From 58a8949a8cdbcfcc774fa3bd337ae27b50ce91b9 Mon Sep 17 00:00:00 2001
From: Damien Elmes <gpg@ankiweb.net>
Date: Sun, 19 Jun 2022 20:08:29 +1000
Subject: [PATCH] Send logs from the backend to the Android log

Closes #24
---
 rslib-bridge/Cargo.lock     | 31 ++++++++++++++++++++++++++
 rslib-bridge/Cargo.toml     |  5 ++++-
 rslib-bridge/src/lib.rs     |  6 ++++-
 rslib-bridge/src/logging.rs | 44 +++++++++++++++++++++++++++++++++++++
 4 files changed, 84 insertions(+), 2 deletions(-)
 create mode 100644 rslib-bridge/src/logging.rs

diff --git a/rslib-bridge/Cargo.lock b/rslib-bridge/Cargo.lock
index 6558a0244..c418c857c 100644
--- a/rslib-bridge/Cargo.lock
+++ b/rslib-bridge/Cargo.lock
@@ -41,6 +41,24 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "android_log-sys"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85965b6739a430150bdd138e2374a98af0c3ee0d030b3bb7fc3bddff58d0102e"
+
+[[package]]
+name = "android_logger"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b74b7ddf197de32e415d197aa21c1c0cb36e01e4794fd801302280ac7847ee02"
+dependencies = [
+ "android_log-sys",
+ "env_logger",
+ "log",
+ "once_cell",
+]
+
 [[package]]
 name = "anki"
 version = "0.0.0"
@@ -403,6 +421,16 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "env_logger"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b2cf0344971ee6c64c31be0d530793fba457d322dfec2810c453d0ef228f9c3"
+dependencies = [
+ "log",
+ "regex",
+]
+
 [[package]]
 name = "error-chain"
 version = "0.12.4"
@@ -1574,11 +1602,13 @@ dependencies = [
 name = "rsdroid"
 version = "0.1.0"
 dependencies = [
+ "android_logger",
  "anki",
  "itertools",
  "jni",
  "lazy_static",
  "lexical-core",
+ "log",
  "num_enum",
  "prost",
  "prost-build",
@@ -1586,6 +1616,7 @@ dependencies = [
  "serde",
  "serde_derive",
  "serde_json",
+ "slog",
 ]
 
 [[package]]
diff --git a/rslib-bridge/Cargo.toml b/rslib-bridge/Cargo.toml
index db28ba8bd..a8a7c9745 100644
--- a/rslib-bridge/Cargo.toml
+++ b/rslib-bridge/Cargo.toml
@@ -23,9 +23,12 @@ lexical-core = "0.7.5"
 
 # picked bundled - TODO: Is this correct?
 rusqlite = { version = "0.26.0", features = ["trace", "functions", "collation", "bundled"] }
+android_logger = "0.11.0"
+log = "0.4.17"
+slog = "2.7.0"
 
 [features]
 no-android = []
 
 [build-dependencies]
-prost-build = "0.9"
\ No newline at end of file
+prost-build = "0.9"
diff --git a/rslib-bridge/src/lib.rs b/rslib-bridge/src/lib.rs
index 63ec16f2d..9dc568583 100644
--- a/rslib-bridge/src/lib.rs
+++ b/rslib-bridge/src/lib.rs
@@ -12,14 +12,18 @@ use prost::Message;
 use std::any::Any;
 use std::panic::{catch_unwind, AssertUnwindSafe};
 
+mod logging;
+
 #[no_mangle]
 pub unsafe extern "C" fn Java_net_ankiweb_rsdroid_NativeMethods_openBackend(
     env: JNIEnv,
     _: JClass,
     args: jbyteArray,
 ) -> jarray {
+    let logger = logging::setup_logging();
+
     let input = env.convert_byte_array(args).unwrap();
-    let result = init_backend(&input, None)
+    let result = init_backend(&input, Some(logger))
         .map(|backend| {
             let backend_ptr = Box::into_raw(Box::new(backend)) as i64;
             Int64 { val: backend_ptr }.encode_to_vec()
diff --git a/rslib-bridge/src/logging.rs b/rslib-bridge/src/logging.rs
new file mode 100644
index 000000000..bcf2de6cf
--- /dev/null
+++ b/rslib-bridge/src/logging.rs
@@ -0,0 +1,44 @@
+//! A simple adaptor that takes log messages from the backend and sends them to
+//! the Android logs.
+
+use android_logger::Config;
+use log::Level;
+use slog::*;
+use std::{fmt, result};
+
+pub struct AndroidSerializer;
+
+impl Serializer for AndroidSerializer {
+    fn emit_arguments(&mut self, key: Key, val: &fmt::Arguments<'_>) -> Result {
+        log::debug!("{}={}", key, val);
+        Ok(())
+    }
+}
+
+pub struct AndroidDrain;
+
+impl Drain for AndroidDrain {
+    type Ok = ();
+    type Err = ();
+
+    fn log(
+        &self,
+        record: &Record<'_>,
+        values: &OwnedKVList,
+    ) -> result::Result<Self::Ok, Self::Err> {
+        log::debug!("{}", record.msg());
+
+        record
+            .kv()
+            .serialize(record, &mut AndroidSerializer)
+            .unwrap();
+        values.serialize(record, &mut AndroidSerializer).unwrap();
+
+        Ok(())
+    }
+}
+
+pub(crate) fn setup_logging() -> Logger {
+    android_logger::init_once(Config::default().with_min_level(Level::Debug));
+    Logger::root(AndroidDrain {}.fuse(), slog_o!())
+}