1 files changed, 138 insertions, 0 deletions
diff --git a/lib/System/Unix/MappedFile.cpp b/lib/System/Unix/MappedFile.cpp
new file mode 100644
index 0000000000..d853acec4f
--- /dev/null
+++ b/lib/System/Unix/MappedFile.cpp
@@ -0,0 +1,138 @@
+//===- Unix/MappedFile.cpp - Unix MappedFile Implementation -----*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file provides the generic Unix implementation of the MappedFile concept.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//===          is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+#include "llvm/System/Process.h"
+#include "Unix.h"
+#include <sys/fcntl.h>
+#include <sys/mman.h>
+
+namespace llvm {
+using namespace sys;
+
+struct sys::MappedFileInfo {
+  int fd_;
+  struct stat sbuf_;
+};
+
+void MappedFile::initialize() {
+  if (path_.exists()) {
+    info_ = new MappedFileInfo;
+    int mode = 0;
+    if (options_&READ_ACCESS) 
+      if (options_&WRITE_ACCESS)
+        mode = O_RDWR;
+      else
+        mode = O_RDONLY;
+    else if (options_&WRITE_ACCESS)
+      mode = O_WRONLY;
+    info_->fd_ = ::open(path_.c_str(),mode);
+    if (info_->fd_ < 0) {
+      delete info_;
+      info_ = 0;
+      ThrowErrno(std::string("Can't open file: ") + path_.get());
+    }
+    struct stat sbuf;
+    if(::fstat(info_->fd_, &info_->sbuf_) < 0) {
+      ::close(info_->fd_);
+      delete info_;
+      info_ = 0;
+      ThrowErrno(std::string("Can't stat file: ") + path_.get());
+    }
+  }
+}
+
+void MappedFile::terminate() {
+  assert(info_ && "MappedFile not initialized");
+  if (info_->fd_ >= 0)
+    ::close(info_->fd_);
+  delete info_;
+  info_ = 0;
+}
+
+void MappedFile::unmap() {
+  assert(info_ && "MappedFile not initialized");
+  if (isMapped()) {
+    if (options_ & WRITE_ACCESS)
+      ::msync(base_, info_->sbuf_.st_size, MS_SYNC);
+    ::munmap(base_, info_->sbuf_.st_size);
+  }
+}
+
+void* MappedFile::map() {
+  if (!isMapped()) {
+    int prot = PROT_NONE;
+    int flags = MAP_FILE;
+    if (options_ == 0) {
+      prot = PROT_READ;
+      flags = MAP_PRIVATE;
+    } else {
+      if (options_ & READ_ACCESS)
+        prot |= PROT_READ;
+      if (options_ & WRITE_ACCESS)
+        prot |= PROT_WRITE;
+      if (options_ & EXEC_ACCESS)
+        prot |= PROT_EXEC;
+      if (options_ & SHARED_MAPPING)
+        flags |= MAP_SHARED;
+      else
+        flags |= MAP_PRIVATE;
+    }
+    size_t map_size = ((info_->sbuf_.st_size / Process::GetPageSize())+1) *
+      Process::GetPageSize();
+
+    base_ = ::mmap(0, map_size, prot, flags, info_->fd_, 0);
+    if (base_ == MAP_FAILED)
+      ThrowErrno(std::string("Can't map file:") + path_.get());
+  }
+  return base_;
+}
+
+size_t MappedFile::size() {
+  assert(info_ && "MappedFile not initialized");
+  return info_->sbuf_.st_size;
+}
+
+void MappedFile::size(size_t new_size) {
+  assert(info_ && "MappedFile not initialized");
+
+  // Take the mapping out of memory
+  this->unmap();
+
+  // Adjust the current size to a page boundary
+  size_t cur_size = ((info_->sbuf_.st_size / Process::GetPageSize())+1) *
+    Process::GetPageSize();
+
+  // Adjust the new_size to a page boundary
+  new_size = ((new_size / Process::GetPageSize())+1) *
+    Process::GetPageSize();
+
+  // If the file needs to be extended
+  if (new_size > cur_size) {
+    // Ensure we can allocate at least the idodes necessary to handle the
+    // file size requested. 
+    ::lseek(info_->fd_, new_size, SEEK_SET);
+    ::write(info_->fd_, "\0", 1);
+  }
+
+  // Seek to current end of file. 
+  this->map();
+}
+
+}
+
+// vim: sw=2 smartindent smarttab tw=80 autoindent expandtab