruption("VersionEdit", msg);
}
return result;
}
std::string VersionEdit::DebugString() const {
std::string r;
r.append("VersionEdit {");
if (has_comparator_) {
r.append("\n Comparator: ");
r.append(comparator_);
}
if (has_log_number_) {
r.append("\n LogNumber: ");
AppendNumberTo(&r, log_number_);
}
if (has_prev_log_number_) {
r.append("\n PrevLogNumber: ");
AppendNumberTo(&r, prev_log_number_);
}
if (has_next_file_number_) {
r.append("\n NextFile: ");
AppendNumberTo(&r, next_file_number_);
}
if (has_last_sequence_) {
r.append("\n LastSeq: ");
AppendNumberTo(&r, last_sequence_);
}
for (size_t i = 0; i < compact_pointers_.size(); i++) {
r.append("\n CompactPointer: ");
AppendNumberTo(&r, compact_pointers_[i].first);
r.append(" ");
r.append(compact_pointers_[i].second.DebugString());
}
for (DeletedFileSet::const_iterator iter = deleted_files_.begin();
iter != deleted_files_.end();
++iter) {
r.append("\n DeleteFile: ");
AppendNumberTo(&r, iter->first);
r.append(" ");
AppendNumberTo(&r, iter->second);
}
for (size_t i = 0; i < new_files_.size(); i++) {
const FileMetaData& f = new_files_[i].second;
r.append("\n AddFile: ");
AppendNumberTo(&r, new_files_[i].first);
r.append(" ");
AppendNumberTo(&r, f.number);
r.append(" ");
AppendNumberTo(&r, f.file_size);
r.append(" ");
r.append(f.smallest.DebugString());
r.append(" .. ");
r.append(f.largest.DebugString());
}
r.append("\n}\n");
return r;
}
} // namespace leveldb