gecko-dev/netwerk/cache2/CacheEntry.h
2017-06-26 14:19:58 -07:00

424 lines
13 KiB
C++

/* 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/. */
#ifndef CacheEntry__h__
#define CacheEntry__h__
#include "nsICacheEntry.h"
#include "CacheFile.h"
#include "nsIRunnable.h"
#include "nsIOutputStream.h"
#include "nsICacheEntryOpenCallback.h"
#include "nsICacheEntryDoomCallback.h"
#include "nsCOMPtr.h"
#include "nsRefPtrHashtable.h"
#include "nsDataHashtable.h"
#include "nsHashKeys.h"
#include "nsString.h"
#include "nsCOMArray.h"
#include "nsThreadUtils.h"
#include "mozilla/Attributes.h"
#include "mozilla/Mutex.h"
#include "mozilla/TimeStamp.h"
static inline uint32_t
PRTimeToSeconds(PRTime t_usec)
{
PRTime usec_per_sec = PR_USEC_PER_SEC;
return uint32_t(t_usec /= usec_per_sec);
}
#define NowInSeconds() PRTimeToSeconds(PR_Now())
class nsIOutputStream;
class nsIURI;
class nsIThread;
namespace mozilla {
namespace net {
class CacheStorageService;
class CacheStorage;
class CacheOutputCloseListener;
class CacheEntryHandle;
class CacheEntry final : public nsICacheEntry
, public nsIRunnable
, public CacheFileListener
{
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSICACHEENTRY
NS_DECL_NSIRUNNABLE
CacheEntry(const nsACString& aStorageID, const nsACString& aURI, const nsACString& aEnhanceID,
bool aUseDisk, bool aSkipSizeCheck, bool aPin);
void AsyncOpen(nsICacheEntryOpenCallback* aCallback, uint32_t aFlags);
CacheEntryHandle* NewHandle();
// For a new and recreated entry w/o a callback, we need to wrap it
// with a handle to detect writing consumer is gone.
CacheEntryHandle* NewWriteHandle();
public:
uint32_t GetMetadataMemoryConsumption();
nsCString const &GetStorageID() const { return mStorageID; }
nsCString const &GetEnhanceID() const { return mEnhanceID; }
nsCString const &GetURI() const { return mURI; }
// Accessible at any time
bool IsUsingDisk() const { return mUseDisk; }
bool IsReferenced() const;
bool IsFileDoomed();
bool IsDoomed() const { return mIsDoomed; }
bool IsPinned() const { return mPinned; }
// Methods for entry management (eviction from memory),
// called only on the management thread.
// TODO make these inline
double GetFrecency() const;
uint32_t GetExpirationTime() const;
uint32_t UseCount() const { return mUseCount; }
bool IsRegistered() const;
bool CanRegister() const;
void SetRegistered(bool aRegistered);
TimeStamp const& LoadStart() const { return mLoadStart; }
enum EPurge {
PURGE_DATA_ONLY_DISK_BACKED,
PURGE_WHOLE_ONLY_DISK_BACKED,
PURGE_WHOLE,
};
bool DeferOrBypassRemovalOnPinStatus(bool aPinned);
bool Purge(uint32_t aWhat);
void PurgeAndDoom();
void DoomAlreadyRemoved();
nsresult HashingKeyWithStorage(nsACString &aResult) const;
nsresult HashingKey(nsACString &aResult) const;
static nsresult HashingKey(const nsACString& aStorageID,
const nsACString& aEnhanceID,
nsIURI* aURI,
nsACString &aResult);
static nsresult HashingKey(const nsACString& aStorageID,
const nsACString& aEnhanceID,
const nsACString& aURISpec,
nsACString &aResult);
// Accessed only on the service management thread
double mFrecency;
::mozilla::Atomic<uint32_t, ::mozilla::Relaxed> mSortingExpirationTime;
// Memory reporting
size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
private:
virtual ~CacheEntry();
// CacheFileListener
NS_IMETHOD OnFileReady(nsresult aResult, bool aIsNew) override;
NS_IMETHOD OnFileDoomed(nsresult aResult) override;
// Keep the service alive during life-time of an entry
RefPtr<CacheStorageService> mService;
// We must monitor when a cache entry whose consumer is responsible
// for writing it the first time gets released. We must then invoke
// waiting callbacks to not break the chain.
class Callback
{
public:
Callback(CacheEntry* aEntry,
nsICacheEntryOpenCallback *aCallback,
bool aReadOnly, bool aCheckOnAnyThread, bool aSecret);
// Special constructor for Callback objects added to the chain
// just to ensure proper defer dooming (recreation) of this entry.
Callback(CacheEntry* aEntry, bool aDoomWhenFoundInPinStatus);
Callback(Callback const &aThat);
~Callback();
// Called when this callback record changes it's owning entry,
// mainly during recreation.
void ExchangeEntry(CacheEntry* aEntry);
// Returns true when an entry is about to be "defer" doomed and this is
// a "defer" callback.
bool DeferDoom(bool *aDoom) const;
// We are raising reference count here to take into account the pending
// callback (that virtually holds a ref to this entry before it gets
// it's pointer).
RefPtr<CacheEntry> mEntry;
nsCOMPtr<nsICacheEntryOpenCallback> mCallback;
nsCOMPtr<nsIEventTarget> mTarget;
bool mReadOnly : 1;
bool mRevalidating : 1;
bool mCheckOnAnyThread : 1;
bool mRecheckAfterWrite : 1;
bool mNotWanted : 1;
bool mSecret : 1;
// These are set only for the defer-doomer Callback instance inserted
// to the callback chain. When any of these is set and also any of
// the corressponding flags on the entry is set, this callback will
// indicate (via DeferDoom()) the entry have to be recreated/doomed.
bool mDoomWhenFoundPinned : 1;
bool mDoomWhenFoundNonPinned : 1;
nsresult OnCheckThread(bool *aOnCheckThread) const;
nsresult OnAvailThread(bool *aOnAvailThread) const;
};
// Since OnCacheEntryAvailable must be invoked on the main thread
// we need a runnable for it...
class AvailableCallbackRunnable : public Runnable
{
public:
AvailableCallbackRunnable(CacheEntry* aEntry,
Callback const &aCallback)
: Runnable("CacheEntry::AvailableCallbackRunnable")
, mEntry(aEntry)
, mCallback(aCallback)
{}
private:
NS_IMETHOD Run() override
{
mEntry->InvokeAvailableCallback(mCallback);
return NS_OK;
}
RefPtr<CacheEntry> mEntry;
Callback mCallback;
};
// Since OnCacheEntryDoomed must be invoked on the main thread
// we need a runnable for it...
class DoomCallbackRunnable : public Runnable
{
public:
DoomCallbackRunnable(CacheEntry* aEntry, nsresult aRv)
: Runnable("net::CacheEntry::DoomCallbackRunnable")
, mEntry(aEntry)
, mRv(aRv)
{
}
private:
NS_IMETHOD Run() override
{
nsCOMPtr<nsICacheEntryDoomCallback> callback;
{
mozilla::MutexAutoLock lock(mEntry->mLock);
mEntry->mDoomCallback.swap(callback);
}
if (callback)
callback->OnCacheEntryDoomed(mRv);
return NS_OK;
}
RefPtr<CacheEntry> mEntry;
nsresult mRv;
};
// Starts the load or just invokes the callback, bypasses (when required)
// if busy. Returns true on job done, false on bypass.
bool Open(Callback & aCallback, bool aTruncate, bool aPriority, bool aBypassIfBusy);
// Loads from disk asynchronously
bool Load(bool aTruncate, bool aPriority);
void RememberCallback(Callback & aCallback);
void InvokeCallbacksLock();
void InvokeCallbacks();
bool InvokeCallbacks(bool aReadOnly);
bool InvokeCallback(Callback & aCallback);
void InvokeAvailableCallback(Callback const & aCallback);
void OnFetched(Callback const & aCallback);
nsresult OpenOutputStreamInternal(int64_t offset, nsIOutputStream * *_retval);
nsresult OpenInputStreamInternal(int64_t offset, const char *aAltDataType, nsIInputStream * *_retval);
void OnHandleClosed(CacheEntryHandle const* aHandle);
private:
friend class CacheEntryHandle;
// Increment/decrements the number of handles keeping this entry.
void AddHandleRef() { ++mHandlesCount; }
void ReleaseHandleRef() { --mHandlesCount; }
// Current number of handles keeping this entry.
uint32_t HandlesCount() const { return mHandlesCount; }
private:
friend class CacheOutputCloseListener;
void OnOutputClosed();
private:
// Schedules a background operation on the management thread.
// When executed on the management thread directly, the operation(s)
// is (are) executed immediately.
void BackgroundOp(uint32_t aOperation, bool aForceAsync = false);
void StoreFrecency(double aFrecency);
// Called only from DoomAlreadyRemoved()
void DoomFile();
// When this entry is doomed the first time, this method removes
// any force-valid timing info for this entry.
void RemoveForcedValidity();
already_AddRefed<CacheEntryHandle> ReopenTruncated(bool aMemoryOnly,
nsICacheEntryOpenCallback* aCallback);
void TransferCallbacks(CacheEntry & aFromEntry);
mozilla::Mutex mLock;
// Reflects the number of existing handles for this entry
::mozilla::ThreadSafeAutoRefCnt mHandlesCount;
nsTArray<Callback> mCallbacks;
nsCOMPtr<nsICacheEntryDoomCallback> mDoomCallback;
RefPtr<CacheFile> mFile;
// Using ReleaseAcquire since we only control access to mFile with this.
// When mFileStatus is read and found success it is ensured there is mFile and
// that it is after a successful call to Init().
::mozilla::Atomic<nsresult, ::mozilla::ReleaseAcquire> mFileStatus;
nsCString mURI;
nsCString mEnhanceID;
nsCString mStorageID;
// mUseDisk, mSkipSizeCheck, mIsDoomed are plain "bool", not "bool:1",
// so as to avoid bitfield races with the byte containing
// mSecurityInfoLoaded et al. See bug 1278524.
//
// Whether it's allowed to persist the data to disk
bool const mUseDisk;
// Whether it should skip max size check.
bool const mSkipSizeCheck;
// Set when entry is doomed with AsyncDoom() or DoomAlreadyRemoved().
bool mIsDoomed;
// Following flags are all synchronized with the cache entry lock.
// Whether security info has already been looked up in metadata.
bool mSecurityInfoLoaded : 1;
// Prevents any callback invocation
bool mPreventCallbacks : 1;
// true: after load and an existing file, or after output stream has been opened.
// note - when opening an input stream, and this flag is false, output stream
// is open along ; this makes input streams on new entries behave correctly
// when EOF is reached (WOULD_BLOCK is returned).
// false: after load and a new file, or dropped to back to false when a writer
// fails to open an output stream.
bool mHasData : 1;
// The indication of pinning this entry was open with
bool mPinned : 1;
// Whether the pinning state of the entry is known (equals to the actual state
// of the cache file)
bool mPinningKnown : 1;
static char const * StateString(uint32_t aState);
enum EState { // transiting to:
NOTLOADED = 0, // -> LOADING | EMPTY
LOADING = 1, // -> EMPTY | READY
EMPTY = 2, // -> WRITING
WRITING = 3, // -> EMPTY | READY
READY = 4, // -> REVALIDATING
REVALIDATING = 5 // -> READY
};
// State of this entry.
EState mState;
enum ERegistration {
NEVERREGISTERED = 0, // The entry has never been registered
REGISTERED = 1, // The entry is stored in the memory pool index
DEREGISTERED = 2 // The entry has been removed from the pool
};
// Accessed only on the management thread. Records the state of registration
// this entry in the memory pool intermediate cache.
ERegistration mRegistration;
// If a new (empty) entry is requested to open an input stream before
// output stream has been opened, we must open output stream internally
// on CacheFile and hold until writer releases the entry or opens the output
// stream for read (then we trade him mOutputStream).
nsCOMPtr<nsIOutputStream> mOutputStream;
// Weak reference to the current writter. There can be more then one
// writer at a time and OnHandleClosed() must be processed only for the
// current one.
CacheEntryHandle* mWriter;
// Background thread scheduled operation. Set (under the lock) one
// of this flags to tell the background thread what to do.
class Ops {
public:
static uint32_t const REGISTER = 1 << 0;
static uint32_t const FRECENCYUPDATE = 1 << 1;
static uint32_t const CALLBACKS = 1 << 2;
static uint32_t const UNREGISTER = 1 << 3;
Ops() : mFlags(0) { }
uint32_t Grab() { uint32_t flags = mFlags; mFlags = 0; return flags; }
bool Set(uint32_t aFlags) { if (mFlags & aFlags) return false; mFlags |= aFlags; return true; }
private:
uint32_t mFlags;
} mBackgroundOperations;
nsCOMPtr<nsISupports> mSecurityInfo;
int64_t mPredictedDataSize;
mozilla::TimeStamp mLoadStart;
uint32_t mUseCount;
};
class CacheEntryHandle : public nsICacheEntry
{
public:
explicit CacheEntryHandle(CacheEntry* aEntry);
CacheEntry* Entry() const { return mEntry; }
NS_DECL_THREADSAFE_ISUPPORTS
NS_FORWARD_NSICACHEENTRY(mEntry->)
private:
virtual ~CacheEntryHandle();
RefPtr<CacheEntry> mEntry;
};
class CacheOutputCloseListener final : public Runnable
{
public:
void OnOutputClosed();
private:
friend class CacheEntry;
virtual ~CacheOutputCloseListener();
NS_DECL_NSIRUNNABLE
explicit CacheOutputCloseListener(CacheEntry* aEntry);
private:
RefPtr<CacheEntry> mEntry;
};
} // namespace net
} // namespace mozilla
#endif