зеркало из https://github.com/mozilla/pjs.git
406 строки
14 KiB
C++
406 строки
14 KiB
C++
/* -*- 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 nsDiskCacheBlockFile.cpp, released
|
|
* April 12, 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 "nsDiskCacheBlockFile.h"
|
|
#include "mozilla/FileUtils.h"
|
|
|
|
/******************************************************************************
|
|
* nsDiskCacheBlockFile -
|
|
*****************************************************************************/
|
|
|
|
/******************************************************************************
|
|
* Open
|
|
*****************************************************************************/
|
|
nsresult
|
|
nsDiskCacheBlockFile::Open(nsILocalFile * blockFile,
|
|
PRUint32 blockSize,
|
|
PRUint32 bitMapSize)
|
|
{
|
|
if (bitMapSize % 32)
|
|
return NS_ERROR_INVALID_ARG;
|
|
|
|
mBlockSize = blockSize;
|
|
mBitMapWords = bitMapSize / 32;
|
|
PRUint32 bitMapBytes = mBitMapWords * 4;
|
|
|
|
// open the file - restricted to user, the data could be confidential
|
|
nsresult rv = blockFile->OpenNSPRFileDesc(PR_RDWR | PR_CREATE_FILE, 00600, &mFD);
|
|
if (NS_FAILED(rv)) return rv; // unable to open or create file
|
|
|
|
// allocate bit map buffer
|
|
mBitMap = new PRUint32[mBitMapWords];
|
|
if (!mBitMap) {
|
|
rv = NS_ERROR_OUT_OF_MEMORY;
|
|
goto error_exit;
|
|
}
|
|
|
|
// check if we just creating the file
|
|
mFileSize = PR_Available(mFD);
|
|
if (mFileSize < 0) {
|
|
// XXX an error occurred. We could call PR_GetError(), but how would that help?
|
|
rv = NS_ERROR_UNEXPECTED;
|
|
goto error_exit;
|
|
}
|
|
if (mFileSize == 0) {
|
|
// initialize bit map and write it
|
|
memset(mBitMap, 0, bitMapBytes);
|
|
if (!Write(0, mBitMap, bitMapBytes))
|
|
goto error_exit;
|
|
|
|
} else if ((PRUint32)mFileSize < bitMapBytes) {
|
|
rv = NS_ERROR_UNEXPECTED; // XXX NS_ERROR_CACHE_INVALID;
|
|
goto error_exit;
|
|
|
|
} else {
|
|
// read the bit map
|
|
const PRInt32 bytesRead = PR_Read(mFD, mBitMap, bitMapBytes);
|
|
if ((bytesRead < 0) || ((PRUint32)bytesRead < bitMapBytes)) {
|
|
rv = NS_ERROR_UNEXPECTED;
|
|
goto error_exit;
|
|
}
|
|
#if defined(IS_LITTLE_ENDIAN)
|
|
// Swap from network format
|
|
for (unsigned int i = 0; i < mBitMapWords; ++i)
|
|
mBitMap[i] = ntohl(mBitMap[i]);
|
|
#endif
|
|
// validate block file size
|
|
// Because not whole blocks are written, the size may be a
|
|
// little bit smaller than used blocks times blocksize,
|
|
// because the last block will generally not be 'whole'.
|
|
const PRUint32 estimatedSize = CalcBlockFileSize();
|
|
if ((PRUint32)mFileSize + blockSize < estimatedSize) {
|
|
rv = NS_ERROR_UNEXPECTED;
|
|
goto error_exit;
|
|
}
|
|
}
|
|
return NS_OK;
|
|
|
|
error_exit:
|
|
Close(PR_FALSE);
|
|
return rv;
|
|
}
|
|
|
|
|
|
/******************************************************************************
|
|
* Close
|
|
*****************************************************************************/
|
|
nsresult
|
|
nsDiskCacheBlockFile::Close(PRBool flush)
|
|
{
|
|
nsresult rv = NS_OK;
|
|
|
|
if (mFD) {
|
|
if (flush)
|
|
rv = FlushBitMap();
|
|
PRStatus err = PR_Close(mFD);
|
|
if (NS_SUCCEEDED(rv) && (err != PR_SUCCESS))
|
|
rv = NS_ERROR_UNEXPECTED;
|
|
mFD = nsnull;
|
|
}
|
|
|
|
if (mBitMap) {
|
|
delete [] mBitMap;
|
|
mBitMap = nsnull;
|
|
}
|
|
|
|
return rv;
|
|
}
|
|
|
|
|
|
/******************************************************************************
|
|
* AllocateBlocks
|
|
*
|
|
* Allocates 1-4 blocks, using a first fit strategy,
|
|
* so that no group of blocks spans a quad block boundary.
|
|
*
|
|
* Returns block number of first block allocated or -1 on failure.
|
|
*
|
|
*****************************************************************************/
|
|
PRInt32
|
|
nsDiskCacheBlockFile::AllocateBlocks(PRInt32 numBlocks)
|
|
{
|
|
const int maxPos = 32 - numBlocks;
|
|
const PRUint32 mask = (0x01 << numBlocks) - 1;
|
|
for (unsigned int i = 0; i < mBitMapWords; ++i) {
|
|
PRUint32 mapWord = ~mBitMap[i]; // flip bits so free bits are 1
|
|
if (mapWord) { // At least one free bit
|
|
// Binary search for first free bit in word
|
|
int bit = 0;
|
|
if ((mapWord & 0x0FFFF) == 0) { bit |= 16; mapWord >>= 16; }
|
|
if ((mapWord & 0x000FF) == 0) { bit |= 8; mapWord >>= 8; }
|
|
if ((mapWord & 0x0000F) == 0) { bit |= 4; mapWord >>= 4; }
|
|
if ((mapWord & 0x00003) == 0) { bit |= 2; mapWord >>= 2; }
|
|
if ((mapWord & 0x00001) == 0) { bit |= 1; mapWord >>= 1; }
|
|
// Find first fit for mask
|
|
for (; bit <= maxPos; ++bit) {
|
|
// all bits selected by mask are 1, so free
|
|
if ((mask & mapWord) == mask) {
|
|
mBitMap[i] |= mask << bit;
|
|
mBitMapDirty = PR_TRUE;
|
|
return (PRInt32)i * 32 + bit;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
|
|
/******************************************************************************
|
|
* DeallocateBlocks
|
|
*****************************************************************************/
|
|
nsresult
|
|
nsDiskCacheBlockFile::DeallocateBlocks( PRInt32 startBlock, PRInt32 numBlocks)
|
|
{
|
|
if (!mFD) return NS_ERROR_NOT_AVAILABLE;
|
|
|
|
if ((startBlock < 0) || ((PRUint32)startBlock > mBitMapWords * 32 - 1) ||
|
|
(numBlocks < 1) || (numBlocks > 4))
|
|
return NS_ERROR_ILLEGAL_VALUE;
|
|
|
|
const PRInt32 startWord = startBlock >> 5; // Divide by 32
|
|
const PRUint32 startBit = startBlock & 31; // Modulo by 32
|
|
|
|
// make sure requested deallocation doesn't span a word boundary
|
|
if (startBit + numBlocks > 32) return NS_ERROR_UNEXPECTED;
|
|
PRUint32 mask = ((0x01 << numBlocks) - 1) << startBit;
|
|
|
|
// make sure requested deallocation is currently allocated
|
|
if ((mBitMap[startWord] & mask) != mask) return NS_ERROR_ABORT;
|
|
|
|
mBitMap[startWord] ^= mask; // flips the bits off;
|
|
mBitMapDirty = PR_TRUE;
|
|
// XXX rv = FlushBitMap(); // coherency vs. performance
|
|
return NS_OK;
|
|
}
|
|
|
|
|
|
/******************************************************************************
|
|
* WriteBlocks
|
|
*****************************************************************************/
|
|
nsresult
|
|
nsDiskCacheBlockFile::WriteBlocks( void * buffer,
|
|
PRUint32 size,
|
|
PRInt32 numBlocks,
|
|
PRInt32 * startBlock)
|
|
{
|
|
// presume buffer != nsnull and startBlock != nsnull
|
|
NS_ENSURE_TRUE(mFD, NS_ERROR_NOT_AVAILABLE);
|
|
|
|
// allocate some blocks in the cache block file
|
|
*startBlock = AllocateBlocks(numBlocks);
|
|
if (*startBlock < 0)
|
|
return NS_ERROR_NOT_AVAILABLE;
|
|
|
|
// seek to block position
|
|
PRInt32 blockPos = mBitMapWords * 4 + *startBlock * mBlockSize;
|
|
|
|
// write the blocks
|
|
return Write(blockPos, buffer, size) ? NS_OK : NS_ERROR_FAILURE;
|
|
}
|
|
|
|
|
|
/******************************************************************************
|
|
* ReadBlocks
|
|
*****************************************************************************/
|
|
nsresult
|
|
nsDiskCacheBlockFile::ReadBlocks( void * buffer,
|
|
PRInt32 startBlock,
|
|
PRInt32 numBlocks,
|
|
PRInt32 * bytesRead)
|
|
{
|
|
// presume buffer != nsnull and bytesRead != bytesRead
|
|
|
|
if (!mFD) return NS_ERROR_NOT_AVAILABLE;
|
|
nsresult rv = VerifyAllocation(startBlock, numBlocks);
|
|
if (NS_FAILED(rv)) return rv;
|
|
|
|
// seek to block position
|
|
PRInt32 blockPos = mBitMapWords * 4 + startBlock * mBlockSize;
|
|
PRInt32 filePos = PR_Seek(mFD, blockPos, PR_SEEK_SET);
|
|
if (filePos != blockPos) return NS_ERROR_UNEXPECTED;
|
|
|
|
// read the blocks
|
|
PRInt32 bytesToRead = *bytesRead;
|
|
if ((bytesToRead <= 0) || ((PRUint32)bytesToRead > mBlockSize * numBlocks)) {
|
|
bytesToRead = mBlockSize * numBlocks;
|
|
}
|
|
*bytesRead = PR_Read(mFD, buffer, bytesToRead);
|
|
|
|
return NS_OK;
|
|
}
|
|
|
|
|
|
/******************************************************************************
|
|
* FlushBitMap
|
|
*****************************************************************************/
|
|
nsresult
|
|
nsDiskCacheBlockFile::FlushBitMap()
|
|
{
|
|
if (!mBitMapDirty) return NS_OK;
|
|
|
|
#if defined(IS_LITTLE_ENDIAN)
|
|
PRUint32 *bitmap = new PRUint32[mBitMapWords];
|
|
// Copy and swap to network format
|
|
PRUint32 *p = bitmap;
|
|
for (unsigned int i = 0; i < mBitMapWords; ++i, ++p)
|
|
*p = htonl(mBitMap[i]);
|
|
#else
|
|
PRUint32 *bitmap = mBitMap;
|
|
#endif
|
|
|
|
// write bitmap
|
|
bool written = Write(0, bitmap, mBitMapWords * 4);
|
|
#if defined(IS_LITTLE_ENDIAN)
|
|
delete [] bitmap;
|
|
#endif
|
|
if (!written)
|
|
return NS_ERROR_UNEXPECTED;
|
|
|
|
PRStatus err = PR_Sync(mFD);
|
|
if (err != PR_SUCCESS) return NS_ERROR_UNEXPECTED;
|
|
|
|
mBitMapDirty = PR_FALSE;
|
|
return NS_OK;
|
|
}
|
|
|
|
|
|
/******************************************************************************
|
|
* VerifyAllocation
|
|
*
|
|
* Return values:
|
|
* NS_OK if all bits are marked allocated
|
|
* NS_ERROR_ILLEGAL_VALUE if parameters don't obey constraints
|
|
* NS_ERROR_FAILURE if some or all the bits are marked unallocated
|
|
*
|
|
*****************************************************************************/
|
|
nsresult
|
|
nsDiskCacheBlockFile::VerifyAllocation( PRInt32 startBlock, PRInt32 numBlocks)
|
|
{
|
|
if ((startBlock < 0) || ((PRUint32)startBlock > mBitMapWords * 32 - 1) ||
|
|
(numBlocks < 1) || (numBlocks > 4))
|
|
return NS_ERROR_ILLEGAL_VALUE;
|
|
|
|
const PRInt32 startWord = startBlock >> 5; // Divide by 32
|
|
const PRUint32 startBit = startBlock & 31; // Modulo by 32
|
|
|
|
// make sure requested deallocation doesn't span a word boundary
|
|
if (startBit + numBlocks > 32) return NS_ERROR_ILLEGAL_VALUE;
|
|
PRUint32 mask = ((0x01 << numBlocks) - 1) << startBit;
|
|
|
|
// check if all specified blocks are currently allocated
|
|
if ((mBitMap[startWord] & mask) != mask) return NS_ERROR_FAILURE;
|
|
|
|
return NS_OK;
|
|
}
|
|
|
|
|
|
/******************************************************************************
|
|
* CalcBlockFileSize
|
|
*
|
|
* Return size of the block file according to the bits set in mBitmap
|
|
*
|
|
*****************************************************************************/
|
|
PRUint32
|
|
nsDiskCacheBlockFile::CalcBlockFileSize()
|
|
{
|
|
// search for last byte in mBitMap with allocated bits
|
|
PRUint32 estimatedSize = mBitMapWords * 4;
|
|
PRInt32 i = mBitMapWords;
|
|
while (--i >= 0) {
|
|
if (mBitMap[i]) break;
|
|
}
|
|
|
|
if (i >= 0) {
|
|
// binary search to find last allocated bit in byte
|
|
PRUint32 mapWord = mBitMap[i];
|
|
PRUint32 lastBit = 31;
|
|
if ((mapWord & 0xFFFF0000) == 0) { lastBit ^= 16; mapWord <<= 16; }
|
|
if ((mapWord & 0xFF000000) == 0) { lastBit ^= 8; mapWord <<= 8; }
|
|
if ((mapWord & 0xF0000000) == 0) { lastBit ^= 4; mapWord <<= 4; }
|
|
if ((mapWord & 0xC0000000) == 0) { lastBit ^= 2; mapWord <<= 2; }
|
|
if ((mapWord & 0x80000000) == 0) { lastBit ^= 1; mapWord <<= 1; }
|
|
estimatedSize += (i * 32 + lastBit + 1) * mBlockSize;
|
|
}
|
|
|
|
return estimatedSize;
|
|
}
|
|
|
|
/******************************************************************************
|
|
* Write
|
|
*
|
|
* Wrapper around PR_Write that grows file in larger chunks to combat fragmentation
|
|
*
|
|
*****************************************************************************/
|
|
bool
|
|
nsDiskCacheBlockFile::Write(PRInt32 offset, const void *buf, PRInt32 amount)
|
|
{
|
|
/* Grow the file to 4mb right away, then double it until the file grows to 20mb.
|
|
20mb is a magic threshold because OSX stops autodefragging files bigger than that.
|
|
Beyond 20mb grow in 4mb chunks.
|
|
*/
|
|
const PRInt32 upTo = offset + amount;
|
|
// Use a conservative definition of 20MB
|
|
const PRInt32 minPreallocate = 4*1024*1024;
|
|
const PRInt32 maxPreallocate = 20*1000*1000;
|
|
if (mFileSize < upTo) {
|
|
// maximal file size
|
|
const PRInt32 maxFileSize = mBitMapWords * 4 * (mBlockSize * 8 + 1);
|
|
if (upTo > maxPreallocate) {
|
|
// grow the file as a multiple of minPreallocate
|
|
mFileSize = ((upTo + minPreallocate - 1) / minPreallocate) * minPreallocate;
|
|
} else {
|
|
// Grow quickly between 1MB to 20MB
|
|
if (mFileSize)
|
|
while(mFileSize < upTo)
|
|
mFileSize *= 2;
|
|
mFileSize = NS_MIN(maxPreallocate, NS_MAX(mFileSize, minPreallocate));
|
|
}
|
|
mFileSize = NS_MIN(mFileSize, maxFileSize);
|
|
// Appears to cause bug 617123? Disabled for now.
|
|
//mozilla::fallocate(mFD, mFileSize);
|
|
}
|
|
if (PR_Seek(mFD, offset, PR_SEEK_SET) != offset)
|
|
return false;
|
|
return PR_Write(mFD, buf, amount) == amount;
|
|
}
|