[pbs-devel] [RFC PATCH proxmox-backup 2/3] tape: media_catalog: add local type aliases to make code more clear

[Dominik Csapak <d.csapak@proxmox.com>]

by adding some type aliases like 'type Store = String',
the more complex types/return values are easier to read.

For example
HashMap<String, u64>

turns into:
HashMap<Snapshot, FileNr>

since those types are not public, the generated cargo docs do not contain them

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
does not have to be applied. it only makes (IMHO) the code more readable
 src/tape/media_catalog.rs | 35 ++++++++++++++++++++---------------
 1 file changed, 20 insertions(+), 15 deletions(-)

diff --git a/src/tape/media_catalog.rs b/src/tape/media_catalog.rs
index 6a9c8ce1..c88a4306 100644
--- a/src/tape/media_catalog.rs
+++ b/src/tape/media_catalog.rs
@@ -31,9 +31,14 @@ use crate::{
     },
 };
 
+type Store = String;
+type Snapshot = String;
+type FileNr = u64;
+type Chunk = [u8; 32];
+
 pub struct DatastoreContent {
-    pub snapshot_index: HashMap<String, u64>, // snapshot => file_nr
-    pub chunk_index: HashMap<[u8;32], u64>, // chunk => file_nr
+    pub snapshot_index: HashMap<Snapshot, FileNr>,
+    pub chunk_index: HashMap<Chunk, FileNr>,
 }
 
 impl DatastoreContent {
@@ -61,11 +66,11 @@ pub struct MediaCatalog  {
 
     log_to_stdout: bool,
 
-    current_archive: Option<(Uuid, u64, String)>, // (uuid, file_nr, store)
+    current_archive: Option<(Uuid, FileNr, Store)>,
 
-    last_entry: Option<(Uuid, u64)>,
+    last_entry: Option<(Uuid, FileNr)>,
 
-    content: HashMap<String, DatastoreContent>,
+    content: HashMap<Store, DatastoreContent>,
 
     pending: Vec<u8>,
 }
@@ -363,13 +368,13 @@ impl MediaCatalog {
     }
 
     /// Accessor to content list
-    pub fn content(&self) -> &HashMap<String, DatastoreContent> {
+    pub fn content(&self) -> &HashMap<Store, DatastoreContent> {
         &self.content
     }
 
     fn load_fast_catalog(
         file: &mut File,
-    ) -> Result<Vec<(String, String)>, Error> {
+    ) -> Result<Vec<(Store, Snapshot)>, Error> {
         let mut list = Vec::new();
         let file = BufReader::new(file);
         for line in file.lines() {
@@ -391,7 +396,7 @@ impl MediaCatalog {
     pub fn snapshot_list(
         base_path: &Path,
         media_id: &MediaId,
-    ) -> Result<Vec<(String, String)>, Error> {
+    ) -> Result<Vec<(Store, Snapshot)>, Error> {
         let uuid = &media_id.label.uuid;
 
         let mut path = base_path.to_owned();
@@ -525,7 +530,7 @@ impl MediaCatalog {
     }
 
     /// Returns the snapshot archive file number
-    pub fn lookup_snapshot(&self, store: &str, snapshot: &str) -> Option<u64> {
+    pub fn lookup_snapshot(&self, store: &str, snapshot: &str) -> Option<FileNr> {
         match self.content.get(store) {
             None => None,
             Some(content) => content.snapshot_index.get(snapshot).copied(),
@@ -533,7 +538,7 @@ impl MediaCatalog {
     }
 
     /// Test if the catalog already contain a chunk
-    pub fn contains_chunk(&self, store: &str, digest: &[u8;32]) -> bool {
+    pub fn contains_chunk(&self, store: &str, digest: &Chunk) -> bool {
         match self.content.get(store) {
             None => false,
             Some(content) => content.chunk_index.contains_key(digest),
@@ -541,7 +546,7 @@ impl MediaCatalog {
     }
 
     /// Returns the chunk archive file number
-    pub fn lookup_chunk(&self, store: &str, digest: &[u8;32]) -> Option<u64> {
+    pub fn lookup_chunk(&self, store: &str, digest: &Chunk) -> Option<FileNr> {
         match self.content.get(store) {
             None => None,
             Some(content) => content.chunk_index.get(digest).copied(),
@@ -612,7 +617,7 @@ impl MediaCatalog {
     /// Only valid after start_chunk_archive.
     pub fn register_chunk(
         &mut self,
-        digest: &[u8;32],
+        digest: &Chunk,
     ) -> Result<(), Error> {
 
         let (file_number, store) = match self.current_archive {
@@ -1030,7 +1035,7 @@ impl MediaSetCatalog {
     }
 
     /// Returns the media uuid and snapshot archive file number
-    pub fn lookup_snapshot(&self, store: &str, snapshot: &str) -> Option<(&Uuid, u64)> {
+    pub fn lookup_snapshot(&self, store: &str, snapshot: &str) -> Option<(&Uuid, FileNr)> {
         for (uuid, catalog) in self.catalog_list.iter() {
             if let Some(nr) = catalog.lookup_snapshot(store, snapshot) {
                 return Some((uuid, nr));
@@ -1040,7 +1045,7 @@ impl MediaSetCatalog {
     }
 
     /// Test if the catalog already contain a chunk
-    pub fn contains_chunk(&self, store: &str, digest: &[u8;32]) -> bool {
+    pub fn contains_chunk(&self, store: &str, digest: &Chunk) -> bool {
         for catalog in self.catalog_list.values() {
             if catalog.contains_chunk(store, digest) {
                 return true;
@@ -1050,7 +1055,7 @@ impl MediaSetCatalog {
     }
 
     /// Returns the media uuid and chunk archive file number
-    pub fn lookup_chunk(&self, store: &str, digest: &[u8;32]) -> Option<(&Uuid, u64)> {
+    pub fn lookup_chunk(&self, store: &str, digest: &Chunk) -> Option<(&Uuid, FileNr)> {
         for (uuid, catalog) in self.catalog_list.iter() {
             if let Some(nr) = catalog.lookup_chunk(store, digest) {
                 return Some((uuid, nr));
-- 
2.30.2