From 7e49a52cee01a26b91253abb38dcc40b5ae727e2 Mon Sep 17 00:00:00 2001
From: Lars Wirzenius <liw@liw.fi>
Date: Mon, 21 Mar 2022 17:15:51 +0200
Subject: feat! drop generation related fields from chunk metadata

Sponsored-by: author
---
 src/index.rs | 72 +++++-------------------------------------------------------
 1 file changed, 6 insertions(+), 66 deletions(-)

(limited to 'src/index.rs')

diff --git a/src/index.rs b/src/index.rs
index a3d95fc..11f3480 100644
--- a/src/index.rs
+++ b/src/index.rs
@@ -9,7 +9,7 @@ use std::path::Path;
 /// A chunk index stored on the disk.
 ///
 /// A chunk index lets the server quickly find chunks based on a
-/// string key/value pair, or whether they are generations.
+/// string key/value pair.
 #[derive(Debug)]
 pub struct Index {
     conn: Connection,
@@ -66,11 +66,6 @@ impl Index {
         sql::find_by_label(&self.conn, label)
     }
 
-    /// Find all backup generations.
-    pub fn find_generations(&self) -> Result<Vec<ChunkId>, IndexError> {
-        sql::find_generations(&self.conn)
-    }
-
     /// Find all chunks.
     pub fn all_chunks(&self) -> Result<Vec<ChunkId>, IndexError> {
         sql::find_chunk_ids(&self.conn)
@@ -125,36 +120,6 @@ mod test {
         let ids: Vec<ChunkId> = idx.find_by_label("abc").unwrap();
         assert_eq!(ids, vec![]);
     }
-
-    #[test]
-    fn has_no_generations_initially() {
-        let dir = tempdir().unwrap();
-        let idx = new_index(dir.path());
-        assert_eq!(idx.find_generations().unwrap(), vec![]);
-    }
-
-    #[test]
-    fn remembers_generation() {
-        let id: ChunkId = "id001".parse().unwrap();
-        let sum = Checksum::sha256_from_str_unchecked("abc");
-        let meta = ChunkMeta::new_generation(&sum, "timestamp");
-        let dir = tempdir().unwrap();
-        let mut idx = new_index(dir.path());
-        idx.insert_meta(id.clone(), meta).unwrap();
-        assert_eq!(idx.find_generations().unwrap(), vec![id]);
-    }
-
-    #[test]
-    fn removes_generation() {
-        let id: ChunkId = "id001".parse().unwrap();
-        let sum = Checksum::sha256_from_str_unchecked("abc");
-        let meta = ChunkMeta::new_generation(&sum, "timestamp");
-        let dir = tempdir().unwrap();
-        let mut idx = new_index(dir.path());
-        idx.insert_meta(id.clone(), meta).unwrap();
-        idx.remove_meta(&id).unwrap();
-        assert_eq!(idx.find_generations().unwrap(), vec![]);
-    }
 }
 
 mod sql {
@@ -170,14 +135,10 @@ mod sql {
         let flags = OpenFlags::SQLITE_OPEN_CREATE | OpenFlags::SQLITE_OPEN_READ_WRITE;
         let conn = Connection::open_with_flags(filename, flags)?;
         conn.execute(
-            "CREATE TABLE chunks (id TEXT PRIMARY KEY, label TEXT, generation INT, ended TEXT)",
+            "CREATE TABLE chunks (id TEXT PRIMARY KEY, label TEXT)",
             params![],
         )?;
         conn.execute("CREATE INDEX label_idx ON chunks (label)", params![])?;
-        conn.execute(
-            "CREATE INDEX generation_idx ON chunks (generation)",
-            params![],
-        )?;
         conn.pragma_update(None, "journal_mode", &"WAL")?;
         Ok(conn)
     }
@@ -194,11 +155,9 @@ mod sql {
     pub fn insert(t: &Transaction, chunkid: &ChunkId, meta: &ChunkMeta) -> Result<(), IndexError> {
         let chunkid = format!("{}", chunkid);
         let label = meta.label();
-        let generation = if meta.is_generation() { 1 } else { 0 };
-        let ended = meta.ended();
         t.execute(
-            "INSERT INTO chunks (id, label, generation, ended) VALUES (?1, ?2, ?3, ?4)",
-            params![chunkid, label, generation, ended],
+            "INSERT INTO chunks (id, label) VALUES (?1, ?2)",
+            params![chunkid, label],
         )?;
         Ok(())
     }
@@ -243,21 +202,9 @@ mod sql {
         Ok(ids)
     }
 
-    /// Find all generations.
-    pub fn find_generations(conn: &Connection) -> Result<Vec<ChunkId>, IndexError> {
-        let mut stmt = conn.prepare("SELECT id FROM chunks WHERE generation IS 1")?;
-        let iter = stmt.query_map(params![], row_to_id)?;
-        let mut ids = vec![];
-        for x in iter {
-            let x = x?;
-            ids.push(x);
-        }
-        Ok(ids)
-    }
-
     /// Find ids of all chunks.
     pub fn find_chunk_ids(conn: &Connection) -> Result<Vec<ChunkId>, IndexError> {
-        let mut stmt = conn.prepare("SELECT id FROM chunks WHERE generation IS 0")?;
+        let mut stmt = conn.prepare("SELECT id FROM chunks")?;
         let iter = stmt.query_map(params![], row_to_id)?;
         let mut ids = vec![];
         for x in iter {
@@ -270,14 +217,7 @@ mod sql {
     fn row_to_meta(row: &Row) -> rusqlite::Result<ChunkMeta> {
         let hash: String = row.get("label")?;
         let sha256 = Checksum::sha256_from_str_unchecked(&hash);
-        let generation: i32 = row.get("generation")?;
-        let meta = if generation == 0 {
-            ChunkMeta::new(&sha256)
-        } else {
-            let ended: String = row.get("ended")?;
-            ChunkMeta::new_generation(&sha256, &ended)
-        };
-        Ok(meta)
+        Ok(ChunkMeta::new(&sha256))
     }
 
     fn row_to_id(row: &Row) -> rusqlite::Result<ChunkId> {
-- 
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