diff --git a/Cargo.lock b/Cargo.lock
index 11c843b60..0515be845 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -69,6 +69,11 @@ dependencies = [
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "autocfg"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "autocfg"
 version = "1.0.0"
@@ -767,6 +772,11 @@ dependencies = [
  "libc 0.2.74 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "fuchsia-cprng"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "fuchsia-zircon"
 version = "0.3.3"
@@ -1818,6 +1828,14 @@ dependencies = [
  "sha-1 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "phf"
+version = "0.7.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "phf_shared 0.7.24 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "phf"
 version = "0.8.0"
@@ -1828,6 +1846,15 @@ dependencies = [
  "proc-macro-hack 0.5.15 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "phf_codegen"
+version = "0.7.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "phf_generator 0.7.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.24 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "phf_codegen"
 version = "0.8.0"
@@ -1837,6 +1864,15 @@ dependencies = [
  "phf_shared 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "phf_generator"
+version = "0.7.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "phf_shared 0.7.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "phf_generator"
 version = "0.8.0"
@@ -1859,6 +1895,14 @@ dependencies = [
  "syn 1.0.22 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "phf_shared"
+version = "0.7.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "siphasher 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "phf_shared"
 version = "0.8.0"
@@ -2077,6 +2121,24 @@ dependencies = [
  "r2d2 0.8.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.74 (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 0.4.2 (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 0.1.4 (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 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rand"
 version = "0.7.3"
@@ -2090,6 +2152,15 @@ dependencies = [
  "rand_pcg 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand_chacha"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rand_chacha"
 version = "0.2.2"
@@ -2099,6 +2170,19 @@ dependencies = [
  "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand_core"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "rand_core"
 version = "0.5.1"
@@ -2107,6 +2191,14 @@ dependencies = [
  "getrandom 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand_hc"
+version = "0.1.0"
+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)",
+]
+
 [[package]]
 name = "rand_hc"
 version = "0.2.0"
@@ -2115,6 +2207,46 @@ dependencies = [
  "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand_isaac"
+version = "0.1.1"
+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)",
+]
+
+[[package]]
+name = "rand_jitter"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.74 (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 = "0.1.3"
+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 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.74 (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 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_pcg"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.7 (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_pcg"
 version = "0.2.1"
@@ -2123,6 +2255,14 @@ dependencies = [
  "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand_xorshift"
+version = "0.1.1"
+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)",
+]
+
 [[package]]
 name = "rayon"
 version = "1.3.0"
@@ -2145,6 +2285,14 @@ dependencies = [
  "num_cpus 1.13.0 (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"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.1.56"
@@ -2186,7 +2334,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "remove_dir_all"
-version = "0.5.2"
+version = "0.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2381,7 +2529,7 @@ dependencies = [
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "nix 0.11.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "percent-encoding 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "remove_dir_all 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "reqwest 0.10.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "scopeguard 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.110 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2647,6 +2795,11 @@ dependencies = [
  "libc 0.2.74 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "siphasher"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "siphasher"
 version = "0.3.3"
@@ -2909,7 +3062,7 @@ dependencies = [
  "libc 0.2.74 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)",
- "remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "remove_dir_all 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -3556,6 +3709,7 @@ dependencies = [
 "checksum arrayvec 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cff77d8686867eceff3105329d4698d96c2391c176d5d03adc90c7389162b5b8"
 "checksum async-trait 0.1.36 (registry+https://github.com/rust-lang/crates.io-index)" = "a265e3abeffdce30b2e26b7a11b222fe37c6067404001b434101457d0385eb92"
 "checksum atty 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)" = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
+"checksum autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "1d49d90015b3c36167a20fe2810c5cd875ad504b39cff3d4eae7977e6b7c1cb2"
 "checksum autocfg 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f8aac770f1885fd7e387acedd76065302551364496e46b3dd00860b2f8359b9d"
 "checksum backtrace 0.3.48 (registry+https://github.com/rust-lang/crates.io-index)" = "0df2f85c8a2abbe3b7d7e748052fdd9b76a0458fdeb16ad4223f5eca78c7c130"
 "checksum base-x 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "1b20b618342cf9891c292c4f5ac2cde7287cc5c87e87e9c769d617793607dec1"
@@ -3629,6 +3783,7 @@ dependencies = [
 "checksum fs2 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "9564fc758e15025b46aa6643b1b77d047d1a56a1aea6e01002ac0c7026876213"
 "checksum fsevent 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5ab7d1bd1bd33cc98b0889831b72da23c0aa4df9cec7e0702f46ecea04b35db6"
 "checksum fsevent-sys 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f41b048a94555da0f42f1d632e2e19510084fb8e303b0daa2816e733fb3644a0"
+"checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
 "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 futf 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "7c9c1ce3fa9336301af935ab852c437817d14cd33690446569392e65170aac3b"
@@ -3746,10 +3901,14 @@ dependencies = [
 "checksum pest_derive 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "833d1ae558dc601e9a60366421196a8d94bc0ac980476d0b67e1d0988d72b2d0"
 "checksum pest_generator 2.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "99b8db626e31e5b81787b9783425769681b347011cc59471e33ea46d2ea0cf55"
 "checksum pest_meta 2.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "54be6e404f5317079812fc8f9f5279de376d8856929e21c184ecf6bbd692a11d"
+"checksum phf 0.7.24 (registry+https://github.com/rust-lang/crates.io-index)" = "b3da44b85f8e8dfaec21adae67f95d93244b2ecf6ad2a692320598dcc8e6dd18"
 "checksum phf 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3dfb61232e34fcb633f43d12c58f83c1df82962dcdfa565a4e866ffc17dafe12"
+"checksum phf_codegen 0.7.24 (registry+https://github.com/rust-lang/crates.io-index)" = "b03e85129e324ad4166b06b2c7491ae27fe3ec353af72e72cd1654c7225d517e"
 "checksum phf_codegen 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "cbffee61585b0411840d3ece935cce9cb6321f01c45477d30066498cd5e1a815"
+"checksum phf_generator 0.7.24 (registry+https://github.com/rust-lang/crates.io-index)" = "09364cc93c159b8b06b1f4dd8a4398984503483891b0c26b867cf431fb132662"
 "checksum phf_generator 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "17367f0cc86f2d25802b2c26ee58a7b23faeccf78a396094c13dced0d0182526"
 "checksum phf_macros 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7f6fde18ff429ffc8fe78e2bf7f8b7a5a5a6e2a8b58bc5a9ac69198bbda9189c"
+"checksum phf_shared 0.7.24 (registry+https://github.com/rust-lang/crates.io-index)" = "234f71a15de2288bcb7e3b6515828d22af7ec8598ee6d24c3b526fa0a80b67a0"
 "checksum phf_shared 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c00cf8b9eafe68dde5e9eaa2cef8ee84a9336a47d566ec55ca16589633b65af7"
 "checksum pin-project 0.4.17 (registry+https://github.com/rust-lang/crates.io-index)" = "edc93aeee735e60ecb40cf740eb319ff23eab1c5748abfdb5c180e4ce49f7791"
 "checksum pin-project-internal 0.4.17 (registry+https://github.com/rust-lang/crates.io-index)" = "e58db2081ba5b4c93bd6be09c40fd36cb9193a8336c384f3b40012e531aa7e40"
@@ -3775,19 +3934,30 @@ dependencies = [
 "checksum quote 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "54a21852a652ad6f610c9510194f398ff6f8692e334fd1145fed931f7fbe44ea"
 "checksum r2d2 0.8.8 (registry+https://github.com/rust-lang/crates.io-index)" = "1497e40855348e4a8a40767d8e55174bce1e445a3ac9254ad44ad468ee0485af"
 "checksum r2d2_postgres 0.16.0 (registry+https://github.com/rust-lang/crates.io-index)" = "707d27f66f43bac1081141f6d9611fffcce7da2841ae97c7ac53619d098efe8f"
+"checksum rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)" = "6d71dacdc3c88c1fde3885a3be3fbab9f35724e6ce99467f7d9c5026132184ca"
 "checksum rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
+"checksum rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "556d3a1ca6600bfcbab7c7c91ccb085ac7fbbcd70e008a98742e7847f4f7bcef"
 "checksum rand_chacha 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f4c8ed856279c9737206bf725bf36935d8666ead7aa69b52be55af369d193402"
+"checksum rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
+"checksum rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9c33a3c44ca05fa6f1807d8e6743f3824e8509beca625669633be0acbdf509dc"
 "checksum rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
+"checksum rand_hc 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7b40677c7be09ae76218dc623efbf7b18e34bced3f38883af07bb75630a21bc4"
 "checksum rand_hc 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
+"checksum rand_isaac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ded997c9d5f13925be2a6fd7e66bf1872597f759fd9dd93513dd7e92e5a5ee08"
+"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_pcg 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "16abd0c1b639e9eb4d7c50c0b8100b0d0f849be2349829c740fe8e6eb4816429"
+"checksum rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cbf7e9e623549b0e21f6e97cf8ecf247c1a8fd2e8a992ae265314300b2455d5c"
 "checksum rayon 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "db6ce3297f9c85e16621bb8cca38a06779ffc31bb8184e1be4bed2be4678a098"
 "checksum rayon-core 1.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "08a89b46efaf957e52b18062fb2f4660f8b8a4dde1807ca002690868ef2c85a9"
+"checksum rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
 "checksum redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)" = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
 "checksum redox_users 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "09b23093265f8d200fa7b4c2c76297f47e681c655f6f1285a8780d6a022f7431"
 "checksum regex 1.3.7 (registry+https://github.com/rust-lang/crates.io-index)" = "a6020f034922e3194c711b82a627453881bc4682166cabb07134a10c26ba7692"
 "checksum regex-automata 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "ae1ded71d66a4a97f5e961fd0cb25a5f366a42a41570d16a763a69c092c26ae4"
 "checksum regex-syntax 0.6.17 (registry+https://github.com/rust-lang/crates.io-index)" = "7fe5bd57d1d7414c6b5ed48563a2c855d995ff777729dcd91c369ec7fea395ae"
-"checksum remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4a83fa3702a688b9359eccba92d153ac33fd2e8462f9e0e3fdf155239ea7792e"
+"checksum remove_dir_all 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3acd125665422973a33ac9d3dd2df85edad0f4ae9b00dafb1a05e43a9f5ef8e7"
 "checksum reqwest 0.10.6 (registry+https://github.com/rust-lang/crates.io-index)" = "3b82c9238b305f26f53443e3a4bc8528d64b8d0bee408ec949eb7bf5635ec680"
 "checksum rle-decode-fast 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cabe4fa914dec5870285fa7f71f602645da47c486e68486d2b4ceb4a343e90ac"
 "checksum route-recognizer 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "ea509065eb0b3c446acdd0102f0d46567dc30902dc0be91d6552035d92b0f4f8"
@@ -3830,6 +4000,7 @@ dependencies = [
 "checksum sha2 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2933378ddfeda7ea26f48c555bdad8bb446bf8a3d17832dc83e380d444cfb8c1"
 "checksum shlex 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7fdf1b9db47230893d76faad238fd6097fd6d6a9245cd7a4d90dbd639536bbd2"
 "checksum signal-hook-registry 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "94f478ede9f64724c5d173d7bb56099ec3e2d9fc2774aac65d34b8b890405f41"
+"checksum siphasher 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "0b8de496cf83d4ed58b6be86c3a275b8602f6ffe98d3024a869e124147a9a3ac"
 "checksum siphasher 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "fa8f3741c7372e75519bd9346068370c9cdaabcc1f9599cbcf2a2719352286b7"
 "checksum slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 "checksum slug 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "39af1ce888a1253c8b9fcfa36626557650fb487c013620a743262d2769a3e9f3"
diff --git a/src/utils/html.rs b/src/utils/html.rs
index b194a9cc0..77d101002 100644
--- a/src/utils/html.rs
+++ b/src/utils/html.rs
@@ -23,6 +23,7 @@ pub(crate) fn rewrite_lol(
 
     let head_handler = |head: &mut Element| {
         head.append(&tera_head, ContentType::Html);
+
         Ok(())
     };
 
@@ -77,11 +78,14 @@ pub(crate) fn rewrite_lol(
 
     // The input and output are always strings, we just use `&[u8]` so we only have to validate once.
     let mut buffer = Vec::new();
+    // TODO: Make the rewriter persistent?
     let mut writer = HtmlRewriter::try_new(settings, |bytes: &[u8]| {
         buffer.extend_from_slice(bytes);
     })
     .expect("utf8 is a valid encoding");
+
     writer.write(html)?;
     writer.end()?;
+
     Ok(buffer)
 }
diff --git a/src/web/metrics.rs b/src/web/metrics.rs
index c2e156374..0d0742593 100644
--- a/src/web/metrics.rs
+++ b/src/web/metrics.rs
@@ -147,6 +147,14 @@ pub static CURRENTLY_RUNNING_THREADS: Lazy<IntGauge> = Lazy::new(|| {
     .unwrap()
 });
 
+pub static HTML_REWRITE_OOMS: Lazy<IntGauge> = Lazy::new(|| {
+    register_int_gauge!(
+        "docsrs_html_rewrite_ooms",
+        "The number of attempted files that failed due to a memory limit"
+    )
+    .unwrap()
+});
+
 pub fn metrics_handler(req: &mut Request) -> IronResult<Response> {
     let pool = extension!(req, Pool);
     let queue = extension!(req, BuildQueue);
diff --git a/src/web/rustdoc.rs b/src/web/rustdoc.rs
index e0434487b..666a64089 100644
--- a/src/web/rustdoc.rs
+++ b/src/web/rustdoc.rs
@@ -14,6 +14,7 @@ use iron::{
     modifiers::Redirect,
     status, Handler, IronError, IronResult, Request, Response, Url,
 };
+use lol_html::errors::RewritingError;
 use router::Router;
 use serde::Serialize;
 
@@ -197,6 +198,7 @@ impl RustdocPage {
         rustdoc_html: &[u8],
         max_parse_memory: usize,
         req: &mut Request,
+        file_path: &str,
     ) -> IronResult<Response> {
         use iron::{headers::ContentType, status::Status};
 
@@ -206,12 +208,23 @@ impl RustdocPage {
             .expect("missing TemplateData from the request extensions");
 
         // Build the page of documentation
-        let ctx = ctry!(req, tera::Context::from_serialize(self),);
+        let ctx = ctry!(req, tera::Context::from_serialize(self));
         // Extract the head and body of the rustdoc file so that we can insert it into our own html
-        let html = ctry!(
-            req,
-            utils::rewrite_lol(rustdoc_html, max_parse_memory, ctx, templates)
-        );
+        // while logging OOM errors from html rewriting
+        let html = match utils::rewrite_lol(rustdoc_html, max_parse_memory, ctx, templates) {
+            Err(RewritingError::MemoryLimitExceeded(..)) => {
+                crate::web::metrics::HTML_REWRITE_OOMS.inc();
+
+                let config = extension!(req, Config);
+                let err = failure::err_msg(format!(
+                    "Failed to serve the rustdoc file '{}' because rewriting it surpassed the memory limit of {} bytes",
+                    file_path, config.max_parse_memory,
+                ));
+
+                ctry!(req, Err(err))
+            }
+            result => ctry!(req, result),
+        };
 
         let mut response = Response::with((Status::Ok, html));
         response.headers.set(ContentType::html());
@@ -339,6 +352,7 @@ pub fn rustdoc_html_server_handler(req: &mut Request) -> IronResult<Response> {
     // Serve non-html files directly
     if !path.ends_with(".html") {
         rendering_time.step("serve asset");
+
         return Ok(file.serve());
     }
 
@@ -392,7 +406,7 @@ pub fn rustdoc_html_server_handler(req: &mut Request) -> IronResult<Response> {
         is_latest_version,
         krate,
     }
-    .into_response(&file.0.content, config.max_parse_memory, req)
+    .into_response(&file.0.content, config.max_parse_memory, req, &path)
 }
 
 /// Checks whether the given path exists.