fix: encode when only create container but no op

Cargo.lock

@@ -302,6 +302,7 @@ version = "0.1.0"
 dependencies = [
  "bincode",
  "columnar_derive",
+ "flate2",
  "itertools",
  "lazy_static",
  "postcard",

crates/loro-core/examples/encoding.rs

@@ -1,10 +1,6 @@
-use std::{
-    io::{Read, Write},
-    time::Instant,
-};
+use std::{io::Read, time::Instant};
 
-use flate2::write::GzEncoder;
-use flate2::{read::GzDecoder, Compression};
+use flate2::read::GzDecoder;
 use loro_core::{configure::Configure, container::registry::ContainerWrapper, LoroCore};
 use serde_json::Value;
 const RAW_DATA: &[u8; 901823] = include_bytes!("../benches/automerge-paper.json.gz");
@@ -64,8 +60,12 @@ fn main() {
     }
 
     println!("Longest continuous bytes length {}", max_count);
-    let mut e = GzEncoder::new(Vec::new(), Compression::new(6));
-    e.write_all(&buf).unwrap();
-    let result = e.finish().unwrap();
-    println!("GZipped Size {}", result.len());
+    use columnar::{compress, CompressConfig};
+    let s = Instant::now();
+    let result = compress(&buf, &CompressConfig::default()).unwrap();
+    println!(
+        "GZipped Size {} time: {}ms",
+        result.len(),
+        s.elapsed().as_millis()
+    );
 }

crates/loro-core/fuzz/Cargo.lock

@@ -8,6 +8,12 @@ version = "0.11.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fe438c63458706e03479442743baae6c88256498e6431708f6dfc520a26515d3"
 
+[[package]]
+name = "adler"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
+
 [[package]]
 name = "aho-corasick"
 version = "0.7.19"
@@ -177,6 +183,7 @@ version = "0.1.0"
 dependencies = [
  "bincode",
  "columnar_derive",
+ "flate2",
  "itertools",
  "lazy_static",
  "postcard",
@@ -206,6 +213,15 @@ dependencies = [
  "volatile-register",
 ]
 
+[[package]]
+name = "crc32fast"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b540bd8bc810d3885c6ea91e2018302f68baba2129ab3e88f32389ee9370880d"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "crdt-list"
 version = "0.3.0"
@@ -303,6 +319,16 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "flate2"
+version = "1.0.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f82b0f4c27ad9f8bfd1f3208d882da2b09c301bc1c828fd3a00d0216d2fbbff6"
+dependencies = [
+ "crc32fast",
+ "miniz_oxide",
+]
+
 [[package]]
 name = "fnv"
 version = "1.0.7"
@@ -504,6 +530,15 @@ version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
 
+[[package]]
+name = "miniz_oxide"
+version = "0.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "96590ba8f175222643a85693f33d26e9c8a015f599c216509b1a6894af675d34"
+dependencies = [
+ "adler",
+]
+
 [[package]]
 name = "nb"
 version = "0.1.3"

crates/loro-core/fuzz/Cargo.toml

@@ -53,3 +53,9 @@ name = "recursive"
 path = "fuzz_targets/recursive.rs"
 test = false
 doc = false
+
+[[bin]]
+name = "encode"
+path = "fuzz_targets/encode.rs"
+test = false
+doc = false

crates/loro-core/fuzz/fuzz_targets/encode.rs

@@ -0,0 +1,8 @@
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+use loro_core::fuzz::{test_single_client_encode, Action};
+
+fuzz_target!(|data: Vec<Action>| {
+    // fuzzed code goes here
+    test_single_client_encode(data)
+});

crates/loro-core/src/container/list/list_container.rs

@@ -411,7 +411,7 @@ impl Container for ListContainer {
         values.into()
     }
 
-    fn to_export(&mut self, op: &mut RemoteOp, gc: bool) {
+    fn to_export(&mut self, op: &mut RemoteOp, _gc: bool) {
         for content in op.contents.iter_mut() {
             if let Some((slice, _pos)) = content
                 .as_normal_mut()

crates/loro-core/src/container/map/map_container.rs

@@ -189,7 +189,7 @@ impl Container for MapContainer {
         todo!()
     }
 
-    fn to_export(&mut self, _op: &mut RemoteOp, gc: bool) {}
+    fn to_export(&mut self, _op: &mut RemoteOp, _gc: bool) {}
 
     fn to_import(&mut self, _op: &mut RemoteOp) {}
 }

crates/loro-core/src/fuzz.rs

@@ -265,6 +265,40 @@ pub fn test_single_client(mut actions: Vec<Action>) {
     }
 }
 
+pub fn test_single_client_encode(mut actions: Vec<Action>) {
+    let mut store = LoroCore::new(Default::default(), None);
+    let mut text_container = store.get_text("hello");
+    let mut ground_truth = String::new();
+    let mut applied = Vec::new();
+    for action in actions
+        .iter_mut()
+        .filter(|x| x.as_del().is_some() || x.as_ins().is_some())
+    {
+        ground_truth.preprocess(action);
+        applied.push(action.clone());
+        // println!("{}", (&applied).table());
+        ground_truth.apply_action(action);
+        match action {
+            Action::Ins { content, pos, .. } => {
+                text_container.insert(&store, *pos, &content.to_string());
+            }
+            Action::Del { pos, len, .. } => {
+                if text_container.text_len() == 0 {
+                    return;
+                }
+
+                text_container.delete(&store, *pos, *len);
+            }
+            _ => {}
+        }
+    }
+    let encode_bytes = store.encode_snapshot();
+    let store2 =
+        LoroCore::decode_snapshot(&encode_bytes, None, crate::configure::Configure::default());
+    let encode_bytes2 = store2.encode_snapshot();
+    assert_eq!(encode_bytes, encode_bytes2);
+}
+
 pub fn minify_error<T, F, N>(site_num: u8, actions: Vec<T>, f: F, normalize: N)
 where
     F: Fn(u8, &mut [T]),
@@ -616,4 +650,13 @@ mod test {
     fn mini() {
         minify_error(8, vec![], test_multi_sites, normalize)
     }
+
+    #[test]
+    fn case_encode() {
+        test_single_client_encode(vec![Ins {
+            content: 49087,
+            pos: 4631600097073807295,
+            site: 191,
+        }])
+    }
 }

crates/loro-core/src/fuzz/recursive.rs

@@ -1,4 +1,4 @@
-use std::{collections::HashSet, fmt::Debug, panic::UnwindSafe, time::Instant};
+use std::{collections::HashSet, fmt::Debug};
 
 use arbitrary::Arbitrary;
 use enum_as_inner::EnumAsInner;

crates/loro-core/src/log_store/encoding.rs

@@ -51,9 +51,11 @@ struct OpEncoding {
     #[columnar(strategy = "Rle", original_type = "u32")]
     container: ContainerIdx,
     /// key index or insert/delete pos
-    prop: usize,
+    #[columnar(strategy = "DeltaRle")]
+    prop: usize, // 18225 bytes
     // TODO: can be compressed
     gc: usize,
+    // #[columnar(compress(level = 0))]
     value: LoroValue,
 }
 
@@ -85,7 +87,6 @@ struct Encoded {
     #[columnar(type = "vec")]
     deps: Vec<DepsEncoding>,
     clients: Clients,
-    // TODO: can be compressed
     containers: Containers,
     keys: Vec<InternalString>,
 }
@@ -206,13 +207,25 @@ fn decode_changes(
     } = encoded;
 
     if change_encodings.is_empty() {
-        return LogStore::new(cfg, None);
+        let store = LogStore::new(cfg, None);
+        if !containers.is_empty() {
+            let mut s = store.write().unwrap();
+            for container in containers.iter() {
+                s.get_or_create_container(container);
+            }
+            drop(s);
+        }
+        return store;
     }
 
     let mut container_reg = ContainerRegistry::new();
     let mut op_iter = ops.into_iter();
     let mut changes = FxHashMap::default();
     let mut deps_iter = deps.into_iter();
+    for container in containers.iter() {
+        container_reg.get_or_create(container);
+    }
+
     for change_encoding in change_encodings {
         let ChangeEncoding {
             client_idx,
@@ -242,8 +255,6 @@ fn decode_changes(
             } = op;
             let container_id = containers[container as usize].clone();
 
-            container_reg.get_or_create(&container_id);
-
             let container_type = container_id.container_type();
             let content = match container_type {
                 ContainerType::Map => {