expose persistent log write method

testing/jormungandr-testing-utils/src/testing/fragments/mod.rs

@@ -8,7 +8,7 @@ pub use self::{
     generator::FragmentGenerator,
     initial_certificates::{signed_delegation_cert, signed_stake_pool_cert, vote_plan_cert},
     node::{FragmentNode, FragmentNodeError, MemPoolCheck},
-    persistent_log::PersistentLogViewer,
+    persistent_log::{write_into_persistent_log, PersistentLogViewer},
     sender::{FragmentSender, FragmentSenderError},
     setup::DummySyncNode,
     setup::{FragmentSenderSetup, FragmentSenderSetupBuilder, VerifyStrategy},

testing/jormungandr-testing-utils/src/testing/fragments/persistent_log.rs

@@ -1,7 +1,12 @@
+use bincode::Options;
 use chain_core::property::Serialize;
 use chain_impl_mockchain::fragment::Fragment;
-use jormungandr_lib::interfaces::load_persistent_fragments_logs_from_folder_path;
-use std::path::PathBuf;
+use jormungandr_lib::interfaces::{
+    load_persistent_fragments_logs_from_folder_path, PersistentFragmentLog,
+};
+use std::fs::File;
+use std::io::{BufWriter, Write};
+use std::path::{Path, PathBuf};
 
 pub struct PersistentLogViewer {
     dir: PathBuf,
@@ -30,3 +35,26 @@ impl PersistentLogViewer {
         self.get_all().len()
     }
 }
+pub fn write_into_persistent_log<P: AsRef<Path>>(
+    persistent_log: P,
+    entries: Vec<PersistentFragmentLog>,
+) -> Result<(), Error> {
+    let mut output = BufWriter::with_capacity(128 * 1024, File::open(persistent_log.as_ref())?);
+
+    for entry in entries {
+        let codec = bincode::DefaultOptions::new().with_fixint_encoding();
+        let serialized = codec
+            .serialize(&entry)
+            .map_err(|_| Error::CannotSerializeEntry)?;
+        output.write_all(&serialized)?;
+    }
+    Ok(())
+}
+
+#[derive(custom_debug::Debug, thiserror::Error)]
+pub enum Error {
+    #[error("cannot serialize entry of persistent log")]
+    CannotSerializeEntry,
+    #[error("cannot serialize entry of persistent log")]
+    Io(#[from] std::io::Error),
+}