chore: Remove HttpBodyChunk in favor of HostString (#451)

Cleanup the host_api interface a bit, by standardizing more on HostString.

Author: elliottt

c-dependencies/js-compute-runtime/builtins/request-response.cpp

@@ -59,7 +59,7 @@ struct ReadResult {
 // Returns a UniqueChars and the length of that string. The UniqueChars value is not
 // null-terminated.
 ReadResult read_from_handle_all(JSContext *cx, uint32_t handle) {
-  std::vector<HttpBodyChunk> chunks;
+  std::vector<HostString> chunks;
   size_t bytes_read = 0;
   HttpBody body{handle};
   while (true) {

c-dependencies/js-compute-runtime/builtins/request-response.h

@@ -3,7 +3,7 @@
 
 #include "builtin.h"
 #include "builtins/headers.h"
-#include "c-at-e-world/c_at_e_world.h"
+#include "host_interface/host_api.h"
 
 namespace builtins {
 

c-dependencies/js-compute-runtime/host_interface/host_api.cpp

@@ -18,8 +18,8 @@ Result<HttpBody> HttpBody::make() {
   return res;
 }
 
-Result<HttpBodyChunk> HttpBody::read(uint32_t chunk_size) const {
-  Result<HttpBodyChunk> res;
+Result<HostString> HttpBody::read(uint32_t chunk_size) const {
+  Result<HostString> res;
 
   fastly_list_u8_t ret;
   fastly_error_t err;

c-dependencies/js-compute-runtime/host_interface/host_api.h

@@ -67,13 +67,27 @@ template <typename T> class Result final {
   T &unwrap() { return std::get<T>(this->result); }
 };
 
-/// A single chunk read from an HttpBody.
-struct HttpBodyChunk final {
+/// A string allocated by the host interface. Holds ownership of the data.
+struct HostString final {
   JS::UniqueChars ptr;
   size_t len;
 
-  HttpBodyChunk() = default;
-  HttpBodyChunk(JS::UniqueChars ptr, size_t len) : ptr{std::move(ptr)}, len{len} {}
+  HostString() = default;
+  explicit HostString(c_at_e_world_string_t str) : ptr{str.ptr}, len{str.len} {}
+  HostString(JS::UniqueChars ptr, size_t len) : ptr{std::move(ptr)}, len{len} {}
+
+  using iterator = char *;
+
+  size_t size() const { return this->len; }
+
+  char *begin() { return this->ptr.get(); }
+  char *end() { return this->begin() + this->len; }
+
+  const char *begin() const { return this->ptr.get(); }
+  const char *end() const { return this->begin() + this->len; }
+
+  /// Conversion to a `std::string_view`.
+  operator std::string_view() { return std::string_view(this->ptr.get(), this->len); }
 };
 
 /// A convenience wrapper for the host calls involving http bodies.
@@ -95,7 +109,7 @@ class HttpBody final {
   static Result<HttpBody> make();
 
   /// Read a chunk from this handle.
-  Result<HttpBodyChunk> read(uint32_t chunk_size) const;
+  Result<HostString> read(uint32_t chunk_size) const;
 
   /// Write a chunk to this handle.
   Result<uint32_t> write(const uint8_t *bytes, size_t len) const;
@@ -113,28 +127,6 @@ class HttpBody final {
   Result<Void> close();
 };
 
-struct HostString final {
-  JS::UniqueChars ptr;
-  size_t len;
-
-  HostString() = default;
-  explicit HostString(c_at_e_world_string_t str) : ptr{str.ptr}, len{str.len} {}
-  HostString(JS::UniqueChars ptr, size_t len) : ptr{std::move(ptr)}, len{len} {}
-
-  using iterator = char *;
-
-  size_t size() const { return this->len; }
-
-  char *begin() { return this->ptr.get(); }
-  char *end() { return this->begin() + this->len; }
-
-  const char *begin() const { return this->ptr.get(); }
-  const char *end() const { return this->begin() + this->len; }
-
-  /// Conversion to a `std::string_view`.
-  operator std::string_view() { return std::string_view(this->ptr.get(), this->len); }
-};
-
 class HttpBase {
 public:
   virtual ~HttpBase() = default;

c-dependencies/js-compute-runtime/js-compute-builtins.cpp

@@ -161,7 +161,7 @@ struct ReadResult {
 // Returns a UniqueChars and the length of that string. The UniqueChars value is not
 // null-terminated.
 ReadResult read_from_handle_all(JSContext *cx, uint32_t handle) {
-  std::vector<HttpBodyChunk> chunks;
+  std::vector<HostString> chunks;
   size_t bytes_read = 0;
   HttpBody body{handle};
   while (true) {