From d38fd5ca748b104e953c682d2990e9d50a6a43ff Mon Sep 17 00:00:00 2001
From: Jef Roosens <roosensjef@gmail.com>
Date: Sun, 21 Jul 2024 21:09:05 +0200
Subject: [PATCH] feat(repo): write db archive parser

---
 libarchive/src/lib.rs            |  2 +-
 libarchive/src/read/mod.rs       |  3 +-
 server/src/repo/mirror/mod.rs    |  3 ++
 server/src/repo/mirror/parser.rs | 75 ++++++++++++++++++++++++++++++++
 server/src/repo/mod.rs           |  8 ++--
 5 files changed, 84 insertions(+), 7 deletions(-)
 create mode 100644 server/src/repo/mirror/mod.rs
 create mode 100644 server/src/repo/mirror/parser.rs

diff --git a/libarchive/src/lib.rs b/libarchive/src/lib.rs
index e8a91f2..8ffc5ff 100644
--- a/libarchive/src/lib.rs
+++ b/libarchive/src/lib.rs
@@ -5,6 +5,6 @@ pub mod write;
 
 pub use archive::{
     Entry, ExtractOption, ExtractOptions, Handle, ReadCompression, ReadFilter, ReadFormat,
-    WriteFilter, WriteFormat,
+    WriteFilter, WriteFormat, FileType,
 };
 pub use error::Result;
diff --git a/libarchive/src/read/mod.rs b/libarchive/src/read/mod.rs
index 579b3e5..596595b 100644
--- a/libarchive/src/read/mod.rs
+++ b/libarchive/src/read/mod.rs
@@ -6,9 +6,10 @@ pub use builder::Builder;
 
 use crate::archive::Handle;
 use crate::ReadFilter;
-use entries::Entries;
+pub use entries::{Entries, ReadEntry};
 use libarchive3_sys::ffi;
 use std::path::Path;
+pub use file::FileReader;
 
 // Represents a read view of an archive
 pub trait Archive: Handle + Sized {
diff --git a/server/src/repo/mirror/mod.rs b/server/src/repo/mirror/mod.rs
new file mode 100644
index 0000000..02a0aab
--- /dev/null
+++ b/server/src/repo/mirror/mod.rs
@@ -0,0 +1,3 @@
+mod parser;
+
+pub use parser::{DbArchiveParser, DbArchiveEntry};
diff --git a/server/src/repo/mirror/parser.rs b/server/src/repo/mirror/parser.rs
new file mode 100644
index 0000000..d5270f4
--- /dev/null
+++ b/server/src/repo/mirror/parser.rs
@@ -0,0 +1,75 @@
+use std::{
+    io::{self, BufRead},
+    path::Path,
+};
+
+use libarchive::{
+    read::{Archive, Builder, Entries, FileReader, ReadEntry},
+    Entry,
+};
+
+pub struct DbArchiveParser<'a, T: 'a + Archive> {
+    entries: Entries<'a, T>,
+}
+
+pub struct DbArchiveEntry {
+    name: String,
+    version: String,
+    filename: String,
+}
+
+impl<'a, T: Archive> DbArchiveParser<'a, T> {
+    pub fn new(ar: &'a mut T) -> Self {
+        Self {
+            entries: Entries::new(ar),
+        }
+    }
+
+    // parse a given entry. If the entry's not a regular file, the function returns None.
+    fn parse_entry(entry: ReadEntry<'a, T>) -> io::Result<DbArchiveEntry> {
+        let reader = io::BufReader::new(entry);
+        let mut lines = reader.lines();
+
+        let mut name: Option<String> = None;
+        let mut version: Option<String> = None;
+        let mut filename: Option<String> = None;
+
+        while let Some(line) = lines.next().transpose()? {
+            match line.as_str() {
+                "%NAME%" => name = lines.next().transpose()?,
+                "%VERSION%" => version = lines.next().transpose()?,
+                "%FILENAME%" => filename = lines.next().transpose()?,
+                _ => {}
+            }
+        }
+
+        if name.is_some() && version.is_some() && filename.is_some() {
+            Ok(DbArchiveEntry {
+                name: name.unwrap(),
+                version: version.unwrap(),
+                filename: filename.unwrap(),
+            })
+        } else {
+            Err(io::Error::other("Missing fields in entry file"))
+        }
+    }
+}
+
+impl<'a, T: Archive> Iterator for DbArchiveParser<'a, T> {
+    type Item = io::Result<DbArchiveEntry>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        while let Some(entry) = self.entries.next() {
+            match entry {
+                Ok(entry) => {
+                    if entry.filetype() == libarchive::FileType::RegularFile {
+                        return Some(Self::parse_entry(entry));
+                    }
+                }
+                Err(err) => return Some(Err(err.into())),
+            }
+        }
+
+        None
+    }
+}
diff --git a/server/src/repo/mod.rs b/server/src/repo/mod.rs
index 4997b8a..96d4bfa 100644
--- a/server/src/repo/mod.rs
+++ b/server/src/repo/mod.rs
@@ -1,6 +1,7 @@
 mod actor;
 mod archive;
 mod handle;
+mod mirror;
 pub mod package;
 
 pub use actor::Actor;
@@ -38,10 +39,7 @@ pub struct SharedState {
 }
 
 impl SharedState {
-    pub fn new(
-        repos_dir: impl AsRef<Path>,
-        conn: DbConn,
-    ) -> Self {
+    pub fn new(repos_dir: impl AsRef<Path>, conn: DbConn) -> Self {
         let (tx, rx) = unbounded_channel();
 
         Self {
@@ -78,7 +76,7 @@ pub fn start(
         std::thread::spawn(|| actor.run());
     }
 
-   let handle = Handle::new(&state);
+    let handle = Handle::new(&state);
 
     for id in repo_ids {
         rt.block_on(handle.register_repo(id))?;