Adds persistence and clean up

Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "experiments"
+name = "nimbus_experiments"
 version = "0.1.0"
 authors = ["Tarik Eshaq <[email protected]>"]
 edition = "2018"
@@ -11,17 +11,24 @@ url = "2.1"
 serde = { version = "1", features = ["rc"] }
 serde_derive = "1"
 serde_json = "1"
-# This now references a local path on my own device. If we end up actually using viaduct,
-# We should maybe publish it as crate (similar to ffi-support)
-viaduct = { path = "../application-services/components/viaduct" }
 anyhow = "1.0"
 rand = "0.7"
 log = "0.4"
+viaduct = { git = "https://github.com/mozilla/application-services" }
 ffi-support = "0.4"
 thiserror = "1"
+rkv = "0.10"
+lazy_static = "1.4"
+uuid = { version = "0.8", features = ["serde", "v4"]}
+prost = "0.6"
+
+[build-dependencies]
+prost-build = { version = "0.6" }
+
+[lib]
+name = "nimbus_experiments"
+crate-type = ["lib"]
 
 [dev-dependencies]
-# This now references a local path on my own device. If we end up actually using viaduct,
-# We should maybe publish it as crate (similar to ffi-support)
-viaduct-reqwest = { path = "../application-services/components/support/viaduct-reqwest" }
+viaduct-reqwest = { git = "https://github.com/mozilla/application-services" }
 

build.rs

@@ -0,0 +1,7 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+fn main() {
+    prost_build::compile_protos(&["src/experiments_msg_types.proto"], &["src/"]).unwrap();
+}

examples/experiment.rs

@@ -1,12 +1,8 @@
 use anyhow::Result;
-use experiments::Experiments;
+use nimbus_experiments::{AppContext, Experiments};
 fn main() -> Result<()> {
     viaduct_reqwest::use_reqwest_backend();
-    let exp = Experiments::new(
-        "https://kinto.dev.mozaws.net/v1/",
-        "default",
-        "messaging-collection",
-    );
+    let exp = Experiments::new(AppContext::default(), "./mydb");
     let enrolled_exp = exp.get_enrolled_experiments();
     exp.get_experiments().iter().for_each(|e| {
         print!(

src/buckets.rs

@@ -2,7 +2,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-
 //! This might be where the bucketing logic can go
 //! It would be different from current experimentation tools
 //! There is a namespacing concept to allow users to be in multiple

src/error.rs

@@ -2,8 +2,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-// Not implemented yet!!!
-// This is purely boilerplate to communicate over the ffi
+//! Not implemented yet!!!
+//! This is purely boilerplate to communicate over the ffi
+//! We should define real variants for our error and use proper
+//! error propegation (we can use the `thiserror` crate for that)
 use ffi_support::{ErrorCode, ExternError};
 #[derive(Debug, thiserror::Error)]
 pub enum Error {

src/experiments.idl

@@ -1,4 +1,7 @@
 # This is a test file for defining WebIDL for uniffi
+# For the time being, it is not used for anything!
+# However, if we use uniffi in the future, we could define
+# The api here. (Unless uniffi changes to a non WebIDL way (looking at you proc-macros))
 namespace experiments {};
 interface Experiments {
     constructor();

src/experiments_msg_types.proto

@@ -0,0 +1,24 @@
+syntax = "proto2";
+
+// This kinda beats the purpose of using protobufs since we have one file here/
+// And a duplicate in the glean PR, but bear with me :)
+// Eventually once we figure out the details of where each part lives, we'll merge the proto files
+// into one
+
+package mozilla.telemetry.glean.protobuf;
+
+option java_package = "mozilla.telemtery.glean";
+option java_outer_classname = "MsgTypes";
+option swift_prefix = "MsgTypes_";
+option optimize_for = LITE_RUNTIME;
+
+message AppContext {
+    optional string app_id = 1;
+    optional string app_version = 2;
+    optional string locale_language = 3;
+    optional string locale_country = 4;
+    optional string device_manufacturer = 5;
+    optional string device_model = 6;
+    optional string region = 7;
+    optional string debug_tag = 8;
+}

src/ffi.rs

@@ -0,0 +1,69 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use std::os::raw::c_char;
+
+use super::{error::Result, msg_types, AppContext, Experiments};
+use ffi_support::{define_handle_map_deleter, ConcurrentHandleMap, ExternError, FfiStr};
+
+lazy_static::lazy_static! {
+    static ref EXPERIMENTS: ConcurrentHandleMap<Experiments> = ConcurrentHandleMap::new();
+}
+
+#[no_mangle]
+pub extern "C" fn experiments_new(
+    app_ctx: *const u8,
+    app_ctx_len: i32,
+    db_path: FfiStr<'_>,
+    error: &mut ExternError,
+) -> u64 {
+    EXPERIMENTS.insert_with_result(error, || -> Result<Experiments> {
+        let app_ctx = unsafe {
+            from_protobuf_ptr::<AppContext, msg_types::AppContext>(app_ctx, app_ctx_len).unwrap()
+        }; // Todo: make the whole function unsafe and implement proper error handling in error.rs
+        log::info!("=================== Initializing experiments ========================");
+        Ok(Experiments::new(app_ctx, db_path.as_str()))
+    })
+}
+
+#[no_mangle]
+pub extern "C" fn experiments_get_branch(
+    handle: u64,
+    branch: FfiStr<'_>,
+    error: &mut ExternError,
+) -> *mut c_char {
+    EXPERIMENTS.call_with_result(error, handle, |experiment| -> Result<String> {
+        log::info!("==================== Getting branch ========================");
+        let branch_name = experiment.get_experiment_branch(branch.as_str())?;
+        Ok(branch_name)
+    })
+}
+
+define_handle_map_deleter!(EXPERIMENTS, experiements_destroy);
+
+/// # Safety
+/// data is a raw pointer to the protobuf data
+/// get_buffer will return an error if the length is invalid,
+/// or if the pointer is a null pointer
+pub unsafe fn from_protobuf_ptr<T, F: prost::Message + Default + Into<T>>(
+    data: *const u8,
+    len: i32,
+) -> anyhow::Result<T> {
+    let buffer = get_buffer(data, len)?;
+    let item: Result<F, _> = prost::Message::decode(buffer);
+    item.map(|inner| inner.into()).map_err(|e| e.into())
+}
+
+unsafe fn get_buffer<'a>(data: *const u8, len: i32) -> anyhow::Result<&'a [u8]> {
+    match len {
+        len if len < 0 => anyhow::bail!("Invalid length"),
+        0 => Ok(&[]),
+        _ => {
+            if data.is_null() {
+                anyhow::bail!("Null pointer")
+            }
+            Ok(std::slice::from_raw_parts(data, len as usize))
+        }
+    }
+}

src/http_client.rs

@@ -2,6 +2,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+//! This is a simple Http client that uses viaduct to retrieve experiment data from the server
+//! Currently configured to use Kinto and the old schema, although that would change once we start
+//! Working on the real Nimbus schema.
+
 use super::Experiment;
 use anyhow::Result;
 use serde_derive::*;
@@ -66,13 +70,11 @@ impl SettingsClient for Client {
             &self.bucket_name, &self.collection_name
         );
         let url = self.base_url.join(&path)?;
-        let req = Request::get(url)
-            .header(
-                "User-Agent",
-                "Experiments Rust Component <[email protected]>",
-            )?;
-            // Note: I removed the auth info which was for a test account that is public
-            // But gitgaurdian complained so I removed it.
+        let req = Request::get(url).header(
+            "User-Agent",
+            "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:77.0) Gecko/20100101 Firefox/77.0",
+        )?;
+        // TODO: Add authentication based on server requirements
         let resp = self.make_request(req)?.json::<RecordsResponse>()?;
         Ok(resp.data)
     }