diff --git a/rust/Cargo.lock b/rust/Cargo.lock
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -2,25 +2,38 @@
 # It is not intended for manual editing.
 [[package]]
 name = "aho-corasick"
-version = "0.6.9"
+version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "arrayvec"
+version = "0.4.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "nodrop 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "autocfg"
-version = "0.1.2"
+version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "bitflags"
-version = "1.0.4"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "byteorder"
-version = "1.3.1"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "cfg-if"
+version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -28,7 +41,7 @@ name = "cloudabi"
 version = "0.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -36,27 +49,72 @@ name = "cpython"
 version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.64 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "python27-sys 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "python3-sys 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
+name = "crossbeam-deque"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-epoch 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "crossbeam-epoch"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "arrayvec 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memoffset 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "scopeguard 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "crossbeam-queue"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-utils 0.6.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.6.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "either"
+version = "1.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "fuchsia-cprng"
-version = "0.1.0"
+version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "hg-core"
 version = "0.1.0"
 dependencies = [
- "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand_pcg 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_pcg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rayon 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -65,7 +123,7 @@ version = "0.1.0"
 dependencies = [
  "cpython 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "hg-core 0.1.0",
- "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.64 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -73,36 +131,60 @@ name = "hgdirectffi"
 version = "0.1.0"
 dependencies = [
  "hg-core 0.1.0",
- "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.64 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "lazy_static"
-version = "1.3.0"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "libc"
-version = "0.2.45"
+version = "0.2.64"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "memchr"
-version = "2.2.0"
+version = "2.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "memoffset"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "nodrop"
+version = "0.1.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "num-traits"
-version = "0.2.6"
+version = "0.2.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "num_cpus"
+version = "1.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.64 (registry+https://github.com/rust-lang/crates.io-index)",
+]
 
 [[package]]
 name = "python27-sys"
 version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.64 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -110,8 +192,8 @@ name = "python3-sys"
 version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.64 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -119,17 +201,17 @@ name = "rand"
 version = "0.6.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "autocfg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
+ "autocfg 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.64 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_hc 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_isaac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand_jitter 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand_os 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand_pcg 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_jitter 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_os 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_pcg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -137,7 +219,7 @@ name = "rand_chacha"
 version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "autocfg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "autocfg 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -146,12 +228,12 @@ name = "rand_core"
 version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rand_core"
-version = "0.4.0"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -172,34 +254,34 @@ dependencies = [
 
 [[package]]
 name = "rand_jitter"
-version = "0.1.2"
+version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.64 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rand_os"
-version = "0.1.2"
+version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "fuchsia-cprng 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.64 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rand_pcg"
-version = "0.1.1"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "autocfg 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -211,6 +293,28 @@ dependencies = [
 ]
 
 [[package]]
+name = "rayon"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-deque 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "either 1.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rayon-core 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rayon-core"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-deque 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-queue 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num_cpus 1.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "rdrand"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -220,23 +324,19 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.1.0"
+version = "1.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "aho-corasick 0.6.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex-syntax 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "aho-corasick 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "utf8-ranges 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "regex-syntax"
-version = "0.6.4"
+version = "0.6.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "ucd-util 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
-]
 
 [[package]]
 name = "rustc_version"
@@ -247,6 +347,11 @@ dependencies = [
 ]
 
 [[package]]
+name = "scopeguard"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "semver"
 version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -264,22 +369,12 @@ name = "thread_local"
 version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
-name = "ucd-util"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "utf8-ranges"
-version = "1.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
 name = "winapi"
-version = "0.3.6"
+version = "0.3.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -297,38 +392,49 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [metadata]
-"checksum aho-corasick 0.6.9 (registry+https://github.com/rust-lang/crates.io-index)" = "1e9a933f4e58658d7b12defcf96dc5c720f20832deebe3e0a19efd3b6aaeeb9e"
-"checksum autocfg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a6d640bee2da49f60a4068a7fae53acde8982514ab7bae8b8cea9e88cbcfd799"
-"checksum bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
-"checksum byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a019b10a2a7cdeb292db131fc8113e57ea2a908f6e7894b0c3c671893b65dbeb"
+"checksum aho-corasick 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)" = "58fb5e95d83b38284460a5fda7d6470aa0b8844d283a0b614b8535e880800d2d"
+"checksum arrayvec 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)" = "cd9fd44efafa8690358b7408d253adf110036b88f55672a933f01d616ad9b1b9"
+"checksum autocfg 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "b671c8fb71b457dd4ae18c4ba1e59aa81793daacc361d82fcd410cef0d491875"
+"checksum bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
+"checksum byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a7c3dd8985a7111efc5c80b44e23ecdd8c007de8ade3b96595387e812b957cf5"
+"checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 "checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
 "checksum cpython 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "85532c648315aeb0829ad216a6a29aa3212cf9319bc7f6daf1404aa0bdd1485f"
-"checksum fuchsia-cprng 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "81f7f8eb465745ea9b02e2704612a9946a59fa40572086c6fd49d6ddcf30bf31"
-"checksum lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bc5729f27f159ddd61f4df6228e827e86643d4d3e7c32183cb30a1c08f604a14"
-"checksum libc 0.2.45 (registry+https://github.com/rust-lang/crates.io-index)" = "2d2857ec59fadc0773853c664d2d18e7198e83883e7060b63c924cb077bd5c74"
-"checksum memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "2efc7bc57c883d4a4d6e3246905283d8dae951bb3bd32f49d6ef297f546e1c39"
-"checksum num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0b3a5d7cc97d6d30d8b9bc8fa19bf45349ffe46241e8816f50f62f6d6aaabee1"
+"checksum crossbeam-deque 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b18cd2e169ad86297e6bc0ad9aa679aee9daa4f19e8163860faf7c164e4f5a71"
+"checksum crossbeam-epoch 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "fedcd6772e37f3da2a9af9bf12ebe046c0dfe657992377b4df982a2b54cd37a9"
+"checksum crossbeam-queue 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7c979cd6cfe72335896575c6b5688da489e420d36a27a0b9eb0c73db574b4a4b"
+"checksum crossbeam-utils 0.6.6 (registry+https://github.com/rust-lang/crates.io-index)" = "04973fa96e96579258a5091af6003abde64af786b860f18622b82e026cca60e6"
+"checksum either 1.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "bb1f6b1ce1c140482ea30ddd3335fc0024ac7ee112895426e0a629a6c20adfe3"
+"checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
+"checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+"checksum libc 0.2.64 (registry+https://github.com/rust-lang/crates.io-index)" = "74dfca3d9957906e8d1e6a0b641dc9a59848e793f1da2165889fd4f62d10d79c"
+"checksum memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "88579771288728879b57485cc7d6b07d648c9f0141eb955f8ab7f9d45394468e"
+"checksum memoffset 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ce6075db033bbbb7ee5a0bbd3a3186bbae616f57fb001c485c7ff77955f8177f"
+"checksum nodrop 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)" = "72ef4a56884ca558e5ddb05a1d1e7e1bfd9a68d9ed024c21704cc98872dae1bb"
+"checksum num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "6ba9a427cfca2be13aa6f6403b0b7e7368fe982bfa16fccc450ce74c46cd9b32"
+"checksum num_cpus 1.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "bcef43580c035376c0705c42792c294b66974abbfd2789b511784023f71f3273"
 "checksum python27-sys 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "372555e88a6bc8109eb641380240dc8d25a128fc48363ec9075664daadffdd5b"
 "checksum python3-sys 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f3a8ebed3f1201fda179f3960609dbbc10cd8c75e9f2afcb03788278f367d8ea"
 "checksum rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)" = "6d71dacdc3c88c1fde3885a3be3fbab9f35724e6ce99467f7d9c5026132184ca"
 "checksum rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "556d3a1ca6600bfcbab7c7c91ccb085ac7fbbcd70e008a98742e7847f4f7bcef"
 "checksum rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
-"checksum rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d0e7a549d590831370895ab7ba4ea0c1b6b011d106b5ff2da6eee112615e6dc0"
+"checksum rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9c33a3c44ca05fa6f1807d8e6743f3824e8509beca625669633be0acbdf509dc"
 "checksum rand_hc 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7b40677c7be09ae76218dc623efbf7b18e34bced3f38883af07bb75630a21bc4"
 "checksum rand_isaac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ded997c9d5f13925be2a6fd7e66bf1872597f759fd9dd93513dd7e92e5a5ee08"
-"checksum rand_jitter 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "080723c6145e37503a2224f801f252e14ac5531cb450f4502698542d188cb3c0"
-"checksum rand_os 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "b7c690732391ae0abafced5015ffb53656abfaec61b342290e5eb56b286a679d"
-"checksum rand_pcg 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "086bd09a33c7044e56bb44d5bdde5a60e7f119a9e95b0775f545de759a32fe05"
+"checksum rand_jitter 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "1166d5c91dc97b88d1decc3285bb0a99ed84b05cfd0bc2341bdf2d43fc41e39b"
+"checksum rand_os 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "7b75f676a1e053fc562eafbb47838d67c84801e38fc1ba459e8f180deabd5071"
+"checksum rand_pcg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "abf9b09b01790cfe0364f52bf32995ea3c39f4d2dd011eac241d2914146d0b44"
 "checksum rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cbf7e9e623549b0e21f6e97cf8ecf247c1a8fd2e8a992ae265314300b2455d5c"
+"checksum rayon 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "83a27732a533a1be0a0035a111fe76db89ad312f6f0347004c220c57f209a123"
+"checksum rayon-core 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "98dcf634205083b17d0861252431eb2acbfb698ab7478a2d20de07954f47ec7b"
 "checksum rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
-"checksum regex 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "37e7cbbd370869ce2e8dff25c7018702d10b21a20ef7135316f8daecd6c25b7f"
-"checksum regex-syntax 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)" = "4e47a2ed29da7a9e1960e1639e7a982e6edc6d49be308a3b02daf511504a16d1"
+"checksum regex 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "dc220bd33bdce8f093101afe22a037b8eb0e5af33592e6a9caafff0d4cb81cbd"
+"checksum regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)" = "11a7e20d1cce64ef2fed88b66d347f88bd9babb82845b2b858f3edbf59a4f716"
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
+"checksum scopeguard 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b42e15e59b18a828bbf5c58ea01debb36b9b096346de35d941dcb89009f24a0d"
 "checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
 "checksum semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
 "checksum thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c6b53e329000edc2b34dbe8545fd20e55a333362d0a321909685a19bd28c3f1b"
-"checksum ucd-util 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "535c204ee4d8434478593480b8f86ab45ec9aae0e83c568ca81abf0fd0e88f86"
-"checksum utf8-ranges 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "796f7e48bef87609f7ade7e06495a87d5cd06c7866e6a5cbfceffc558a243737"
-"checksum winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "92c1eb33641e276cfa214a0522acad57be5c56b10cb348b3c5117db75f3ac4b0"
+"checksum winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 "checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
diff --git a/rust/hg-core/Cargo.toml b/rust/hg-core/Cargo.toml
--- a/rust/hg-core/Cargo.toml
+++ b/rust/hg-core/Cargo.toml
@@ -15,3 +15,4 @@ memchr = "2.2.0"
 rand = "0.6.5"
 rand_pcg = "0.1.1"
 regex = "1.1.0"
+rayon = "1.2.0"
diff --git a/rust/hg-core/src/dirstate.rs b/rust/hg-core/src/dirstate.rs
--- a/rust/hg-core/src/dirstate.rs
+++ b/rust/hg-core/src/dirstate.rs
@@ -13,6 +13,7 @@ use std::convert::TryFrom;
 pub mod dirs_multiset;
 pub mod dirstate_map;
 pub mod parsers;
+pub mod status;
 
 #[derive(Debug, PartialEq, Clone)]
 pub struct DirstateParents {
diff --git a/rust/hg-core/src/dirstate/status.rs b/rust/hg-core/src/dirstate/status.rs
new file mode 100644
--- /dev/null
+++ b/rust/hg-core/src/dirstate/status.rs
@@ -0,0 +1,248 @@
+// status.rs
+//
+// Copyright 2019 Raphaël Gomès <rgomes@octobus.net>
+//
+// This software may be used and distributed according to the terms of the
+// GNU General Public License version 2 or any later version.
+
+//! Rust implementation of dirstate.status (dirstate.py).
+//! It is currently missing a lot of functionality compared to the Python one
+//! and will only be triggered in narrow cases.
+
+use crate::utils::files::HgMetadata;
+use crate::utils::hg_path::{hg_path_to_path_buf, HgPath, HgPathBuf};
+use crate::{DirstateEntry, DirstateMap, EntryState};
+use rayon::prelude::*;
+use std::collections::HashMap;
+use std::fs::Metadata;
+use std::path::Path;
+
+/// Get stat data about the files explicitly specified by match.
+/// TODO subrepos
+fn walk_explicit(
+    files: &[impl AsRef<HgPath> + Sync],
+    dmap: &DirstateMap,
+    root_dir: impl AsRef<Path> + Sync,
+) -> std::io::Result<HashMap<HgPathBuf, Option<HgMetadata>>> {
+    let mut results = HashMap::new();
+
+    // A tuple of the normalized filename and the `Result` of the call to
+    // `symlink_metadata` for separate handling.
+    type WalkTuple<'a> = (&'a HgPath, std::io::Result<Metadata>);
+
+    let stats_res: std::io::Result<Vec<WalkTuple>> = files
+        .par_iter()
+        .map(|filename| {
+            // TODO normalization
+            let normalized = filename.as_ref();
+
+            let target_filename =
+                root_dir.as_ref().join(hg_path_to_path_buf(normalized)?);
+
+            Ok((normalized, target_filename.symlink_metadata()))
+        })
+        .collect();
+
+    for res in stats_res? {
+        match res {
+            (normalized, Ok(stat)) => {
+                if stat.is_file() {
+                    results.insert(
+                        normalized.to_owned(),
+                        Some(HgMetadata::from_metadata(stat)),
+                    );
+                } else {
+                    if dmap.contains_key(normalized) {
+                        results.insert(normalized.to_owned(), None);
+                    }
+                }
+            }
+            (normalized, Err(_)) => {
+                if dmap.contains_key(normalized) {
+                    results.insert(normalized.to_owned(), None);
+                }
+            }
+        };
+    }
+
+    Ok(results)
+}
+
+// Stat all entries in the `DirstateMap` and return their new metadata.
+pub fn stat_dmap_entries(
+    dmap: &DirstateMap,
+    results: &HashMap<HgPathBuf, Option<HgMetadata>>,
+    root_dir: impl AsRef<Path> + Sync,
+) -> std::io::Result<Vec<(HgPathBuf, Option<HgMetadata>)>> {
+    dmap.par_iter()
+        .filter_map(
+            // Getting file metadata is costly, so we don't do it if the
+            // file is already present in the results, hence `filter_map`
+            |(filename, _)| -> Option<
+                std::io::Result<(HgPathBuf, Option<HgMetadata>)>
+            > {
+                if results.contains_key(filename) {
+                    return None;
+                }
+                let meta = match hg_path_to_path_buf(filename) {
+                    Ok(p) => root_dir.as_ref().join(p).symlink_metadata(),
+                    Err(e) => return Some(Err(e.into())),
+                };
+
+                Some(match meta {
+                    Ok(ref m)
+                        if !(m.file_type().is_file()
+                            || m.file_type().is_symlink()) =>
+                    {
+                        Ok((filename.to_owned(), None))
+                    }
+                    Ok(m) => Ok((
+                        filename.to_owned(),
+                        Some(HgMetadata::from_metadata(m)),
+                    )),
+                    Err(ref e)
+                        if e.kind() == std::io::ErrorKind::NotFound
+                            || e.raw_os_error() == Some(20) =>
+                    {
+                        // Rust does not yet have an `ErrorKind` for
+                        // `NotADirectory` (errno 20)
+                        // It happens if the dirstate contains `foo/bar` and
+                        // foo is not a directory
+                        Ok((filename.to_owned(), None))
+                    }
+                    Err(e) => Err(e),
+                })
+            },
+        )
+        .collect()
+}
+
+pub struct StatusResult {
+    pub modified: Vec<HgPathBuf>,
+    pub added: Vec<HgPathBuf>,
+    pub removed: Vec<HgPathBuf>,
+    pub deleted: Vec<HgPathBuf>,
+    pub clean: Vec<HgPathBuf>,
+    // TODO ignored
+    // TODO unknown
+}
+
+fn build_response(
+    dmap: &DirstateMap,
+    list_clean: bool,
+    last_normal_time: i64,
+    check_exec: bool,
+    results: HashMap<HgPathBuf, Option<HgMetadata>>,
+) -> (Vec<HgPathBuf>, StatusResult) {
+    let mut lookup = vec![];
+    let mut modified = vec![];
+    let mut added = vec![];
+    let mut removed = vec![];
+    let mut deleted = vec![];
+    let mut clean = vec![];
+
+    for (filename, metadata_option) in results.into_iter() {
+        let DirstateEntry {
+            state,
+            mode,
+            mtime,
+            size,
+        } = match dmap.get(&filename) {
+            None => {
+                continue;
+            }
+            Some(e) => *e,
+        };
+
+        match metadata_option {
+            None => {
+                match state {
+                    EntryState::Normal
+                    | EntryState::Merged
+                    | EntryState::Added => deleted.push(filename),
+                    EntryState::Removed => removed.push(filename),
+                    _ => {}
+                };
+            }
+            Some(HgMetadata {
+                st_mode,
+                st_size,
+                st_mtime,
+                ..
+            }) => {
+                match state {
+                    EntryState::Normal => {
+                        // Dates and times that are outside the 31-bit signed
+                        // range are compared modulo 2^31. This should prevent
+                        // it from behaving badly with very large files or
+                        // corrupt dates while still having a high probability
+                        // of detecting changes. (issue2608)
+                        let range_mask = 0x7fffffff;
+
+                        let size_changed = (size != st_size as i32)
+                            && size != (st_size as i32 & range_mask);
+                        let mode_changed = (mode ^ st_mode as i32) & 0o100
+                            != 0o000
+                            && check_exec;
+                        if size >= 0
+                            && (size_changed || mode_changed)
+                            || size == -2  // other parent
+                            || dmap.copy_map.contains_key(&filename)
+                        {
+                            modified.push(filename);
+                        } else if mtime != st_mtime as i32
+                            && mtime != (st_mtime as i32 & range_mask)
+                        {
+                            lookup.push(filename);
+                        } else if st_mtime == last_normal_time {
+                            // the file may have just been marked as normal and
+                            // it may have changed in the same second without
+                            // changing its size. This can happen if we quickly
+                            // do multiple commits. Force lookup, so we don't
+                            // miss such a racy file change.
+                            lookup.push(filename);
+                        } else if list_clean {
+                            clean.push(filename);
+                        }
+                    }
+                    EntryState::Merged => modified.push(filename),
+                    EntryState::Added => added.push(filename),
+                    EntryState::Removed => removed.push(filename),
+                    EntryState::Unknown => {}
+                }
+            }
+        }
+    }
+
+    (
+        lookup,
+        StatusResult {
+            modified,
+            added,
+            removed,
+            deleted,
+            clean,
+        },
+    )
+}
+
+pub fn status(
+    dmap: &DirstateMap,
+    root_dir: impl AsRef<Path> + Sync + Copy,
+    files: &[impl AsRef<HgPath> + Sync],
+    list_clean: bool,
+    last_normal_time: i64,
+    check_exec: bool,
+) -> std::io::Result<(Vec<HgPathBuf>, StatusResult)> {
+    let mut results = walk_explicit(files, &dmap, root_dir)?;
+
+    results.extend(stat_dmap_entries(&dmap, &results, root_dir)?);
+
+    Ok(build_response(
+        &dmap,
+        list_clean,
+        last_normal_time,
+        check_exec,
+        results,
+    ))
+}
diff --git a/rust/hg-core/src/lib.rs b/rust/hg-core/src/lib.rs
--- a/rust/hg-core/src/lib.rs
+++ b/rust/hg-core/src/lib.rs
@@ -12,6 +12,7 @@ pub use dirstate::{
     dirs_multiset::{DirsMultiset, DirsMultisetIter},
     dirstate_map::DirstateMap,
     parsers::{pack_dirstate, parse_dirstate, PARENT_SIZE},
+    status::status,
     CopyMap, CopyMapIter, DirstateEntry, DirstateParents, EntryState,
     StateMap, StateMapIter,
 };
diff --git a/rust/hg-core/src/utils/files.rs b/rust/hg-core/src/utils/files.rs
--- a/rust/hg-core/src/utils/files.rs
+++ b/rust/hg-core/src/utils/files.rs
@@ -12,6 +12,7 @@
 use crate::utils::hg_path::{HgPath, HgPathBuf};
 use std::iter::FusedIterator;
 
+use std::fs::Metadata;
 use std::path::Path;
 
 pub fn get_path_from_bytes(bytes: &[u8]) -> &Path {
@@ -76,6 +77,32 @@ pub fn normalize_case(path: &HgPath) -> 
     path.to_ascii_lowercase()
 }
 
+#[derive(Eq, PartialEq, Ord, PartialOrd, Copy, Clone)]
+pub struct HgMetadata {
+    pub st_dev: u64,
+    pub st_mode: u32,
+    pub st_nlink: u64,
+    pub st_size: u64,
+    pub st_mtime: i64,
+    pub st_ctime: i64,
+}
+
+// TODO support other plaforms
+#[cfg(unix)]
+impl HgMetadata {
+    pub fn from_metadata(metadata: Metadata) -> Self {
+        use std::os::unix::fs::MetadataExt;
+        Self {
+            st_dev: metadata.dev(),
+            st_mode: metadata.mode(),
+            st_nlink: metadata.nlink(),
+            st_size: metadata.size(),
+            st_mtime: metadata.mtime(),
+            st_ctime: metadata.ctime(),
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;