From 21ad98ae4e44b6ee9d2b806368e795337c64d36e Mon Sep 17 00:00:00 2001
From: Anastasia Lubennikova <anastasia@neon.tech>
Date: Wed, 8 Jun 2022 22:22:43 +0300
Subject: [PATCH] WIP import_timeline_from_tar

---
 pageserver/src/import_datadir.rs | 125 +++++++++++++++++++++++++++++++
 1 file changed, 125 insertions(+)

diff --git a/pageserver/src/import_datadir.rs b/pageserver/src/import_datadir.rs
index 703ee8f1b1..db637c0df7 100644
--- a/pageserver/src/import_datadir.rs
+++ b/pageserver/src/import_datadir.rs
@@ -22,6 +22,8 @@ use postgres_ffi::{pg_constants, ControlFileData, DBState_DB_SHUTDOWNED};
 use postgres_ffi::{Oid, TransactionId};
 use utils::lsn::Lsn;
 
+use postgres::CopyOutReader;
+
 ///
 /// Import all relation data pages from local disk into the repository.
 ///
@@ -403,3 +405,126 @@ fn import_wal<R: Repository>(
 
     Ok(())
 }
+
+pub fn import_timeline_from_tar<R: Repository>(
+    tline: &mut DatadirTimeline<R>,
+    copyreader: CopyOutReader,
+    lsn: Lsn,
+) -> Result<()> {
+    let mut ar = tar::Archive::new(copyreader);
+
+    let mut modification = tline.begin_modification(lsn);
+    modification.init_empty()?;
+
+    for e in ar.entries().unwrap() {
+        let mut entry = e.unwrap();
+        let header = entry.header();
+        let file_path = header.path().unwrap().into_owned();
+
+        match header.entry_type() {
+            tar::EntryType::Regular => {
+                let mut buffer = Vec::new();
+                // read the whole entry
+                entry.read_to_end(&mut buffer).unwrap();
+
+                import_file(&mut modification, &file_path.as_ref(), &buffer)?;
+            }
+            tar::EntryType::Directory => {
+                println!("tar::EntryType::Directory {}", file_path.display());
+            }
+            _ => {
+                panic!("tar::EntryType::?? {}", file_path.display());
+            }
+        }
+    }
+    Ok(())
+}
+
+pub fn import_file<R: Repository>(
+    modification: &mut DatadirModification<R>,
+    file_path: &Path,
+    buffer: &[u8],
+) -> Result<()> {
+    if file_path.starts_with("global") {
+        let spcnode = pg_constants::GLOBALTABLESPACE_OID;
+        let dbnode = 0;
+
+        match file_path.file_name().unwrap().to_string_lossy().as_ref() {
+            "pg_control" => {
+                println!("pg_control file {}", file_path.display());
+
+                // Import it as ControlFile
+                modification.put_control_file(Bytes::copy_from_slice(&buffer[..]))?;
+
+                // Extract the checkpoint record and import it separately.
+                let pg_control = ControlFileData::decode(&buffer)?;
+                let checkpoint_bytes = pg_control.checkPointCopy.encode()?;
+                modification.put_checkpoint(checkpoint_bytes)?;
+            }
+            "pg_filenode.map" => {
+                ("pg_filenode.map file {}", file_path.display());
+            }
+            _ => {
+                println!("global relfile {}", file_path.display());
+                //TODO
+            }
+        }
+    } else if file_path.starts_with("base") {
+        let spcnode = pg_constants::DEFAULTTABLESPACE_OID;
+        let dbnode: u32 = file_path
+            .iter()
+            .skip(1)
+            .next()
+            .unwrap()
+            .to_string_lossy()
+            .parse()
+            .unwrap();
+
+        match file_path.file_name().unwrap().to_string_lossy().as_ref() {
+            "pg_filenode.map" => {
+                println!(
+                    "dbnode {} pg_filenode.map file {}",
+                    dbnode,
+                    file_path.display()
+                );
+                modification.put_relmap_file(
+                    spcnode,
+                    dbnode,
+                    Bytes::copy_from_slice(&buffer[..]),
+                )?;
+            }
+            _ => {
+                println!("dbnode {} relfile {}", dbnode, file_path.display());
+                //TODO
+            }
+        }
+    } else if file_path.starts_with("pg_xact") {
+        println!(
+            "pg_xact {} ",
+            file_path.file_name().unwrap().to_string_lossy().as_ref()
+        );
+        // TODO
+    } else if file_path.starts_with("pg_multixact/offset") {
+        println!(
+            "pg_multixact/offset {}",
+            file_path.file_name().unwrap().to_string_lossy().as_ref()
+        );
+        // TODO
+    } else if file_path.starts_with("pg_multixact/members") {
+        println!(
+            "pg_multixact/members {}",
+            file_path.file_name().unwrap().to_string_lossy().as_ref()
+        );
+        // TODO
+    } else if file_path.starts_with("pg_twophase") {
+        let xid = u32::from_str_radix(&file_path.file_name().unwrap().to_string_lossy(), 16)?;
+
+        println!(
+            "xid {} pg_twophase {}",
+            xid,
+            file_path.file_name().unwrap().to_string_lossy().as_ref()
+        );
+        modification.put_twophase_file(xid, Bytes::copy_from_slice(&buffer[..]))?;
+    }
+    Ok(())
+}