michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsTemporaryFileInputStream.h"
michael@0: #include "nsStreamUtils.h"
michael@0: #include <algorithm>
michael@0: 
michael@0: NS_IMPL_ISUPPORTS(nsTemporaryFileInputStream, nsIInputStream)
michael@0: 
michael@0: nsTemporaryFileInputStream::nsTemporaryFileInputStream(FileDescOwner* aFileDescOwner, uint64_t aStartPos, uint64_t aEndPos)
michael@0:   : mFileDescOwner(aFileDescOwner),
michael@0:     mStartPos(aStartPos),
michael@0:     mEndPos(aEndPos),
michael@0:     mClosed(false)
michael@0: { 
michael@0:   NS_ASSERTION(aStartPos <= aEndPos, "StartPos should less equal than EndPos!");
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsTemporaryFileInputStream::Close()
michael@0: {
michael@0:   mClosed = true;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsTemporaryFileInputStream::Available(uint64_t * bytesAvailable)
michael@0: {
michael@0:   if (mClosed)
michael@0:     return NS_BASE_STREAM_CLOSED;
michael@0: 
michael@0:   NS_ASSERTION(mStartPos <= mEndPos, "StartPos should less equal than EndPos!");
michael@0: 
michael@0:   *bytesAvailable = mEndPos - mStartPos;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsTemporaryFileInputStream::Read(char* buffer, uint32_t count, uint32_t* bytesRead)
michael@0: {
michael@0:   return ReadSegments(NS_CopySegmentToBuffer, buffer, count, bytesRead);
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsTemporaryFileInputStream::ReadSegments(nsWriteSegmentFun writer,
michael@0:                                          void *            closure,
michael@0:                                          uint32_t          count,
michael@0:                                          uint32_t *        result)
michael@0: {
michael@0:   NS_ASSERTION(result, "null ptr");
michael@0:   NS_ASSERTION(mStartPos <= mEndPos, "bad stream state");
michael@0:   *result = 0;
michael@0: 
michael@0:   if (mClosed) {
michael@0:     return NS_BASE_STREAM_CLOSED;
michael@0:   }
michael@0: 
michael@0:   mozilla::MutexAutoLock lock(mFileDescOwner->FileMutex());
michael@0:   PR_Seek64(mFileDescOwner->mFD, mStartPos, PR_SEEK_SET);
michael@0: 
michael@0:   count = std::min(count, uint32_t(mEndPos - mStartPos));
michael@0:   uint32_t remainBufCount = count;
michael@0: 
michael@0:   char buf[4096];
michael@0:   while (remainBufCount > 0) {
michael@0:     uint32_t bufCount = std::min(remainBufCount, (uint32_t)sizeof(buf));
michael@0:     int32_t read_result = PR_Read(mFileDescOwner->mFD, buf, bufCount);
michael@0:     if (read_result < 0) {
michael@0:       return NS_ErrorAccordingToNSPR();
michael@0:     }
michael@0:     uint32_t write_result = 0;
michael@0:     nsresult rv = writer(this, closure, buf,
michael@0:                          count - remainBufCount, bufCount, &write_result);
michael@0:     remainBufCount -= bufCount;
michael@0:     if (NS_SUCCEEDED(rv)) {
michael@0:       NS_ASSERTION(write_result <= bufCount,
michael@0:                    "writer should not write more than we asked it to write");
michael@0:     }
michael@0:     mStartPos += bufCount;
michael@0:   }
michael@0:   *result = count;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsTemporaryFileInputStream::IsNonBlocking(bool * nonBlocking)
michael@0: {
michael@0:   *nonBlocking = false;
michael@0:   return NS_OK;
michael@0: }
michael@0: