Add FileHandleFileWriter

util/file/file_writer.cc

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 19 matching lines @@
 
 #if defined(OS_POSIX)
 // Ensure type compatibility between WritableIoVec and iovec.
 static_assert(sizeof(WritableIoVec) == sizeof(iovec), "WritableIoVec size");
 static_assert(offsetof(WritableIoVec, iov_base) == offsetof(iovec, iov_base),
               "WritableIoVec base offset");
 static_assert(offsetof(WritableIoVec, iov_len) == offsetof(iovec, iov_len),
               "WritableIoVec len offset");
 #endif  // OS_POSIX
 
-FileWriter::FileWriter() : file_() {
+WeakFileHandleFileWriter::WeakFileHandleFileWriter(FileHandle file_handle)
+    : file_handle_(file_handle) {
 }
 
-FileWriter::~FileWriter() {
+WeakFileHandleFileWriter::~WeakFileHandleFileWriter() {
 }
 
-bool FileWriter::Open(const base::FilePath& path,
-                      FileWriteMode write_mode,
-                      FilePermissions permissions) {
-  CHECK(!file_.is_valid());
-  file_.reset(LoggingOpenFileForWrite(path, write_mode, permissions));
-  return file_.is_valid();
-}
-
-void FileWriter::Close() {
-  CHECK(file_.is_valid());
-
-  file_.reset();
-}
-
-bool FileWriter::Write(const void* data, size_t size) {
-  DCHECK(file_.is_valid());
+bool WeakFileHandleFileWriter::Write(const void* data, size_t size) {
+  DCHECK_NE(file_handle_, kInvalidFileHandle);
 
   // TODO(mark): Write no more than SSIZE_MAX bytes in a single call.
-  ssize_t written = WriteFile(file_.get(), data, size);
+  ssize_t written = WriteFile(file_handle_, data, size);
   if (written < 0) {
     PLOG(ERROR) << "write";
     return false;
   } else if (written == 0) {
     LOG(ERROR) << "write: returned 0";
     return false;
   }
 
   return true;
 }
 
-bool FileWriter::WriteIoVec(std::vector<WritableIoVec>* iovecs) {
-  DCHECK(file_.is_valid());
+bool WeakFileHandleFileWriter::WriteIoVec(std::vector<WritableIoVec>* iovecs) {
+  DCHECK_NE(file_handle_, kInvalidFileHandle);
 
 #if defined(OS_POSIX)
 
   ssize_t size = 0;
   for (const WritableIoVec& iov : *iovecs) {
     // TODO(mark): Check to avoid overflow of ssize_t, and fail with EINVAL.
     size += iov.iov_len;
   }
 
   // Get an iovec*, because that’s what writev wants. The only difference
   // between WritableIoVec and iovec is that WritableIoVec’s iov_base is a
   // pointer to a const buffer, where iovec’s iov_base isn’t. writev doesn’t
   // actually write to the data, so this cast is safe here. iovec’s iov_base is
   // non-const because the same structure is used for readv and writev, and
   // readv needs to write to the buffer that iov_base points to.
   iovec* iov = reinterpret_cast<iovec*>(&(*iovecs)[0]);
   size_t remaining_iovecs = iovecs->size();
 
   while (size > 0) {
     size_t writev_iovec_count =
         std::min(remaining_iovecs, implicit_cast<size_t>(IOV_MAX));
     ssize_t written =
-        HANDLE_EINTR(writev(file_.get(), iov, writev_iovec_count));
+        HANDLE_EINTR(writev(file_handle_, iov, writev_iovec_count));
     if (written < 0) {
       PLOG(ERROR) << "writev";
       return false;
     } else if (written == 0) {
       LOG(ERROR) << "writev: returned 0";
       return false;
     }
 
     size -= written;
     DCHECK_GE(size, 0);
@@ skipping 31 matching lines @@
 
 #ifndef NDEBUG
   // The interface says that |iovecs| is not sacred, so scramble it to make sure
   // that nobody depends on it.
   memset(&(*iovecs)[0], 0xa5, sizeof((*iovecs)[0]) * iovecs->size());
 #endif
 
   return true;
 }
 
+FileOffset WeakFileHandleFileWriter::Seek(FileOffset offset, int whence) {
+  DCHECK_NE(file_handle_, kInvalidFileHandle);
+  return LoggingSeekFile(file_handle_, offset, whence);
+}
+
+FileWriter::FileWriter()
+    : file_(),
+      weak_file_handle_file_writer_(kInvalidFileHandle) {
+}
+
+FileWriter::~FileWriter() {
+}
+
+bool FileWriter::Open(const base::FilePath& path,
+                      FileWriteMode write_mode,
+                      FilePermissions permissions) {
+  CHECK(!file_.is_valid());
+  file_.reset(LoggingOpenFileForWrite(path, write_mode, permissions));
+  if (!file_.is_valid()) {
+    return false;
+  }
+
+  weak_file_handle_file_writer_.set_file_handle(file_.get());
+  return true;
+}
+
+void FileWriter::Close() {
+  CHECK(file_.is_valid());
+
+  weak_file_handle_file_writer_.set_file_handle(kInvalidFileHandle);
+  file_.reset();
+}
+
+bool FileWriter::Write(const void* data, size_t size) {
+  DCHECK(file_.is_valid());
+  return weak_file_handle_file_writer_.Write(data, size);
+}
+
+bool FileWriter::WriteIoVec(std::vector<WritableIoVec>* iovecs) {
+  DCHECK(file_.is_valid());
+  return weak_file_handle_file_writer_.WriteIoVec(iovecs);
+}
+
 FileOffset FileWriter::Seek(FileOffset offset, int whence) {
   DCHECK(file_.is_valid());
-  return LoggingSeekFile(file_.get(), offset, whence);
+  return weak_file_handle_file_writer_.Seek(offset, whence);
 }
 
 }  // namespace crashpad