gecko/netwerk/cache/nsDiskCacheStreams.cpp

703 lines
21 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* 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 "nsCache.h"
#include "nsDiskCache.h"
#include "nsDiskCacheDevice.h"
#include "nsDiskCacheStreams.h"
#include "nsCacheService.h"
#include "mozilla/FileUtils.h"
#include "nsThreadUtils.h"
#include "mozilla/Telemetry.h"
#include "mozilla/TimeStamp.h"
#include <algorithm>
// 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)
// 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,
uint32_t endOfStream);
virtual ~nsDiskCacheInputStream();
NS_DECL_ISUPPORTS
NS_DECL_NSIINPUTSTREAM
private:
nsDiskCacheStreamIO * mStreamIO; // backpointer to parent
PRFileDesc * mFD;
const char * mBuffer;
uint32_t mStreamEnd;
uint32_t mPos; // stream position
bool mClosed;
};
NS_IMPL_THREADSAFE_ISUPPORTS1(nsDiskCacheInputStream, nsIInputStream)
nsDiskCacheInputStream::nsDiskCacheInputStream( nsDiskCacheStreamIO * parent,
PRFileDesc * fileDesc,
const char * buffer,
uint32_t endOfStream)
: mStreamIO(parent)
, mFD(fileDesc)
, mBuffer(buffer)
, mStreamEnd(endOfStream)
, mPos(0)
, mClosed(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 = nullptr;
}
mClosed = true;
}
return NS_OK;
}
NS_IMETHODIMP
nsDiskCacheInputStream::Available(uint64_t * 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, uint32_t count, uint32_t * bytesRead)
{
*bytesRead = 0;
if (mClosed) {
CACHE_LOG_DEBUG(("CACHE: nsDiskCacheInputStream::Read "
"[stream=%p] stream was closed",
this, buffer, count));
return NS_OK;
}
if (mPos == mStreamEnd) {
CACHE_LOG_DEBUG(("CACHE: nsDiskCacheInputStream::Read "
"[stream=%p] stream at end of file",
this, buffer, count));
return NS_OK;
}
if (mPos > mStreamEnd) {
CACHE_LOG_DEBUG(("CACHE: nsDiskCacheInputStream::Read "
"[stream=%p] stream past end of file (!)",
this, buffer, count));
return NS_ERROR_UNEXPECTED;
}
if (count > mStreamEnd - mPos)
count = mStreamEnd - mPos;
if (mFD) {
// just read from file
int32_t result = PR_Read(mFD, buffer, count);
if (result < 0) {
nsresult rv = NS_ErrorAccordingToNSPR();
CACHE_LOG_DEBUG(("CACHE: nsDiskCacheInputStream::Read PR_Read failed"
"[stream=%p, rv=%d, NSPR error %s",
this, int(rv), PR_ErrorToName(PR_GetError())));
return rv;
}
mPos += (uint32_t)result;
*bytesRead = (uint32_t)result;
} else if (mBuffer) {
// read data from mBuffer
memcpy(buffer, mBuffer + mPos, count);
mPos += count;
*bytesRead = count;
} else {
// no data source for input stream
}
CACHE_LOG_DEBUG(("CACHE: nsDiskCacheInputStream::Read "
"[stream=%p, count=%ud, byteRead=%ud] ",
this, unsigned(count), unsigned(*bytesRead)));
return NS_OK;
}
NS_IMETHODIMP
nsDiskCacheInputStream::ReadSegments(nsWriteSegmentFun writer,
void * closure,
uint32_t count,
uint32_t * bytesRead)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsDiskCacheInputStream::IsNonBlocking(bool * nonBlocking)
{
*nonBlocking = false;
return NS_OK;
}
/******************************************************************************
* nsDiskCacheStreamIO
*****************************************************************************/
NS_IMPL_THREADSAFE_ISUPPORTS1(nsDiskCacheStreamIO, nsIOutputStream)
nsDiskCacheStreamIO::nsDiskCacheStreamIO(nsDiskCacheBinding * binding)
: mBinding(binding)
, mInStreamCount(0)
, mFD(nullptr)
, mStreamEnd(0)
, mBufSize(0)
, mBuffer(nullptr)
, mOutputStreamIsOpen(false)
{
mDevice = (nsDiskCacheDevice *)mBinding->mCacheEntry->CacheDevice();
// acquire "death grip" on cache service
nsCacheService *service = nsCacheService::GlobalInstance();
NS_ADDREF(service);
}
nsDiskCacheStreamIO::~nsDiskCacheStreamIO()
{
nsCacheService::AssertOwnsLock();
// Close the outputstream
if (mBinding && mOutputStreamIsOpen) {
(void)CloseOutputStream();
}
// release "death grip" on cache service
nsCacheService *service = nsCacheService::GlobalInstance();
NS_RELEASE(service);
// assert streams closed
NS_ASSERTION(!mOutputStreamIsOpen, "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(uint32_t offset, nsIInputStream ** inputStream)
{
NS_ENSURE_ARG_POINTER(inputStream);
NS_ENSURE_TRUE(offset == 0, NS_ERROR_NOT_IMPLEMENTED);
*inputStream = nullptr;
if (!mBinding) return NS_ERROR_NOT_AVAILABLE;
if (mOutputStreamIsOpen) {
NS_WARNING("already have an output stream open");
return NS_ERROR_NOT_AVAILABLE;
}
nsresult rv;
PRFileDesc * fd = nullptr;
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(mStreamEnd);
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(uint32_t offset, nsIOutputStream ** outputStream)
{
NS_ENSURE_ARG_POINTER(outputStream);
*outputStream = nullptr;
if (!mBinding) return NS_ERROR_NOT_AVAILABLE;
NS_ASSERTION(!mOutputStreamIsOpen, "already have an output stream open");
NS_ASSERTION(mInStreamCount == 0, "we already have input streams open");
if (mOutputStreamIsOpen || mInStreamCount) return NS_ERROR_NOT_AVAILABLE;
mStreamEnd = mBinding->mCacheEntry->DataSize();
// Inits file or buffer and truncate at the desired offset
nsresult rv = SeekAndTruncate(offset);
if (NS_FAILED(rv)) return rv;
mOutputStreamIsOpen = true;
NS_ADDREF(*outputStream = this);
return NS_OK;
}
nsresult
nsDiskCacheStreamIO::ClearBinding()
{
nsresult rv = NS_OK;
if (mBinding && mOutputStreamIsOpen)
rv = CloseOutputStream();
mBinding = nullptr;
return rv;
}
NS_IMETHODIMP
nsDiskCacheStreamIO::Close()
{
if (!mOutputStreamIsOpen) return NS_OK;
mozilla::TimeStamp start = mozilla::TimeStamp::Now();
// grab service lock
nsCacheServiceAutoLock lock(LOCK_TELEM(NSDISKCACHESTREAMIO_CLOSEOUTPUTSTREAM));
if (!mBinding) { // if we're severed, just clear member variables
mOutputStreamIsOpen = false;
return NS_ERROR_NOT_AVAILABLE;
}
nsresult rv = CloseOutputStream();
if (NS_FAILED(rv))
NS_WARNING("CloseOutputStream() failed");
mozilla::Telemetry::ID id;
if (NS_IsMainThread())
id = mozilla::Telemetry::NETWORK_DISK_CACHE_STREAMIO_CLOSE_MAIN_THREAD;
else
id = mozilla::Telemetry::NETWORK_DISK_CACHE_STREAMIO_CLOSE;
mozilla::Telemetry::AccumulateTimeDelta(id, start);
return rv;
}
nsresult
nsDiskCacheStreamIO::CloseOutputStream()
{
NS_ASSERTION(mBinding, "oops");
CACHE_LOG_DEBUG(("CACHE: CloseOutputStream [%x doomed=%u]\n",
mBinding->mRecord.HashNumber(), mBinding->mDoomed));
// Mark outputstream as closed, even if saving the stream fails
mOutputStreamIsOpen = false;
// When writing to a file, just close the file
if (mFD) {
(void) PR_Close(mFD);
mFD = nullptr;
return NS_OK;
}
// write data to cache blocks, or flush mBuffer to file
NS_ASSERTION(mStreamEnd <= kMaxBufferSize, "stream is bigger than buffer");
nsDiskCacheMap *cacheMap = mDevice->CacheMap(); // get map reference
nsDiskCacheRecord * record = &mBinding->mRecord;
nsresult rv = NS_OK;
// delete existing storage
if (record->DataLocationInitialized()) {
rv = cacheMap->DeleteStorage(record, nsDiskCache::kData);
NS_ENSURE_SUCCESS(rv, rv);
// Only call UpdateRecord when there is no data to write,
// because WriteDataCacheBlocks / FlushBufferToFile calls it.
if ((mStreamEnd == 0) && (!mBinding->mDoomed)) {
rv = cacheMap->UpdateRecord(record);
if (NS_FAILED(rv)) {
NS_WARNING("cacheMap->UpdateRecord() failed.");
return rv; // XXX doom cache entry
}
}
}
if (mStreamEnd == 0) return NS_OK; // nothing to write
// try to write to the cache blocks
rv = cacheMap->WriteDataCacheBlocks(mBinding, mBuffer, mStreamEnd);
if (NS_FAILED(rv)) {
NS_WARNING("WriteDataCacheBlocks() failed.");
// failed to store in cacheblocks, save as separate file
rv = FlushBufferToFile(); // initializes DataFileLocation() if necessary
if (mFD) {
UpdateFileSize();
(void) PR_Close(mFD);
mFD = nullptr;
}
else
NS_WARNING("no file descriptor");
}
return rv;
}
// 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()
NS_IMETHODIMP
nsDiskCacheStreamIO::Write( const char * buffer,
uint32_t count,
uint32_t * bytesWritten)
{
NS_ENSURE_ARG_POINTER(buffer);
NS_ENSURE_ARG_POINTER(bytesWritten);
if (!mOutputStreamIsOpen) return NS_BASE_STREAM_CLOSED;
*bytesWritten = 0; // always initialize to zero in case of errors
NS_ASSERTION(count, "Write called with count of zero");
if (count == 0) {
return NS_OK; // nothing to write
}
// grab service lock
nsCacheServiceAutoLock lock(LOCK_TELEM(NSDISKCACHESTREAMIO_WRITE));
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;
}
// Not writing to file, and it will fit in the cachedatablocks?
if (!mFD && (mStreamEnd + count <= kMaxBufferSize)) {
// We have more data than the current buffer size?
if ((mStreamEnd + count > mBufSize) && (mBufSize < kMaxBufferSize)) {
// Increase buffer to the maximum size.
mBuffer = (char *) moz_xrealloc(mBuffer, kMaxBufferSize);
mBufSize = kMaxBufferSize;
}
// Store in the buffer but only if it fits
if (mStreamEnd + count <= mBufSize) {
memcpy(mBuffer + mStreamEnd, buffer, count);
mStreamEnd += count;
*bytesWritten = count;
return NS_OK;
}
}
// There are more bytes than fit in the buffer/cacheblocks, switch to file
if (!mFD) {
// Opens a cache file and write the buffer to it
nsresult rv = FlushBufferToFile();
if (NS_FAILED(rv)) {
return rv;
}
}
// Write directly to the file
if (PR_Write(mFD, buffer, count) != (int32_t)count) {
NS_WARNING("failed to write all data");
return NS_ERROR_UNEXPECTED; // NS_ErrorAccordingToNSPR()
}
mStreamEnd += count;
*bytesWritten = count;
UpdateFileSize();
NS_ASSERTION(mBinding->mCacheEntry->DataSize() == mStreamEnd, "bad stream");
return NS_OK;
}
void
nsDiskCacheStreamIO::UpdateFileSize()
{
NS_ASSERTION(mFD, "nsDiskCacheStreamIO::UpdateFileSize should not have been called");
nsDiskCacheRecord * record = &mBinding->mRecord;
const uint32_t oldSizeK = record->DataFileSize();
uint32_t 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(int flags, PRFileDesc ** fd)
{
NS_ENSURE_ARG_POINTER(fd);
CACHE_LOG_DEBUG(("nsDiskCacheStreamIO::OpenCacheFile"));
nsresult rv;
nsDiskCacheMap * cacheMap = mDevice->CacheMap();
nsCOMPtr<nsIFile> localFile;
rv = cacheMap->GetLocalFileForDiskCacheRecord(&mBinding->mRecord,
nsDiskCache::kData,
!!(flags & PR_CREATE_FILE),
getter_AddRefs(localFile));
if (NS_FAILED(rv)) return rv;
// create PRFileDesc for input stream - the 00600 is just for consistency
return localFile->OpenNSPRFileDesc(flags, 00600, fd);
}
nsresult
nsDiskCacheStreamIO::ReadCacheBlocks(uint32_t bufferSize)
{
NS_ASSERTION(mStreamEnd == mBinding->mCacheEntry->DataSize(), "bad stream");
NS_ASSERTION(bufferSize <= kMaxBufferSize, "bufferSize too large for buffer");
NS_ASSERTION(mStreamEnd <= bufferSize, "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) {
mBuffer = (char *) moz_xmalloc(bufferSize);
mBufSize = bufferSize;
}
// read data stored in cache block files
nsDiskCacheMap *map = mDevice->CacheMap(); // get map reference
return map->ReadDataCacheBlocks(mBinding, mBuffer, mStreamEnd);
}
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;
int64_t dataSize = mBinding->mCacheEntry->PredictedDataSize();
if (dataSize != -1)
mozilla::fallocate(mFD, std::min<int64_t>(dataSize, kPreallocateLimit));
}
// write buffer to the file when there is data in it
if (mStreamEnd > 0) {
if (!mBuffer) {
NS_RUNTIMEABORT("Fix me!");
}
if (PR_Write(mFD, mBuffer, mStreamEnd) != (int32_t)mStreamEnd) {
NS_WARNING("failed to flush all data");
return NS_ERROR_UNEXPECTED; // NS_ErrorAccordingToNSPR()
}
}
// buffer is no longer valid
DeleteBuffer();
return NS_OK;
}
void
nsDiskCacheStreamIO::DeleteBuffer()
{
if (mBuffer) {
free(mBuffer);
mBuffer = nullptr;
mBufSize = 0;
}
}
size_t
nsDiskCacheStreamIO::SizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf)
{
size_t usage = aMallocSizeOf(this);
usage += aMallocSizeOf(mFD);
usage += aMallocSizeOf(mBuffer);
return usage;
}
nsresult
nsDiskCacheStreamIO::SeekAndTruncate(uint32_t offset)
{
if (!mBinding) return NS_ERROR_NOT_AVAILABLE;
if (uint32_t(offset) > mStreamEnd) return NS_ERROR_FAILURE;
// Set the current end to the desired offset
mStreamEnd = offset;
// Currently stored in file?
if (mBinding->mRecord.DataLocationInitialized() &&
(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 (offset) {
if (PR_Seek(mFD, offset, PR_SEEK_SET) == -1)
return NS_ErrorAccordingToNSPR();
}
nsDiskCache::Truncate(mFD, offset);
UpdateFileSize();
// When we starting at zero again, close file and start with buffer.
// If offset is non-zero (and within buffer) an option would be
// to read the file into the buffer, but chance is high that it is
// rewritten to the file anyway.
if (offset == 0) {
// close file descriptor
(void) PR_Close(mFD);
mFD = nullptr;
}
return NS_OK;
}
// read data into mBuffer if not read yet.
if (offset && !mBuffer) {
nsresult rv = ReadCacheBlocks(kMaxBufferSize);
if (NS_FAILED(rv)) return rv;
}
// stream buffer sanity check
NS_ASSERTION(mStreamEnd <= kMaxBufferSize, "bad stream");
return NS_OK;
}
NS_IMETHODIMP
nsDiskCacheStreamIO::Flush()
{
if (!mOutputStreamIsOpen) return NS_BASE_STREAM_CLOSED;
return NS_OK;
}
NS_IMETHODIMP
nsDiskCacheStreamIO::WriteFrom(nsIInputStream *inStream, uint32_t count, uint32_t *bytesWritten)
{
NS_NOTREACHED("WriteFrom");
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsDiskCacheStreamIO::WriteSegments( nsReadSegmentFun reader,
void * closure,
uint32_t count,
uint32_t * bytesWritten)
{
NS_NOTREACHED("WriteSegments");
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsDiskCacheStreamIO::IsNonBlocking(bool * nonBlocking)
{
*nonBlocking = false;
return NS_OK;
}