[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..1c495804e9badfd62002b98a5da8934fc3095eef 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 +152,17 @@ 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()) {

[binji, 2014/01/07 21:40:29]

nit: no braces for single-line ifs

+    return "";

[binji, 2014/01/07 21:40:29]

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 +190,8 @@ Error KernelObject::AcquireHandle(int fd, ScopedKernelHandle* out_handle) {
   return EBADF;
 }
 
-int KernelObject::AllocateFD(const ScopedKernelHandle& handle) {
+int KernelObject::AllocateFD(const ScopedKernelHandle& handle,
+                             std::string path) {
   AUTO_LOCK(handle_lock_);
   int id;
 
@@ -196,6 +208,12 @@ 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()) {
+    std::string abs_path = GetAbsParts(path).Join();
+    fd_paths_[id] = abs_path;

[binji, 2014/01/07 21:40:29]

nit: fs_paths_[id] = GetAbsParts(path).Join();

+  }
   return id;
 }
 
@@ -221,6 +239,9 @@ 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