fs: refactor stats array to be more generic

- Pass kFsStatsFieldsLength between JS and C++ instead of using the
  magic number 14
- Pass the global stats array to the completion callback of
  asynchronous FSReqWrap similar to how the stats arrays are passed
  to the FSReqPromise resolvers
- Abstract the stats converter and take an offset to compute the
  old stats in fs.watchFile
- Use templates in node::FillStatsArray and FSReqPromise in preparation
  for BigInt intergration
- Put the global stat array filler in node_internals.h because it is
  shared by node_file.cc and node_stat_watcher.cc

PR-URL: https://github.com/nodejs/node/pull/19714
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 42 insertions, 2 deletions

diff --git a/src/node_internals.h b/src/node_internals.h
index 6439ccc7a2..8cc1aa1a8f 100644
--- a/src/node_internals.h
+++ b/src/node_internals.h
@@ -307,8 +307,48 @@ v8::Maybe<bool> ProcessEmitDeprecationWarning(Environment* env,
                                               const char* warning,
                                               const char* deprecation_code);
 
-void FillStatsArray(AliasedBuffer<double, v8::Float64Array>* fields_ptr,
-                    const uv_stat_t* s, int offset = 0);
+template <typename NativeT, typename V8T>
+void FillStatsArray(AliasedBuffer<NativeT, V8T>* fields_ptr,
+                    const uv_stat_t* s, int offset = 0) {
+  AliasedBuffer<NativeT, V8T>& fields = *fields_ptr;
+  fields[offset + 0] = s->st_dev;
+  fields[offset + 1] = s->st_mode;
+  fields[offset + 2] = s->st_nlink;
+  fields[offset + 3] = s->st_uid;
+  fields[offset + 4] = s->st_gid;
+  fields[offset + 5] = s->st_rdev;
+#if defined(__POSIX__)
+  fields[offset + 6] = s->st_blksize;
+#else
+  fields[offset + 6] = -1;
+#endif
+  fields[offset + 7] = s->st_ino;
+  fields[offset + 8] = s->st_size;
+#if defined(__POSIX__)
+  fields[offset + 9] = s->st_blocks;
+#else
+  fields[offset + 9] = -1;
+#endif
+// Dates.
+// NO-LINT because the fields are 'long' and we just want to cast to `unsigned`
+#define X(idx, name)                                                    \
+  /* NOLINTNEXTLINE(runtime/int) */                                     \
+  fields[offset + idx] = ((unsigned long)(s->st_##name.tv_sec) * 1e3) + \
+  /* NOLINTNEXTLINE(runtime/int) */                                     \
+                ((unsigned long)(s->st_##name.tv_nsec) / 1e6);          \
+
+  X(10, atim)
+  X(11, mtim)
+  X(12, ctim)
+  X(13, birthtim)
+#undef X
+}
+
+inline void FillGlobalStatsArray(Environment* env,
+                                 const uv_stat_t* s,
+                                 int offset = 0) {
+  node::FillStatsArray(env->fs_stats_field_array(), s, offset);
+}
 
 void SetupProcessObject(Environment* env,
                         int argc,