1 files changed, 34 insertions, 0 deletions
diff --git a/mozglue/linker/Mappable.cpp b/mozglue/linker/Mappable.cpp
new file mode 100644
index 0000000000..55a7aadfcc
--- /dev/null
+++ b/mozglue/linker/Mappable.cpp
@@ -0,0 +1,34 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <fcntl.h>
+#include <sys/stat.h>
+
+#include "Mappable.h"
+
+Mappable* Mappable::Create(const char* path) {
+  int fd = open(path, O_RDONLY);
+  if (fd != -1) return new Mappable(fd);
+  return nullptr;
+}
+
+MemoryRange Mappable::mmap(const void* addr, size_t length, int prot, int flags,
+                           off_t offset) {
+  MOZ_ASSERT(fd && *fd != -1);
+  MOZ_ASSERT(!(flags & MAP_SHARED));
+  flags |= MAP_PRIVATE;
+
+  return MemoryRange::mmap(const_cast<void*>(addr), length, prot, flags, *fd,
+                           offset);
+}
+
+void Mappable::finalize() {
+  /* Close file ; equivalent to close(fd.forget()) */
+  fd.emplace(-1);
+}
+
+size_t Mappable::GetLength() const {
+  struct stat st;
+  return fstat(*fd, &st) ? 0 : st.st_size;
+}