diff options
Diffstat (limited to 'netwerk/base/nsTemporaryFileInputStream.cpp')
| -rw-r--r-- | netwerk/base/nsTemporaryFileInputStream.cpp | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/netwerk/base/nsTemporaryFileInputStream.cpp b/netwerk/base/nsTemporaryFileInputStream.cpp new file mode 100644 index 0000000000..c7c5b06486 --- /dev/null +++ b/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(); +} |