import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

netwerk/base/nsTemporaryFileInputStream.cpp

@@ -0,0 +1,252 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "nsTemporaryFileInputStream.h"
+#include "nsStreamUtils.h"
+#include <algorithm>
+
+typedef mozilla::ipc::FileDescriptor::PlatformHandleType FileHandleType;
+
+NS_IMPL_ISUPPORTS(nsTemporaryFileInputStream,
+                  nsIInputStream,
+                  nsISeekableStream,
+                  nsIIPCSerializableInputStream)
+
+nsTemporaryFileInputStream::nsTemporaryFileInputStream(FileDescOwner* aFileDescOwner, uint64_t aStartPos, uint64_t aEndPos)
+  : mFileDescOwner(aFileDescOwner),
+    mStartPos(aStartPos),
+    mCurPos(aStartPos),
+    mEndPos(aEndPos),
+    mClosed(false)
+{ 
+  NS_ASSERTION(aStartPos <= aEndPos, "StartPos should less equal than EndPos!");
+}
+
+nsTemporaryFileInputStream::nsTemporaryFileInputStream()
+  : mStartPos(0),
+    mCurPos(0),
+    mEndPos(0),
+    mClosed(false)
+{
+}
+
+NS_IMETHODIMP
+nsTemporaryFileInputStream::Close()
+{
+  mClosed = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTemporaryFileInputStream::Available(uint64_t * bytesAvailable)
+{
+  if (mClosed)
+    return NS_BASE_STREAM_CLOSED;
+
+  NS_ASSERTION(mCurPos <= mEndPos, "CurPos should less equal than EndPos!");
+
+  *bytesAvailable = mEndPos - mCurPos;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTemporaryFileInputStream::Read(char* buffer, uint32_t count, uint32_t* bytesRead)
+{
+  return ReadSegments(NS_CopySegmentToBuffer, buffer, count, bytesRead);
+}
+
+NS_IMETHODIMP
+nsTemporaryFileInputStream::ReadSegments(nsWriteSegmentFun writer,
+                                         void *            closure,
+                                         uint32_t          count,
+                                         uint32_t *        result)
+{
+  NS_ASSERTION(result, "null ptr");
+  NS_ASSERTION(mCurPos <= mEndPos, "bad stream state");
+  *result = 0;
+
+  if (mClosed) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  mozilla::MutexAutoLock lock(mFileDescOwner->FileMutex());
+  int64_t offset = PR_Seek64(mFileDescOwner->mFD, mCurPos, PR_SEEK_SET);
+  if (offset == -1) {
+    return NS_ErrorAccordingToNSPR();
+  }
+
+  // Limit requested count to the amount remaining in our section of the file.
+  count = std::min(count, uint32_t(mEndPos - mCurPos));
+
+  char buf[4096];
+  while (*result < count) {
+    uint32_t bufCount = std::min(count - *result, (uint32_t) sizeof(buf));
+    int32_t bytesRead = PR_Read(mFileDescOwner->mFD, buf, bufCount);
+    if (bytesRead == 0) {
+      mClosed = true;
+      return NS_OK;
+    }
+
+    if (bytesRead < 0) {
+      return NS_ErrorAccordingToNSPR();
+    }
+
+    int32_t bytesWritten = 0;
+    while (bytesWritten < bytesRead) {
+      uint32_t writerCount = 0;
+      nsresult rv = writer(this, closure, buf + bytesWritten, *result,
+                           bytesRead - bytesWritten, &writerCount);
+      if (NS_FAILED(rv) || writerCount == 0) {
+        // nsIInputStream::ReadSegments' contract specifies that errors
+        // from writer are not propagated to ReadSegments' caller.
+        //
+        // If writer fails, leaving bytes still in buf, that's okay: we
+        // only update mCurPos to reflect successful writes, so the call
+        // to PR_Seek64 at the top will restart us at the right spot.
+        return NS_OK;
+      }
+      NS_ASSERTION(writerCount <= (uint32_t) (bytesRead - bytesWritten),
+                   "writer should not write more than we asked it to write");
+      bytesWritten += writerCount;
+      *result += writerCount;
+      mCurPos += writerCount;
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTemporaryFileInputStream::IsNonBlocking(bool * nonBlocking)
+{
+  *nonBlocking = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTemporaryFileInputStream::Seek(int32_t aWhence, int64_t aOffset)
+{
+  if (mClosed) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  switch (aWhence) {
+    case nsISeekableStream::NS_SEEK_SET:
+      aOffset += mStartPos;
+      break;
+
+    case nsISeekableStream::NS_SEEK_CUR:
+      aOffset += mCurPos;
+      break;
+
+    case nsISeekableStream::NS_SEEK_END:
+      aOffset += mEndPos;
+      break;
+
+    default:
+      return NS_ERROR_FAILURE;
+  }
+
+  if (aOffset < (int64_t)mStartPos || aOffset > (int64_t)mEndPos) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  mCurPos = aOffset;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTemporaryFileInputStream::Tell(int64_t* aPos)
+{
+  if (!aPos) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (mClosed) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  MOZ_ASSERT(mStartPos <= mCurPos, "StartPos should less equal than CurPos!");
+  *aPos = mCurPos - mStartPos;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsTemporaryFileInputStream::SetEOF()
+{
+  if (mClosed) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  return Close();
+}
+
+void
+nsTemporaryFileInputStream::Serialize(InputStreamParams& aParams,
+                                      FileDescriptorArray& aFileDescriptors)
+{
+  TemporaryFileInputStreamParams params;
+
+  MutexAutoLock lock(mFileDescOwner->FileMutex());
+  MOZ_ASSERT(mFileDescOwner->mFD);
+  if (!mClosed) {
+    FileHandleType fd = FileHandleType(PR_FileDesc2NativeHandle(mFileDescOwner->mFD));
+    NS_ASSERTION(fd, "This should never be null!");
+
+    DebugOnly<FileDescriptor*> dbgFD = aFileDescriptors.AppendElement(fd);
+    NS_ASSERTION(dbgFD->IsValid(), "Sending an invalid file descriptor!");
+
+    params.fileDescriptorIndex() = aFileDescriptors.Length() - 1;
+
+    Close();
+  } else {
+    NS_WARNING("The stream is already closed. "
+               "Sending an invalid file descriptor to the other process!");
+
+    params.fileDescriptorIndex() = UINT32_MAX;
+  }
+  params.startPos() = mCurPos;
+  params.endPos() = mEndPos;
+  aParams = params;
+}
+
+bool
+nsTemporaryFileInputStream::Deserialize(const InputStreamParams& aParams,
+                                        const FileDescriptorArray& aFileDescriptors)
+{
+  const TemporaryFileInputStreamParams& params = aParams.get_TemporaryFileInputStreamParams();
+
+  uint32_t fileDescriptorIndex = params.fileDescriptorIndex();
+  FileDescriptor fd;
+  if (fileDescriptorIndex < aFileDescriptors.Length()) {
+    fd = aFileDescriptors[fileDescriptorIndex];
+    NS_WARNING_ASSERTION(fd.IsValid(),
+                         "Received an invalid file descriptor!");
+  } else {
+    NS_WARNING("Received a bad file descriptor index!");
+  }
+
+  if (fd.IsValid()) {
+    auto rawFD = fd.ClonePlatformHandle();
+    PRFileDesc* fileDesc = PR_ImportFile(PROsfd(rawFD.release()));
+    if (!fileDesc) {
+      NS_WARNING("Failed to import file handle!");
+      return false;
+    }
+    mFileDescOwner = new FileDescOwner(fileDesc);
+  } else {
+    mClosed = true;
+  }
+
+  mStartPos = mCurPos = params.startPos();
+  mEndPos = params.endPos();
+  return true;
+}
+
+Maybe<uint64_t>
+nsTemporaryFileInputStream::ExpectedSerializedLength()
+{
+  return Nothing();
+}