[NaCl SDK] Map active fds to absolute paths.

native_client_sdk/src/libraries/nacl_io/kernel_object.cc

Index: native_client_sdk/src/libraries/nacl_io/kernel_object.cc
diff --git a/native_client_sdk/src/libraries/nacl_io/kernel_object.cc b/native_client_sdk/src/libraries/nacl_io/kernel_object.cc
index fccc5c85fd0cfe7da600482c4d9103531b2266ff..c356607810472d6df64b3c23fea17fa2e10dc9ac 100644
--- a/native_client_sdk/src/libraries/nacl_io/kernel_object.cc
+++ b/native_client_sdk/src/libraries/nacl_io/kernel_object.cc
@@ -152,6 +152,16 @@ Error KernelObject::GetFDFlags(int fd, int* out_flags) {
   return 0;
 }
 
+std::string KernelObject::GetFDPath(int fd) {
+  AUTO_LOCK(handle_lock_);
+
+  FdPathMap_t::iterator iter = fd_paths_.find(fd);
+  if (iter == fd_paths_.end())
+    return std::string();
+
+  return iter->second;
+}
+
 Error KernelObject::SetFDFlags(int fd, int flags) {
   AUTO_LOCK(handle_lock_);
   if (fd < 0 || fd >= static_cast<int>(handle_map_.size()))
@@ -179,7 +189,25 @@ Error KernelObject::AcquireHandle(int fd, ScopedKernelHandle* out_handle) {
   return EBADF;
 }
 
-int KernelObject::AllocateFD(const ScopedKernelHandle& handle) {
+Error KernelObject::AcquireHandleAndPath(int fd, ScopedKernelHandle* out_handle,
+                                         std::string &out_path){

[Sam Clegg, 2014/01/07 23:56:39]

Put '&' next to the type according to the local style.

+  out_handle->reset(NULL);
+
+  AUTO_LOCK(handle_lock_);
+  if (fd < 0 || fd >= static_cast<int>(handle_map_.size()))
+    return EBADF;
+
+  *out_handle = handle_map_[fd].handle;
+  if (!out_handle)
+    return EBADF;
+
+  out_path = fd_paths_[fd];
+
+  return 0;
+}
+
+int KernelObject::AllocateFD(const ScopedKernelHandle& handle,
+                             std::string path) {

[Sam Clegg, 2014/01/07 23:56:39]

Why not pass string by reference here too?

   AUTO_LOCK(handle_lock_);
   int id;
 
@@ -196,10 +224,16 @@ int KernelObject::AllocateFD(const ScopedKernelHandle& handle) {
     id = handle_map_.size();
     handle_map_.push_back(descriptor);
   }
+  // With our final fd identifier, we insert into our fd_paths_ mapping as long
+  // as path is non-NULL.
+  if (!path.empty())
+    fd_paths_[id] = GetAbsParts(path).Join();
+
   return id;
 }
 
-void KernelObject::FreeAndReassignFD(int fd, const ScopedKernelHandle& handle) {
+void KernelObject::FreeAndReassignFD(int fd, const ScopedKernelHandle& handle,
+                                     const std::string &path) {

[Sam Clegg, 2014/01/07 23:56:39]

& next to type name.

   if (NULL == handle) {
     FreeFD(fd);
   } else {
@@ -210,6 +244,8 @@ void KernelObject::FreeAndReassignFD(int fd, const ScopedKernelHandle& handle) {
       handle_map_.resize(fd + 1);
 
     handle_map_[fd] = Descriptor_t(handle);
+    // Safe even if oldfd has no path.
+    fd_paths_[fd] = path;
   }
 }
 
@@ -221,6 +257,9 @@ void KernelObject::FreeFD(int fd) {
 
   // Force lower numbered FD to be available first.
   std::push_heap(free_fds_.begin(), free_fds_.end(), std::greater<int>());
+  //
+  // Remove the FD from the map of fd to absolute path
+  fd_paths_.erase(fd);
 }
 
 }  // namespace nacl_io