deps: introduce experimental llhttp HTTP parser

LICENSE

@@ -606,6 +606,32 @@ The externally maintained libraries used by Node.js are:
         n° 289016). Three clause BSD license.
   """
 
+- llhttp, located at deps/llhttp, is licensed as follows:
+  """
+    This software is licensed under the MIT License.
+
+    Copyright Fedor Indutny, 2018.
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the
+    "Software"), to deal in the Software without restriction, including
+    without limitation the rights to use, copy, modify, merge, publish,
+    distribute, sublicense, and/or sell copies of the Software, and to permit
+    persons to whom the Software is furnished to do so, subject to the
+    following conditions:
+
+    The above copyright notice and this permission notice shall be included
+    in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+    NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+    DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+    OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+    USE OR OTHER DEALINGS IN THE SOFTWARE.
+  """
+
 - OpenSSL, located at deps/openssl, is licensed as follows:
   """
     Copyright (c) 1998-2018 The OpenSSL Project.  All rights reserved.

configure.py

@@ -182,6 +182,11 @@
     help='Use the specified path to system CA (PEM format) in addition to '
          'the OpenSSL supplied CA store or compiled-in Mozilla CA copy.')
 
+parser.add_option('--experimental-http-parser',
+    action='store_true',
+    dest='experimental_http_parser',
+    help='use llhttp instead of http_parser')
+
 shared_optgroup.add_option('--shared-http-parser',
     action='store_true',
     dest='shared_http_parser',
@@ -1100,6 +1105,9 @@ def configure_node(o):
   else:
     o['variables']['node_target_type'] = 'executable'
 
+  o['variables']['node_experimental_http_parser'] = \
+      b(options.experimental_http_parser)
+
 def configure_library(lib, output):
   shared_lib = 'shared_' + lib
   output['variables']['node_' + shared_lib] = b(getattr(options, shared_lib))

deps/llhttp/LICENSE-MIT

@@ -0,0 +1,22 @@
+This software is licensed under the MIT License.
+
+Copyright Fedor Indutny, 2018.
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to permit
+persons to whom the Software is furnished to do so, subject to the
+following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+USE OR OTHER DEALINGS IN THE SOFTWARE.

deps/llhttp/README.md

@@ -0,0 +1,129 @@
+# llhttp
+[![Build Status](https://secure.travis-ci.org/indutny/llhttp.svg)](http://travis-ci.org/indutny/llhttp)
+
+Port of [http_parser][0] to [llparse][1].
+
+## Why?
+
+Let's face it, [http_parser][0] is practically unmaintainable. Even
+introduction of a single new method results in a significant code churn.
+
+This project aims to:
+
+* Make it maintainable
+* Verifiable
+* Improving benchmarks where possible
+
+## How?
+
+Over time, different approaches for improving [http_parser][0]'s code base
+were tried. However, all of them failed due to resulting significant performance
+degradation.
+
+This project is a port of [http_parser][0] to TypeScript. [llparse][1] is used
+to generate the output C and/or bitcode artifacts, which could be compiled and
+linked with the embedder's program (like [Node.js][7]).
+
+## Peformance
+
+So far llhttp outperforms http_parser:
+
+|                 | input size |  bandwidth   |  reqs/sec  |   time  |
+|:----------------|-----------:|-------------:|-----------:|--------:|
+| **llhttp** _(C)_ | 8192.00 mb | 1497.88 mb/s | 3020458.87 ops/sec | 5.47 s |
+| **llhttp** _(bitcode)_ | 8192.00 mb | 1131.75 mb/s | 2282171.24 ops/sec | 7.24 s |
+| **http_parser** | 8192.00 mb | 694.66 mb/s | 1406180.33 req/sec | 11.79 s |
+
+llhttp is faster by approximately **116%**.
+
+## Maintenance
+
+llhttp project has about 1400 lines of TypeScript code describing the parser
+itself and around 450 lines of C code and headers providing the helper methods.
+The whole [http_parser][0] is implemented in approximately 2500 lines of C, and
+436 lines of headers.
+
+All optimizations and multi-character matching in llhttp are generated
+automatically, and thus doesn't add any extra maintenance cost. On the contrary,
+most of http_parser's code is hand-optimized and unrolled. Instead describing
+"how" it should parse the HTTP requests/responses, a maintainer should
+implement the new features in [http_parser][0] cautiously, considering
+possible performance degradation and manually optimizing the new code.
+
+## Verification
+
+The state machine graph is encoded explicitly in llhttp. The [llparse][1]
+automatically checks the graph for absence of loops and correct reporting of the
+input ranges (spans) like header names and values. In the future, additional
+checks could be performed to get even stricter verification of the llhttp.
+
+## Usage
+
+```C
+#include "llhttp.h"
+
+llhttp_t parser;
+llhttp_settings_t settings;
+
+/* Initialize user callbacks and settings */
+llhttp_settings_init(&settings);
+
+/* Set user callback */
+settings.on_message_complete = handle_on_message_complete;
+
+/* Initialize the parser in HTTP_BOTH mode, meaning that it will select between
+ * HTTP_REQUEST and HTTP_RESPONSE parsing automatically while reading the first
+ * input.
+ */
+llhttp_init(&parser, HTTP_BOTH, &settings);
+
+/* Use `llhttp_set_type(&parser, HTTP_REQUEST);` to override the mode */
+
+/* Parse request! */
+const char* request = "GET / HTTP/1.1\r\n\r\n";
+int request_len = strlen(request);
+
+enum llhttp_errno err = llhttp_execute(&parser, request, request_len);
+if (err == HPE_OK) {
+  /* Successfully parsed! */
+} else {
+  fprintf(stderr, "Parse error: %s %s\n", llhttp_errno_name(err),
+          parser.reason);
+}
+```
+
+---
+
+#### LICENSE
+
+This software is licensed under the MIT License.
+
+Copyright Fedor Indutny, 2018.
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to permit
+persons to whom the Software is furnished to do so, subject to the
+following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+[0]: https://github.com/nodejs/http-parser
+[1]: https://github.com/indutny/llparse
+[2]: https://en.wikipedia.org/wiki/Register_allocation#Spilling
+[3]: https://en.wikipedia.org/wiki/Tail_call
+[4]: https://llvm.org/docs/LangRef.html
+[5]: https://llvm.org/docs/LangRef.html#call-instruction
+[6]: https://clang.llvm.org/
+[7]: https://github.com/nodejs/node

deps/llhttp/common.gypi

@@ -0,0 +1,46 @@
+{
+  'target_defaults': {
+    'default_configuration': 'Debug',
+    'configurations': {
+      # TODO: hoist these out and put them somewhere common, because
+      #       RuntimeLibrary MUST MATCH across the entire project
+      'Debug': {
+        'defines': [ 'DEBUG', '_DEBUG' ],
+        'cflags': [ '-Wall', '-Wextra', '-O0', '-g', '-ftrapv' ],
+        'msvs_settings': {
+          'VCCLCompilerTool': {
+            'RuntimeLibrary': 1, # static debug
+          },
+        },
+      },
+      'Release': {
+        'defines': [ 'NDEBUG' ],
+        'cflags': [ '-Wall', '-Wextra', '-O3' ],
+        'msvs_settings': {
+          'VCCLCompilerTool': {
+            'RuntimeLibrary': 0, # static release
+          },
+        },
+      }
+    },
+    'msvs_settings': {
+      'VCCLCompilerTool': {
+        # Compile as C++. llhttp.c is actually C99, but C++ is
+        # close enough in this case.
+        'CompileAs': 2,
+      },
+      'VCLibrarianTool': {
+      },
+      'VCLinkerTool': {
+        'GenerateDebugInformation': 'true',
+      },
+    },
+    'conditions': [
+      ['OS == "win"', {
+        'defines': [
+          'WIN32'
+        ],
+      }]
+    ],
+  },
+}