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gecko-dev/netwerk/cache/nsDiskCacheStreams.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is nsDiskCacheStreams.cpp, released
* June 13, 2001.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 2001
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Gordon Sheridan <gordon@netscape.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "nsDiskCache.h"
#include "nsDiskCacheDevice.h"
#include "nsDiskCacheStreams.h"
#include "nsCacheService.h"
#include "mozilla/FileUtils.h"
#include "nsIDiskCacheStreamInternal.h"
// Assumptions:
// - cache descriptors live for life of streams
// - streams will only be used by FileTransport,
// they will not be directly accessible to clients
// - overlapped I/O is NOT supported
/******************************************************************************
* nsDiskCacheInputStream
*****************************************************************************/
class nsDiskCacheInputStream : public nsIInputStream {
public:
nsDiskCacheInputStream( nsDiskCacheStreamIO * parent,
PRFileDesc * fileDesc,
const char * buffer,
PRUint32 endOfStream);
virtual ~nsDiskCacheInputStream();
NS_DECL_ISUPPORTS
NS_DECL_NSIINPUTSTREAM
private:
nsDiskCacheStreamIO * mStreamIO; // backpointer to parent
PRFileDesc * mFD;
const char * mBuffer;
PRUint32 mStreamEnd;
PRUint32 mPos; // stream position
PRBool mClosed;
};
NS_IMPL_THREADSAFE_ISUPPORTS1(nsDiskCacheInputStream, nsIInputStream)
nsDiskCacheInputStream::nsDiskCacheInputStream( nsDiskCacheStreamIO * parent,
PRFileDesc * fileDesc,
const char * buffer,
PRUint32 endOfStream)
: mStreamIO(parent)
, mFD(fileDesc)
, mBuffer(buffer)
, mStreamEnd(endOfStream)
, mPos(0)
, mClosed(PR_FALSE)
{
NS_ADDREF(mStreamIO);
mStreamIO->IncrementInputStreamCount();
}
nsDiskCacheInputStream::~nsDiskCacheInputStream()
{
Close();
mStreamIO->DecrementInputStreamCount();
NS_RELEASE(mStreamIO);
}
NS_IMETHODIMP
nsDiskCacheInputStream::Close()
{
if (!mClosed) {
if (mFD) {
(void) PR_Close(mFD);
mFD = nsnull;
}
mClosed = PR_TRUE;
}
return NS_OK;
}
NS_IMETHODIMP
nsDiskCacheInputStream::Available(PRUint32 * bytesAvailable)
{
if (mClosed) return NS_BASE_STREAM_CLOSED;
if (mStreamEnd < mPos) return NS_ERROR_UNEXPECTED;
*bytesAvailable = mStreamEnd - mPos;
return NS_OK;
}
NS_IMETHODIMP
nsDiskCacheInputStream::Read(char * buffer, PRUint32 count, PRUint32 * bytesRead)
{
*bytesRead = 0;
if (mClosed)
return NS_OK;
if (mPos == mStreamEnd) return NS_OK;
if (mPos > mStreamEnd) return NS_ERROR_UNEXPECTED;
if (count > mStreamEnd - mPos)
count = mStreamEnd - mPos;
if (mFD) {
// just read from file
PRInt32 result = PR_Read(mFD, buffer, count);
if (result < 0) return NS_ErrorAccordingToNSPR();
mPos += (PRUint32)result;
*bytesRead = (PRUint32)result;
} else if (mBuffer) {
// read data from mBuffer
memcpy(buffer, mBuffer + mPos, count);
mPos += count;
*bytesRead = count;
} else {
// no data source for input stream
}
return NS_OK;
}
NS_IMETHODIMP
nsDiskCacheInputStream::ReadSegments(nsWriteSegmentFun writer,
void * closure,
PRUint32 count,
PRUint32 * bytesRead)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsDiskCacheInputStream::IsNonBlocking(PRBool * nonBlocking)
{
*nonBlocking = PR_FALSE;
return NS_OK;
}
/******************************************************************************
* nsDiskCacheOutputStream
*****************************************************************************/
class nsDiskCacheOutputStream : public nsIOutputStream
, public nsIDiskCacheStreamInternal
{
public:
nsDiskCacheOutputStream( nsDiskCacheStreamIO * parent);
virtual ~nsDiskCacheOutputStream();
NS_DECL_ISUPPORTS
NS_DECL_NSIOUTPUTSTREAM
NS_DECL_NSIDISKCACHESTREAMINTERNAL
void ReleaseStreamIO() { NS_IF_RELEASE(mStreamIO); }
private:
nsDiskCacheStreamIO * mStreamIO; // backpointer to parent
PRBool mClosed;
};
NS_IMPL_THREADSAFE_ISUPPORTS2(nsDiskCacheOutputStream,
nsIOutputStream,
nsIDiskCacheStreamInternal)
nsDiskCacheOutputStream::nsDiskCacheOutputStream( nsDiskCacheStreamIO * parent)
: mStreamIO(parent)
, mClosed(PR_FALSE)
{
NS_ADDREF(mStreamIO);
}
nsDiskCacheOutputStream::~nsDiskCacheOutputStream()
{
Close();
ReleaseStreamIO();
}
NS_IMETHODIMP
nsDiskCacheOutputStream::Close()
{
if (!mClosed) {
mClosed = PR_TRUE;
// tell parent streamIO we are closing
mStreamIO->CloseOutputStream(this);
}
return NS_OK;
}
NS_IMETHODIMP
nsDiskCacheOutputStream::CloseInternal()
{
if (!mClosed) {
mClosed = PR_TRUE;
// tell parent streamIO we are closing
mStreamIO->CloseOutputStreamInternal(this);
}
return NS_OK;
}
NS_IMETHODIMP
nsDiskCacheOutputStream::Flush()
{
if (mClosed) return NS_BASE_STREAM_CLOSED;
// yeah, yeah, well get to it...eventually...
return NS_OK;
}
NS_IMETHODIMP
nsDiskCacheOutputStream::Write(const char *buf, PRUint32 count, PRUint32 *bytesWritten)
{
if (mClosed) return NS_BASE_STREAM_CLOSED;
return mStreamIO->Write(buf, count, bytesWritten);
}
NS_IMETHODIMP
nsDiskCacheOutputStream::WriteFrom(nsIInputStream *inStream, PRUint32 count, PRUint32 *bytesWritten)
{
NS_NOTREACHED("WriteFrom");
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsDiskCacheOutputStream::WriteSegments( nsReadSegmentFun reader,
void * closure,
PRUint32 count,
PRUint32 * bytesWritten)
{
NS_NOTREACHED("WriteSegments");
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsDiskCacheOutputStream::IsNonBlocking(PRBool * nonBlocking)
{
*nonBlocking = PR_FALSE;
return NS_OK;
}
/******************************************************************************
* nsDiskCacheStreamIO
*****************************************************************************/
NS_IMPL_THREADSAFE_ISUPPORTS0(nsDiskCacheStreamIO)
// we pick 16k as the max buffer size because that is the threshold above which
// we are unable to store the data in the cache block files
// see nsDiskCacheMap.[cpp,h]
#define kMaxBufferSize (16 * 1024)
nsDiskCacheStreamIO::nsDiskCacheStreamIO(nsDiskCacheBinding * binding)
: mBinding(binding)
, mOutStream(nsnull)
, mInStreamCount(0)
, mFD(nsnull)
, mStreamPos(0)
, mStreamEnd(0)
, mBufPos(0)
, mBufEnd(0)
, mBufSize(0)
, mBufDirty(PR_FALSE)
, mBuffer(nsnull)
{
mDevice = (nsDiskCacheDevice *)mBinding->mCacheEntry->CacheDevice();
// acquire "death grip" on cache service
nsCacheService *service = nsCacheService::GlobalInstance();
NS_ADDREF(service);
}
nsDiskCacheStreamIO::~nsDiskCacheStreamIO()
{
Close();
// release "death grip" on cache service
nsCacheService *service = nsCacheService::GlobalInstance();
NS_RELEASE(service);
}
void
nsDiskCacheStreamIO::Close()
{
// this should only be called from our destructor
// no one is interested in us anymore, so we don't need to grab any locks
// assert streams closed
NS_ASSERTION(!mOutStream, "output stream still open");
NS_ASSERTION(mInStreamCount == 0, "input stream still open");
NS_ASSERTION(!mFD, "file descriptor not closed");
DeleteBuffer();
}
// NOTE: called with service lock held
nsresult
nsDiskCacheStreamIO::GetInputStream(PRUint32 offset, nsIInputStream ** inputStream)
{
NS_ENSURE_ARG_POINTER(inputStream);
NS_ENSURE_TRUE(offset == 0, NS_ERROR_NOT_IMPLEMENTED);
*inputStream = nsnull;
if (!mBinding) return NS_ERROR_NOT_AVAILABLE;
if (mOutStream) {
NS_WARNING("already have an output stream open");
return NS_ERROR_NOT_AVAILABLE;
}
nsresult rv;
PRFileDesc * fd = nsnull;
mStreamEnd = mBinding->mCacheEntry->DataSize();
if (mStreamEnd == 0) {
// there's no data to read
NS_ASSERTION(!mBinding->mRecord.DataLocationInitialized(), "storage allocated for zero data size");
} else if (mBinding->mRecord.DataFile() == 0) {
// open file desc for data
rv = OpenCacheFile(PR_RDONLY, &fd);
if (NS_FAILED(rv)) return rv; // unable to open file
NS_ASSERTION(fd, "cache stream lacking open file.");
} else if (!mBuffer) {
// read block file for data
rv = ReadCacheBlocks();
if (NS_FAILED(rv)) return rv;
}
// else, mBuffer already contains all of the data (left over from a
// previous block-file read or write).
NS_ASSERTION(!(fd && mBuffer), "ambiguous data sources for input stream");
// create a new input stream
nsDiskCacheInputStream * inStream = new nsDiskCacheInputStream(this, fd, mBuffer, mStreamEnd);
if (!inStream) return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(*inputStream = inStream);
return NS_OK;
}
// NOTE: called with service lock held
nsresult
nsDiskCacheStreamIO::GetOutputStream(PRUint32 offset, nsIOutputStream ** outputStream)
{
NS_ENSURE_ARG_POINTER(outputStream);
*outputStream = nsnull;
if (!mBinding) return NS_ERROR_NOT_AVAILABLE;
NS_ASSERTION(!mOutStream, "already have an output stream open");
NS_ASSERTION(mInStreamCount == 0, "we already have input streams open");
if (mOutStream || mInStreamCount) return NS_ERROR_NOT_AVAILABLE;
// mBuffer lazily allocated, but might exist if a previous stream already
// created one.
mBufPos = 0;
mStreamPos = 0;
mStreamEnd = mBinding->mCacheEntry->DataSize();
nsresult rv;
if (offset) {
rv = Seek(PR_SEEK_SET, offset);
if (NS_FAILED(rv)) return rv;
}
rv = SetEOF();
if (NS_FAILED(rv)) return rv;
// create a new output stream
mOutStream = new nsDiskCacheOutputStream(this);
if (!mOutStream) return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(*outputStream = mOutStream);
return NS_OK;
}
void
nsDiskCacheStreamIO::ClearBinding()
{
if (mBinding && mOutStream)
Flush();
mBinding = nsnull;
}
nsresult
nsDiskCacheStreamIO::CloseOutputStream(nsDiskCacheOutputStream * outputStream)
{
nsCacheServiceAutoLock lock; // grab service lock
return CloseOutputStreamInternal(outputStream);
}
nsresult
nsDiskCacheStreamIO::CloseOutputStreamInternal(
nsDiskCacheOutputStream * outputStream)
{
nsresult rv;
if (outputStream != mOutStream) {
NS_WARNING("mismatched output streams");
return NS_ERROR_UNEXPECTED;
}
// output stream is closing
if (!mBinding) { // if we're severed, just clear member variables
NS_ASSERTION(!mBufDirty, "oops");
mOutStream = nsnull;
outputStream->ReleaseStreamIO();
return NS_ERROR_NOT_AVAILABLE;
}
rv = Flush();
if (NS_FAILED(rv))
NS_WARNING("Flush() failed");
mOutStream = nsnull;
return rv;
}
nsresult
nsDiskCacheStreamIO::Flush()
{
NS_ASSERTION(mBinding, "oops");
CACHE_LOG_DEBUG(("CACHE: Flush [%x doomed=%u]\n",
mBinding->mRecord.HashNumber(), mBinding->mDoomed));
if (!mBufDirty) {
if (mFD) {
(void) PR_Close(mFD);
mFD = nsnull;
}
return NS_OK;
}
// write data to cache blocks, or flush mBuffer to file
nsDiskCacheMap *cacheMap = mDevice->CacheMap(); // get map reference
nsresult rv;
PRBool written = PR_FALSE;
if ((mStreamEnd <= kMaxBufferSize) &&
(mBinding->mCacheEntry->StoragePolicy() != nsICache::STORE_ON_DISK_AS_FILE)) {
// store data (if any) in cache block files
mBufDirty = PR_FALSE;
// delete existing storage
nsDiskCacheRecord * record = &mBinding->mRecord;
if (record->DataLocationInitialized()) {
rv = cacheMap->DeleteStorage(record, nsDiskCache::kData);
if (NS_FAILED(rv)) {
NS_WARNING("cacheMap->DeleteStorage() failed.");
cacheMap->DeleteRecord(record);
return rv;
}
}
// flush buffer to block files
written = PR_TRUE;
if (mStreamEnd > 0) {
rv = cacheMap->WriteDataCacheBlocks(mBinding, mBuffer, mBufEnd);
if (NS_FAILED(rv)) {
NS_WARNING("WriteDataCacheBlocks() failed.");
written = PR_FALSE;
}
}
}
if (!written) {
// make sure we save as separate file
rv = FlushBufferToFile(); // initializes DataFileLocation() if necessary
if (mFD) {
// Update the file size of the disk file in the cache
UpdateFileSize();
// close file descriptor
(void) PR_Close(mFD);
mFD = nsnull;
}
else
NS_WARNING("no file descriptor");
// close mFD first if possible before returning if FlushBufferToFile
// failed
NS_ENSURE_SUCCESS(rv, rv);
// since the data location is on disk as a single file, the only value
// in keeping mBuffer around is to avoid an extra malloc the next time
// we need to write to this file. reading will use a file descriptor.
// therefore, it's probably not worth optimizing for the subsequent
// write, so we unconditionally delete mBuffer here.
DeleteBuffer();
}
// XXX do we need this here? WriteDataCacheBlocks() calls UpdateRecord()
// update cache map if entry isn't doomed
if (!mBinding->mDoomed) {
rv = cacheMap->UpdateRecord(&mBinding->mRecord);
if (NS_FAILED(rv)) {
NS_WARNING("cacheMap->UpdateRecord() failed.");
return rv; // XXX doom cache entry
}
}
return NS_OK;
}
// assumptions:
// only one thread writing at a time
// never have both output and input streams open
// OnDataSizeChanged() will have already been called to update entry->DataSize()
nsresult
nsDiskCacheStreamIO::Write( const char * buffer,
PRUint32 count,
PRUint32 * bytesWritten)
{
nsresult rv = NS_OK;
nsCacheServiceAutoLock lock; // grab service lock
if (!mBinding) return NS_ERROR_NOT_AVAILABLE;
if (mInStreamCount) {
// we have open input streams already
// this is an error until we support overlapped I/O
NS_WARNING("Attempting to write to cache entry with open input streams.\n");
return NS_ERROR_NOT_AVAILABLE;
}
NS_ASSERTION(count, "Write called with count of zero");
NS_ASSERTION(mBufPos <= mBufEnd, "streamIO buffer corrupted");
PRUint32 bytesLeft = count;
PRBool flushed = PR_FALSE;
while (bytesLeft) {
if (mBufPos == mBufSize) {
if (mBufSize < kMaxBufferSize) {
mBufSize = kMaxBufferSize;
char *buffer = mBuffer;
mBuffer = (char *) realloc(mBuffer, mBufSize);
if (!mBuffer) {
free(buffer);
mBufSize = 0;
break;
}
} else {
nsresult rv = FlushBufferToFile();
if (NS_FAILED(rv)) break;
flushed = PR_TRUE;
}
}
PRUint32 chunkSize = bytesLeft;
if (chunkSize > (mBufSize - mBufPos))
chunkSize = mBufSize - mBufPos;
memcpy(mBuffer + mBufPos, buffer, chunkSize);
mBufDirty = PR_TRUE;
mBufPos += chunkSize;
bytesLeft -= chunkSize;
buffer += chunkSize;
if (mBufEnd < mBufPos)
mBufEnd = mBufPos;
}
if (bytesLeft) {
*bytesWritten = 0;
return NS_ERROR_FAILURE;
}
*bytesWritten = count;
// update mStreamPos, mStreamEnd
mStreamPos += count;
if (mStreamEnd < mStreamPos) {
mStreamEnd = mStreamPos;
NS_ASSERTION(mBinding->mCacheEntry->DataSize() == mStreamEnd, "bad stream");
// If we have flushed to a file, update the file size
if (flushed && mFD) {
UpdateFileSize();
}
}
return rv;
}
void
nsDiskCacheStreamIO::UpdateFileSize()
{
NS_ASSERTION(mFD, "nsDiskCacheStreamIO::UpdateFileSize should not have been called");
nsDiskCacheRecord * record = &mBinding->mRecord;
const PRUint32 oldSizeK = record->DataFileSize();
PRUint32 newSizeK = (mStreamEnd + 0x03FF) >> 10;
// make sure the size won't overflow (bug #651100)
if (newSizeK > kMaxDataSizeK)
newSizeK = kMaxDataSizeK;
if (newSizeK == oldSizeK) return;
record->SetDataFileSize(newSizeK);
// update cache size totals
nsDiskCacheMap * cacheMap = mDevice->CacheMap();
cacheMap->DecrementTotalSize(oldSizeK); // decrement old size
cacheMap->IncrementTotalSize(newSizeK); // increment new size
if (!mBinding->mDoomed) {
nsresult rv = cacheMap->UpdateRecord(record);
if (NS_FAILED(rv)) {
NS_WARNING("cacheMap->UpdateRecord() failed.");
// XXX doom cache entry?
}
}
}
nsresult
nsDiskCacheStreamIO::OpenCacheFile(PRIntn flags, PRFileDesc ** fd)
{
NS_ENSURE_ARG_POINTER(fd);
nsresult rv;
nsDiskCacheMap * cacheMap = mDevice->CacheMap();
rv = cacheMap->GetLocalFileForDiskCacheRecord(&mBinding->mRecord,
nsDiskCache::kData,
!!(flags & PR_CREATE_FILE),
getter_AddRefs(mLocalFile));
if (NS_FAILED(rv)) return rv;
// create PRFileDesc for input stream - the 00600 is just for consistency
rv = mLocalFile->OpenNSPRFileDesc(flags, 00600, fd);
if (NS_FAILED(rv)) return rv; // unable to open file
return NS_OK;
}
nsresult
nsDiskCacheStreamIO::ReadCacheBlocks()
{
NS_ASSERTION(mStreamEnd == mBinding->mCacheEntry->DataSize(), "bad stream");
NS_ASSERTION(mStreamEnd <= kMaxBufferSize, "data too large for buffer");
nsDiskCacheRecord * record = &mBinding->mRecord;
if (!record->DataLocationInitialized()) return NS_OK;
NS_ASSERTION(record->DataFile() != kSeparateFile, "attempt to read cache blocks on separate file");
if (!mBuffer) {
// allocate buffer
mBuffer = (char *) malloc(mStreamEnd);
if (!mBuffer) {
return NS_ERROR_OUT_OF_MEMORY;
}
mBufSize = mStreamEnd;
}
// read data stored in cache block files
nsDiskCacheMap *map = mDevice->CacheMap(); // get map reference
nsresult rv = map->ReadDataCacheBlocks(mBinding, mBuffer, mStreamEnd);
if (NS_FAILED(rv)) return rv;
// update streamIO variables
mBufPos = 0;
mBufEnd = mStreamEnd;
return NS_OK;
}
nsresult
nsDiskCacheStreamIO::FlushBufferToFile()
{
nsresult rv;
nsDiskCacheRecord * record = &mBinding->mRecord;
if (!mFD) {
if (record->DataLocationInitialized() && (record->DataFile() > 0)) {
// remove cache block storage
nsDiskCacheMap * cacheMap = mDevice->CacheMap();
rv = cacheMap->DeleteStorage(record, nsDiskCache::kData);
if (NS_FAILED(rv)) return rv;
}
record->SetDataFileGeneration(mBinding->mGeneration);
// allocate file
rv = OpenCacheFile(PR_RDWR | PR_CREATE_FILE, &mFD);
if (NS_FAILED(rv)) return rv;
PRInt64 dataSize = mBinding->mCacheEntry->PredictedDataSize();
if (dataSize != -1)
mozilla::fallocate(mFD, PR_MIN(dataSize, kPreallocateLimit));
}
// write buffer
PRInt32 bytesWritten = PR_Write(mFD, mBuffer, mBufEnd);
if (PRUint32(bytesWritten) != mBufEnd) {
NS_WARNING("failed to flush all data");
return NS_ERROR_UNEXPECTED; // NS_ErrorAccordingToNSPR()
}
mBufDirty = PR_FALSE;
// reset buffer
mBufPos = 0;
mBufEnd = 0;
return NS_OK;
}
void
nsDiskCacheStreamIO::DeleteBuffer()
{
if (mBuffer) {
NS_ASSERTION(!mBufDirty, "deleting dirty buffer");
free(mBuffer);
mBuffer = nsnull;
mBufPos = 0;
mBufEnd = 0;
mBufSize = 0;
}
}
// NOTE: called with service lock held
nsresult
nsDiskCacheStreamIO::Seek(PRInt32 whence, PRInt32 offset)
{
PRInt32 newPos;
if (!mBinding) return NS_ERROR_NOT_AVAILABLE;
if (PRUint32(offset) > mStreamEnd) return NS_ERROR_FAILURE;
if (mBinding->mRecord.DataLocationInitialized()) {
if (mBinding->mRecord.DataFile() == 0) {
if (!mFD) {
// we need an mFD, we better open it now
nsresult rv = OpenCacheFile(PR_RDWR | PR_CREATE_FILE, &mFD);
if (NS_FAILED(rv)) return rv;
}
}
}
if (mFD) {
// do we have data in the buffer that needs to be flushed?
if (mBufDirty) {
// XXX optimization: are we just moving within the current buffer?
nsresult rv = FlushBufferToFile();
if (NS_FAILED(rv)) return rv;
}
newPos = PR_Seek(mFD, offset, (PRSeekWhence)whence);
if (newPos == -1)
return NS_ErrorAccordingToNSPR();
mStreamPos = (PRUint32) newPos;
mBufPos = 0;
mBufEnd = 0;
return NS_OK;
}
// else, seek in mBuffer
switch(whence) {
case PR_SEEK_SET:
newPos = offset;
break;
case PR_SEEK_CUR: // relative from current posistion
newPos = offset + (PRUint32)mStreamPos;
break;
case PR_SEEK_END: // relative from end
newPos = offset + (PRUint32)mBufEnd;
break;
default:
return NS_ERROR_INVALID_ARG;
}
// read data into mBuffer if not read yet.
if (mStreamEnd && !mBufEnd) {
if (newPos > 0) {
nsresult rv = ReadCacheBlocks();
if (NS_FAILED(rv)) return rv;
}
}
// stream buffer sanity checks
NS_ASSERTION(mBufEnd <= kMaxBufferSize, "bad stream");
NS_ASSERTION(mBufPos <= mBufEnd, "bad stream");
NS_ASSERTION(mStreamPos == mBufPos, "bad stream");
NS_ASSERTION(mStreamEnd == mBufEnd, "bad stream");
if ((newPos < 0) || (PRUint32(newPos) > mBufEnd)) {
NS_WARNING("seek offset out of range");
return NS_ERROR_INVALID_ARG;
}
mStreamPos = newPos;
mBufPos = newPos;
return NS_OK;
}
// called only from nsDiskCacheOutputStream::Tell
nsresult
nsDiskCacheStreamIO::Tell(PRUint32 * result)
{
NS_ENSURE_ARG_POINTER(result);
*result = mStreamPos;
return NS_OK;
}
// NOTE: called with service lock held
nsresult
nsDiskCacheStreamIO::SetEOF()
{
nsresult rv;
PRBool needToCloseFD = PR_FALSE;
NS_ASSERTION(mStreamPos <= mStreamEnd, "bad stream");
if (!mBinding) return NS_ERROR_NOT_AVAILABLE;
if (mBinding->mRecord.DataLocationInitialized()) {
if (mBinding->mRecord.DataFile() == 0) {
if (!mFD) {
// we need an mFD, we better open it now
rv = OpenCacheFile(PR_RDWR | PR_CREATE_FILE, &mFD);
if (NS_FAILED(rv)) return rv;
needToCloseFD = PR_TRUE;
}
} else {
// data in cache block files
if ((mStreamPos != 0) && (mStreamPos != mBufPos)) {
// only read data if there will be some left after truncation
rv = ReadCacheBlocks();
if (NS_FAILED(rv)) return rv;
}
// We need to make sure we reflect this change in Flush().
// In particular, if mStreamPos is 0 and we never write to
// the buffer, we want the storage to be deleted.
mBufDirty = PR_TRUE;
}
}
if (mFD) {
rv = nsDiskCache::Truncate(mFD, mStreamPos);
#ifdef DEBUG
PRUint32 oldSizeK = (mStreamEnd + 0x03FF) >> 10;
NS_ASSERTION(mBinding->mRecord.DataFileSize() == oldSizeK, "bad disk cache entry size");
} else {
// data stored in buffer.
NS_ASSERTION(mStreamEnd <= kMaxBufferSize, "buffer truncation inadequate");
NS_ASSERTION(mBufPos == mStreamPos, "bad stream");
NS_ASSERTION(mBuffer ? mBufEnd == mStreamEnd : PR_TRUE, "bad stream");
#endif
}
NS_ASSERTION(mStreamEnd == mBinding->mCacheEntry->DataSize(), "cache entry not updated");
// we expect nsCacheEntryDescriptor::TransportWrapper::OpenOutputStream()
// to eventually update the cache entry
mStreamEnd = mStreamPos;
mBufEnd = mBufPos;
if (mFD) {
UpdateFileSize();
if (needToCloseFD) {
(void) PR_Close(mFD);
mFD = nsnull;
}
}
return NS_OK;
}
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