LCOV - code coverage report
Current view: top level - pageserver/src/tenant/storage_layer - layer_desc.rs (source / functions) Coverage Total Hit
Test: 1e20c4f2b28aa592527961bb32170ebbd2c9172f.info Lines: 86.1 % 165 142
Test Date: 2025-07-16 12:29:03 Functions: 75.0 % 24 18

            Line data    Source code
       1              : use core::fmt::Display;
       2              : use std::ops::Range;
       3              : 
       4              : use pageserver_api::key::Key;
       5              : use pageserver_api::shard::TenantShardId;
       6              : use serde::{Deserialize, Serialize};
       7              : #[cfg(test)]
       8              : use utils::id::TenantId;
       9              : use utils::id::TimelineId;
      10              : use utils::lsn::Lsn;
      11              : 
      12              : use super::{DeltaLayerName, ImageLayerName, LayerName};
      13              : 
      14              : /// A unique identifier of a persistent layer.
      15              : ///
      16              : /// This is different from `LayerDescriptor`, which is only used in the benchmarks.
      17              : /// This struct contains all necessary information to find the image / delta layer. It also provides
      18              : /// a unified way to generate layer information like file name.
      19            0 : #[derive(Debug, PartialEq, Eq, Clone, Serialize, Deserialize, Hash)]
      20              : pub struct PersistentLayerDesc {
      21              :     pub tenant_shard_id: TenantShardId,
      22              :     pub timeline_id: TimelineId,
      23              :     /// Range of keys that this layer covers
      24              :     pub key_range: Range<Key>,
      25              :     /// Inclusive start, exclusive end of the LSN range that this layer holds.
      26              :     ///
      27              :     /// - For an open in-memory layer, the end bound is MAX_LSN
      28              :     /// - For a frozen in-memory layer or a delta layer, the end bound is a valid lsn after the
      29              :     ///   range start
      30              :     /// - An image layer represents snapshot at one LSN, so end_lsn is always the snapshot LSN + 1
      31              :     pub lsn_range: Range<Lsn>,
      32              :     /// Whether this is a delta layer, and also, is this incremental.
      33              :     pub is_delta: bool,
      34              :     pub file_size: u64,
      35              : }
      36              : 
      37              : /// A unique identifier of a persistent layer within the context of one timeline.
      38              : #[derive(Debug, PartialEq, Eq, Clone, Hash)]
      39              : pub struct PersistentLayerKey {
      40              :     pub key_range: Range<Key>,
      41              :     pub lsn_range: Range<Lsn>,
      42              :     pub is_delta: bool,
      43              : }
      44              : 
      45              : impl std::fmt::Display for PersistentLayerKey {
      46           29 :     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
      47           29 :         write!(
      48           29 :             f,
      49           29 :             "{}..{} {}..{} is_delta={}",
      50              :             self.key_range.start,
      51              :             self.key_range.end,
      52              :             self.lsn_range.start,
      53              :             self.lsn_range.end,
      54              :             self.is_delta
      55              :         )
      56           29 :     }
      57              : }
      58              : 
      59              : impl From<ImageLayerName> for PersistentLayerKey {
      60            0 :     fn from(image_layer_name: ImageLayerName) -> Self {
      61            0 :         Self {
      62            0 :             key_range: image_layer_name.key_range,
      63            0 :             lsn_range: PersistentLayerDesc::image_layer_lsn_range(image_layer_name.lsn),
      64            0 :             is_delta: false,
      65            0 :         }
      66            0 :     }
      67              : }
      68              : 
      69              : impl From<DeltaLayerName> for PersistentLayerKey {
      70            0 :     fn from(delta_layer_name: DeltaLayerName) -> Self {
      71            0 :         Self {
      72            0 :             key_range: delta_layer_name.key_range,
      73            0 :             lsn_range: delta_layer_name.lsn_range,
      74            0 :             is_delta: true,
      75            0 :         }
      76            0 :     }
      77              : }
      78              : 
      79              : impl From<LayerName> for PersistentLayerKey {
      80            0 :     fn from(layer_name: LayerName) -> Self {
      81            0 :         match layer_name {
      82            0 :             LayerName::Image(i) => i.into(),
      83            0 :             LayerName::Delta(d) => d.into(),
      84              :         }
      85            0 :     }
      86              : }
      87              : impl PersistentLayerDesc {
      88       443056 :     pub fn key(&self) -> PersistentLayerKey {
      89       443056 :         PersistentLayerKey {
      90       443056 :             key_range: self.key_range.clone(),
      91       443056 :             lsn_range: self.lsn_range.clone(),
      92       443056 :             is_delta: self.is_delta,
      93       443056 :         }
      94       443056 :     }
      95              : 
      96         1129 :     pub fn short_id(&self) -> impl Display {
      97         1129 :         self.layer_name()
      98         1129 :     }
      99              : 
     100              :     #[cfg(test)]
     101           34 :     pub fn new_test(key_range: Range<Key>, lsn_range: Range<Lsn>, is_delta: bool) -> Self {
     102           34 :         Self {
     103           34 :             tenant_shard_id: TenantShardId::unsharded(TenantId::generate()),
     104           34 :             timeline_id: TimelineId::generate(),
     105           34 :             key_range,
     106           34 :             lsn_range,
     107           34 :             is_delta,
     108           34 :             file_size: 0,
     109           34 :         }
     110           34 :     }
     111              : 
     112          213 :     pub fn new_img(
     113          213 :         tenant_shard_id: TenantShardId,
     114          213 :         timeline_id: TimelineId,
     115          213 :         key_range: Range<Key>,
     116          213 :         lsn: Lsn,
     117          213 :         file_size: u64,
     118          213 :     ) -> Self {
     119          213 :         Self {
     120          213 :             tenant_shard_id,
     121          213 :             timeline_id,
     122          213 :             key_range,
     123          213 :             lsn_range: Self::image_layer_lsn_range(lsn),
     124          213 :             is_delta: false,
     125          213 :             file_size,
     126          213 :         }
     127          213 :     }
     128              : 
     129          813 :     pub fn new_delta(
     130          813 :         tenant_shard_id: TenantShardId,
     131          813 :         timeline_id: TimelineId,
     132          813 :         key_range: Range<Key>,
     133          813 :         lsn_range: Range<Lsn>,
     134          813 :         file_size: u64,
     135          813 :     ) -> Self {
     136          813 :         Self {
     137          813 :             tenant_shard_id,
     138          813 :             timeline_id,
     139          813 :             key_range,
     140          813 :             lsn_range,
     141          813 :             is_delta: true,
     142          813 :             file_size,
     143          813 :         }
     144          813 :     }
     145              : 
     146           61 :     pub fn from_filename(
     147           61 :         tenant_shard_id: TenantShardId,
     148           61 :         timeline_id: TimelineId,
     149           61 :         filename: LayerName,
     150           61 :         file_size: u64,
     151           61 :     ) -> Self {
     152           61 :         match filename {
     153            2 :             LayerName::Image(i) => {
     154            2 :                 Self::new_img(tenant_shard_id, timeline_id, i.key_range, i.lsn, file_size)
     155              :             }
     156           59 :             LayerName::Delta(d) => Self::new_delta(
     157           59 :                 tenant_shard_id,
     158           59 :                 timeline_id,
     159           59 :                 d.key_range,
     160           59 :                 d.lsn_range,
     161           59 :                 file_size,
     162              :             ),
     163              :         }
     164           61 :     }
     165              : 
     166              :     /// Get the LSN that the image layer covers.
     167      1270361 :     pub fn image_layer_lsn(&self) -> Lsn {
     168      1270361 :         assert!(!self.is_delta);
     169      1270361 :         assert!(self.lsn_range.start + 1 == self.lsn_range.end);
     170      1270361 :         self.lsn_range.start
     171      1270361 :     }
     172              : 
     173              :     /// Get the LSN range corresponding to a single image layer LSN.
     174         1224 :     pub fn image_layer_lsn_range(lsn: Lsn) -> Range<Lsn> {
     175         1224 :         lsn..(lsn + 1)
     176         1224 :     }
     177              : 
     178              :     /// Get a delta layer name for this layer.
     179              :     ///
     180              :     /// Panic: if this is not a delta layer.
     181       895769 :     pub fn delta_layer_name(&self) -> DeltaLayerName {
     182       895769 :         assert!(self.is_delta);
     183       895769 :         DeltaLayerName {
     184       895769 :             key_range: self.key_range.clone(),
     185       895769 :             lsn_range: self.lsn_range.clone(),
     186       895769 :         }
     187       895769 :     }
     188              : 
     189              :     /// Get a image layer name for this layer.
     190              :     ///
     191              :     /// Panic: if this is not an image layer, or the lsn range is invalid
     192         1808 :     pub fn image_layer_name(&self) -> ImageLayerName {
     193         1808 :         assert!(!self.is_delta);
     194         1808 :         assert!(self.lsn_range.start + 1 == self.lsn_range.end);
     195         1808 :         ImageLayerName {
     196         1808 :             key_range: self.key_range.clone(),
     197         1808 :             lsn: self.lsn_range.start,
     198         1808 :         }
     199         1808 :     }
     200              : 
     201       897577 :     pub fn layer_name(&self) -> LayerName {
     202       897577 :         if self.is_delta {
     203       895769 :             self.delta_layer_name().into()
     204              :         } else {
     205         1808 :             self.image_layer_name().into()
     206              :         }
     207       897577 :     }
     208              : 
     209              :     // TODO: remove this in the future once we refactor timeline APIs.
     210              : 
     211      3266816 :     pub fn get_lsn_range(&self) -> Range<Lsn> {
     212      3266816 :         self.lsn_range.clone()
     213      3266816 :     }
     214              : 
     215        53347 :     pub fn get_key_range(&self) -> Range<Key> {
     216        53347 :         self.key_range.clone()
     217        53347 :     }
     218              : 
     219            0 :     pub fn get_timeline_id(&self) -> TimelineId {
     220            0 :         self.timeline_id
     221            0 :     }
     222              : 
     223              :     /// Does this layer only contain some data for the key-range (incremental),
     224              :     /// or does it contain a version of every page? This is important to know
     225              :     /// for garbage collecting old layers: an incremental layer depends on
     226              :     /// the previous non-incremental layer.
     227         2766 :     pub fn is_incremental(&self) -> bool {
     228         2766 :         self.is_delta
     229         2766 :     }
     230              : 
     231      3825666 :     pub fn is_delta(&self) -> bool {
     232      3825666 :         self.is_delta
     233      3825666 :     }
     234              : 
     235            8 :     pub fn dump(&self) {
     236            8 :         if self.is_delta {
     237            7 :             println!(
     238            7 :                 "----- delta layer for ten {} tli {} keys {}-{} lsn {}-{} is_incremental {} size {} ----",
     239            7 :                 self.tenant_shard_id,
     240            7 :                 self.timeline_id,
     241            7 :                 self.key_range.start,
     242            7 :                 self.key_range.end,
     243            7 :                 self.lsn_range.start,
     244            7 :                 self.lsn_range.end,
     245            7 :                 self.is_incremental(),
     246            7 :                 self.file_size,
     247            7 :             );
     248            7 :         } else {
     249            1 :             println!(
     250            1 :                 "----- image layer for ten {} tli {} key {}-{} at {} is_incremental {} size {} ----",
     251            1 :                 self.tenant_shard_id,
     252            1 :                 self.timeline_id,
     253            1 :                 self.key_range.start,
     254            1 :                 self.key_range.end,
     255            1 :                 self.image_layer_lsn(),
     256            1 :                 self.is_incremental(),
     257            1 :                 self.file_size
     258            1 :             );
     259            1 :         }
     260            8 :     }
     261              : 
     262          117 :     pub fn file_size(&self) -> u64 {
     263          117 :         self.file_size
     264          117 :     }
     265              : }
        

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