From: isaacs <i@izs.me>
Date: Wed, 21 Aug 2013 22:36:50 +0000 (-0700)
Subject: process: Add internal _rawDebug() method
X-Git-Tag: v0.11.7~10
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=906a175a0b40fc56dfafbe0929e4fbbb4df68ff2;p=platform%2Fupstream%2Fnodejs.git

process: Add internal _rawDebug() method

This is useful when we need to push some debugging messages out to
stderr, without going through the Writable class, or triggering any kind
of nextTick or callback behavior.
---

diff --git a/src/node.cc b/src/node.cc
index c26c1d2..3f49ec4 100644
--- a/src/node.cc
+++ b/src/node.cc
@@ -2525,6 +2525,22 @@ static void SignalExit(int signal) {
 }
 
 
+// Most of the time, it's best to use `console.error` to write
+// to the process.stderr stream.  However, in some cases, such as
+// when debugging the stream.Writable class or the process.nextTick
+// function, it is useful to bypass JavaScript entirely.
+static void RawDebug(const FunctionCallbackInfo<Value>& args) {
+  HandleScope scope(node_isolate);
+
+  assert(args.Length() == 1 && args[0]->IsString() &&
+         "must be called with a single string");
+
+  String::Utf8Value message(args[0]);
+  fprintf(stderr, "%s\n", *message);
+  fflush(stderr);
+}
+
+
 void Load(Handle<Object> process_l) {
   HandleScope handle_scope(node_isolate);
 
@@ -2581,6 +2597,8 @@ void Load(Handle<Object> process_l) {
   // thrown during process startup.
   try_catch.SetVerbose(true);
 
+  NODE_SET_METHOD(process_l, "_rawDebug", RawDebug);
+
   Local<Value> arg = process_l;
   f->Call(global, 1, &arg);
 }
diff --git a/src/node.js b/src/node.js
index 2df4ebb..3c7ede8 100644
--- a/src/node.js
+++ b/src/node.js
@@ -55,6 +55,8 @@
 
     startup.processChannel();
 
+    startup.processRawDebug();
+
     startup.resolveArgv0();
 
     // There are various modes that Node can run in. The most common two
@@ -649,7 +651,17 @@
       cp._forkChild(fd);
       assert(process.send);
     }
-  }
+  };
+
+
+  startup.processRawDebug = function() {
+    var format = NativeModule.require('util').format;
+    var rawDebug = process._rawDebug;
+    process._rawDebug = function() {
+      rawDebug(format.apply(null, arguments));
+    };
+  };
+
 
   startup.resolveArgv0 = function() {
     var cwd = process.cwd();
diff --git a/test/simple/test-process-raw-debug.js b/test/simple/test-process-raw-debug.js
new file mode 100644
index 0000000..260725d
--- /dev/null
+++ b/test/simple/test-process-raw-debug.js
@@ -0,0 +1,70 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// 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.
+
+var common = require('../common');
+var assert = require('assert');
+
+switch (process.argv[2]) {
+  case 'child':
+    return child();
+  case undefined:
+    return parent();
+  default:
+    throw new Error('wtf? ' + process.argv[2]);
+}
+
+function parent() {
+  var spawn = require('child_process').spawn;
+  var child = spawn(process.execPath, [__filename, 'child']);
+
+  var output = '';
+
+  child.stderr.on('data', function(c) {
+    output += c;
+  });
+
+  child.stderr.setEncoding('utf8');
+
+  child.stderr.on('end', function() {
+    assert.equal(output, 'I can still debug!\n');
+    console.log('ok - got expected message');
+  });
+
+  child.on('exit', function(c) {
+    assert(!c);
+    console.log('ok - child exited nicely');
+  });
+}
+
+function child() {
+  // even when all hope is lost...
+
+  process.nextTick = function() {
+    throw new Error('No ticking!');
+  };
+
+  var stderr = process.stderr;
+  stderr.write = function() {
+    throw new Error('No writing to stderr!');
+  };
+
+  process._rawDebug('I can still %s!', 'debug');
+}