refactor: add a type alias for generation ids

This will make it harder to accidentally use a string. Can still be
confused with a chunk id.

Sponsored-by: author

8 files changed, 23 insertions, 19 deletions

diff --git a/src/backup_progress.rs b/src/backup_progress.rs
index fd07978..30b6228 100644
--- a/src/backup_progress.rs
+++ b/src/backup_progress.rs
@@ -1,3 +1,4 @@
+use crate::generation::GenId;
 use indicatif::{ProgressBar, ProgressStyle};
 use std::path::Path;
 
@@ -58,7 +59,7 @@ impl BackupProgress {
         Self { progress }
     }
 
-    pub fn download_generation(gen_id: &str) -> Self {
+    pub fn download_generation(gen_id: &GenId) -> Self {
         let progress = ProgressBar::new(0);
         let parts = vec!["{msg}", "elapsed: {elapsed}", "{spinner}"];
         progress.set_style(ProgressStyle::default_bar().template(&parts.join("\n")));
diff --git a/src/backup_run.rs b/src/backup_run.rs
index dee1d11..3b107bb 100644
--- a/src/backup_run.rs
+++ b/src/backup_run.rs
@@ -6,7 +6,9 @@ use crate::config::ClientConfig;
 use crate::error::ObnamError;
 use crate::fsentry::FilesystemEntry;
 use crate::fsiter::{AnnotatedFsEntry, FsIterError, FsIterator};
-use crate::generation::{LocalGeneration, LocalGenerationError, NascentError, NascentGeneration};
+use crate::generation::{
+    GenId, LocalGeneration, LocalGenerationError, NascentError, NascentGeneration,
+};
 use crate::policy::BackupPolicy;
 use log::{info, warn};
 use std::path::{Path, PathBuf};
@@ -72,7 +74,7 @@ impl<'a> BackupRun<'a> {
 
     pub fn start(
         &mut self,
-        genid: Option<&str>,
+        genid: Option<&GenId>,
         oldname: &Path,
     ) -> Result<LocalGeneration, ObnamError> {
         match genid {
@@ -94,7 +96,7 @@ impl<'a> BackupRun<'a> {
 
     fn fetch_previous_generation(
         &self,
-        genid: &str,
+        genid: &GenId,
         oldname: &Path,
     ) -> Result<LocalGeneration, ObnamError> {
         let progress = BackupProgress::download_generation(genid);
diff --git a/src/client.rs b/src/client.rs
index ca0104f..b866471 100644
--- a/src/client.rs
+++ b/src/client.rs
@@ -6,7 +6,7 @@ use crate::chunkmeta::ChunkMeta;
 use crate::cipher::{CipherEngine, CipherError};
 use crate::config::{ClientConfig, ClientConfigError};
 use crate::fsentry::{FilesystemEntry, FilesystemKind};
-use crate::generation::{FinishedGeneration, LocalGeneration, LocalGenerationError};
+use crate::generation::{FinishedGeneration, GenId, LocalGeneration, LocalGenerationError};
 use crate::genlist::GenerationList;
 
 use chrono::{DateTime, Local};
@@ -101,16 +101,15 @@ impl AsyncBackupClient {
         self.chunk_client.fetch_chunk(chunk_id).await
     }
 
-    async fn fetch_generation_chunk(&self, gen_id: &str) -> Result<GenerationChunk, ClientError> {
-        let chunk_id = ChunkId::recreate(gen_id);
-        let chunk = self.fetch_chunk(&chunk_id).await?;
+    async fn fetch_generation_chunk(&self, gen_id: &GenId) -> Result<GenerationChunk, ClientError> {
+        let chunk = self.fetch_chunk(gen_id).await?;
         let gen = GenerationChunk::from_data_chunk(&chunk)?;
         Ok(gen)
     }
 
     pub async fn fetch_generation(
         &self,
-        gen_id: &str,
+        gen_id: &GenId,
         dbname: &Path,
     ) -> Result<LocalGeneration, ClientError> {
         let gen = self.fetch_generation_chunk(gen_id).await?;
@@ -323,16 +322,15 @@ impl BackupClient {
         self.chunk_client.fetch_chunk(chunk_id)
     }
 
-    fn fetch_generation_chunk(&self, gen_id: &str) -> Result<GenerationChunk, ClientError> {
-        let chunk_id = ChunkId::recreate(gen_id);
-        let chunk = self.fetch_chunk(&chunk_id)?;
+    fn fetch_generation_chunk(&self, gen_id: &GenId) -> Result<GenerationChunk, ClientError> {
+        let chunk = self.fetch_chunk(gen_id)?;
         let gen = GenerationChunk::from_data_chunk(&chunk)?;
         Ok(gen)
     }
 
     pub fn fetch_generation(
         &self,
-        gen_id: &str,
+        gen_id: &GenId,
         dbname: &Path,
     ) -> Result<LocalGeneration, ClientError> {
         let gen = self.fetch_generation_chunk(gen_id)?;
diff --git a/src/cmd/list_files.rs b/src/cmd/list_files.rs
index e511327..bdec55b 100644
--- a/src/cmd/list_files.rs
+++ b/src/cmd/list_files.rs
@@ -25,7 +25,7 @@ impl ListFiles {
         let client = AsyncBackupClient::new(config)?;
 
         let genlist = client.list_generations().await?;
-        let gen_id: String = genlist.resolve(&self.gen_id)?;
+        let gen_id = genlist.resolve(&self.gen_id)?;
 
         let gen = client.fetch_generation(&gen_id, temp.path()).await?;
         for file in gen.files()?.iter()? {
diff --git a/src/cmd/restore.rs b/src/cmd/restore.rs
index c770501..8d05481 100644
--- a/src/cmd/restore.rs
+++ b/src/cmd/restore.rs
@@ -40,7 +40,7 @@ impl Restore {
         let client = AsyncBackupClient::new(config)?;
 
         let genlist = client.list_generations().await?;
-        let gen_id: String = genlist.resolve(&self.gen_id)?;
+        let gen_id = genlist.resolve(&self.gen_id)?;
         info!("generation id is {}", gen_id);
 
         let gen = client.fetch_generation(&gen_id, temp.path()).await?;
diff --git a/src/cmd/show_gen.rs b/src/cmd/show_gen.rs
index 8df26c2..fb7e1bd 100644
--- a/src/cmd/show_gen.rs
+++ b/src/cmd/show_gen.rs
@@ -24,7 +24,7 @@ impl ShowGeneration {
         let client = AsyncBackupClient::new(config)?;
 
         let genlist = client.list_generations().await?;
-        let gen_id: String = genlist.resolve(&self.gen_id)?;
+        let gen_id = genlist.resolve(&self.gen_id)?;
         let gen = client.fetch_generation(&gen_id, temp.path()).await?;
         let mut files = gen.files()?;
         let mut files = files.iter()?;
diff --git a/src/generation.rs b/src/generation.rs
index 25fc14d..66b4647 100644
--- a/src/generation.rs
+++ b/src/generation.rs
@@ -9,6 +9,9 @@ use std::path::{Path, PathBuf};
 /// An identifier for a file in a generation.
 type FileId = i64;
 
+/// An identifier for a generation.
+pub type GenId = ChunkId;
+
 /// A nascent backup generation.
 ///
 /// A nascent generation is one that is being prepared. It isn't
diff --git a/src/genlist.rs b/src/genlist.rs
index 21f558c..edc405a 100644
--- a/src/genlist.rs
+++ b/src/genlist.rs
@@ -1,5 +1,5 @@
 use crate::chunkid::ChunkId;
-use crate::generation::FinishedGeneration;
+use crate::generation::{FinishedGeneration, GenId};
 
 pub struct GenerationList {
     list: Vec<FinishedGeneration>,
@@ -22,7 +22,7 @@ impl GenerationList {
         self.list.iter()
     }
 
-    pub fn resolve(&self, genref: &str) -> Result<String, GenerationListError> {
+    pub fn resolve(&self, genref: &str) -> Result<GenId, GenerationListError> {
         let gen = if self.list.is_empty() {
             None
         } else if genref == "latest" {
@@ -45,7 +45,7 @@ impl GenerationList {
             None => Err(GenerationListError::UnknownGeneration(ChunkId::recreate(
                 genref,
             ))),
-            Some(gen) => Ok(gen.id().to_string()),
+            Some(gen) => Ok(gen.id()),
         }
     }
 }