v8: integrate node-heapdump into core

Adds `v8.writeHeapSnapshot(filename)` with impl adapted
from the `node-heapdump` module.

Also, adds a v8.getHeapSnapshot() alternative that returns
a Readable Stream

PR-URL: https://github.com/nodejs/node/pull/26501
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/src/node_internals.h b/src/node_internals.h
index 355e4ae9fd..d2eadf5109 100644
--- a/src/node_internals.h
+++ b/src/node_internals.h
@@ -299,6 +299,41 @@ v8::MaybeLocal<v8::Value> StartExecution(Environment* env,
 namespace profiler {
 void StartCoverageCollection(Environment* env);
 }
+
+#ifdef _WIN32
+typedef SYSTEMTIME TIME_TYPE;
+#else  // UNIX, OSX
+typedef struct tm TIME_TYPE;
+#endif
+
+class DiagnosticFilename {
+ public:
+  static void LocalTime(TIME_TYPE* tm_struct);
+
+  DiagnosticFilename(Environment* env,
+                     const char* prefix,
+                     const char* ext,
+                     int seq = -1) :
+      filename_(MakeFilename(env->thread_id(), prefix, ext, seq)) {}
+
+  DiagnosticFilename(uint64_t thread_id,
+                     const char* prefix,
+                     const char* ext,
+                     int seq = -1) :
+      filename_(MakeFilename(thread_id, prefix, ext, seq)) {}
+
+  const char* operator*() const { return filename_.c_str(); }
+
+ private:
+  static std::string MakeFilename(
+      uint64_t thread_id,
+      const char* prefix,
+      const char* ext,
+      int seq = -1);
+
+  std::string filename_;
+};
+
 }  // namespace node
 
 #endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS