bindings: add bindings for metalog

Summary: Expose metalog APIs to Python.

Reviewed By: kulshrax

Differential Revision: D18273001

fbshipit-source-id: b8fbf0c22a925e3e5373498076a3392901c00aed

edenscmnative/bindings/Cargo.toml

@@ -22,6 +22,7 @@ pydag = { path = "modules/pydag" }
 pyedenapi = { path = "modules/pyedenapi" }
 pylz4 = { path = "modules/pylz4" }
 pymanifest = { path = "modules/pymanifest" }
+pymetalog = { path = "modules/pymetalog" }
 pymutationstore = { path = "modules/pymutationstore" }
 pynodemap = { path = "modules/pynodemap" }
 pypathmatcher = { path = "modules/pypathmatcher" }

edenscmnative/bindings/modules/pymetalog/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "pymetalog"
+version = "0.1.0"
+edition = "2018"
+
+[dependencies]
+cpython = { version = "0.3", features = ["python27-sys"], default-features = false }
+cpython-ext = { path = "../../../../lib/cpython-ext" }
+cpython-failure = { path = "../../../../lib/cpython-failure" }
+encoding = { path = "../../../../lib/encoding" }
+metalog = { path = "../../../../lib/metalog" }

edenscmnative/bindings/modules/pymetalog/src/lib.rs

@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This software may be used and distributed according to the terms of the
+ * GNU General Public License version 2.
+ */
+
+#![allow(non_camel_case_types)]
+
+use ::metalog::{CommitOptions, Id20, MetaLog};
+use cpython::*;
+use cpython_ext::Bytes;
+use cpython_failure::ResultPyErrExt;
+use std::cell::RefCell;
+use std::time::SystemTime;
+
+pub fn init_module(py: Python, package: &str) -> PyResult<PyModule> {
+    let name = [package, "metalog"].join(".");
+    let m = PyModule::new(py, &name)?;
+    m.add_class::<metalog>(py)?;
+    Ok(m)
+}
+
+py_class!(class metalog |py| {
+    data log: RefCell<MetaLog>;
+
+    def __new__(_cls, path: String, root: Option<Bytes> = None) -> PyResult<Self> {
+        let root = root.and_then(|s| Id20::from_slice(s.as_ref()).ok());
+        let log = MetaLog::open(&path, root).map_pyerr::<exc::IOError>(py)?;
+        Self::create_instance(py, RefCell::new(log))
+    }
+
+    @staticmethod
+    def listroots(path: String) -> PyResult<Vec<Bytes>> {
+        let root_ids = MetaLog::list_roots(&path).map_pyerr::<exc::IOError>(py)?;
+        Ok(root_ids.into_iter().map(|id| Bytes::from(id.as_ref().to_vec())).collect())
+    }
+
+    /// Lookup an item by key. Return None if the key does not exist.
+    def get(&self, key: &str) -> PyResult<Option<Bytes>> {
+        let log = self.log(py).borrow();
+        let data = log.get(key).map_pyerr::<exc::IOError>(py)?;
+        Ok(data.map(Bytes::from))
+    }
+
+    /// Set an item. Return the Id of value.
+    def set(&self, key: &str, value: Bytes) -> PyResult<Bytes> {
+        let mut log = self.log(py).borrow_mut();
+        let id = log.set(key, value.as_ref()).map_pyerr::<exc::IOError>(py)?;
+        Ok(Bytes::from(id.as_ref().to_vec()))
+    }
+
+    /// Remove an item. Does not raise if the key does not exist.
+    def remove(&self, key: &str) -> PyResult<PyObject> {
+        let mut log = self.log(py).borrow_mut();
+        log.remove(key).map_pyerr::<exc::IOError>(py)?;
+        Ok(py.None())
+    }
+
+    /// Get all keys.
+    def keys(&self) -> PyResult<Vec<Bytes>> {
+        let keys = self.log(py).borrow()
+            .keys().iter().map(|s| Bytes::from(s.as_bytes().to_vec())).collect();
+        Ok(keys)
+    }
+
+    /// Write pending data to disk. Raise if race condition is detected.
+    def commit(&self, message: &str, time: Option<u64> = None, pending: bool = false) -> PyResult<Bytes> {
+        let mut opts = CommitOptions::default();
+        opts.detached = pending;
+        opts.timestamp = time.unwrap_or_else(|| {
+            SystemTime::now()
+                .duration_since(SystemTime::UNIX_EPOCH)
+                .map(|d| d.as_secs()).unwrap_or(0)
+        });
+        opts.message = message;
+        let id = self.log(py).borrow_mut().commit(opts).map_pyerr::<exc::IOError>(py)?;
+        Ok(Bytes::from(id.as_ref().to_vec()))
+    }
+
+    /// Why the change was made.
+    def message(&self) -> PyResult<Bytes> {
+        Ok(Bytes::from(self.log(py).borrow().message().to_string()))
+    }
+
+    /// When the change was made.
+    def timestamp(&self) -> PyResult<u64> {
+        Ok(self.log(py).borrow().timestamp())
+    }
+
+    def __getitem__(&self, key: String) -> PyResult<Option<Bytes>> {
+        self.get(py, &key)
+    }
+
+    def __setitem__(&self, key: String, value: Bytes) -> PyResult<()> {
+        self.set(py, &key, value)?;
+        Ok(())
+    }
+
+    def __delitem__(&self, key: String) -> PyResult<()> {
+        self.remove(py, &key)?;
+        Ok(())
+    }
+});

edenscmnative/bindings/src/lib.rs

@@ -28,6 +28,7 @@ pub fn populate_module(py: Python<'_>, module: &PyModule) -> PyResult<PyObject>
     m.add(py, "edenapi", pyedenapi::init_module(py, &name)?)?;
     m.add(py, "lz4", pylz4::init_module(py, &name)?)?;
     m.add(py, "manifest", pymanifest::init_module(py, &name)?)?;
+    m.add(py, "metalog", pymetalog::init_module(py, &name)?)?;
     m.add(
         py,
         "mutationstore",