Custom height db dump

.changelog/unreleased/improvements/1468-custom-height-db-dump.md

@@ -0,0 +1,2 @@
+- Adds the possibility to dump the state of the db at a custom height.
+  ([\#1468](https://github.com/anoma/namada/pull/1468))

apps/src/lib/cli.rs

@@ -2341,7 +2341,7 @@ pub mod args {
         }),
     );
     pub const BLOCK_HEIGHT: Arg<BlockHeight> = arg("block-height");
-    // pub const BLOCK_HEIGHT_OPT: ArgOpt<BlockHeight> = arg_opt("height");
+    pub const BLOCK_HEIGHT_OPT: ArgOpt<BlockHeight> = arg_opt("height");
     pub const BROADCAST_ONLY: ArgFlag = flag("broadcast-only");
     pub const CHAIN_ID: Arg<ChainId> = arg("chain-id");
     pub const CHAIN_ID_OPT: ArgOpt<ChainId> = CHAIN_ID.opt();
@@ -2608,41 +2608,41 @@ pub mod args {
     #[derive(Clone, Debug)]
     pub struct LedgerDumpDb {
         // TODO: allow to specify height
-        // pub block_height: Option<BlockHeight>,
+        pub block_height: Option<BlockHeight>,
         pub out_file_path: PathBuf,
         pub historic: bool,
     }
 
     impl Args for LedgerDumpDb {
         fn parse(matches: &ArgMatches) -> Self {
-            // let block_height = BLOCK_HEIGHT_OPT.parse(matches);
+            let block_height = BLOCK_HEIGHT_OPT.parse(matches);
             let out_file_path = OUT_FILE_PATH_OPT
                 .parse(matches)
                 .unwrap_or_else(|| PathBuf::from("db_dump".to_string()));
             let historic = HISTORIC.parse(matches);
 
             Self {
-                // block_height,
+                block_height,
                 out_file_path,
                 historic,
             }
         }
 
         fn def(app: App) -> App {
-            app
-                // .arg(BLOCK_HEIGHT_OPT.def().help(
-                //     "The block height to dump. Defaults to latest committed
-                // block.", ))
-                .arg(OUT_FILE_PATH_OPT.def().help(
-                    "Path for the output file (omitting file extension). \
-                     Defaults to \"db_dump.{block_height}.toml\" in the \
-                     current working directory.",
-                ))
-                .arg(
-                    HISTORIC.def().help(
-                        "If provided, dump also the diff of the last height",
-                    ),
-                )
+            app.arg(BLOCK_HEIGHT_OPT.def().help(
+                "The block height to dump. Defaults to latest committed
+                block.",
+            ))
+            .arg(OUT_FILE_PATH_OPT.def().help(
+                "Path for the output file (omitting file extension). Defaults \
+                 to \"db_dump.{block_height}.toml\" in the current working \
+                 directory.",
+            ))
+            .arg(
+                HISTORIC
+                    .def()
+                    .help("If provided, dump also the diff of the last height"),
+            )
         }
     }
 

apps/src/lib/node/ledger/mod.rs

@@ -215,7 +215,7 @@ pub fn reset(config: config::Ledger) -> Result<(), shell::Error> {
 pub fn dump_db(
     config: config::Ledger,
     args::LedgerDumpDb {
-        // block_height,
+        block_height,
         out_file_path,
         historic,
     }: args::LedgerDumpDb,
@@ -226,7 +226,7 @@ pub fn dump_db(
     let db_path = config.shell.db_dir(&chain_id);
 
     let db = storage::PersistentDB::open(db_path, None);
-    db.dump_last_block(out_file_path, historic);
+    db.dump_block(out_file_path, historic, block_height);
 }
 
 /// Roll Namada state back to the previous height

apps/src/lib/node/ledger/storage/rocksdb.rs

@@ -34,10 +34,12 @@
 //!     - `header`: block's header
 
 use std::fs::File;
+use std::io::BufWriter;
 use std::path::Path;
 use std::str::FromStr;
 use std::sync::Mutex;
 
+use ark_serialize::Write;
 use borsh::{BorshDeserialize, BorshSerialize};
 use data_encoding::HEXLOWER;
 use namada::core::types::ethereum_structs;
@@ -252,23 +254,27 @@ impl RocksDB {
     }
 
     /// Dump last known block
-    pub fn dump_last_block(
+    pub fn dump_block(
         &self,
         out_file_path: std::path::PathBuf,
         historic: bool,
+        height: Option<BlockHeight>,
     ) {
         // Find the last block height
         let state_cf = self
             .get_column_family(STATE_CF)
             .expect("State column family should exist");
-        let height: BlockHeight = types::decode(
+
+        let last_height: BlockHeight = types::decode(
             self.0
                 .get_cf(state_cf, "height")
                 .expect("Unable to read DB")
                 .expect("No block height found"),
         )
         .expect("Unable to decode block height");
 
+        let height = height.unwrap_or(last_height);
+
         let full_path = out_file_path
             .with_file_name(format!(
                 "{}_{height}",
@@ -306,10 +312,46 @@ impl RocksDB {
         }
 
         // subspace
-        let cf = self
-            .get_column_family(SUBSPACE_CF)
-            .expect("Subspace column family should exist");
-        self.dump_it(cf, None, &mut file);
+        if height != last_height {
+            // Restoring subspace at specified height
+            let restored_subspace = self
+                .iter_prefix(None)
+                .par_bridge()
+                .fold(
+                    || "".to_string(),
+                    |mut cur, (key, _value, _gas)| match self
+                        .read_subspace_val_with_height(
+                            &Key::from(key.to_db_key()),
+                            height,
+                            last_height,
+                        )
+                        .expect("Unable to find subspace key")
+                    {
+                        Some(value) => {
+                            let val = HEXLOWER.encode(&value);
+                            let new_line = format!("\"{key}\" = \"{val}\"\n");
+                            cur.push_str(new_line.as_str());
+                            cur
+                        }
+                        None => cur,
+                    },
+                )
+                .reduce(
+                    || "".to_string(),
+                    |mut a: String, b: String| {
+                        a.push_str(&b);
+                        a
+                    },
+                );
+            file.write_all(restored_subspace.as_bytes())
+                .expect("Unable to write to output file");
+        } else {
+            // Just dump the current subspace
+            let cf = self
+                .get_column_family(SUBSPACE_CF)
+                .expect("Subspace column family should exist");
+            self.dump_it(cf, None, &mut file);
+        }
 
         println!("Done writing to {}", full_path.to_string_lossy());
     }
@@ -321,8 +363,6 @@ impl RocksDB {
         prefix: Option<String>,
         file: &mut File,
     ) {
-        use std::io::Write;
-
         let read_opts = make_iter_read_opts(prefix.clone());
         let iter = if let Some(prefix) = prefix {
             self.0.iterator_cf_opt(
@@ -334,16 +374,18 @@ impl RocksDB {
             self.0.iterator_cf_opt(cf, read_opts, IteratorMode::Start)
         };
 
+        let mut buf = BufWriter::new(file);
         for (key, raw_val, _gas) in PersistentPrefixIterator(
             PrefixIterator::new(iter, String::default()),
             // Empty string to prevent prefix stripping, the prefix is
             // already in the enclosed iterator
         ) {
             let val = HEXLOWER.encode(&raw_val);
             let bytes = format!("\"{key}\" = \"{val}\"\n");
-            file.write_all(bytes.as_bytes())
-                .expect("Unable to write to output file");
+            buf.write_all(bytes.as_bytes())
+                .expect("Unable to write to buffer");
         }
+        buf.flush().expect("Unable to write to output file");
     }
 
     /// Rollback to previous block. Given the inner working of tendermint