initial Watcher impl

5 files changed, 413 insertions, 27 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 3b8df0c8a..fccf8a65e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -87,6 +87,11 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "bitflags"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "bitflags"
 version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
@@ -110,6 +115,15 @@ version = "1.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "bytes"
+version = "0.4.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "iovec 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "cargo_metadata"
 version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -336,6 +350,16 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "filetime"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
+ "redox_syscall 0.1.51 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "flexi_logger"
 version = "0.10.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -352,6 +376,24 @@ version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "fsevent"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fsevent-sys 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "fsevent-sys"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "fst"
 version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -375,6 +417,11 @@ version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "futures"
+version = "0.1.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "gen_lsp_server"
 version = "0.1.0"
 dependencies = [
@@ -437,6 +484,28 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "inotify"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
+ "inotify-sys 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio-io 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio-reactor 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "inotify-sys"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "insta"
 version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -456,6 +525,15 @@ dependencies = [
 ]
 
 [[package]]
+name = "iovec"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "itertools"
 version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -474,11 +552,25 @@ version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "kernel32-sys"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "lazy_static"
 version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "lazycell"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "libc"
 version = "0.2.48"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -511,7 +603,7 @@ version = "0.55.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-derive 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-derive 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.85 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.85 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -554,16 +646,83 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "mio"
+version = "0.6.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "iovec 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazycell 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "miow 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "net2 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)",
+ "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "mio-extras"
+version = "2.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "lazycell 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "miow"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "net2 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ws2_32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "net2"
+version = "0.2.33"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "nodrop"
 version = "0.1.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "notify"
+version = "4.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "filetime 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fsevent 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fsevent-sys 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "inotify 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio-extras 2.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "walkdir 2.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "num-derive"
-version = "0.2.3"
+version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro2 0.4.26 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 0.15.26 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -726,7 +885,7 @@ dependencies = [
  "ra_syntax 0.1.0",
  "relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "salsa 0.10.0-alpha4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "salsa 0.10.0-alpha5 (registry+https://github.com/rust-lang/crates.io-index)",
  "test_utils 0.1.0",
 ]
 
@@ -849,7 +1008,9 @@ name = "ra_vfs"
 version = "0.1.0"
 dependencies = [
  "crossbeam-channel 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "drop_bomb 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "notify 4.0.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "ra_arena 0.1.0",
  "relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1097,7 +1258,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "salsa"
-version = "0.10.0-alpha4"
+version = "0.10.0-alpha5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "derive-new 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1106,13 +1267,13 @@ dependencies = [
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "salsa-macros 0.10.0-alpha4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "salsa-macros 0.10.0-alpha5 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.6.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "salsa-macros"
-version = "0.10.0-alpha4"
+version = "0.10.0-alpha5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "heck 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1199,6 +1360,11 @@ dependencies = [
 ]
 
 [[package]]
+name = "slab"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "slug"
 version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1382,6 +1548,42 @@ dependencies = [
 ]
 
 [[package]]
+name = "tokio-executor"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-utils 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "tokio-io"
+version = "0.1.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bytes 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "tokio-reactor"
+version = "0.1.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-utils 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num_cpus 1.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio-executor 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio-io 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "tools"
 version = "0.1.0"
 dependencies = [
@@ -1557,6 +1759,11 @@ dependencies = [
 
 [[package]]
 name = "winapi"
+version = "0.2.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winapi"
 version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
@@ -1565,6 +1772,11 @@ dependencies = [
 ]
 
 [[package]]
+name = "winapi-build"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "winapi-i686-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1583,6 +1795,15 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
+name = "ws2_32-sys"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "yaml-rust"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1602,10 +1823,12 @@ dependencies = [
 "checksum base64 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0b25d992356d2eb0ed82172f5248873db5560c4721f564b13cb5193bda5e668e"
 "checksum bit-set 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6f1efcc46c18245a69c38fcc5cc650f16d3a59d034f3106e9ed63748f695730a"
 "checksum bit-vec 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "4440d5cb623bb7390ae27fec0bb6c61111969860f8e3ae198bfa0663645e67cf"
+"checksum bitflags 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "aad18937a628ec6abcd26d1489012cc0e18c21798210f491af69ded9b881106d"
 "checksum bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
 "checksum block-buffer 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "a076c298b9ecdb530ed9d967e74a6027d6a7478924520acddcddc24c1c8ab3ab"
 "checksum byte-tools 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "560c32574a12a89ecd91f5e742165893f86e3ab98d21f8ea548658eb9eef5f40"
 "checksum byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a019b10a2a7cdeb292db131fc8113e57ea2a908f6e7894b0c3c671893b65dbeb"
+"checksum bytes 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)" = "40ade3d27603c2cb345eb0912aec461a6dec7e06a4ae48589904e808335c7afa"
 "checksum cargo_metadata 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "585784cac9b05c93a53b17a0b24a5cdd1dfdda5256f030e089b549d2390cc720"
 "checksum cc 1.0.28 (registry+https://github.com/rust-lang/crates.io-index)" = "bb4a8b715cb4597106ea87c7c84b2f1d452c7492033765df7f32651e66fcf749"
 "checksum cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "082bb9b28e00d3c9d39cc03e64ce4cea0f1bb9b3fde493f0cbc008472d22bdf4"
@@ -1633,11 +1856,15 @@ dependencies = [
 "checksum failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "795bd83d3abeb9220f257e597aa0080a508b27533824adf336529648f6abf7e2"
 "checksum failure_derive 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "ea1063915fd7ef4309e222a5a07cf9c319fb9c7836b1f89b85458672dbb127e1"
 "checksum fake-simd 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e88a8acf291dafb59c2d96e8f59828f3838bb1a70398823ade51a84de6a6deed"
+"checksum filetime 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "a2df5c1a8c4be27e7707789dc42ae65976e60b394afd293d1419ab915833e646"
 "checksum flexi_logger 0.10.5 (registry+https://github.com/rust-lang/crates.io-index)" = "bbd731387787f54fa333fa426e173fe42ea3d1123636b2b27ad802025fc5d182"
 "checksum fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2fad85553e09a6f881f739c29f0b00b0f01357c743266d478b68951ce23285f3"
+"checksum fsevent 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)" = "c4bbbf71584aeed076100b5665ac14e3d85eeb31fdbb45fbd41ef9a682b5ec05"
+"checksum fsevent-sys 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "1a772d36c338d07a032d5375a36f15f9a7043bf0cb8ce7cee658e037c6032874"
 "checksum fst 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "db72126ca7dff566cdbbdd54af44668c544897d9d3862b198141f176f1238bdf"
 "checksum fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2e9763c69ebaae630ba35f74888db465e49e259ba1bc0eda7d06f4a067615d82"
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
+"checksum futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)" = "49e7653e374fe0d0c12de4250f0bdb60680b8c80eed558c5c7538eec9c89e21b"
 "checksum generic-array 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ef25c5683767570c2bbd7deba372926a55eaae9982d7726ee2a1050239d45b9d"
 "checksum glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "8be18de09a56b60ed0edf84bc9df007e30040691af7acd1c41874faac5895bfb"
 "checksum heck 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "20564e78d53d2bb135c343b3f47714a56af2061f1c928fdb541dc7b9fdd94205"
@@ -1645,11 +1872,16 @@ dependencies = [
 "checksum idna 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "38f09e0f0b1fb55fdee1f17470ad800da77af5186a1a76c026b679358b7e844e"
 "checksum im 12.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "0627d417829c1d763d602687634869f254fc79f7e22dea6c824dab993db857e4"
 "checksum indexmap 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7e81a7c05f79578dbc15793d8b619db9ba32b4577003ef3af1a91c416798c58d"
+"checksum inotify 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "40b54539f3910d6f84fbf9a643efd6e3aa6e4f001426c0329576128255994718"
+"checksum inotify-sys 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "e74a1aa87c59aeff6ef2cc2fa62d41bc43f54952f55652656b18a02fd5e356c0"
 "checksum insta 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6ff57d9cbc4664b54a972c321155c7703794bc0f5c9944f29c36f40d10d626f3"
+"checksum iovec 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "dbe6e417e7d0975db6512b90796e8ce223145ac4e33c377e4a42882a0e88bb08"
 "checksum itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5b8467d9c1cebe26feb08c640139247fac215782d35371ade9a2136ed6085358"
 "checksum itoa 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "1306f3464951f30e30d12373d31c79fbd52d236e5e896fd92f96ec7babbbe60b"
 "checksum join_to_string 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "4dc7a5290e8c2606ce2be49f456d50f69173cb96d1541e4f66e34ac8b331a98f"
+"checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a374c89b9db55895453a74c1e38861d9deec0b01b405a82516e9d5de4820dea1"
+"checksum lazycell 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
 "checksum libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)" = "e962c7641008ac010fa60a7dfdc1712449f29c44ef2d4702394aea943ee75047"
 "checksum linked-hash-map 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "70fb39025bc7cdd76305867c4eccf2f2dcf6e9a57f5b21a93e1c2d86cd03ec9e"
 "checksum lock_api 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "62ebf1391f6acad60e5c8b43706dde4582df75c06698ab44511d15016bc2442c"
@@ -1660,8 +1892,13 @@ dependencies = [
 "checksum memchr 2.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "e1dd4eaac298c32ce07eb6ed9242eda7d82955b9170b7d6db59b2e02cc63fcb8"
 "checksum memmap 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e2ffa2c986de11a9df78620c01eeaaf27d94d3ff02bf81bfcca953102dd0c6ff"
 "checksum memoffset 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0f9dc261e2b62d7a622bf416ea3c5245cdd5d9a7fcc428c0d06804dfce1775b3"
+"checksum mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)" = "71646331f2619b1026cc302f87a2b8b648d5c6dd6937846a16cc8ce0f347f432"
+"checksum mio-extras 2.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "46e73a04c2fa6250b8d802134d56d554a9ec2922bf977777c805ea5def61ce40"
+"checksum miow 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8c1f2f3b1cf331de6896aabf6e9d55dca90356cc9960cca7eaaf408a355ae919"
+"checksum net2 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)" = "42550d9fb7b6684a6d404d9fa7250c2eb2646df731d1c06afc06dcee9e1bcf88"
 "checksum nodrop 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "2f9667ddcc6cc8a43afc9b7917599d7216aa09c463919ea32c59ed6cac8bc945"
-"checksum num-derive 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "8af1847c907c2f04d7bfd572fb25bbb4385c637fe5be163cf2f8c5d778fe1e7d"
+"checksum notify 4.0.7 (registry+https://github.com/rust-lang/crates.io-index)" = "c968cf37cf949114b00d51b0b23536d1c3a4a3963767cf4c969c65a6af78dc7d"
+"checksum num-derive 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "d9fe8fcafd1b86a37ce8a1cfa15ae504817e0c8c2e7ad42767371461ac1d316d"
 "checksum num-integer 0.1.39 (registry+https://github.com/rust-lang/crates.io-index)" = "e83d528d2677f0518c570baf2b7abdcf0cd2d248860b68507bdcb3e91d4c0cea"
 "checksum num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0b3a5d7cc97d6d30d8b9bc8fa19bf45349ffe46241e8816f50f62f6d6aaabee1"
 "checksum num_cpus 1.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5a69d464bdc213aaaff628444e99578ede64e9c854025aa43b9796530afa9238"
@@ -1704,8 +1941,8 @@ dependencies = [
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
 "checksum rusty-fork 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9591f190d2852720b679c21f66ad929f9f1d7bb09d1193c26167586029d8489c"
 "checksum ryu 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "eb9e9b8cde282a9fe6a42dd4681319bfb63f121b8a8ee9439c6f4107e58a46f7"
-"checksum salsa 0.10.0-alpha4 (registry+https://github.com/rust-lang/crates.io-index)" = "3f442595eae948da8fbb2aa1e13940d9d2d70031753a27a5d1434f91b706ff12"
-"checksum salsa-macros 0.10.0-alpha4 (registry+https://github.com/rust-lang/crates.io-index)" = "2e6c1a1bee4eb44881438e80c1a26db1c3b957b6cc51765615d429019babdec2"
+"checksum salsa 0.10.0-alpha5 (registry+https://github.com/rust-lang/crates.io-index)" = "8b5e2535d707dc5ced81106d3b71d806cfeef8a6e8a567472fde7ffd56b770dd"
+"checksum salsa-macros 0.10.0-alpha5 (registry+https://github.com/rust-lang/crates.io-index)" = "e7c5da4c649f6d4fc1864fcd9a379b1f7c6d570b278559c84a6e15981c949cc6"
 "checksum same-file 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "8f20c4be53a8a1ff4c1f1b2bd14570d2f634628709752f0702ecdd2b3f9a5267"
 "checksum scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "94258f53601af11e6a49f722422f6e3425c52b06245a5cf9bc09908b174f5e27"
 "checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
@@ -1715,6 +1952,7 @@ dependencies = [
 "checksum serde_json 1.0.37 (registry+https://github.com/rust-lang/crates.io-index)" = "4b90a9fbe1211e57d3e1c15670f1cb00802988fb23a1a4aad7a2b63544f1920e"
 "checksum serde_yaml 0.8.8 (registry+https://github.com/rust-lang/crates.io-index)" = "0887a8e097a69559b56aa2526bf7aff7c3048cf627dff781f0b56a6001534593"
 "checksum sha-1 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "51b9d1f3b5de8a167ab06834a7c883bd197f2191e1dda1a22d9ccfeedbf9aded"
+"checksum slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 "checksum slug 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "b3bc762e6a4b6c6fcaade73e77f9ebc6991b676f88bb2358bddb56560f073373"
 "checksum smallvec 0.6.8 (registry+https://github.com/rust-lang/crates.io-index)" = "88aea073965ab29f6edb5493faf96ad662fb18aa9eeb186a3b7057951605ed15"
 "checksum smol_str 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "9af1035bc5d742ab6b7ab16713e41cc2ffe78cb474f6f43cd696b2d16052007e"
@@ -1733,6 +1971,9 @@ dependencies = [
 "checksum thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c6b53e329000edc2b34dbe8545fd20e55a333362d0a321909685a19bd28c3f1b"
 "checksum threadpool 1.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e2f0c90a5f3459330ac8bc0d2f879c693bb7a2f59689c1083fc4ef83834da865"
 "checksum time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)" = "db8dcfca086c1143c9270ac42a2bbd8a7ee477b78ac8e45b19abfb0cbede4b6f"
+"checksum tokio-executor 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "30c6dbf2d1ad1de300b393910e8a3aa272b724a400b6531da03eed99e329fbf0"
+"checksum tokio-io 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)" = "b53aeb9d3f5ccf2ebb29e19788f96987fa1355f8fe45ea193928eaaaf3ae820f"
+"checksum tokio-reactor 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "afbcdb0f0d2a1e4c440af82d7bbf0bf91a8a8c0575bcd20c05d15be7e9d3a02f"
 "checksum typenum 1.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "612d636f949607bdf9b123b4a6f6d966dedf3ff669f7f045890d3a4a73948169"
 "checksum ucd-trie 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "71a9c5b1fe77426cf144cc30e49e955270f5086e31a6441dfa8b32efc09b9d77"
 "checksum ucd-util 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "535c204ee4d8434478593480b8f86ab45ec9aae0e83c568ca81abf0fd0e88f86"
@@ -1757,8 +1998,11 @@ dependencies = [
 "checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 "checksum wait-timeout 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "b9f3bf741a801531993db6478b95682117471f76916f5e690dd8d45395b09349"
 "checksum walkdir 2.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "9d9d7ed3431229a144296213105a390676cc49c9b6a72bd19f3176c98e129fa1"
+"checksum winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "167dc9d6949a9b857f3451275e911c3f44255842c1f7a76f33c55103a909087a"
 "checksum winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "92c1eb33641e276cfa214a0522acad57be5c56b10cb348b3c5117db75f3ac4b0"
+"checksum winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2d315eee3b34aca4797b2da6b13ed88266e6d612562a0c46390af8299fc699bc"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 "checksum winapi-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "afc5508759c5bf4285e61feb862b6083c8480aec864fa17a81fdec6f69b461ab"
 "checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
+"checksum ws2_32-sys 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d59cefebd0c892fa2dd6de581e937301d8552cb44489cdff035c6187cb63fa5e"
 "checksum yaml-rust 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "95acf0db5515d07da9965ec0e0ba6cc2d825e2caeb7303b66ca441729801254e"
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index ddd20a41f..e5a0603d1 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -11,7 +11,7 @@ use gen_lsp_server::{
 };
 use lsp_types::NumberOrString;
 use ra_ide_api::{Canceled, FileId, LibraryData};
-use ra_vfs::VfsTask;
+use ra_vfs::{VfsTask, WatcherChange};
 use rustc_hash::FxHashSet;
 use serde::{de::DeserializeOwned, Serialize};
 use threadpool::ThreadPool;
@@ -113,6 +113,7 @@ enum Event {
     Msg(RawMessage),
     Task(Task),
     Vfs(VfsTask),
+    Watcher(WatcherChange),
     Lib(LibraryData),
 }
 
@@ -149,6 +150,7 @@ impl fmt::Debug for Event {
             Event::Task(it) => fmt::Debug::fmt(it, f),
             Event::Vfs(it) => fmt::Debug::fmt(it, f),
             Event::Lib(it) => fmt::Debug::fmt(it, f),
+            Event::Watcher(it) => fmt::Debug::fmt(it, f),
         }
     }
 }
@@ -183,6 +185,10 @@ fn main_loop_inner(
                 Ok(task) => Event::Vfs(task),
                 Err(RecvError) => bail!("vfs died"),
             },
+            recv(state.vfs.read().change_receiver()) -> change => match change {
+                Ok(change) => Event::Watcher(change),
+                Err(RecvError) => bail!("vfs watcher died"),
+            },
             recv(libdata_receiver) -> data => Event::Lib(data.unwrap())
         };
         log::info!("loop_turn = {:?}", event);
@@ -194,6 +200,10 @@ fn main_loop_inner(
                 state.vfs.write().handle_task(task);
                 state_changed = true;
             }
+            Event::Watcher(change) => {
+                state.vfs.write().handle_change(change);
+                state_changed = true;
+            }
             Event::Lib(lib) => {
                 feedback(internal_mode, "library loaded", msg_sender);
                 state.add_lib(lib);
@@ -365,7 +375,7 @@ fn on_notification(
             if let Some(file_id) = state
                 .vfs
                 .write()
-                .add_file_overlay(&path, params.text_document.text)
+                .add_file_overlay(&path, Some(params.text_document.text))
             {
                 subs.add_sub(FileId(file_id.0.into()));
             }
@@ -384,7 +394,10 @@ fn on_notification(
                 .pop()
                 .ok_or_else(|| format_err!("empty changes"))?
                 .text;
-            state.vfs.write().change_file_overlay(path.as_path(), text);
+            state
+                .vfs
+                .write()
+                .change_file_overlay(path.as_path(), Some(text));
             return Ok(());
         }
         Err(not) => not,
diff --git a/crates/ra_vfs/Cargo.toml b/crates/ra_vfs/Cargo.toml
index e637063c9..f7a972e91 100644
--- a/crates/ra_vfs/Cargo.toml
+++ b/crates/ra_vfs/Cargo.toml
@@ -10,6 +10,8 @@ relative-path = "0.4.0"
 rustc-hash = "1.0"
 crossbeam-channel = "0.3.5"
 log = "0.4.6"
+notify = "4"
+drop_bomb = "0.1.0"
 
 thread_worker = { path = "../thread_worker" }
 ra_arena = { path = "../ra_arena" }
diff --git a/crates/ra_vfs/src/lib.rs b/crates/ra_vfs/src/lib.rs
index cdea18d73..5336822b3 100644
--- a/crates/ra_vfs/src/lib.rs
+++ b/crates/ra_vfs/src/lib.rs
@@ -14,26 +14,26 @@
 //! which are watched for changes. Typically, there will be a root for each
 //! Cargo package.
 mod io;
+mod watcher;
 
 use std::{
-    fmt,
-    mem,
-    thread,
     cmp::Reverse,
-    path::{Path, PathBuf},
     ffi::OsStr,
+    fmt, fs, mem,
+    path::{Path, PathBuf},
     sync::Arc,
-    fs,
+    thread,
 };
 
-use rustc_hash::{FxHashMap, FxHashSet};
-use relative_path::RelativePathBuf;
 use crossbeam_channel::Receiver;
-use walkdir::DirEntry;
+use ra_arena::{impl_arena_id, Arena, RawId};
+use relative_path::RelativePathBuf;
+use rustc_hash::{FxHashMap, FxHashSet};
 use thread_worker::WorkerHandle;
-use ra_arena::{Arena, RawId, impl_arena_id};
+use walkdir::DirEntry;
 
 pub use crate::io::TaskResult as VfsTask;
+pub use crate::watcher::{Watcher, WatcherChange};
 
 /// `RootFilter` is a predicate that checks if a file can belong to a root. If
 /// several filters match a file (nested dirs), the most nested one wins.
@@ -85,6 +85,7 @@ pub struct Vfs {
     pending_changes: Vec<VfsChange>,
     worker: io::Worker,
     worker_handle: WorkerHandle,
+    watcher: Watcher,
 }
 
 impl fmt::Debug for Vfs {
@@ -97,12 +98,15 @@ impl Vfs {
     pub fn new(mut roots: Vec<PathBuf>) -> (Vfs, Vec<VfsRoot>) {
         let (worker, worker_handle) = io::start();
 
+        let watcher = Watcher::new().unwrap(); // TODO return Result?
+
         let mut res = Vfs {
             roots: Arena::default(),
             files: Arena::default(),
             root2files: FxHashMap::default(),
             worker,
             worker_handle,
+            watcher,
             pending_changes: Vec::new(),
         };
 
@@ -129,6 +133,7 @@ impl Vfs {
                 filter: Box::new(filter),
             };
             res.worker.inp.send(task).unwrap();
+            res.watcher.watch(path).unwrap();
         }
         let roots = res.roots.iter().map(|(id, _)| id).collect();
         (res, roots)
@@ -183,6 +188,10 @@ impl Vfs {
         &self.worker.out
     }
 
+    pub fn change_receiver(&self) -> &Receiver<WatcherChange> {
+        &self.watcher.change_receiver()
+    }
+
     pub fn handle_task(&mut self, task: io::TaskResult) {
         let mut files = Vec::new();
         // While we were scanning the root in the backgound, a file might have
@@ -209,22 +218,41 @@ impl Vfs {
         self.pending_changes.push(change);
     }
 
-    pub fn add_file_overlay(&mut self, path: &Path, text: String) -> Option<VfsFile> {
+    pub fn handle_change(&mut self, change: WatcherChange) {
+        match change {
+            WatcherChange::Create(path) => {
+                self.add_file_overlay(&path, None);
+            }
+            WatcherChange::Remove(path) => {
+                self.remove_file_overlay(&path);
+            }
+            WatcherChange::Rename(src, dst) => {
+                self.remove_file_overlay(&src);
+                self.add_file_overlay(&dst, None);
+            }
+            WatcherChange::Write(path) => {
+                self.change_file_overlay(&path, None);
+            }
+        }
+    }
+
+    pub fn add_file_overlay(&mut self, path: &Path, text: Option<String>) -> Option<VfsFile> {
         let mut res = None;
-        if let Some((root, path, file)) = self.find_root(path) {
+        if let Some((root, rel_path, file)) = self.find_root(path) {
+            let text = text.unwrap_or_else(|| fs::read_to_string(&path).unwrap_or_default());
             let text = Arc::new(text);
             let change = if let Some(file) = file {
                 res = Some(file);
                 self.change_file(file, Arc::clone(&text));
                 VfsChange::ChangeFile { file, text }
             } else {
-                let file = self.add_file(root, path.clone(), Arc::clone(&text));
+                let file = self.add_file(root, rel_path.clone(), Arc::clone(&text));
                 res = Some(file);
                 VfsChange::AddFile {
                     file,
                     text,
                     root,
-                    path,
+                    path: rel_path,
                 }
             };
             self.pending_changes.push(change);
@@ -232,8 +260,10 @@ impl Vfs {
         res
     }
 
-    pub fn change_file_overlay(&mut self, path: &Path, new_text: String) {
+    pub fn change_file_overlay(&mut self, path: &Path, new_text: Option<String>) {
         if let Some((_root, _path, file)) = self.find_root(path) {
+            let new_text =
+                new_text.unwrap_or_else(|| fs::read_to_string(&path).unwrap_or_default());
             let file = file.expect("can't change a file which wasn't added");
             let text = Arc::new(new_text);
             self.change_file(file, Arc::clone(&text));
@@ -267,6 +297,7 @@ impl Vfs {
 
     /// Sutdown the VFS and terminate the background watching thread.
     pub fn shutdown(self) -> thread::Result<()> {
+        let _ = self.watcher.shutdown();
         let _ = self.worker.shutdown();
         self.worker_handle.shutdown()
     }
diff --git a/crates/ra_vfs/src/watcher.rs b/crates/ra_vfs/src/watcher.rs
new file mode 100644
index 000000000..cc05f949e
--- /dev/null
+++ b/crates/ra_vfs/src/watcher.rs
@@ -0,0 +1,96 @@
+use std::{
+    path::{Path, PathBuf},
+    sync::mpsc,
+    thread,
+    time::Duration,
+};
+
+use crossbeam_channel::Receiver;
+use drop_bomb::DropBomb;
+use notify::{DebouncedEvent, RecommendedWatcher, RecursiveMode, Watcher as NotifyWatcher};
+
+pub struct Watcher {
+    receiver: Receiver<WatcherChange>,
+    watcher: RecommendedWatcher,
+    thread: thread::JoinHandle<()>,
+    bomb: DropBomb,
+}
+
+#[derive(Debug)]
+pub enum WatcherChange {
+    Create(PathBuf),
+    Write(PathBuf),
+    Remove(PathBuf),
+    Rename(PathBuf, PathBuf),
+}
+
+impl WatcherChange {
+    fn from_debounced_event(ev: DebouncedEvent) -> Option<WatcherChange> {
+        match ev {
+            DebouncedEvent::NoticeWrite(_)
+            | DebouncedEvent::NoticeRemove(_)
+            | DebouncedEvent::Chmod(_)
+            | DebouncedEvent::Rescan => {
+                // ignore
+                None
+            }
+            DebouncedEvent::Create(path) => Some(WatcherChange::Create(path)),
+            DebouncedEvent::Write(path) => Some(WatcherChange::Write(path)),
+            DebouncedEvent::Remove(path) => Some(WatcherChange::Remove(path)),
+            DebouncedEvent::Rename(src, dst) => Some(WatcherChange::Rename(src, dst)),
+            DebouncedEvent::Error(err, path) => {
+                // TODO
+                log::warn!("watch error {}, {:?}", err, path);
+                None
+            }
+        }
+    }
+}
+
+impl Watcher {
+    pub fn new() -> Result<Watcher, Box<std::error::Error>> {
+        let (input_sender, input_receiver) = mpsc::channel();
+        let watcher = notify::watcher(input_sender, Duration::from_millis(250))?;
+        let (output_sender, output_receiver) = crossbeam_channel::unbounded();
+        let thread = thread::spawn(move || loop {
+            match input_receiver.recv() {
+                Ok(ev) => {
+                    // forward relevant events only
+                    if let Some(change) = WatcherChange::from_debounced_event(ev) {
+                        output_sender.send(change).unwrap();
+                    }
+                }
+                Err(err) => {
+                    log::debug!("Watcher stopped ({})", err);
+                    break;
+                }
+            }
+        });
+        Ok(Watcher {
+            receiver: output_receiver,
+            watcher,
+            thread,
+            bomb: DropBomb::new(format!("Watcher was not shutdown")),
+        })
+    }
+
+    pub fn watch(&mut self, root: impl AsRef<Path>) -> Result<(), Box<std::error::Error>> {
+        self.watcher.watch(root, RecursiveMode::Recursive)?;
+        Ok(())
+    }
+
+    pub fn change_receiver(&self) -> &Receiver<WatcherChange> {
+        &self.receiver
+    }
+
+    pub fn shutdown(mut self) -> thread::Result<()> {
+        self.bomb.defuse();
+        drop(self.watcher);
+        let res = self.thread.join();
+        match &res {
+            Ok(()) => log::info!("... Watcher terminated with ok"),
+            Err(_) => log::error!("... Watcher terminated with err"),
+        }
+        res
+    }
+}