Mostly implement simple-cas.

cas-simple/src/wfile.rs

@@ -0,0 +1,106 @@
+// This file is part of bsv.
+//
+// bsv is free software: you can redistribute it and/or modify it under the
+// terms of the GNU Affero General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// cdb is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for
+// more details.
+//
+// You should have received a copy of the Affero GNU General Public License
+// along with cdb.  If not, see <https://www.gnu.org/licenses/>.
+
+
+use std::path::{PathBuf};
+
+use cas_core::{
+    Error, ObjectId, Result, Writer,
+};
+
+use crate::utils::{obj_path, tmp_dir};
+
+
+pub struct WFile {
+    file: tempfile::NamedTempFile,
+    db_path: PathBuf,
+}
+
+impl WFile {
+    pub fn new(db_path: PathBuf) -> Result<Self> {
+        let file = tempfile::NamedTempFile::new_in(tmp_dir(&db_path)).or_else(|err|
+            Err(Error::error(format!("failed to create_file: {}", err))))?;
+        Ok(WFile {
+            file,
+            db_path,
+        })
+    }
+}
+
+impl std::io::Write for WFile {
+    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        self.file.write(buf)
+    }
+
+    fn flush(&mut self) -> std::io::Result<()> {
+        self.file.flush()
+    }
+}
+
+impl Writer for WFile {
+    fn finalize(self: Box<Self>) -> Result<ObjectId> {
+        Err(Error::error("reader pipline has no digest step"))
+    }
+
+    fn _finalize(self: Box<Self>, oid: ObjectId) -> Result<ObjectId> {
+        let path = obj_path(&self.db_path, &oid);
+        std::fs::create_dir_all(
+            path.parent().expect("cannot access to object parent directory")
+        ).or_else(|err|
+            Err(Error::error(format!("failed to create object dir: {}", err))))?;
+        self.file.persist(path).or_else(|err|
+            Err(Error::error(format!("failed to persist file: {}", err))))?;
+        Ok(oid)
+    }
+}
+
+
+#[cfg(test)]
+mod tests {
+    use std::str::FromStr;
+
+    use crate::utils::{obj_dir, obj_path};
+    use super::*;
+
+    #[test]
+    fn test_wfile() {
+        use std::io::{Read, Write};
+
+        let data = b"Hello World!";
+        let oid = ObjectId::from_str(
+            "7f83b1657ff1fc53b92dc18148a1d65dfc2d4b1fa3d677284addd200126d9069"
+        ).expect("invalid object id");
+
+        let dir = tempfile::TempDir::new()
+            .expect("failed to create tmp dir");
+
+        std::fs::create_dir(tmp_dir(dir.path())).expect("failed to create db/obj dir");
+        std::fs::create_dir(obj_dir(dir.path())).expect("failed to create db/tmp dir");
+
+        {
+            let mut writer = Box::new(WFile::new(dir.path().to_path_buf()).expect("failed to create WFile"));
+            writer.write(data).expect("failed to write to WFile");
+            let oid2 = writer._finalize(oid.clone()).expect("failed to finalize WFile");
+
+            assert_eq!(oid2, oid);
+        }
+
+        let mut file = std::fs::File::open(obj_path(dir.path(), &oid)).expect("failed to open object file");
+        let mut buf = Vec::new();
+        file.read_to_end(&mut buf).expect("failed to read object file");
+
+        assert_eq!(buf, data);
+    }
+}