feat: restore a generation

1 files changed, 57 insertions, 5 deletions

diff --git a/src/generation.rs b/src/generation.rs
index ca1f8d5..b9edb74 100644
--- a/src/generation.rs
+++ b/src/generation.rs
@@ -1,9 +1,11 @@
-use crate::fsentry::FilesystemEntry;
+use crate::fsentry::{FilesystemEntry, FilesystemKind};
+use std::ffi::OsStr;
+use std::os::unix::ffi::OsStrExt;
 //use crate::fsiter::FsIterator;
 use crate::chunkid::ChunkId;
-use rusqlite::{params, Connection, OpenFlags, Transaction};
+use rusqlite::{params, Connection, OpenFlags, Row, Transaction};
 use std::os::unix::ffi::OsStringExt;
-use std::path::Path;
+use std::path::{Path, PathBuf};
 
 /// A backup generation.
 pub struct Generation {
@@ -12,7 +14,7 @@ pub struct Generation {
 }
 
 impl Generation {
-    pub fn new<P>(filename: P) -> anyhow::Result<Self>
+    pub fn create<P>(filename: P) -> anyhow::Result<Self>
     where
         P: AsRef<Path>,
     {
@@ -30,6 +32,16 @@ impl Generation {
         Ok(Self { conn, fileno: 0 })
     }
 
+    pub fn open<P>(filename: P) -> anyhow::Result<Self>
+    where
+        P: AsRef<Path>,
+    {
+        let flags = OpenFlags::SQLITE_OPEN_READ_WRITE;
+        let conn = Connection::open_with_flags(filename, flags)?;
+        conn.pragma_update(None, "journal_mode", &"WAL")?;
+        Ok(Self { conn, fileno: 0 })
+    }
+
     pub fn insert(&mut self, e: FilesystemEntry, ids: &[ChunkId]) -> anyhow::Result<()> {
         let t = self.conn.transaction()?;
         insert_one(&t, e, self.fileno, ids)?;
@@ -51,6 +63,46 @@ impl Generation {
         t.commit()?;
         Ok(())
     }
+
+    pub fn files(&self) -> anyhow::Result<Vec<(u64, FilesystemEntry)>> {
+        let mut stmt = self.conn.prepare("SELECT * FROM files")?;
+        let iter = stmt.query_map(params![], |row| row_to_entry(row))?;
+        let mut files: Vec<(u64, FilesystemEntry)> = vec![];
+        for x in iter {
+            let (fileid, entry) = x?;
+            files.push((fileid, entry));
+        }
+        Ok(files)
+    }
+
+    pub fn chunkids(&self, fileid: u64) -> anyhow::Result<Vec<ChunkId>> {
+        let fileid = fileid as i64;
+        let mut stmt = self
+            .conn
+            .prepare("SELECT chunkid FROM chunks WHERE fileid = ?1")?;
+        let iter = stmt.query_map(params![fileid], |row| Ok(row.get(0)?))?;
+        let mut ids: Vec<ChunkId> = vec![];
+        for x in iter {
+            let fileid: String = x?;
+            ids.push(ChunkId::from(&fileid));
+        }
+        Ok(ids)
+    }
+}
+
+fn row_to_entry(row: &Row) -> rusqlite::Result<(u64, FilesystemEntry)> {
+    let fileid: i64 = row.get(row.column_index("fileid")?)?;
+    let fileid = fileid as u64;
+    let path: Vec<u8> = row.get(row.column_index("path")?)?;
+    let path: &OsStr = OsStrExt::from_bytes(&path);
+    let path: PathBuf = PathBuf::from(path);
+    let kind = row.get(row.column_index("kind")?)?;
+    let kind = FilesystemKind::from_code(kind).unwrap();
+    let entry = match kind {
+        FilesystemKind::Regular => FilesystemEntry::regular(path, 0),
+        FilesystemKind::Directory => FilesystemEntry::directory(path),
+    };
+    Ok((fileid, entry))
 }
 
 fn insert_one(
@@ -85,7 +137,7 @@ mod test {
     fn empty() {
         let filename = NamedTempFile::new().unwrap().path().to_path_buf();
         {
-            let mut _gen = Generation::new(&filename).unwrap();
+            let mut _gen = Generation::create(&filename).unwrap();
             // _gen is dropped here; the connection is close; the file
             // should not be removed.
         }