diff options
Diffstat (limited to 'db/version_edit.cc')
| -rw-r--r-- | db/version_edit.cc | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/db/version_edit.cc b/db/version_edit.cc new file mode 100644 index 0000000..f10a2d5 --- /dev/null +++ b/db/version_edit.cc @@ -0,0 +1,266 @@ +// 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 |