revert r6938

(i.e. reapply 6935, with fix)
Review URL: http://codereview.chromium.org/14087

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@6953 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 72 insertions, 27 deletions

diff --git a/base/file_util.cc b/base/file_util.cc
index 10e08d5..1cf22b7 100644
--- a/base/file_util.cc
+++ b/base/file_util.cc
@@ -275,6 +275,29 @@ bool CloseFile(FILE* file) {
   return fclose(file) == 0;
 }
 
+///////////////////////////////////////////////
+// MemoryMappedFile
+
+MemoryMappedFile::~MemoryMappedFile() {
+  CloseHandles();
+}
+
+bool MemoryMappedFile::Initialize(const FilePath& file_name) {
+  if (IsValid())
+    return false;
+
+  if (!MapFileToMemory(file_name)) {
+    CloseHandles();
+    return false;
+  }
+
+  return true;
+}
+
+bool MemoryMappedFile::IsValid() {
+  return data_ != NULL;
+}
+
 // Deprecated functions ----------------------------------------------------
 
 bool AbsolutePath(std::wstring* path_str) {
diff --git a/base/file_util.h b/base/file_util.h
index 854703f..d1cfb05 100644
--- a/base/file_util.h
+++ b/base/file_util.h
@@ -414,8 +414,6 @@ class FileEnumerator {
   DISALLOW_EVIL_CONSTRUCTORS(FileEnumerator);
 };
 
-// TODO(port): port this class to posix.
-#if defined(OS_WIN)
 class MemoryMappedFile {
  public:
   // The default constructor sets all members to invalid/null values.
@@ -429,8 +427,8 @@ class MemoryMappedFile {
   // Later we may want to allow the user to specify access.
   bool Initialize(const FilePath& file_name);
 
-  const uint8* Data() const { return data_; }
-  size_t Length() const { return length_; }
+  const uint8* data() const { return data_; }
+  size_t length() const { return length_; }
 
   // Is file_ a valid file handle that points to an open, memory mapped file?
   bool IsValid();
@@ -443,14 +441,18 @@ class MemoryMappedFile {
   // Closes all open handles. Later we may want to make this public.
   void CloseHandles();
 
+#if defined(OS_WIN)
   HANDLE file_;
   HANDLE file_mapping_;
-  const uint8* data_;
+#elif defined(OS_POSIX)
+  // The file descriptor.
+  int file_;
+#endif
+  uint8* data_;
   size_t length_;
 
   DISALLOW_COPY_AND_ASSIGN(MemoryMappedFile);
 };
-#endif  // defined(OS_WIN)
 
 // Renames a file using the SHFileOperation API to ensure that the target file
 // gets the correct default security descriptor in the new path.
diff --git a/base/file_util_posix.cc b/base/file_util_posix.cc
index 153f70a..7448ed8 100644
--- a/base/file_util_posix.cc
+++ b/base/file_util_posix.cc
@@ -12,6 +12,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <sys/errno.h>
+#include <sys/mman.h>
 #include <sys/stat.h>
 #include <time.h>
 
@@ -378,6 +379,9 @@ bool SetCurrentDirectory(const FilePath& path) {
   return !ret;
 }
 
+///////////////////////////////////////////////
+// FileEnumerator
+
 FileEnumerator::FileEnumerator(const FilePath& root_path,
                                bool recursive,
                                FileEnumerator::FILE_TYPE file_type)
@@ -479,5 +483,41 @@ FilePath FileEnumerator::Next() {
   return Next();
 }
 
+///////////////////////////////////////////////
+// MemoryMappedFile
+
+MemoryMappedFile::MemoryMappedFile()
+    : file_(-1),
+      data_(NULL),
+      length_(0) {
+}
+
+bool MemoryMappedFile::MapFileToMemory(const FilePath& file_name) {
+  file_ = open(file_name.value().c_str(), O_RDONLY);
+  if (file_ == -1)
+    return false;
+
+  struct stat file_stat;
+  if (fstat(file_, &file_stat) == -1)
+    return false;
+  length_ = file_stat.st_size;
+
+  data_ = static_cast<uint8*>(
+      mmap(NULL, length_, PROT_READ, MAP_SHARED, file_, 0));
+  if (data_ == MAP_FAILED)
+    data_ = NULL;
+  return data_ != NULL;
+}
+
+void MemoryMappedFile::CloseHandles() {
+  if (data_ != NULL)
+    munmap(data_, length_);
+  if (file_ != -1)
+    close(file_);
+
+  data_ = NULL;
+  length_ = 0;
+  file_ = -1;
+}
 
 } // namespace file_util
diff --git a/base/file_util_win.cc b/base/file_util_win.cc
index c287129..8f372b1 100644
--- a/base/file_util_win.cc
+++ b/base/file_util_win.cc
@@ -704,22 +704,6 @@ MemoryMappedFile::MemoryMappedFile()
       length_(INVALID_FILE_SIZE) {
 }
 
-MemoryMappedFile::~MemoryMappedFile() {
-  CloseHandles();
-}
-
-bool MemoryMappedFile::Initialize(const FilePath& file_name) {
-  if (IsValid())
-    return false;
-
-  if (!MapFileToMemory(file_name)) {
-    CloseHandles();
-    return false;
-  }
-
-  return true;
-}
-
 bool MemoryMappedFile::MapFileToMemory(const FilePath& file_name) {
   file_ = ::CreateFile(file_name.value().c_str(), GENERIC_READ,
                        FILE_SHARE_READ, NULL, OPEN_EXISTING,
@@ -736,15 +720,11 @@ bool MemoryMappedFile::MapFileToMemory(const FilePath& file_name) {
   if (file_mapping_ == INVALID_HANDLE_VALUE)
     return false;
 
-  data_ = reinterpret_cast<const uint8*>(
+  data_ = static_cast<uint8*>(
       ::MapViewOfFile(file_mapping_, FILE_MAP_READ, 0, 0, length_));
   return data_ != NULL;
 }
 
-bool MemoryMappedFile::IsValid() {
-  return data_ != NULL;
-}
-
 void MemoryMappedFile::CloseHandles() {
   if (data_)
     ::UnmapViewOfFile(data_);