1 files changed, 154 insertions, 0 deletions
diff --git a/lib/System/Unix/MappedFile.inc b/lib/System/Unix/MappedFile.inc
new file mode 100644
index 0000000..91b92ec
--- /dev/null
+++ b/lib/System/Unix/MappedFile.inc
@@ -0,0 +1,154 @@
+//===- 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 "Unix.h"
+#include "llvm/System/Process.h"
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+
+namespace llvm {
+using namespace sys;
+
+struct sys::MappedFileInfo {
+  int   FD;
+  off_t Size;
+};
+
+bool MappedFile::initialize(std::string* ErrMsg) {
+  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;
+
+  int FD = ::open(path_.c_str(), mode);
+  if (FD < 0) {
+    MakeErrMsg(ErrMsg, "can't open file '" + path_.toString() + "'");
+    return true;
+  } 
+  const FileStatus *Status = path_.getFileStatus(false, ErrMsg);
+  if (!Status) {
+    ::close(FD);
+    return true;
+  }
+  info_ = new MappedFileInfo;
+  info_->FD = FD;
+  info_->Size = Status->getSize();
+  return false;
+}
+
+void MappedFile::terminate() {
+  assert(info_ && "MappedFile not initialized");
+  ::close(info_->FD);
+  delete info_;
+  info_ = 0;
+}
+
+void MappedFile::unmap() {
+  assert(info_ && "MappedFile not initialized");
+  if (isMapped()) {
+    if (options_ & WRITE_ACCESS)
+      ::msync(base_, info_->Size, MS_SYNC);
+    ::munmap(base_, info_->Size);
+    base_ = 0;  // Mark this as non-mapped.
+  }
+}
+
+void* MappedFile::map(std::string* ErrMsg) {
+  assert(info_ && "MappedFile not initialized");
+  if (!isMapped()) {
+    int prot = PROT_NONE;
+    int flags = 0;
+#ifdef MAP_FILE
+    flags |= MAP_FILE;
+#endif
+    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_->Size / Process::GetPageSize())+1) *
+      Process::GetPageSize();
+
+    base_ = ::mmap(0, map_size, prot, flags, info_->FD, 0);
+    if (base_ == MAP_FAILED) {
+      MakeErrMsg(ErrMsg, "Can't map file:" + path_.toString());
+      return 0;
+    }
+  }
+  return base_;
+}
+
+size_t MappedFile::size() const {
+  assert(info_ && "MappedFile not initialized");
+  return info_->Size;
+}
+
+bool MappedFile::size(size_t new_size, std::string* ErrMsg) {
+  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_->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. 
+    if ((off_t)-1 == ::lseek(info_->FD, new_size, SEEK_SET))
+      return MakeErrMsg(ErrMsg, "Can't lseek: ");
+    if (-1 == ::write(info_->FD, "\0", 1))
+      return MakeErrMsg(ErrMsg, "Can't write: ");
+  }
+
+  // Put the mapping back into memory.
+  return this->map(ErrMsg);
+}
+
+}
+