Noissue - Use buffer for FileSystem IO

src/DefaultFileSystem.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 48 matching lines @@
 #else
   // POSIX systems: assume that file system encoding is UTF-8 and just use the
   // file paths as they are.
   std::string NormalizePath(const std::string& path)
   {
     return path;
   }
 #endif
 }
 
-std::shared_ptr<std::istream>
+FileSystem::IOBuffer
 DefaultFileSystem::Read(const std::string& path) const
 {
-  std::shared_ptr<std::istream> result(new std::ifstream(NormalizePath(path).c_str()));
-  if (result->fail())
+  std::ifstream file(NormalizePath(path).c_str(), std::ios_base::binary);
+  if (file.fail())
     throw RuntimeErrorWithErrno("Failed to open " + path);
-  return result;
+
+  file.seekg(0, std::ios_base::end);
+  auto dataSize = file.tellg();
+  file.seekg(0, std::ios_base::beg);
+
+  IOBuffer data(dataSize);
+  file.read(reinterpret_cast<std::ifstream::char_type*>(data.data()),

[sergei, 2017/07/07 07:27:36]

I would prefer to rather use static_cast but it seems fine here.

[hub, 2017/07/07 12:51:00]

static_cast<> is rejected by the compiler:

../src/DefaultFileSystem.cpp:81:13: error: static_cast from 'value_type *' (aka
'unsigned char *') to 'std::ifstream::char_type *' (aka 'char *') is not allowed
  file.read(static_cast<std::ifstream::char_type*>(data.data()),
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

[sergei, 2017/07/07 13:19:37]

Yeah, one has to firstly cast it to void*, basically reinterpret_cast is fine.

+            data.size());
+  return data;
 }
 
 void DefaultFileSystem::Write(const std::string& path,
-                              std::istream& data)
+                              const IOBuffer& data)
 {
   std::ofstream file(NormalizePath(path).c_str(), std::ios_base::out | std::ios_base::binary);
-  file << Utils::Slurp(data);
+  file.write(reinterpret_cast<const std::ofstream::char_type*>(data.data()),
+             data.size());
 }
 
 void DefaultFileSystem::Move(const std::string& fromPath,
                              const std::string& toPath)
 {
   if (rename(NormalizePath(fromPath).c_str(), NormalizePath(toPath).c_str()))
     throw RuntimeErrorWithErrno("Failed to move " + fromPath + " to " + toPath);
 }
 
 void DefaultFileSystem::Remove(const std::string& path)
@@ skipping 94 matching lines @@
 void DefaultFileSystem::SetBasePath(const std::string& path)
 {
   basePath = path;
 
   if (*basePath.rbegin() == PATH_SEPARATOR)
   {
     basePath.resize(basePath.size() - 1);
   }
 }