src: extract AllocatedBuffer from env.h

Cleanup up env.h by removing things that are not
specific to `Environment`.

PR-URL: https://github.com/nodejs/node/pull/33291
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: David Carlier <devnexen@gmail.com>

1 files changed, 63 insertions, 0 deletions

diff --git a/src/allocated_buffer.h b/src/allocated_buffer.h
new file mode 100644
index 00000000000..b54f74b2d27
--- /dev/null
+++ b/src/allocated_buffer.h
@@ -0,0 +1,63 @@
+#ifndef SRC_ALLOCATED_BUFFER_H_
+#define SRC_ALLOCATED_BUFFER_H_
+
+#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
+
+#include "base_object.h"
+#include "uv.h"
+#include "v8.h"
+
+namespace node {
+
+class Environment;
+
+// A unique-pointer-ish object that is compatible with the JS engine's
+// ArrayBuffer::Allocator.
+struct AllocatedBuffer {
+ public:
+  enum AllocateManagedFlags {
+    ALLOCATE_MANAGED_FLAG_NONE,
+    ALLOCATE_MANAGED_UNCHECKED
+  };
+
+  // Utilities that allocate memory using the Isolate's ArrayBuffer::Allocator.
+  // In particular, using AllocateManaged() will provide a RAII-style object
+  // with easy conversion to `Buffer` and `ArrayBuffer` objects.
+  inline static AllocatedBuffer AllocateManaged(
+      Environment* env,
+      size_t size,
+      int flags = ALLOCATE_MANAGED_FLAG_NONE);
+
+  explicit inline AllocatedBuffer(Environment* env = nullptr);
+  inline AllocatedBuffer(Environment* env, uv_buf_t buf);
+  inline ~AllocatedBuffer();
+  inline void Resize(size_t len);
+
+  inline uv_buf_t release();
+  inline char* data();
+  inline const char* data() const;
+  inline size_t size() const;
+  inline void clear();
+
+  inline v8::MaybeLocal<v8::Object> ToBuffer();
+  inline v8::Local<v8::ArrayBuffer> ToArrayBuffer();
+
+  inline AllocatedBuffer(AllocatedBuffer&& other);
+  inline AllocatedBuffer& operator=(AllocatedBuffer&& other);
+  AllocatedBuffer(const AllocatedBuffer& other) = delete;
+  AllocatedBuffer& operator=(const AllocatedBuffer& other) = delete;
+
+ private:
+  Environment* env_;
+  // We do not pass this to libuv directly, but uv_buf_t is a convenient way
+  // to represent a chunk of memory, and plays nicely with other parts of core.
+  uv_buf_t buffer_;
+
+  friend class Environment;
+};
+
+}  // namespace node
+
+#endif  // NODE_WANT_INTERNALS
+
+#endif  // SRC_ALLOCATED_BUFFER_H_