src: standardise context embedder indices

PR-URL: https://github.com/nodejs/node/pull/19135
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Matheus Marchini <matheus@sthima.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/src/node_context_data.h b/src/node_context_data.h
new file mode 100644
index 0000000000..9d3145bb80
--- /dev/null
+++ b/src/node_context_data.h
@@ -0,0 +1,25 @@
+#ifndef SRC_NODE_CONTEXT_DATA_H_
+#define SRC_NODE_CONTEXT_DATA_H_
+
+namespace node {
+
+// Pick an index that's hopefully out of the way when we're embedded inside
+// another application. Performance-wise or memory-wise it doesn't matter:
+// Context::SetAlignedPointerInEmbedderData() is backed by a FixedArray,
+// worst case we pay a one-time penalty for resizing the array.
+#ifndef NODE_CONTEXT_EMBEDDER_DATA_INDEX
+#define NODE_CONTEXT_EMBEDDER_DATA_INDEX 32
+#endif
+
+#ifndef NODE_CONTEXT_SANDBOX_OBJECT_INDEX
+#define NODE_CONTEXT_SANDBOX_OBJECT_INDEX 33
+#endif
+
+enum ContextEmbedderIndex {
+  kEnvironment = NODE_CONTEXT_EMBEDDER_DATA_INDEX,
+  kSandboxObject = NODE_CONTEXT_SANDBOX_OBJECT_INDEX,
+};
+
+}  // namespace node
+
+#endif  // SRC_NODE_CONTEXT_DATA_H_