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Diffstat (limited to 'netwerk/cache2/CacheFileMetadata.cpp')
| -rw-r--r-- | netwerk/cache2/CacheFileMetadata.cpp | 1042 |
1 files changed, 1042 insertions, 0 deletions
diff --git a/netwerk/cache2/CacheFileMetadata.cpp b/netwerk/cache2/CacheFileMetadata.cpp new file mode 100644 index 0000000000..4299b30a25 --- /dev/null +++ b/netwerk/cache2/CacheFileMetadata.cpp @@ -0,0 +1,1042 @@ +/* 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 "CacheLog.h" +#include "CacheFileMetadata.h" + +#include "CacheFileIOManager.h" +#include "nsICacheEntry.h" +#include "CacheHashUtils.h" +#include "CacheFileChunk.h" +#include "CacheFileUtils.h" +#include "nsILoadContextInfo.h" +#include "nsICacheEntry.h" // for nsICacheEntryMetaDataVisitor +#include "../cache/nsCacheUtils.h" +#include "nsIFile.h" +#include "mozilla/ScopeExit.h" +#include "mozilla/Telemetry.h" +#include "mozilla/DebugOnly.h" +#include "mozilla/IntegerPrintfMacros.h" +#include "prnetdb.h" + +namespace mozilla::net { + +#define kMinMetadataRead 1024 // TODO find optimal value from telemetry +#define kAlignSize 4096 + +// Most of the cache entries fit into one chunk due to current chunk size. Make +// sure to tweak this value if kChunkSize is going to change. +#define kInitialHashArraySize 1 + +// Initial elements buffer size. +#define kInitialBufSize 64 + +// Max size of elements in bytes. +#define kMaxElementsSize (64 * 1024) + +#define NOW_SECONDS() (uint32_t(PR_Now() / PR_USEC_PER_SEC)) + +NS_IMPL_ISUPPORTS(CacheFileMetadata, CacheFileIOListener) + +CacheFileMetadata::CacheFileMetadata( + CacheFileHandle* aHandle, const nsACString& aKey, + NotNull<CacheFileUtils::CacheFileLock*> aLock) + : CacheMemoryConsumer(NORMAL), + mHandle(aHandle), + mOffset(-1), + mIsDirty(false), + mAnonymous(false), + mAllocExactSize(false), + mFirstRead(true), + mLock(aLock) { + LOG(("CacheFileMetadata::CacheFileMetadata() [this=%p, handle=%p, key=%s]", + this, aHandle, PromiseFlatCString(aKey).get())); + + memset(&mMetaHdr, 0, sizeof(CacheFileMetadataHeader)); + mMetaHdr.mVersion = kCacheEntryVersion; + mMetaHdr.mExpirationTime = nsICacheEntry::NO_EXPIRATION_TIME; + mKey = aKey; + + DebugOnly<nsresult> rv{}; + rv = ParseKey(aKey); + MOZ_ASSERT(NS_SUCCEEDED(rv)); +} + +CacheFileMetadata::CacheFileMetadata( + bool aMemoryOnly, bool aPinned, const nsACString& aKey, + NotNull<CacheFileUtils::CacheFileLock*> aLock) + : CacheMemoryConsumer(aMemoryOnly ? MEMORY_ONLY : NORMAL), + mIsDirty(true), + mAnonymous(false), + mAllocExactSize(false), + mFirstRead(true), + mLock(aLock) { + LOG(("CacheFileMetadata::CacheFileMetadata() [this=%p, key=%s]", this, + PromiseFlatCString(aKey).get())); + + memset(&mMetaHdr, 0, sizeof(CacheFileMetadataHeader)); + mMetaHdr.mVersion = kCacheEntryVersion; + if (aPinned) { + AddFlags(kCacheEntryIsPinned); + } + mMetaHdr.mExpirationTime = nsICacheEntry::NO_EXPIRATION_TIME; + mKey = aKey; + mMetaHdr.mKeySize = mKey.Length(); + + DebugOnly<nsresult> rv{}; + rv = ParseKey(aKey); + MOZ_ASSERT(NS_SUCCEEDED(rv)); +} + +CacheFileMetadata::CacheFileMetadata() + : CacheMemoryConsumer(DONT_REPORT /* This is a helper class */), + mIsDirty(false), + mAnonymous(false), + mAllocExactSize(false), + mFirstRead(true), + mLock(new CacheFileUtils::CacheFileLock()) { + LOG(("CacheFileMetadata::CacheFileMetadata() [this=%p]", this)); + + memset(&mMetaHdr, 0, sizeof(CacheFileMetadataHeader)); +} + +CacheFileMetadata::~CacheFileMetadata() { + LOG(("CacheFileMetadata::~CacheFileMetadata() [this=%p]", this)); + + MOZ_ASSERT(!mListener); + + if (mHashArray) { + CacheFileUtils::FreeBuffer(mHashArray); + mHashArray = nullptr; + mHashArraySize = 0; + } + + if (mBuf) { + CacheFileUtils::FreeBuffer(mBuf); + mBuf = nullptr; + mBufSize = 0; + } +} + +void CacheFileMetadata::SetHandle(CacheFileHandle* aHandle) { + LOG(("CacheFileMetadata::SetHandle() [this=%p, handle=%p]", this, aHandle)); + + MOZ_ASSERT(!mHandle); + + mHandle = aHandle; +} + +void CacheFileMetadata::ReadMetadata(CacheFileMetadataListener* aListener) { + LOG(("CacheFileMetadata::ReadMetadata() [this=%p, listener=%p]", this, + aListener)); + + MOZ_ASSERT(!mListener); + MOZ_ASSERT(!mHashArray); + MOZ_ASSERT(!mBuf); + MOZ_ASSERT(!mWriteBuf); + + nsresult rv; + + int64_t size = mHandle->FileSize(); + MOZ_ASSERT(size != -1); + + if (size == 0) { + // this is a new entry + LOG( + ("CacheFileMetadata::ReadMetadata() - Filesize == 0, creating empty " + "metadata. [this=%p]", + this)); + + InitEmptyMetadata(); + aListener->OnMetadataRead(NS_OK); + return; + } + + if (size < int64_t(sizeof(CacheFileMetadataHeader) + 2 * sizeof(uint32_t))) { + // there must be at least checksum, header and offset + LOG( + ("CacheFileMetadata::ReadMetadata() - File is corrupted, creating " + "empty metadata. [this=%p, filesize=%" PRId64 "]", + this, size)); + + InitEmptyMetadata(); + aListener->OnMetadataRead(NS_OK); + return; + } + + // Set offset so that we read at least kMinMetadataRead if the file is big + // enough. + int64_t offset; + if (size < kMinMetadataRead) { + offset = 0; + } else { + offset = size - kMinMetadataRead; + } + + // round offset to kAlignSize blocks + offset = (offset / kAlignSize) * kAlignSize; + + mBufSize = size - offset; + mBuf = static_cast<char*>(moz_xmalloc(mBufSize)); + + DoMemoryReport(MemoryUsage()); + + LOG( + ("CacheFileMetadata::ReadMetadata() - Reading metadata from disk, trying " + "offset=%" PRId64 ", filesize=%" PRId64 " [this=%p]", + offset, size, this)); + + mReadStart = mozilla::TimeStamp::Now(); + mListener = aListener; + rv = CacheFileIOManager::Read(mHandle, offset, mBuf, mBufSize, this); + if (NS_FAILED(rv)) { + LOG( + ("CacheFileMetadata::ReadMetadata() - CacheFileIOManager::Read() failed" + " synchronously, creating empty metadata. [this=%p, rv=0x%08" PRIx32 + "]", + this, static_cast<uint32_t>(rv))); + + mListener = nullptr; + InitEmptyMetadata(); + aListener->OnMetadataRead(NS_OK); + } +} + +uint32_t CacheFileMetadata::CalcMetadataSize(uint32_t aElementsSize, + uint32_t aHashCount) { + return sizeof(uint32_t) + // hash of the metadata + aHashCount * sizeof(CacheHash::Hash16_t) + // array of chunk hashes + sizeof(CacheFileMetadataHeader) + // metadata header + mKey.Length() + 1 + // key with trailing null + aElementsSize + // elements + sizeof(uint32_t); // offset +} + +nsresult CacheFileMetadata::WriteMetadata( + uint32_t aOffset, CacheFileMetadataListener* aListener) { + LOG(("CacheFileMetadata::WriteMetadata() [this=%p, offset=%d, listener=%p]", + this, aOffset, aListener)); + + MOZ_ASSERT(!mListener); + MOZ_ASSERT(!mWriteBuf); + + nsresult rv; + + mIsDirty = false; + + mWriteBuf = + static_cast<char*>(malloc(CalcMetadataSize(mElementsSize, mHashCount))); + if (!mWriteBuf) { + return NS_ERROR_OUT_OF_MEMORY; + } + + char* p = mWriteBuf + sizeof(uint32_t); + if (mHashCount) { + memcpy(p, mHashArray, mHashCount * sizeof(CacheHash::Hash16_t)); + p += mHashCount * sizeof(CacheHash::Hash16_t); + } + mMetaHdr.WriteToBuf(p); + p += sizeof(CacheFileMetadataHeader); + memcpy(p, mKey.get(), mKey.Length()); + p += mKey.Length(); + *p = 0; + p++; + if (mElementsSize) { + memcpy(p, mBuf, mElementsSize); + p += mElementsSize; + } + + CacheHash::Hash32_t hash; + hash = CacheHash::Hash(mWriteBuf + sizeof(uint32_t), + p - mWriteBuf - sizeof(uint32_t)); + NetworkEndian::writeUint32(mWriteBuf, hash); + + NetworkEndian::writeUint32(p, aOffset); + p += sizeof(uint32_t); + + char* writeBuffer = mWriteBuf; + if (aListener) { + mListener = aListener; + } else { + // We are not going to pass |this| as a callback so the buffer will be + // released by CacheFileIOManager. Just null out mWriteBuf here. + mWriteBuf = nullptr; + } + + rv = CacheFileIOManager::Write(mHandle, aOffset, writeBuffer, p - writeBuffer, + true, true, aListener ? this : nullptr); + if (NS_FAILED(rv)) { + LOG( + ("CacheFileMetadata::WriteMetadata() - CacheFileIOManager::Write() " + "failed synchronously. [this=%p, rv=0x%08" PRIx32 "]", + this, static_cast<uint32_t>(rv))); + + mListener = nullptr; + if (mWriteBuf) { + CacheFileUtils::FreeBuffer(mWriteBuf); + mWriteBuf = nullptr; + } + NS_ENSURE_SUCCESS(rv, rv); + } + + DoMemoryReport(MemoryUsage()); + + return NS_OK; +} + +nsresult CacheFileMetadata::SyncReadMetadata(nsIFile* aFile) { + LOG(("CacheFileMetadata::SyncReadMetadata() [this=%p]", this)); + + MOZ_ASSERT(!mListener); + MOZ_ASSERT(!mHandle); + MOZ_ASSERT(!mHashArray); + MOZ_ASSERT(!mBuf); + MOZ_ASSERT(!mWriteBuf); + MOZ_ASSERT(mKey.IsEmpty()); + + nsresult rv; + + int64_t fileSize; + rv = aFile->GetFileSize(&fileSize); + if (NS_FAILED(rv)) { + // Don't bloat the console + return rv; + } + + PRFileDesc* fd; + rv = aFile->OpenNSPRFileDesc(PR_RDONLY, 0600, &fd); + NS_ENSURE_SUCCESS(rv, rv); + + int64_t offset = PR_Seek64(fd, fileSize - sizeof(uint32_t), PR_SEEK_SET); + if (offset == -1) { + PR_Close(fd); + return NS_ERROR_FAILURE; + } + + uint32_t metaOffset; + int32_t bytesRead = PR_Read(fd, &metaOffset, sizeof(uint32_t)); + if (bytesRead != sizeof(uint32_t)) { + PR_Close(fd); + return NS_ERROR_FAILURE; + } + + metaOffset = NetworkEndian::readUint32(&metaOffset); + if (metaOffset > fileSize) { + PR_Close(fd); + return NS_ERROR_FAILURE; + } + + mBuf = static_cast<char*>(malloc(fileSize - metaOffset)); + if (!mBuf) { + return NS_ERROR_OUT_OF_MEMORY; + } + mBufSize = fileSize - metaOffset; + + DoMemoryReport(MemoryUsage()); + + offset = PR_Seek64(fd, metaOffset, PR_SEEK_SET); + if (offset == -1) { + PR_Close(fd); + return NS_ERROR_FAILURE; + } + + bytesRead = PR_Read(fd, mBuf, mBufSize); + PR_Close(fd); + if (bytesRead != static_cast<int32_t>(mBufSize)) { + return NS_ERROR_FAILURE; + } + + rv = ParseMetadata(metaOffset, 0, false); + NS_ENSURE_SUCCESS(rv, rv); + + return NS_OK; +} + +const char* CacheFileMetadata::GetElement(const char* aKey) { + const char* data = mBuf; + const char* limit = mBuf + mElementsSize; + + while (data != limit) { + size_t maxLen = limit - data; + size_t keyLen = strnlen(data, maxLen); + MOZ_RELEASE_ASSERT(keyLen != maxLen, + "Metadata elements corrupted. Key " + "isn't null terminated!"); + MOZ_RELEASE_ASSERT(keyLen + 1 != maxLen, + "Metadata elements corrupted. " + "There is no value for the key!"); + + const char* value = data + keyLen + 1; + maxLen = limit - value; + size_t valueLen = strnlen(value, maxLen); + MOZ_RELEASE_ASSERT(valueLen != maxLen, + "Metadata elements corrupted. Value " + "isn't null terminated!"); + + if (strcmp(data, aKey) == 0) { + LOG(("CacheFileMetadata::GetElement() - Key found [this=%p, key=%s]", + this, aKey)); + return value; + } + + // point to next pair + data += keyLen + valueLen + 2; + } + LOG(("CacheFileMetadata::GetElement() - Key not found [this=%p, key=%s]", + this, aKey)); + return nullptr; +} + +nsresult CacheFileMetadata::SetElement(const char* aKey, const char* aValue) { + LOG(("CacheFileMetadata::SetElement() [this=%p, key=%s, value=%p]", this, + aKey, aValue)); + + mLock->Lock().AssertCurrentThreadOwns(); + + MarkDirty(); + + nsresult rv; + + const uint32_t keySize = strlen(aKey) + 1; + char* pos = const_cast<char*>(GetElement(aKey)); + + if (!aValue) { + // No value means remove the key/value pair completely, if existing + if (pos) { + uint32_t oldValueSize = strlen(pos) + 1; + uint32_t offset = pos - mBuf; + uint32_t remainder = mElementsSize - (offset + oldValueSize); + + memmove(pos - keySize, pos + oldValueSize, remainder); + mElementsSize -= keySize + oldValueSize; + } + return NS_OK; + } + + const uint32_t valueSize = strlen(aValue) + 1; + uint32_t newSize = mElementsSize + valueSize; + if (pos) { + const uint32_t oldValueSize = strlen(pos) + 1; + const uint32_t offset = pos - mBuf; + const uint32_t remainder = mElementsSize - (offset + oldValueSize); + + // Update the value in place + newSize -= oldValueSize; + rv = EnsureBuffer(newSize); + if (NS_FAILED(rv)) { + return rv; + } + + // Move the remainder to the right place + pos = mBuf + offset; + memmove(pos + valueSize, pos + oldValueSize, remainder); + } else { + // allocate new meta data element + newSize += keySize; + rv = EnsureBuffer(newSize); + if (NS_FAILED(rv)) { + return rv; + } + + // Add after last element + pos = mBuf + mElementsSize; + memcpy(pos, aKey, keySize); + pos += keySize; + } + + // Update value + memcpy(pos, aValue, valueSize); + mElementsSize = newSize; + + return NS_OK; +} + +void CacheFileMetadata::Visit(nsICacheEntryMetaDataVisitor* aVisitor) { + const char* data = mBuf; + const char* limit = mBuf + mElementsSize; + + while (data < limit) { + // Point to the value part + const char* value = data + strlen(data) + 1; + MOZ_ASSERT(value < limit, "Metadata elements corrupted"); + + aVisitor->OnMetaDataElement(data, value); + + // Skip value part + data = value + strlen(value) + 1; + } + + MOZ_ASSERT(data == limit, "Metadata elements corrupted"); +} + +CacheHash::Hash16_t CacheFileMetadata::GetHash(uint32_t aIndex) { + mLock->Lock().AssertCurrentThreadOwns(); + + MOZ_ASSERT(aIndex < mHashCount); + return NetworkEndian::readUint16(&mHashArray[aIndex]); +} + +nsresult CacheFileMetadata::SetHash(uint32_t aIndex, + CacheHash::Hash16_t aHash) { + LOG(("CacheFileMetadata::SetHash() [this=%p, idx=%d, hash=%x]", this, aIndex, + aHash)); + + mLock->Lock().AssertCurrentThreadOwns(); + + MarkDirty(); + + MOZ_ASSERT(aIndex <= mHashCount); + + if (aIndex > mHashCount) { + return NS_ERROR_INVALID_ARG; + } + if (aIndex == mHashCount) { + if ((aIndex + 1) * sizeof(CacheHash::Hash16_t) > mHashArraySize) { + // reallocate hash array buffer + if (mHashArraySize == 0) { + mHashArraySize = kInitialHashArraySize * sizeof(CacheHash::Hash16_t); + } else { + mHashArraySize *= 2; + } + mHashArray = static_cast<CacheHash::Hash16_t*>( + moz_xrealloc(mHashArray, mHashArraySize)); + } + + mHashCount++; + } + + NetworkEndian::writeUint16(&mHashArray[aIndex], aHash); + + DoMemoryReport(MemoryUsage()); + + return NS_OK; +} + +nsresult CacheFileMetadata::RemoveHash(uint32_t aIndex) { + LOG(("CacheFileMetadata::RemoveHash() [this=%p, idx=%d]", this, aIndex)); + + mLock->Lock().AssertCurrentThreadOwns(); + + MarkDirty(); + + MOZ_ASSERT((aIndex + 1) == mHashCount, "Can remove only last hash!"); + + if (aIndex + 1 != mHashCount) { + return NS_ERROR_INVALID_ARG; + } + + mHashCount--; + return NS_OK; +} + +void CacheFileMetadata::AddFlags(uint32_t aFlags) { + MarkDirty(false); + mMetaHdr.mFlags |= aFlags; +} + +void CacheFileMetadata::RemoveFlags(uint32_t aFlags) { + MarkDirty(false); + mMetaHdr.mFlags &= ~aFlags; +} + +void CacheFileMetadata::SetExpirationTime(uint32_t aExpirationTime) { + LOG(("CacheFileMetadata::SetExpirationTime() [this=%p, expirationTime=%d]", + this, aExpirationTime)); + + MarkDirty(false); + mMetaHdr.mExpirationTime = aExpirationTime; +} + +void CacheFileMetadata::SetFrecency(uint32_t aFrecency) { + LOG(("CacheFileMetadata::SetFrecency() [this=%p, frecency=%f]", this, + (double)aFrecency)); + + MarkDirty(false); + mMetaHdr.mFrecency = aFrecency; +} + +void CacheFileMetadata::OnFetched() { + MarkDirty(false); + + mMetaHdr.mLastFetched = NOW_SECONDS(); + ++mMetaHdr.mFetchCount; +} + +void CacheFileMetadata::MarkDirty(bool aUpdateLastModified) { + mIsDirty = true; + if (aUpdateLastModified) { + mMetaHdr.mLastModified = NOW_SECONDS(); + } +} + +nsresult CacheFileMetadata::OnFileOpened(CacheFileHandle* aHandle, + nsresult aResult) { + MOZ_CRASH("CacheFileMetadata::OnFileOpened should not be called!"); + return NS_ERROR_UNEXPECTED; +} + +nsresult CacheFileMetadata::OnDataWritten(CacheFileHandle* aHandle, + const char* aBuf, nsresult aResult) { + LOG( + ("CacheFileMetadata::OnDataWritten() [this=%p, handle=%p, " + "result=0x%08" PRIx32 "]", + this, aHandle, static_cast<uint32_t>(aResult))); + + nsCOMPtr<CacheFileMetadataListener> listener; + { + MutexAutoLock lock(mLock->Lock()); + + MOZ_ASSERT(mListener); + MOZ_ASSERT(mWriteBuf); + + CacheFileUtils::FreeBuffer(mWriteBuf); + mWriteBuf = nullptr; + + mListener.swap(listener); + DoMemoryReport(MemoryUsage()); + } + + listener->OnMetadataWritten(aResult); + + return NS_OK; +} + +nsresult CacheFileMetadata::OnDataRead(CacheFileHandle* aHandle, char* aBuf, + nsresult aResult) { + LOG(( + "CacheFileMetadata::OnDataRead() [this=%p, handle=%p, result=0x%08" PRIx32 + "]", + this, aHandle, static_cast<uint32_t>(aResult))); + + MOZ_ASSERT(mListener); + + nsresult rv; + nsCOMPtr<CacheFileMetadataListener> listener; + + auto notifyListenerOutsideLock = mozilla::MakeScopeExit([&listener] { + if (listener) { + listener->OnMetadataRead(NS_OK); + } + }); + + MutexAutoLock lock(mLock->Lock()); + + if (NS_FAILED(aResult)) { + LOG( + ("CacheFileMetadata::OnDataRead() - CacheFileIOManager::Read() failed" + ", creating empty metadata. [this=%p, rv=0x%08" PRIx32 "]", + this, static_cast<uint32_t>(aResult))); + + InitEmptyMetadata(); + + mListener.swap(listener); + return NS_OK; + } + + if (mFirstRead) { + Telemetry::AccumulateTimeDelta( + Telemetry::NETWORK_CACHE_METADATA_FIRST_READ_TIME_MS, mReadStart); + } else { + Telemetry::AccumulateTimeDelta( + Telemetry::NETWORK_CACHE_METADATA_SECOND_READ_TIME_MS, mReadStart); + } + + // check whether we have read all necessary data + uint32_t realOffset = + NetworkEndian::readUint32(mBuf + mBufSize - sizeof(uint32_t)); + + int64_t size = mHandle->FileSize(); + MOZ_ASSERT(size != -1); + + if (realOffset >= size) { + LOG( + ("CacheFileMetadata::OnDataRead() - Invalid realOffset, creating " + "empty metadata. [this=%p, realOffset=%u, size=%" PRId64 "]", + this, realOffset, size)); + + InitEmptyMetadata(); + + mListener.swap(listener); + return NS_OK; + } + + uint32_t maxHashCount = size / kChunkSize; + uint32_t maxMetadataSize = CalcMetadataSize(kMaxElementsSize, maxHashCount); + if (size - realOffset > maxMetadataSize) { + LOG( + ("CacheFileMetadata::OnDataRead() - Invalid realOffset, metadata would " + "be too big, creating empty metadata. [this=%p, realOffset=%u, " + "maxMetadataSize=%u, size=%" PRId64 "]", + this, realOffset, maxMetadataSize, size)); + + InitEmptyMetadata(); + + mListener.swap(listener); + return NS_OK; + } + + uint32_t usedOffset = size - mBufSize; + + if (realOffset < usedOffset) { + uint32_t missing = usedOffset - realOffset; + // we need to read more data + char* newBuf = static_cast<char*>(realloc(mBuf, mBufSize + missing)); + if (!newBuf) { + LOG( + ("CacheFileMetadata::OnDataRead() - Error allocating %d more bytes " + "for the missing part of the metadata, creating empty metadata. " + "[this=%p]", + missing, this)); + + InitEmptyMetadata(); + + mListener.swap(listener); + return NS_OK; + } + + mBuf = newBuf; + memmove(mBuf + missing, mBuf, mBufSize); + mBufSize += missing; + + DoMemoryReport(MemoryUsage()); + + LOG( + ("CacheFileMetadata::OnDataRead() - We need to read %d more bytes to " + "have full metadata. [this=%p]", + missing, this)); + + mFirstRead = false; + mReadStart = mozilla::TimeStamp::Now(); + rv = CacheFileIOManager::Read(mHandle, realOffset, mBuf, missing, this); + if (NS_FAILED(rv)) { + LOG( + ("CacheFileMetadata::OnDataRead() - CacheFileIOManager::Read() " + "failed synchronously, creating empty metadata. [this=%p, " + "rv=0x%08" PRIx32 "]", + this, static_cast<uint32_t>(rv))); + + InitEmptyMetadata(); + + mListener.swap(listener); + return NS_OK; + } + + return NS_OK; + } + + Telemetry::Accumulate(Telemetry::NETWORK_CACHE_METADATA_SIZE_2, + size - realOffset); + + // We have all data according to offset information at the end of the entry. + // Try to parse it. + rv = ParseMetadata(realOffset, realOffset - usedOffset, true); + if (NS_FAILED(rv)) { + LOG( + ("CacheFileMetadata::OnDataRead() - Error parsing metadata, creating " + "empty metadata. [this=%p]", + this)); + InitEmptyMetadata(); + } else { + // Shrink elements buffer. + mBuf = static_cast<char*>(moz_xrealloc(mBuf, mElementsSize)); + mBufSize = mElementsSize; + + // There is usually no or just one call to SetMetadataElement() when the + // metadata is parsed from disk. Avoid allocating power of two sized buffer + // which we do in case of newly created metadata. + mAllocExactSize = true; + } + + mListener.swap(listener); + + return NS_OK; +} + +nsresult CacheFileMetadata::OnFileDoomed(CacheFileHandle* aHandle, + nsresult aResult) { + MOZ_CRASH("CacheFileMetadata::OnFileDoomed should not be called!"); + return NS_ERROR_UNEXPECTED; +} + +nsresult CacheFileMetadata::OnEOFSet(CacheFileHandle* aHandle, + nsresult aResult) { + MOZ_CRASH("CacheFileMetadata::OnEOFSet should not be called!"); + return NS_ERROR_UNEXPECTED; +} + +nsresult CacheFileMetadata::OnFileRenamed(CacheFileHandle* aHandle, + nsresult aResult) { + MOZ_CRASH("CacheFileMetadata::OnFileRenamed should not be called!"); + return NS_ERROR_UNEXPECTED; +} + +void CacheFileMetadata::InitEmptyMetadata() { + if (mBuf) { + CacheFileUtils::FreeBuffer(mBuf); + mBuf = nullptr; + mBufSize = 0; + } + mAllocExactSize = false; + mOffset = 0; + mMetaHdr.mVersion = kCacheEntryVersion; + mMetaHdr.mFetchCount = 0; + mMetaHdr.mExpirationTime = nsICacheEntry::NO_EXPIRATION_TIME; + mMetaHdr.mKeySize = mKey.Length(); + + // Deliberately not touching the "kCacheEntryIsPinned" flag. + + DoMemoryReport(MemoryUsage()); + + // We're creating a new entry. If there is any old data truncate it. + if (mHandle) { + mHandle->SetPinned(Pinned()); + // We can pronounce the handle as invalid now, because it simply + // doesn't have the correct metadata. This will cause IO operations + // be bypassed during shutdown (mainly dooming it, when a channel + // is canceled by closing the window.) + mHandle->SetInvalid(); + if (mHandle->FileExists() && mHandle->FileSize()) { + CacheFileIOManager::TruncateSeekSetEOF(mHandle, 0, 0, nullptr); + } + } +} + +nsresult CacheFileMetadata::ParseMetadata(uint32_t aMetaOffset, + uint32_t aBufOffset, bool aHaveKey) { + LOG( + ("CacheFileMetadata::ParseMetadata() [this=%p, metaOffset=%d, " + "bufOffset=%d, haveKey=%u]", + this, aMetaOffset, aBufOffset, aHaveKey)); + + nsresult rv; + + uint32_t metaposOffset = mBufSize - sizeof(uint32_t); + uint32_t hashesOffset = aBufOffset + sizeof(uint32_t); + uint32_t hashCount = aMetaOffset / kChunkSize; + if (aMetaOffset % kChunkSize) hashCount++; + uint32_t hashesLen = hashCount * sizeof(CacheHash::Hash16_t); + uint32_t hdrOffset = hashesOffset + hashesLen; + uint32_t keyOffset = hdrOffset + sizeof(CacheFileMetadataHeader); + + LOG( + ("CacheFileMetadata::ParseMetadata() [this=%p]\n metaposOffset=%d\n " + "hashesOffset=%d\n hashCount=%d\n hashesLen=%d\n hdfOffset=%d\n " + "keyOffset=%d\n", + this, metaposOffset, hashesOffset, hashCount, hashesLen, hdrOffset, + keyOffset)); + + if (keyOffset > metaposOffset) { + LOG(("CacheFileMetadata::ParseMetadata() - Wrong keyOffset! [this=%p]", + this)); + return NS_ERROR_FILE_CORRUPTED; + } + + mMetaHdr.ReadFromBuf(mBuf + hdrOffset); + + if (mMetaHdr.mVersion == 1) { + // Backward compatibility before we've added flags to the header + keyOffset -= sizeof(uint32_t); + } else if (mMetaHdr.mVersion == 2) { + // Version 2 just lacks the ability to store alternative data. Nothing to do + // here. + } else if (mMetaHdr.mVersion != kCacheEntryVersion) { + LOG( + ("CacheFileMetadata::ParseMetadata() - Not a version we understand to. " + "[version=0x%x, this=%p]", + mMetaHdr.mVersion, this)); + return NS_ERROR_UNEXPECTED; + } + + // Update the version stored in the header to make writes + // store the header in the current version form. + mMetaHdr.mVersion = kCacheEntryVersion; + + uint32_t elementsOffset = mMetaHdr.mKeySize + keyOffset + 1; + + if (elementsOffset > metaposOffset) { + LOG( + ("CacheFileMetadata::ParseMetadata() - Wrong elementsOffset %d " + "[this=%p]", + elementsOffset, this)); + return NS_ERROR_FILE_CORRUPTED; + } + + // check that key ends with \0 + if (mBuf[elementsOffset - 1] != 0) { + LOG( + ("CacheFileMetadata::ParseMetadata() - Elements not null terminated. " + "[this=%p]", + this)); + return NS_ERROR_FILE_CORRUPTED; + } + + if (!aHaveKey) { + // get the key form metadata + mKey.Assign(mBuf + keyOffset, mMetaHdr.mKeySize); + + rv = ParseKey(mKey); + if (NS_FAILED(rv)) return rv; + } else { + if (mMetaHdr.mKeySize != mKey.Length()) { + LOG( + ("CacheFileMetadata::ParseMetadata() - Key collision (1), key=%s " + "[this=%p]", + nsCString(mBuf + keyOffset, mMetaHdr.mKeySize).get(), this)); + return NS_ERROR_FILE_CORRUPTED; + } + + if (memcmp(mKey.get(), mBuf + keyOffset, mKey.Length()) != 0) { + LOG( + ("CacheFileMetadata::ParseMetadata() - Key collision (2), key=%s " + "[this=%p]", + nsCString(mBuf + keyOffset, mMetaHdr.mKeySize).get(), this)); + return NS_ERROR_FILE_CORRUPTED; + } + } + + // check metadata hash (data from hashesOffset to metaposOffset) + CacheHash::Hash32_t hashComputed, hashExpected; + hashComputed = + CacheHash::Hash(mBuf + hashesOffset, metaposOffset - hashesOffset); + hashExpected = NetworkEndian::readUint32(mBuf + aBufOffset); + + if (hashComputed != hashExpected) { + LOG( + ("CacheFileMetadata::ParseMetadata() - Metadata hash mismatch! Hash of " + "the metadata is %x, hash in file is %x [this=%p]", + hashComputed, hashExpected, this)); + return NS_ERROR_FILE_CORRUPTED; + } + + // check elements + rv = CheckElements(mBuf + elementsOffset, metaposOffset - elementsOffset); + if (NS_FAILED(rv)) return rv; + + if (mHandle) { + if (!mHandle->SetPinned(Pinned())) { + LOG( + ("CacheFileMetadata::ParseMetadata() - handle was doomed for this " + "pinning state, truncate the file [this=%p, pinned=%d]", + this, Pinned())); + return NS_ERROR_FILE_CORRUPTED; + } + } + + mHashArraySize = hashesLen; + mHashCount = hashCount; + if (mHashArraySize) { + mHashArray = static_cast<CacheHash::Hash16_t*>(moz_xmalloc(mHashArraySize)); + memcpy(mHashArray, mBuf + hashesOffset, mHashArraySize); + } + + MarkDirty(); + + mElementsSize = metaposOffset - elementsOffset; + memmove(mBuf, mBuf + elementsOffset, mElementsSize); + mOffset = aMetaOffset; + + DoMemoryReport(MemoryUsage()); + + return NS_OK; +} + +nsresult CacheFileMetadata::CheckElements(const char* aBuf, uint32_t aSize) { + if (aSize) { + // Check if the metadata ends with a zero byte. + if (aBuf[aSize - 1] != 0) { + NS_ERROR("Metadata elements are not null terminated"); + LOG( + ("CacheFileMetadata::CheckElements() - Elements are not null " + "terminated. [this=%p]", + this)); + return NS_ERROR_FILE_CORRUPTED; + } + // Check that there are an even number of zero bytes + // to match the pattern { key \0 value \0 } + bool odd = false; + for (uint32_t i = 0; i < aSize; i++) { + if (aBuf[i] == 0) odd = !odd; + } + if (odd) { + NS_ERROR("Metadata elements are malformed"); + LOG( + ("CacheFileMetadata::CheckElements() - Elements are malformed. " + "[this=%p]", + this)); + return NS_ERROR_FILE_CORRUPTED; + } + } + return NS_OK; +} + +nsresult CacheFileMetadata::EnsureBuffer(uint32_t aSize) { + if (aSize > kMaxElementsSize) { + return NS_ERROR_FAILURE; + } + + if (mBufSize < aSize) { + if (mAllocExactSize) { + // If this is not the only allocation, use power of two for following + // allocations. + mAllocExactSize = false; + } else { + // find smallest power of 2 greater than or equal to aSize + --aSize; + aSize |= aSize >> 1; + aSize |= aSize >> 2; + aSize |= aSize >> 4; + aSize |= aSize >> 8; + aSize |= aSize >> 16; + ++aSize; + } + + if (aSize < kInitialBufSize) { + aSize = kInitialBufSize; + } + + char* newBuf = static_cast<char*>(realloc(mBuf, aSize)); + if (!newBuf) { + return NS_ERROR_OUT_OF_MEMORY; + } + mBufSize = aSize; + mBuf = newBuf; + + DoMemoryReport(MemoryUsage()); + } + + return NS_OK; +} + +nsresult CacheFileMetadata::ParseKey(const nsACString& aKey) { + nsCOMPtr<nsILoadContextInfo> info = CacheFileUtils::ParseKey(aKey); + NS_ENSURE_TRUE(info, NS_ERROR_FAILURE); + + mAnonymous = info->IsAnonymous(); + mOriginAttributes = *info->OriginAttributesPtr(); + + return NS_OK; +} + +// Memory reporting + +size_t CacheFileMetadata::SizeOfExcludingThis( + mozilla::MallocSizeOf mallocSizeOf) const { + size_t n = 0; + // mHandle reported via CacheFileIOManager. + n += mKey.SizeOfExcludingThisIfUnshared(mallocSizeOf); + n += mallocSizeOf(mHashArray); + n += mallocSizeOf(mBuf); + // Ignore mWriteBuf, it's not safe to access it when metadata is being + // written and it's null otherwise. + // mListener is usually the owning CacheFile. + + return n; +} + +size_t CacheFileMetadata::SizeOfIncludingThis( + mozilla::MallocSizeOf mallocSizeOf) const { + return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf); +} + +} // namespace mozilla::net |