Line data Source code
1 : #![warn(missing_docs)]
2 :
3 : use serde::{de::Visitor, Deserialize, Serialize};
4 : use std::fmt;
5 : use std::ops::{Add, AddAssign};
6 : use std::str::FromStr;
7 : use std::sync::atomic::{AtomicU64, Ordering};
8 :
9 : use crate::seqwait::MonotonicCounter;
10 :
11 : /// Transaction log block size in bytes
12 : pub const XLOG_BLCKSZ: u32 = 8192;
13 :
14 : /// A Postgres LSN (Log Sequence Number), also known as an XLogRecPtr
15 : #[derive(Clone, Copy, Eq, Ord, PartialEq, PartialOrd, Hash)]
16 : pub struct Lsn(pub u64);
17 :
18 : impl Serialize for Lsn {
19 61784 : fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
20 61784 : where
21 61784 : S: serde::Serializer,
22 61784 : {
23 61784 : if serializer.is_human_readable() {
24 51297 : serializer.collect_str(self)
25 : } else {
26 10487 : self.0.serialize(serializer)
27 : }
28 61784 : }
29 : }
30 :
31 : impl<'de> Deserialize<'de> for Lsn {
32 73735 : fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
33 73735 : where
34 73735 : D: serde::Deserializer<'de>,
35 73735 : {
36 : struct LsnVisitor {
37 : is_human_readable_deserializer: bool,
38 : }
39 :
40 : impl<'de> Visitor<'de> for LsnVisitor {
41 : type Value = Lsn;
42 :
43 2 : fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
44 2 : if self.is_human_readable_deserializer {
45 1 : formatter.write_str(
46 1 : "value in form of hex string({upper_u32_hex}/{lower_u32_hex}) representing u64 integer",
47 1 : )
48 : } else {
49 1 : formatter.write_str("value in form of integer(u64)")
50 : }
51 2 : }
52 :
53 73078 : fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E>
54 73078 : where
55 73078 : E: serde::de::Error,
56 73078 : {
57 73078 : Ok(Lsn(v))
58 73078 : }
59 :
60 655 : fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
61 655 : where
62 655 : E: serde::de::Error,
63 655 : {
64 655 : Lsn::from_str(v).map_err(|e| E::custom(e))
65 655 : }
66 : }
67 :
68 73735 : if deserializer.is_human_readable() {
69 656 : deserializer.deserialize_str(LsnVisitor {
70 656 : is_human_readable_deserializer: true,
71 656 : })
72 : } else {
73 73079 : deserializer.deserialize_u64(LsnVisitor {
74 73079 : is_human_readable_deserializer: false,
75 73079 : })
76 : }
77 73735 : }
78 : }
79 :
80 : /// Allows (de)serialization of an `Lsn` always as `u64`.
81 : ///
82 : /// ### Example
83 : ///
84 : /// ```rust
85 : /// # use serde::{Serialize, Deserialize};
86 : /// use utils::lsn::Lsn;
87 : ///
88 : /// #[derive(PartialEq, Serialize, Deserialize, Debug)]
89 : /// struct Foo {
90 : /// #[serde(with = "utils::lsn::serde_as_u64")]
91 : /// always_u64: Lsn,
92 : /// }
93 : ///
94 : /// let orig = Foo { always_u64: Lsn(1234) };
95 : ///
96 : /// let res = serde_json::to_string(&orig).unwrap();
97 : /// assert_eq!(res, r#"{"always_u64":1234}"#);
98 : ///
99 : /// let foo = serde_json::from_str::<Foo>(&res).unwrap();
100 : /// assert_eq!(foo, orig);
101 : /// ```
102 : ///
103 : pub mod serde_as_u64 {
104 : use super::Lsn;
105 :
106 : /// Serializes the Lsn as u64 disregarding the human readability of the format.
107 : ///
108 : /// Meant to be used via `#[serde(with = "...")]` or `#[serde(serialize_with = "...")]`.
109 0 : pub fn serialize<S: serde::Serializer>(lsn: &Lsn, serializer: S) -> Result<S::Ok, S::Error> {
110 : use serde::Serialize;
111 0 : lsn.0.serialize(serializer)
112 0 : }
113 :
114 : /// Deserializes the Lsn as u64 disregarding the human readability of the format.
115 : ///
116 : /// Meant to be used via `#[serde(with = "...")]` or `#[serde(deserialize_with = "...")]`.
117 0 : pub fn deserialize<'de, D: serde::Deserializer<'de>>(deserializer: D) -> Result<Lsn, D::Error> {
118 : use serde::Deserialize;
119 0 : u64::deserialize(deserializer).map(Lsn)
120 0 : }
121 : }
122 :
123 : /// We tried to parse an LSN from a string, but failed
124 0 : #[derive(Debug, PartialEq, Eq, thiserror::Error)]
125 : #[error("LsnParseError")]
126 : pub struct LsnParseError;
127 :
128 : impl Lsn {
129 : /// Maximum possible value for an LSN
130 : pub const MAX: Lsn = Lsn(u64::MAX);
131 :
132 : /// Invalid value for InvalidXLogRecPtr, as defined in xlogdefs.h
133 : pub const INVALID: Lsn = Lsn(0);
134 :
135 : /// Subtract a number, returning None on overflow.
136 19813 : pub fn checked_sub<T: Into<u64>>(self, other: T) -> Option<Lsn> {
137 19813 : let other: u64 = other.into();
138 19813 : self.0.checked_sub(other).map(Lsn)
139 19813 : }
140 :
141 : /// Subtract a number, returning the difference as i128 to avoid overflow.
142 14409064 : pub fn widening_sub<T: Into<u64>>(self, other: T) -> i128 {
143 14409064 : let other: u64 = other.into();
144 14409064 : i128::from(self.0) - i128::from(other)
145 14409064 : }
146 :
147 : /// Parse an LSN from a string in the form `0000000000000000`
148 14829 : pub fn from_hex<S>(s: S) -> Result<Self, LsnParseError>
149 14829 : where
150 14829 : S: AsRef<str>,
151 14829 : {
152 14829 : let s: &str = s.as_ref();
153 14829 : let n = u64::from_str_radix(s, 16).or(Err(LsnParseError))?;
154 14828 : Ok(Lsn(n))
155 14829 : }
156 :
157 : /// Compute the offset into a segment
158 : #[inline]
159 2472012 : pub fn segment_offset(self, seg_sz: usize) -> usize {
160 2472012 : (self.0 % seg_sz as u64) as usize
161 2472012 : }
162 :
163 : /// Compute LSN of the segment start.
164 : #[inline]
165 0 : pub fn segment_lsn(self, seg_sz: usize) -> Lsn {
166 0 : Lsn(self.0 - (self.0 % seg_sz as u64))
167 0 : }
168 :
169 : /// Compute the segment number
170 : #[inline]
171 68100 : pub fn segment_number(self, seg_sz: usize) -> u64 {
172 68100 : self.0 / seg_sz as u64
173 68100 : }
174 :
175 : /// Compute the offset into a block
176 : #[inline]
177 2386024 : pub fn block_offset(self) -> u64 {
178 : const BLCKSZ: u64 = XLOG_BLCKSZ as u64;
179 2386024 : self.0 % BLCKSZ
180 2386024 : }
181 :
182 : /// Compute the block offset of the first byte of this Lsn within this
183 : /// segment
184 : #[inline]
185 0 : pub fn page_lsn(self) -> Lsn {
186 0 : Lsn(self.0 - self.block_offset())
187 0 : }
188 :
189 : /// Compute the block offset of the first byte of this Lsn within this
190 : /// segment
191 : #[inline]
192 0 : pub fn page_offset_in_segment(self, seg_sz: usize) -> u64 {
193 0 : (self.0 - self.block_offset()) - self.segment_lsn(seg_sz).0
194 0 : }
195 :
196 : /// Compute the bytes remaining in this block
197 : ///
198 : /// If the LSN is already at the block boundary, it will return `XLOG_BLCKSZ`.
199 : #[inline]
200 2301875 : pub fn remaining_in_block(self) -> u64 {
201 : const BLCKSZ: u64 = XLOG_BLCKSZ as u64;
202 2301875 : BLCKSZ - (self.0 % BLCKSZ)
203 2301875 : }
204 :
205 : /// Compute the bytes remaining to fill a chunk of some size
206 : ///
207 : /// If the LSN is already at the chunk boundary, it will return 0.
208 4 : pub fn calc_padding<T: Into<u64>>(self, sz: T) -> u64 {
209 4 : let sz: u64 = sz.into();
210 4 : // By using wrapping_sub, we can subtract first and then mod second.
211 4 : // If it's done the other way around, then we would return a full
212 4 : // chunk size if we're already at the chunk boundary.
213 4 : // (Regular subtraction will panic on overflow in debug builds.)
214 4 : (sz.wrapping_sub(self.0)) % sz
215 4 : }
216 :
217 : /// Align LSN on 8-byte boundary (alignment of WAL records).
218 16319742 : pub fn align(&self) -> Lsn {
219 16319742 : Lsn((self.0 + 7) & !7)
220 16319742 : }
221 :
222 : /// Align LSN on 8-byte boundary (alignment of WAL records).
223 15841194 : pub fn is_aligned(&self) -> bool {
224 15841194 : *self == self.align()
225 15841194 : }
226 :
227 : /// Return if the LSN is valid
228 : /// mimics postgres XLogRecPtrIsInvalid macro
229 26172074 : pub fn is_valid(self) -> bool {
230 26172074 : self != Lsn::INVALID
231 26172074 : }
232 : }
233 :
234 : impl From<u64> for Lsn {
235 45670 : fn from(n: u64) -> Self {
236 45670 : Lsn(n)
237 45670 : }
238 : }
239 :
240 : impl From<Lsn> for u64 {
241 14793104 : fn from(lsn: Lsn) -> u64 {
242 14793104 : lsn.0
243 14793104 : }
244 : }
245 :
246 : impl FromStr for Lsn {
247 : type Err = LsnParseError;
248 :
249 : /// Parse an LSN from a string in the form `00000000/00000000`
250 : ///
251 : /// If the input string is missing the '/' character, then use `Lsn::from_hex`
252 2460 : fn from_str(s: &str) -> Result<Self, Self::Err> {
253 2460 : let mut splitter = s.trim().split('/');
254 2460 : if let (Some(left), Some(right), None) = (splitter.next(), splitter.next(), splitter.next())
255 : {
256 2460 : let left_num = u32::from_str_radix(left, 16).map_err(|_| LsnParseError)?;
257 2457 : let right_num = u32::from_str_radix(right, 16).map_err(|_| LsnParseError)?;
258 2455 : Ok(Lsn((left_num as u64) << 32 | right_num as u64))
259 : } else {
260 0 : Err(LsnParseError)
261 : }
262 2460 : }
263 : }
264 :
265 : impl fmt::Display for Lsn {
266 15503631 : fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
267 15503631 : write!(f, "{:X}/{:X}", self.0 >> 32, self.0 & 0xffffffff)
268 15503631 : }
269 : }
270 :
271 : impl fmt::Debug for Lsn {
272 22029 : fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
273 22029 : write!(f, "{:X}/{:X}", self.0 >> 32, self.0 & 0xffffffff)
274 22029 : }
275 : }
276 :
277 : impl Add<u64> for Lsn {
278 : type Output = Lsn;
279 :
280 8898593 : fn add(self, other: u64) -> Self::Output {
281 8898593 : // panic if the addition overflows.
282 8898593 : Lsn(self.0.checked_add(other).unwrap())
283 8898593 : }
284 : }
285 :
286 : impl AddAssign<u64> for Lsn {
287 2249119 : fn add_assign(&mut self, other: u64) {
288 2249119 : // panic if the addition overflows.
289 2249119 : self.0 = self.0.checked_add(other).unwrap();
290 2249119 : }
291 : }
292 :
293 : /// An [`Lsn`] that can be accessed atomically.
294 : pub struct AtomicLsn {
295 : inner: AtomicU64,
296 : }
297 :
298 : impl AtomicLsn {
299 : /// Creates a new atomic `Lsn`.
300 6211 : pub fn new(val: u64) -> Self {
301 6211 : AtomicLsn {
302 6211 : inner: AtomicU64::new(val),
303 6211 : }
304 6211 : }
305 :
306 : /// Atomically retrieve the `Lsn` value from memory.
307 14420786 : pub fn load(&self) -> Lsn {
308 14420786 : Lsn(self.inner.load(Ordering::Acquire))
309 14420786 : }
310 :
311 : /// Atomically store a new `Lsn` value to memory.
312 6304 : pub fn store(&self, lsn: Lsn) {
313 6304 : self.inner.store(lsn.0, Ordering::Release);
314 6304 : }
315 :
316 : /// Adds to the current value, returning the previous value.
317 : ///
318 : /// This operation will panic on overflow.
319 1 : pub fn fetch_add(&self, val: u64) -> Lsn {
320 1 : let prev = self.inner.fetch_add(val, Ordering::AcqRel);
321 1 : assert!(prev.checked_add(val).is_some(), "AtomicLsn overflow");
322 1 : Lsn(prev)
323 1 : }
324 :
325 : /// Atomically sets the Lsn to the max of old and new value, returning the old value.
326 3428 : pub fn fetch_max(&self, lsn: Lsn) -> Lsn {
327 3428 : let prev = self.inner.fetch_max(lsn.0, Ordering::AcqRel);
328 3428 : Lsn(prev)
329 3428 : }
330 : }
331 :
332 : impl From<Lsn> for AtomicLsn {
333 18 : fn from(lsn: Lsn) -> Self {
334 18 : Self::new(lsn.0)
335 18 : }
336 : }
337 :
338 : /// Pair of LSN's pointing to the end of the last valid record and previous one
339 : #[derive(Debug, Clone, Copy)]
340 : pub struct RecordLsn {
341 : /// LSN at the end of the current record
342 : pub last: Lsn,
343 : /// LSN at the end of the previous record
344 : pub prev: Lsn,
345 : }
346 :
347 : /// Expose `self.last` as counter to be able to use RecordLsn in SeqWait
348 : impl MonotonicCounter<Lsn> for RecordLsn {
349 14413278 : fn cnt_advance(&mut self, lsn: Lsn) {
350 14413278 : assert!(self.last <= lsn);
351 14413278 : let new_prev = self.last;
352 14413278 : self.last = lsn;
353 14413278 : self.prev = new_prev;
354 14413278 : }
355 16513006 : fn cnt_value(&self) -> Lsn {
356 16513006 : self.last
357 16513006 : }
358 : }
359 :
360 : /// Implements [`rand::distributions::uniform::UniformSampler`] so we can sample [`Lsn`]s.
361 : ///
362 : /// This is used by the `pagebench` pageserver benchmarking tool.
363 : pub struct LsnSampler(<u64 as rand::distributions::uniform::SampleUniform>::Sampler);
364 :
365 : impl rand::distributions::uniform::SampleUniform for Lsn {
366 : type Sampler = LsnSampler;
367 : }
368 :
369 : impl rand::distributions::uniform::UniformSampler for LsnSampler {
370 : type X = Lsn;
371 :
372 0 : fn new<B1, B2>(low: B1, high: B2) -> Self
373 0 : where
374 0 : B1: rand::distributions::uniform::SampleBorrow<Self::X> + Sized,
375 0 : B2: rand::distributions::uniform::SampleBorrow<Self::X> + Sized,
376 0 : {
377 0 : Self(
378 0 : <u64 as rand::distributions::uniform::SampleUniform>::Sampler::new(
379 0 : low.borrow().0,
380 0 : high.borrow().0,
381 0 : ),
382 0 : )
383 0 : }
384 :
385 0 : fn new_inclusive<B1, B2>(low: B1, high: B2) -> Self
386 0 : where
387 0 : B1: rand::distributions::uniform::SampleBorrow<Self::X> + Sized,
388 0 : B2: rand::distributions::uniform::SampleBorrow<Self::X> + Sized,
389 0 : {
390 0 : Self(
391 0 : <u64 as rand::distributions::uniform::SampleUniform>::Sampler::new_inclusive(
392 0 : low.borrow().0,
393 0 : high.borrow().0,
394 0 : ),
395 0 : )
396 0 : }
397 :
398 0 : fn sample<R: rand::prelude::Rng + ?Sized>(&self, rng: &mut R) -> Self::X {
399 0 : Lsn(self.0.sample(rng))
400 0 : }
401 : }
402 :
403 : #[cfg(test)]
404 : mod tests {
405 : use crate::bin_ser::BeSer;
406 :
407 : use super::*;
408 :
409 : use serde_assert::{Deserializer, Serializer, Token, Tokens};
410 :
411 : #[test]
412 1 : fn test_lsn_strings() {
413 1 : assert_eq!("12345678/AAAA5555".parse(), Ok(Lsn(0x12345678AAAA5555)));
414 1 : assert_eq!("aaaa/bbbb".parse(), Ok(Lsn(0x0000AAAA0000BBBB)));
415 1 : assert_eq!("1/A".parse(), Ok(Lsn(0x000000010000000A)));
416 1 : assert_eq!("0/0".parse(), Ok(Lsn(0)));
417 1 : "ABCDEFG/12345678".parse::<Lsn>().unwrap_err();
418 1 : "123456789/AAAA5555".parse::<Lsn>().unwrap_err();
419 1 : "12345678/AAAA55550".parse::<Lsn>().unwrap_err();
420 1 : "-1/0".parse::<Lsn>().unwrap_err();
421 1 : "1/-1".parse::<Lsn>().unwrap_err();
422 1 :
423 1 : assert_eq!(format!("{}", Lsn(0x12345678AAAA5555)), "12345678/AAAA5555");
424 1 : assert_eq!(format!("{}", Lsn(0x000000010000000A)), "1/A");
425 :
426 1 : assert_eq!(
427 1 : Lsn::from_hex("12345678AAAA5555"),
428 1 : Ok(Lsn(0x12345678AAAA5555))
429 1 : );
430 1 : assert_eq!(Lsn::from_hex("0"), Ok(Lsn(0)));
431 1 : assert_eq!(Lsn::from_hex("F12345678AAAA5555"), Err(LsnParseError));
432 :
433 1 : let expected_lsn = Lsn(0x3C490F8);
434 1 : assert_eq!(" 0/3C490F8".parse(), Ok(expected_lsn));
435 1 : assert_eq!("0/3C490F8 ".parse(), Ok(expected_lsn));
436 1 : assert_eq!(" 0/3C490F8 ".parse(), Ok(expected_lsn));
437 1 : }
438 :
439 : #[test]
440 1 : fn test_lsn_math() {
441 1 : assert_eq!(Lsn(1234) + 11u64, Lsn(1245));
442 :
443 1 : assert_eq!(
444 1 : {
445 1 : let mut lsn = Lsn(1234);
446 1 : lsn += 11u64;
447 1 : lsn
448 1 : },
449 1 : Lsn(1245)
450 1 : );
451 :
452 1 : assert_eq!(Lsn(1234).checked_sub(1233u64), Some(Lsn(1)));
453 1 : assert_eq!(Lsn(1234).checked_sub(1235u64), None);
454 :
455 1 : assert_eq!(Lsn(1235).widening_sub(1234u64), 1);
456 1 : assert_eq!(Lsn(1234).widening_sub(1235u64), -1);
457 1 : assert_eq!(Lsn(u64::MAX).widening_sub(0u64), i128::from(u64::MAX));
458 1 : assert_eq!(Lsn(0).widening_sub(u64::MAX), -i128::from(u64::MAX));
459 :
460 1 : let seg_sz: usize = 16 * 1024 * 1024;
461 1 : assert_eq!(Lsn(0x1000007).segment_offset(seg_sz), 7);
462 1 : assert_eq!(Lsn(0x1000007).segment_number(seg_sz), 1u64);
463 :
464 1 : assert_eq!(Lsn(0x4007).block_offset(), 7u64);
465 1 : assert_eq!(Lsn(0x4000).block_offset(), 0u64);
466 1 : assert_eq!(Lsn(0x4007).remaining_in_block(), 8185u64);
467 1 : assert_eq!(Lsn(0x4000).remaining_in_block(), 8192u64);
468 :
469 1 : assert_eq!(Lsn(0xffff01).calc_padding(seg_sz as u64), 255u64);
470 1 : assert_eq!(Lsn(0x2000000).calc_padding(seg_sz as u64), 0u64);
471 1 : assert_eq!(Lsn(0xffff01).calc_padding(8u32), 7u64);
472 1 : assert_eq!(Lsn(0xffff00).calc_padding(8u32), 0u64);
473 1 : }
474 :
475 : #[test]
476 1 : fn test_atomic_lsn() {
477 1 : let lsn = AtomicLsn::new(0);
478 1 : assert_eq!(lsn.fetch_add(1234), Lsn(0));
479 1 : assert_eq!(lsn.load(), Lsn(1234));
480 1 : lsn.store(Lsn(5678));
481 1 : assert_eq!(lsn.load(), Lsn(5678));
482 :
483 1 : assert_eq!(lsn.fetch_max(Lsn(6000)), Lsn(5678));
484 1 : assert_eq!(lsn.fetch_max(Lsn(5000)), Lsn(6000));
485 1 : }
486 :
487 : #[test]
488 1 : fn test_lsn_serde() {
489 1 : let original_lsn = Lsn(0x0123456789abcdef);
490 1 : let expected_readable_tokens = Tokens(vec![Token::U64(0x0123456789abcdef)]);
491 1 : let expected_non_readable_tokens =
492 1 : Tokens(vec![Token::Str(String::from("1234567/89ABCDEF"))]);
493 1 :
494 1 : // Testing human_readable ser/de
495 1 : let serializer = Serializer::builder().is_human_readable(false).build();
496 1 : let readable_ser_tokens = original_lsn.serialize(&serializer).unwrap();
497 1 : assert_eq!(readable_ser_tokens, expected_readable_tokens);
498 :
499 1 : let mut deserializer = Deserializer::builder()
500 1 : .is_human_readable(false)
501 1 : .tokens(readable_ser_tokens)
502 1 : .build();
503 1 : let des_lsn = Lsn::deserialize(&mut deserializer).unwrap();
504 1 : assert_eq!(des_lsn, original_lsn);
505 :
506 : // Testing NON human_readable ser/de
507 1 : let serializer = Serializer::builder().is_human_readable(true).build();
508 1 : let non_readable_ser_tokens = original_lsn.serialize(&serializer).unwrap();
509 1 : assert_eq!(non_readable_ser_tokens, expected_non_readable_tokens);
510 :
511 1 : let mut deserializer = Deserializer::builder()
512 1 : .is_human_readable(true)
513 1 : .tokens(non_readable_ser_tokens)
514 1 : .build();
515 1 : let des_lsn = Lsn::deserialize(&mut deserializer).unwrap();
516 1 : assert_eq!(des_lsn, original_lsn);
517 :
518 : // Testing mismatching ser/de
519 1 : let serializer = Serializer::builder().is_human_readable(false).build();
520 1 : let non_readable_ser_tokens = original_lsn.serialize(&serializer).unwrap();
521 1 :
522 1 : let mut deserializer = Deserializer::builder()
523 1 : .is_human_readable(true)
524 1 : .tokens(non_readable_ser_tokens)
525 1 : .build();
526 1 : Lsn::deserialize(&mut deserializer).unwrap_err();
527 1 :
528 1 : let serializer = Serializer::builder().is_human_readable(true).build();
529 1 : let readable_ser_tokens = original_lsn.serialize(&serializer).unwrap();
530 1 :
531 1 : let mut deserializer = Deserializer::builder()
532 1 : .is_human_readable(false)
533 1 : .tokens(readable_ser_tokens)
534 1 : .build();
535 1 : Lsn::deserialize(&mut deserializer).unwrap_err();
536 1 : }
537 :
538 : #[test]
539 1 : fn test_lsn_ensure_roundtrip() {
540 1 : let original_lsn = Lsn(0xaaaabbbb);
541 1 :
542 1 : let serializer = Serializer::builder().is_human_readable(false).build();
543 1 : let ser_tokens = original_lsn.serialize(&serializer).unwrap();
544 1 :
545 1 : let mut deserializer = Deserializer::builder()
546 1 : .is_human_readable(false)
547 1 : .tokens(ser_tokens)
548 1 : .build();
549 1 :
550 1 : let des_lsn = Lsn::deserialize(&mut deserializer).unwrap();
551 1 : assert_eq!(des_lsn, original_lsn);
552 1 : }
553 :
554 : #[test]
555 1 : fn test_lsn_bincode_serde() {
556 1 : let lsn = Lsn(0x0123456789abcdef);
557 1 : let expected_bytes = [0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef];
558 1 :
559 1 : let ser_bytes = lsn.ser().unwrap();
560 1 : assert_eq!(ser_bytes, expected_bytes);
561 :
562 1 : let des_lsn = Lsn::des(&ser_bytes).unwrap();
563 1 : assert_eq!(des_lsn, lsn);
564 1 : }
565 :
566 : #[test]
567 1 : fn test_lsn_bincode_ensure_roundtrip() {
568 1 : let original_lsn = Lsn(0x01_02_03_04_05_06_07_08);
569 1 : let expected_bytes = vec![0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08];
570 1 :
571 1 : let ser_bytes = original_lsn.ser().unwrap();
572 1 : assert_eq!(ser_bytes, expected_bytes);
573 :
574 1 : let des_lsn = Lsn::des(&ser_bytes).unwrap();
575 1 : assert_eq!(des_lsn, original_lsn);
576 1 : }
577 : }
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