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https://github.com/luxfi/zapdb.git
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Manish R JainandGitHub
c2f22eaa17
This PR significantly improves Badger's disk usage behavior. Breaking: This PR increases the magic version from 7 to 8. So, no older Badger directories would work with this change. With this PR, we no longer use value log as write-ahead log. Instead, each MemTable has its own WAL. Value logs now only write values which are greater than ValueThreshold, while MemTable WAL only writes smaller values and value pointers. On a crash and restart, the MemTable WALs are replayed to apply updates to Skiplist. When MemTables are flushed to L0, the corresponding WALs are deleted. This PR makes big changes to how value log GC works: - Discard stats are now stored in a separate file, instead of within the LSM tree. - GC only picks up value logs based off discard stats. - GC no longer does sampling, it uses discard stats to inform when a value log needs to be GCed. - Value log would now no longer grow indefinitely, because of the shift to MemTable WAL. - Removed the `badger gc` tool. - Value Log Head pointer tracking is removed. - Only the last value log file is replayed on every start, and truncated as necessary. This PR also makes a bunch of other changes: - Removes ValueLogLoadingMode (always uses mmap now). - Removes TableLoadingMode (always uses mmap now). - Removes Truncate option. - Removes KeepL0InMemory option.
68 lines
1.7 KiB
Go
68 lines
1.7 KiB
Go
/*
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* Copyright 2019 Dgraph Labs, Inc. and Contributors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package y
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import (
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"bytes"
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"crypto/aes"
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"crypto/cipher"
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"crypto/rand"
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"io"
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)
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// XORBlock encrypts the given data with AES and XOR's with IV.
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// Can be used for both encryption and decryption. IV is of
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// AES block size.
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func XORBlock(dst, src, key, iv []byte) error {
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block, err := aes.NewCipher(key)
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if err != nil {
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return err
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}
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stream := cipher.NewCTR(block, iv)
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stream.XORKeyStream(dst, src)
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return nil
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}
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func XORBlockAllocate(src, key, iv []byte) ([]byte, error) {
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, err
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}
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stream := cipher.NewCTR(block, iv)
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dst := make([]byte, len(src))
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stream.XORKeyStream(dst, src)
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return dst, nil
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}
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func XORBlockStream(w io.Writer, src, key, iv []byte) error {
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block, err := aes.NewCipher(key)
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if err != nil {
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return err
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}
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stream := cipher.NewCTR(block, iv)
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sw := cipher.StreamWriter{S: stream, W: w}
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_, err = io.Copy(sw, bytes.NewReader(src))
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return Wrapf(err, "XORBlockStream")
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}
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// GenerateIV generates IV.
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func GenerateIV() ([]byte, error) {
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iv := make([]byte, aes.BlockSize)
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_, err := rand.Read(iv)
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return iv, err
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}
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