src: add /json/protocol endpoint to inspector

Embed the compressed and minified protocol.json from the bundled
v8_inspector and make it available through the /json/protocol endpoint.

Refs: nodejs/diagnostics#52
PR-URL: #7491
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

deps/zlib/zlib.gyp

@@ -12,6 +12,7 @@
         {
           'target_name': 'zlib',
           'type': 'static_library',
+          'defines': [ 'ZLIB_CONST' ],
           'sources': [
             'adler32.c',
             'compress.c',
@@ -44,6 +45,7 @@
             '.',
           ],
           'direct_dependent_settings': {
+            'defines': [ 'ZLIB_CONST' ],
             'include_dirs': [
               '.',
             ],
@@ -72,10 +74,12 @@
           'direct_dependent_settings': {
             'defines': [
               'USE_SYSTEM_ZLIB',
+              'ZLIB_CONST',
             ],
           },
           'defines': [
             'USE_SYSTEM_ZLIB',
+            'ZLIB_CONST',
           ],
           'link_settings': {
             'libraries': [

node.gyp

@@ -323,6 +323,7 @@
           'dependencies': [
             'deps/v8_inspector/third_party/v8_inspector/platform/'
                 'v8_inspector/v8_inspector.gyp:v8_inspector_stl',
+            'v8_inspector_compress_protocol_json#host',
           ],
           'include_dirs': [
             'deps/v8_inspector/third_party/v8_inspector',
@@ -651,6 +652,34 @@
         } ]
       ]
     },
+    {
+      'target_name': 'v8_inspector_compress_protocol_json',
+      'type': 'none',
+      'toolsets': ['host'],
+      'conditions': [
+        [ 'v8_inspector=="true"', {
+          'actions': [
+            {
+              'action_name': 'v8_inspector_compress_protocol_json',
+              'process_outputs_as_sources': 1,
+              'inputs': [
+                'deps/v8_inspector/third_party/'
+                    'v8_inspector/platform/v8_inspector/js_protocol.json',
+              ],
+              'outputs': [
+                '<(SHARED_INTERMEDIATE_DIR)/v8_inspector_protocol_json.h',
+              ],
+              'action': [
+                'python',
+                'tools/compress_json.py',
+                '<@(_inputs)',
+                '<@(_outputs)',
+              ],
+            },
+          ],
+        }],
+      ],
+    },
     {
       'target_name': 'node_js2c',
       'type': 'none',

src/inspector_agent.cc

@@ -8,6 +8,7 @@
 #include "node_version.h"
 #include "v8-platform.h"
 #include "util.h"
+#include "zlib.h"
 
 #include "platform/v8_inspector/public/InspectorVersion.h"
 #include "platform/v8_inspector/public/V8Inspector.h"
@@ -41,6 +42,10 @@ const char TAG_DISCONNECT[] = "#disconnect";
 const char DEVTOOLS_PATH[] = "/node";
 const char DEVTOOLS_HASH[] = V8_INSPECTOR_REVISION;
 
+static const uint8_t PROTOCOL_JSON[] = {
+#include "v8_inspector_protocol_json.h"  // NOLINT(build/include_order)
+};
+
 void PrintDebuggerReadyMessage(int port) {
   fprintf(stderr, "Debugger listening on port %d.\n"
     "Warning: This is an experimental feature and could change at any time.\n"
@@ -161,6 +166,27 @@ void SendTargentsListResponse(InspectorSocket* socket,
   SendHttpResponse(socket, buffer.data(), len);
 }
 
+void SendProtocolJson(InspectorSocket* socket) {
+  z_stream strm;
+  strm.zalloc = Z_NULL;
+  strm.zfree = Z_NULL;
+  strm.opaque = Z_NULL;
+  CHECK_EQ(Z_OK, inflateInit(&strm));
+  static const size_t kDecompressedSize =
+      PROTOCOL_JSON[0] * 0x10000u +
+      PROTOCOL_JSON[1] * 0x100u +
+      PROTOCOL_JSON[2];
+  strm.next_in = PROTOCOL_JSON + 3;
+  strm.avail_in = sizeof(PROTOCOL_JSON) - 3;
+  std::vector<char> data(kDecompressedSize);
+  strm.next_out = reinterpret_cast<Byte*>(&data[0]);
+  strm.avail_out = data.size();
+  CHECK_EQ(Z_STREAM_END, inflate(&strm, Z_FINISH));
+  CHECK_EQ(0, strm.avail_out);
+  CHECK_EQ(Z_OK, inflateEnd(&strm));
+  SendHttpResponse(socket, &data[0], data.size());
+}
+
 const char* match_path_segment(const char* path, const char* expected) {
   size_t len = strlen(expected);
   if (StringEqualNoCaseN(path, expected, len)) {
@@ -179,6 +205,8 @@ bool RespondToGet(InspectorSocket* socket, const std::string& script_name_,
 
   if (match_path_segment(command, "list") || command[0] == '\0') {
     SendTargentsListResponse(socket, script_name_, script_path_, port);
+  } else if (match_path_segment(command, "protocol")) {
+    SendProtocolJson(socket);
   } else if (match_path_segment(command, "version")) {
     SendVersionResponse(socket);
   } else {

test/common.js

@@ -16,6 +16,7 @@ exports.testDir = __dirname;
 exports.fixturesDir = path.join(exports.testDir, 'fixtures');
 exports.libDir = path.join(exports.testDir, '../lib');
 exports.tmpDirName = 'tmp';
+// PORT should match the definition in test/testpy/__init__.py.
 exports.PORT = +process.env.NODE_COMMON_PORT || 12346;
 exports.isWindows = process.platform === 'win32';
 exports.isWOW64 = exports.isWindows &&

test/parallel/test-v8-inspector-json-protocol.js

@@ -0,0 +1,22 @@
+// Flags: --inspect={PORT}
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const http = require('http');
+
+const options = {
+  path: '/json/protocol',
+  port: common.PORT,
+  host: common.localhostIPv4,
+};
+
+http.get(options, common.mustCall((res) => {
+  let body = '';
+  res.setEncoding('utf8');
+  res.on('data', (data) => body += data);
+  res.on('end', common.mustCall(() => {
+    assert(body.length > 0);
+    assert.deepStrictEqual(JSON.stringify(JSON.parse(body)), body);
+  }));
+}));

test/testpy/__init__.py

@@ -61,7 +61,10 @@ def GetCommand(self):
     source = open(self.file).read()
     flags_match = FLAGS_PATTERN.search(source)
     if flags_match:
-      result += flags_match.group(1).strip().split()
+      # PORT should match the definition in test/common.js.
+      env = { 'PORT': int(os.getenv('NODE_COMMON_PORT', '12346')) }
+      env['PORT'] += self.thread_id * 100
+      result += flags_match.group(1).strip().format(**env).split()
     files_match = FILES_PATTERN.search(source);
     additional_files = []
     if files_match:

tools/compress_json.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env python
+
+import json
+import struct
+import sys
+import zlib
+
+if __name__ == '__main__':
+  fp = open(sys.argv[1])
+  obj = json.load(fp)
+  text = json.dumps(obj, separators=(',', ':'))
+  data = zlib.compress(text, zlib.Z_BEST_COMPRESSION)
+
+  # To make decompression a little easier, we prepend the compressed data
+  # with the size of the uncompressed data as a 24 bits BE unsigned integer.
+  assert len(text) < 1 << 24, 'Uncompressed JSON must be < 16 MB.'
+  data = struct.pack('>I', len(text))[1:4] + data
+
+  step = 20
+  slices = (data[i:i+step] for i in xrange(0, len(data), step))
+  slices = map(lambda s: ','.join(str(ord(c)) for c in s), slices)
+  text = ',\n'.join(slices)
+
+  fp = open(sys.argv[2], 'w')
+  fp.write(text)