Add in-memory storage engine-a

pageserver/src/inmem_storage.rs

@@ -0,0 +1,345 @@
+//!
+//! An implementation of the ObjectStore interface, backed by BTreeMap
+//!
+use crate::object_key::*;
+use crate::object_store::ObjectStore;
+use crate::repository::RelTag;
+use crate::PageServerConf;
+use crate::ZTimelineId;
+use anyhow::{bail, Result};
+use serde::{Deserialize, Serialize};
+use std::collections::{BTreeMap, HashSet};
+use std::fs::File;
+use std::io::prelude::*;
+use std::ops::Bound::*;
+use std::sync::RwLock;
+use zenith_utils::bin_ser::BeSer;
+use zenith_utils::lsn::Lsn;
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Deserialize, Serialize)]
+pub struct StorageKey {
+    obj_key: ObjectKey,
+    lsn: Lsn,
+}
+
+impl StorageKey {
+    /// The first key for a given timeline
+    fn timeline_start(timeline: ZTimelineId) -> Self {
+        Self {
+            obj_key: ObjectKey {
+                timeline,
+                tag: ObjectTag::FirstTag,
+            },
+            lsn: Lsn(0),
+        }
+    }
+}
+
+pub struct InmemObjectStore {
+    conf: &'static PageServerConf,
+    db: RwLock<BTreeMap<StorageKey, Vec<u8>>>,
+}
+
+impl ObjectStore for InmemObjectStore {
+    fn get(&self, key: &ObjectKey, lsn: Lsn) -> Result<Vec<u8>> {
+        let db = self.db.read().unwrap();
+        let val = db.get(&StorageKey {
+            obj_key: key.clone(),
+            lsn,
+        });
+        if let Some(val) = val {
+            Ok(val.clone())
+        } else {
+            bail!("could not find page {:?}", key);
+        }
+    }
+
+    fn get_next_key(&self, key: &ObjectKey) -> Result<Option<ObjectKey>> {
+        let search_key = StorageKey {
+            obj_key: key.clone(),
+            lsn: Lsn(0),
+        };
+        let db = self.db.read().unwrap();
+        for pair in db.range(&search_key..) {
+            let key = pair.0;
+            return Ok(Some(key.obj_key.clone()));
+        }
+        Ok(None)
+    }
+
+    fn put(&self, key: &ObjectKey, lsn: Lsn, value: &[u8]) -> Result<()> {
+        let mut db = self.db.write().unwrap();
+        db.insert(
+            StorageKey {
+                obj_key: key.clone(),
+                lsn,
+            },
+            value.to_vec(),
+        );
+        Ok(())
+    }
+
+    fn unlink(&self, key: &ObjectKey, lsn: Lsn) -> Result<()> {
+        let mut db = self.db.write().unwrap();
+        db.remove(&StorageKey {
+            obj_key: key.clone(),
+            lsn,
+        });
+        Ok(())
+    }
+
+    /// Iterate through page versions of given page, starting from the given LSN.
+    /// The versions are walked in descending LSN order.
+    fn object_versions<'a>(
+        &'a self,
+        key: &ObjectKey,
+        lsn: Lsn,
+    ) -> Result<Box<dyn Iterator<Item = (Lsn, Vec<u8>)> + 'a>> {
+        let from = StorageKey {
+            obj_key: key.clone(),
+            lsn: Lsn(0),
+        };
+        let till = StorageKey {
+            obj_key: key.clone(),
+            lsn,
+        };
+        let db = self.db.read().unwrap();
+        let versions: Vec<(Lsn, Vec<u8>)> = db
+            .range(from..=till)
+            .map(|pair| (pair.0.lsn, pair.1.clone()))
+            .collect();
+        Ok(Box::new(InmemObjectVersionIter::new(versions)))
+    }
+
+    /// Iterate through all timeline objects
+    fn list_objects<'a>(
+        &'a self,
+        timeline: ZTimelineId,
+        nonrel_only: bool,
+        lsn: Lsn,
+    ) -> Result<Box<dyn Iterator<Item = ObjectTag> + 'a>> {
+        let curr_key = StorageKey::timeline_start(timeline);
+
+        Ok(Box::new(InmemObjectIter {
+            store: &self,
+            curr_key,
+            timeline,
+            nonrel_only,
+            lsn,
+        }))
+    }
+
+    /// Get a list of all distinct relations in given tablespace and database.
+    ///
+    /// TODO: This implementation is very inefficient, it scans
+    /// through all entries in the given database. In practice, this
+    /// is used for CREATE DATABASE, and usually the template database is small.
+    /// But if it's not, this will be slow.
+    fn list_rels(
+        &self,
+        timelineid: ZTimelineId,
+        spcnode: u32,
+        dbnode: u32,
+        lsn: Lsn,
+    ) -> Result<HashSet<RelTag>> {
+        // FIXME: This scans everything. Very slow
+
+        let mut rels: HashSet<RelTag> = HashSet::new();
+
+        let mut search_rel_tag = RelTag {
+            spcnode,
+            dbnode,
+            relnode: 0,
+            forknum: 0u8,
+        };
+        let db = self.db.read().unwrap();
+        'outer: loop {
+            let search_key = StorageKey {
+                obj_key: ObjectKey {
+                    timeline: timelineid,
+                    tag: ObjectTag::RelationMetadata(search_rel_tag),
+                },
+                lsn: Lsn(0),
+            };
+            for pair in db.range(&search_key..) {
+                let key = pair.0;
+
+                if let ObjectTag::RelationMetadata(rel_tag) = key.obj_key.tag {
+                    if spcnode != 0 && rel_tag.spcnode != spcnode
+                        || dbnode != 0 && rel_tag.dbnode != dbnode
+                    {
+                        break 'outer;
+                    }
+                    if key.lsn <= lsn {
+                        // visible in this snapshot
+                        rels.insert(rel_tag);
+                    }
+                    search_rel_tag = rel_tag;
+                    // skip to next relation
+                    // FIXME: What if relnode is u32::MAX ?
+                    search_rel_tag.relnode += 1;
+                    continue 'outer;
+                } else {
+                    // no more relation metadata entries
+                    break 'outer;
+                }
+            }
+        }
+
+        Ok(rels)
+    }
+
+    /// Iterate through versions of all objects in a timeline.
+    ///
+    /// Returns objects in increasing key-version order.
+    /// Returns all versions up to and including the specified LSN.
+    fn objects<'a>(
+        &'a self,
+        timeline: ZTimelineId,
+        lsn: Lsn,
+    ) -> Result<Box<dyn Iterator<Item = Result<(ObjectTag, Lsn, Vec<u8>)>> + 'a>> {
+        let curr_key = StorageKey::timeline_start(timeline);
+
+        Ok(Box::new(InmemObjects {
+            store: &self,
+            curr_key,
+            timeline,
+            lsn,
+        }))
+    }
+
+    fn compact(&self) {}
+}
+
+impl Drop for InmemObjectStore {
+    fn drop(&mut self) {
+        let path = self.conf.workdir.join("objstore.dmp");
+        let mut f = File::create(path).unwrap();
+        f.write(&self.db.ser().unwrap()).unwrap();
+    }
+}
+
+impl InmemObjectStore {
+    pub fn open(conf: &'static PageServerConf) -> Result<InmemObjectStore> {
+        let path = conf.workdir.join("objstore.dmp");
+        let mut f = File::open(path)?;
+        let mut buffer = Vec::new();
+        // read the whole file
+        f.read_to_end(&mut buffer)?;
+        let db = RwLock::new(BTreeMap::des(&buffer)?);
+        Ok(InmemObjectStore { conf: conf, db })
+    }
+
+    pub fn create(conf: &'static PageServerConf) -> Result<InmemObjectStore> {
+        Ok(InmemObjectStore {
+            conf: conf,
+            db: RwLock::new(BTreeMap::new()),
+        })
+    }
+}
+
+///
+/// Iterator for `object_versions`. Returns all page versions of a given block, in
+/// reverse LSN order.
+///
+struct InmemObjectVersionIter {
+    versions: Vec<(Lsn, Vec<u8>)>,
+    curr: usize,
+}
+impl InmemObjectVersionIter {
+    fn new(versions: Vec<(Lsn, Vec<u8>)>) -> InmemObjectVersionIter {
+        let curr = versions.len();
+        InmemObjectVersionIter { versions, curr }
+    }
+}
+impl Iterator for InmemObjectVersionIter {
+    type Item = (Lsn, Vec<u8>);
+
+    fn next(&mut self) -> std::option::Option<Self::Item> {
+        if self.curr == 0 {
+            None
+        } else {
+            self.curr -= 1;
+            Some(self.versions[self.curr].clone())
+        }
+    }
+}
+
+struct InmemObjects<'r> {
+    store: &'r InmemObjectStore,
+    curr_key: StorageKey,
+    timeline: ZTimelineId,
+    lsn: Lsn,
+}
+
+impl<'r> Iterator for InmemObjects<'r> {
+    // TODO consider returning Box<[u8]>
+    type Item = Result<(ObjectTag, Lsn, Vec<u8>)>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.next_result().transpose()
+    }
+}
+
+impl<'r> InmemObjects<'r> {
+    fn next_result(&mut self) -> Result<Option<(ObjectTag, Lsn, Vec<u8>)>> {
+        let db = self.store.db.read().unwrap();
+        for pair in db.range((Excluded(&self.curr_key), Unbounded)) {
+            let key = pair.0;
+            if key.obj_key.timeline != self.timeline {
+                return Ok(None);
+            }
+            if key.lsn > self.lsn {
+                // TODO can speed up by seeking iterator
+                continue;
+            }
+            self.curr_key = key.clone();
+            let value = pair.1.clone();
+            return Ok(Some((key.obj_key.tag, key.lsn, value)));
+        }
+        Ok(None)
+    }
+}
+
+///
+/// Iterator for `list_objects`. Returns all objects preceeding specified LSN
+///
+struct InmemObjectIter<'a> {
+    store: &'a InmemObjectStore,
+    curr_key: StorageKey,
+    timeline: ZTimelineId,
+    nonrel_only: bool,
+    lsn: Lsn,
+}
+
+impl<'a> Iterator for InmemObjectIter<'a> {
+    type Item = ObjectTag;
+
+    fn next(&mut self) -> std::option::Option<Self::Item> {
+        let db = self.store.db.read().unwrap();
+        'outer: loop {
+            for pair in db.range((Excluded(&self.curr_key), Unbounded)) {
+                let key = pair.0;
+                if key.obj_key.timeline != self.timeline {
+                    return None;
+                }
+                self.curr_key = key.clone();
+                self.curr_key.lsn = Lsn(u64::MAX); // next seek should skip all versions
+                if key.lsn <= self.lsn {
+                    // visible in this snapshot
+                    if self.nonrel_only {
+                        match key.obj_key.tag {
+                            ObjectTag::RelationMetadata(_) => return None,
+                            ObjectTag::RelationBuffer(_) => return None,
+                            _ => return Some(key.obj_key.tag),
+                        }
+                    } else {
+                        return Some(key.obj_key.tag);
+                    }
+                }
+                continue 'outer;
+            }
+            return None;
+        }
+    }
+}

test_runner/batch_others/test_bulk_insert.py

@@ -0,0 +1,25 @@
+from contextlib import closing
+import psycopg2.extras
+
+pytest_plugins = ("fixtures.zenith_fixtures")
+
+#
+# Test insertion of larg number of records
+#
+# This test is pretty tightly coupled with the current implementation of page version storage
+# and garbage collection in object_repository.rs.
+#
+def test_bulk_insert(zenith_cli, pageserver, postgres, pg_bin):
+    zenith_cli.run(["branch", "test_bulk_insert", "empty"])
+    pg = postgres.create_start('test_bulk_insert')
+
+    with closing(pg.connect()) as conn:
+        with conn.cursor() as cur:
+          cur.execute("create table t(c1 bigint, c2 bigint, c3 bigint, c4 bigint, c5 bigint)")
+          cur.execute("create index on t(c1)")
+          cur.execute("create index on t(c2)")
+          cur.execute("create index on t(c3)")
+          cur.execute("create index on t(c4)")
+          cur.execute("create index on t(c5)")
+          cur.execute("insert into t values (generate_series(1,1000000),generate_series(1,1000000),generate_series(1,1000000),generate_series(1,1000000),generate_series(1,1000000))")
+          cur.execute("insert into t values (generate_series(1,1000000),random()*1000000,random()*1000000,random()*1000000,random()*1000000)")

test_runner/batch_others/test_seq_scan.py

@@ -0,0 +1,26 @@
+from contextlib import closing
+import psycopg2.extras
+import time
+
+pytest_plugins = ("fixtures.zenith_fixtures")
+
+#
+# Test insertion of larg number of records
+#
+# This test is pretty tightly coupled with the current implementation of page version storage
+# and garbage collection in object_repository.rs.
+#
+def test_seq_scan(zenith_cli, pageserver, postgres, pg_bin):
+    zenith_cli.run(["branch", "test_seq_scan", "empty"])
+    pg = postgres.create_start('test_seq_scan')
+
+    with closing(pg.connect()) as conn:
+        with conn.cursor() as cur:
+          cur.execute("create table t(c1 bigint, c2 bigint, c3 bigint, c4 bigint, c5 bigint)")
+          cur.execute("insert into t values (generate_series(1,1000000),generate_series(1,1000000),generate_series(1,1000000),generate_series(1,1000000),generate_series(1,1000000))")
+          cur.execute("set max_parallel_workers_per_gather=0");
+          for i in range(100):
+              start = time.time()
+              cur.execute("select count(*) from t");
+              stop = time.time()
+              print(f'Elapsed time for iterating through 1000000 records is {stop - start}')