src: combine internal file read utils

Author: devsnek

src/module_wrap.cc

@@ -510,29 +510,6 @@ inline bool ShouldBeTreatedAsRelativeOrAbsolutePath(
   return false;
 }
 
-std::string ReadFile(uv_file file) {
-  std::string contents;
-  uv_fs_t req;
-  char buffer_memory[4096];
-  uv_buf_t buf = uv_buf_init(buffer_memory, sizeof(buffer_memory));
-
-  do {
-    const int r = uv_fs_read(nullptr,
-                             &req,
-                             file,
-                             &buf,
-                             1,
-                             contents.length(),  // offset
-                             nullptr);
-    uv_fs_req_cleanup(&req);
-
-    if (r <= 0)
-      break;
-    contents.append(buf.base, r);
-  } while (true);
-  return contents;
-}
-
 enum DescriptorType {
   FILE,
   DIRECTORY,
@@ -583,16 +560,6 @@ DescriptorType CheckDescriptorAtPath(const std::string& path) {
   return type;
 }
 
-Maybe<std::string> ReadIfFile(const std::string& path) {
-  Maybe<uv_file> fd = OpenDescriptor(path);
-  if (fd.IsNothing()) return Nothing<std::string>();
-  DescriptorType type = CheckDescriptorAtFile(fd.FromJust());
-  if (type != FILE) return Nothing<std::string>();
-  std::string source = ReadFile(fd.FromJust());
-  CloseDescriptor(fd.FromJust());
-  return Just(source);
-}
-
 using Exists = PackageConfig::Exists;
 using IsValid = PackageConfig::IsValid;
 using HasMain = PackageConfig::HasMain;
@@ -614,7 +581,7 @@ Maybe<const PackageConfig*> GetPackageConfig(Environment* env,
     return Just(pcfg);
   }
 
-  Maybe<std::string> source = ReadIfFile(path);
+  Maybe<std::string> source = ReadFileSync(path);
 
   if (source.IsNothing()) {
     auto entry = env->package_json_cache.emplace(path,

src/node_file.cc

@@ -812,56 +812,22 @@ void Close(const FunctionCallbackInfo<Value>& args) {
 static void InternalModuleReadJSON(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
   Isolate* isolate = env->isolate();
-  uv_loop_t* loop = env->event_loop();
 
   CHECK(args[0]->IsString());
   node::Utf8Value path(isolate, args[0]);
 
-  if (strlen(*path) != path.length())
-    return;  // Contains a nul byte.
-
-  uv_fs_t open_req;
-  const int fd = uv_fs_open(loop, &open_req, *path, O_RDONLY, 0, nullptr);
-  uv_fs_req_cleanup(&open_req);
-
-  if (fd < 0) {
+  std::string chars;
+  const ssize_t nread = ReadFileSyncRaw(*path, path.length(), &chars);
+  if (nread < 0) {
     return;
   }
 
-  std::shared_ptr<void> defer_close(nullptr, [fd, loop] (...) {
-    uv_fs_t close_req;
-    CHECK_EQ(0, uv_fs_close(loop, &close_req, fd, nullptr));
-    uv_fs_req_cleanup(&close_req);
-  });
-
-  const size_t kBlockSize = 32 << 10;
-  std::vector<char> chars;
-  int64_t offset = 0;
-  ssize_t numchars;
-  do {
-    const size_t start = chars.size();
-    chars.resize(start + kBlockSize);
-
-    uv_buf_t buf;
-    buf.base = &chars[start];
-    buf.len = kBlockSize;
-
-    uv_fs_t read_req;
-    numchars = uv_fs_read(loop, &read_req, fd, &buf, 1, offset, nullptr);
-    uv_fs_req_cleanup(&read_req);
-
-    if (numchars < 0)
-      return;
-
-    offset += numchars;
-  } while (static_cast<size_t>(numchars) == kBlockSize);
-
   size_t start = 0;
-  if (offset >= 3 && 0 == memcmp(&chars[0], "\xEF\xBB\xBF", 3)) {
+  if (nread >= 3 && 0 == memcmp(&chars[0], "\xEF\xBB\xBF", 3)) {
     start = 3;  // Skip UTF-8 BOM.
   }
 
-  const size_t size = offset - start;
+  const size_t size = nread - start;
   char* p = &chars[start];
   char* pe = &chars[size];
   char* pos[2];

src/node_native_module.cc

@@ -1,5 +1,6 @@
 #include "node_native_module.h"
 #include "util-inl.h"
+#include "node_internals.h"
 
 namespace node {
 namespace native_module {
@@ -195,33 +196,7 @@ MaybeLocal<String> NativeModuleLoader::LoadBuiltinModuleSource(Isolate* isolate,
                                                                const char* id) {
 #ifdef NODE_BUILTIN_MODULES_PATH
   std::string filename = OnDiskFileName(id);
-
-  uv_fs_t req;
-  uv_file file =
-      uv_fs_open(nullptr, &req, filename.c_str(), O_RDONLY, 0, nullptr);
-  CHECK_GE(req.result, 0);
-  uv_fs_req_cleanup(&req);
-
-  std::shared_ptr<void> defer_close(nullptr, [file](...) {
-    uv_fs_t close_req;
-    CHECK_EQ(0, uv_fs_close(nullptr, &close_req, file, nullptr));
-    uv_fs_req_cleanup(&close_req);
-  });
-
-  std::string contents;
-  char buffer[4096];
-  uv_buf_t buf = uv_buf_init(buffer, sizeof(buffer));
-
-  while (true) {
-    const int r =
-        uv_fs_read(nullptr, &req, file, &buf, 1, contents.length(), nullptr);
-    CHECK_GE(req.result, 0);
-    uv_fs_req_cleanup(&req);
-    if (r <= 0) {
-      break;
-    }
-    contents.append(buf.base, r);
-  }
+  std::string contents = ReadFileSync(filename).FromJust();
 
   return String::NewFromUtf8(
       isolate, contents.c_str(), v8::NewStringType::kNormal, contents.length());

src/util.cc

@@ -56,7 +56,10 @@ namespace node {
 
 using v8::ArrayBufferView;
 using v8::Isolate;
+using v8::Just;
 using v8::Local;
+using v8::Maybe;
+using v8::Nothing;
 using v8::String;
 using v8::Value;
 
@@ -218,6 +221,62 @@ int WriteFileSync(v8::Isolate* isolate,
   return WriteFileSync(path, buf);
 }
 
+ssize_t ReadFileSyncRaw(
+    const char* path, size_t path_len, std::string* contents) {
+  if (strlen(path) != path_len) {
+    return UV_EINVAL;  // Contains a nul byte.
+  }
+
+  uv_fs_t req;
+
+  const int fd = uv_fs_open(nullptr, &req, path, O_RDONLY, 0, nullptr);
+  uv_fs_req_cleanup(&req);
+  if (fd < 0) {
+    return static_cast<ssize_t>(fd);
+  }
+
+  std::shared_ptr<void> defer_close(nullptr, [fd] (...) {
+    uv_fs_t close_req;
+    CHECK_EQ(0, uv_fs_close(nullptr, &close_req, fd, nullptr));
+    uv_fs_req_cleanup(&close_req);
+  });
+
+  const size_t kBlockSize = 32 << 10;
+  size_t offset = 0;
+  while (true) {
+    contents->resize(offset + kBlockSize);
+
+    uv_buf_t buf;
+    buf.base = &(*contents)[offset];
+    buf.len = kBlockSize;
+
+    const ssize_t r = uv_fs_read(nullptr, &req, fd, &buf, 1, offset, nullptr);
+    uv_fs_req_cleanup(&req);
+
+    if (r < 0) {
+      return r;
+    }
+
+    offset += r;
+
+    if (static_cast<size_t>(r) != kBlockSize) {
+      break;
+    }
+  }
+
+  return static_cast<ssize_t>(offset);
+}
+
+Maybe<std::string> ReadFileSync(const std::string& path) {
+  std::string contents;
+  const ssize_t nread = ReadFileSyncRaw(path.c_str(), path.length(), &contents);
+  if (nread < 0) {
+    return Nothing<std::string>();
+  }
+  contents.resize(static_cast<size_t>(nread));
+  return Just(contents);
+}
+
 void DiagnosticFilename::LocalTime(TIME_TYPE* tm_struct) {
 #ifdef _WIN32
   GetLocalTime(tm_struct);

src/util.h

@@ -764,6 +764,10 @@ class PersistentToLocal {
   }
 };
 
+ssize_t ReadFileSyncRaw(
+    const char* path, size_t path_len, std::string* contents);
+v8::Maybe<std::string> ReadFileSync(const std::string& path);
+
 }  // namespace node
 
 #endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS