gecko-dev/netwerk/cache/nsCacheEntry.cpp
Nicholas Nethercote f976bf5495 Bug 1179071 - Merge RemovingIterator into Iterator. r=froydnj.
The original motivation for the Iterator/RemovingIterator split was that
PLDHashTable Checker class would treat them differently. But that didn't end up
happening (see bug 1131308). So this patch merges them. This is a small code
size win now but it will become bigger when I add iterators to nsTHashTable and
nsBaseHashtable.

The only complication is that PLDHashTable::Iter() is now non-const, which is
a problem if you use it in a const method. So I added PLDHashTable::ConstIter()
which is used in just two places. It's a bit of a hack -- effectively a
const_cast -- but I don't think it's too bad.
2015-07-06 22:02:26 -07:00

509 lines
13 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 "nspr.h"
#include "nsCacheEntry.h"
#include "nsCacheEntryDescriptor.h"
#include "nsCacheMetaData.h"
#include "nsCacheRequest.h"
#include "nsThreadUtils.h"
#include "nsError.h"
#include "nsICacheService.h"
#include "nsCacheService.h"
#include "nsCacheDevice.h"
#include "nsHashKeys.h"
using namespace mozilla;
nsCacheEntry::nsCacheEntry(const nsACString & key,
bool streamBased,
nsCacheStoragePolicy storagePolicy)
: mKey(key),
mFetchCount(0),
mLastFetched(0),
mLastModified(0),
mExpirationTime(nsICache::NO_EXPIRATION_TIME),
mFlags(0),
mPredictedDataSize(-1),
mDataSize(0),
mCacheDevice(nullptr),
mCustomDevice(nullptr),
mData(nullptr)
{
MOZ_COUNT_CTOR(nsCacheEntry);
PR_INIT_CLIST(this);
PR_INIT_CLIST(&mRequestQ);
PR_INIT_CLIST(&mDescriptorQ);
if (streamBased) MarkStreamBased();
SetStoragePolicy(storagePolicy);
MarkPublic();
}
nsCacheEntry::~nsCacheEntry()
{
MOZ_COUNT_DTOR(nsCacheEntry);
if (mData)
nsCacheService::ReleaseObject_Locked(mData, mThread);
}
nsresult
nsCacheEntry::Create( const char * key,
bool streamBased,
nsCacheStoragePolicy storagePolicy,
nsCacheDevice * device,
nsCacheEntry ** result)
{
nsCacheEntry* entry = new nsCacheEntry(nsCString(key),
streamBased,
storagePolicy);
entry->SetCacheDevice(device);
*result = entry;
return NS_OK;
}
void
nsCacheEntry::Fetched()
{
mLastFetched = SecondsFromPRTime(PR_Now());
++mFetchCount;
MarkEntryDirty();
}
const char *
nsCacheEntry::GetDeviceID()
{
if (mCacheDevice) return mCacheDevice->GetDeviceID();
return nullptr;
}
void
nsCacheEntry::TouchData()
{
mLastModified = SecondsFromPRTime(PR_Now());
MarkDataDirty();
}
void
nsCacheEntry::SetData(nsISupports * data)
{
if (mData) {
nsCacheService::ReleaseObject_Locked(mData, mThread);
mData = nullptr;
}
if (data) {
NS_ADDREF(mData = data);
mThread = do_GetCurrentThread();
}
}
void
nsCacheEntry::TouchMetaData()
{
mLastModified = SecondsFromPRTime(PR_Now());
MarkMetaDataDirty();
}
/**
* cache entry states
* 0 descriptors (new entry)
* 0 descriptors (existing, bound entry)
* n descriptors (existing, bound entry) valid
* n descriptors (existing, bound entry) not valid (wait until valid or doomed)
*/
nsresult
nsCacheEntry::RequestAccess(nsCacheRequest * request, nsCacheAccessMode *accessGranted)
{
nsresult rv = NS_OK;
if (IsDoomed()) return NS_ERROR_CACHE_ENTRY_DOOMED;
if (!IsInitialized()) {
// brand new, unbound entry
if (request->IsStreamBased()) MarkStreamBased();
MarkInitialized();
*accessGranted = request->AccessRequested() & nsICache::ACCESS_WRITE;
NS_ASSERTION(*accessGranted, "new cache entry for READ-ONLY request");
PR_APPEND_LINK(request, &mRequestQ);
return rv;
}
if (IsStreamData() != request->IsStreamBased()) {
*accessGranted = nsICache::ACCESS_NONE;
return request->IsStreamBased() ?
NS_ERROR_CACHE_DATA_IS_NOT_STREAM : NS_ERROR_CACHE_DATA_IS_STREAM;
}
if (PR_CLIST_IS_EMPTY(&mDescriptorQ)) {
// 1st descriptor for existing bound entry
*accessGranted = request->AccessRequested();
if (*accessGranted & nsICache::ACCESS_WRITE) {
MarkInvalid();
} else {
MarkValid();
}
} else {
// nth request for existing, bound entry
*accessGranted = request->AccessRequested() & ~nsICache::ACCESS_WRITE;
if (!IsValid())
rv = NS_ERROR_CACHE_WAIT_FOR_VALIDATION;
}
PR_APPEND_LINK(request,&mRequestQ);
return rv;
}
nsresult
nsCacheEntry::CreateDescriptor(nsCacheRequest * request,
nsCacheAccessMode accessGranted,
nsICacheEntryDescriptor ** result)
{
NS_ENSURE_ARG_POINTER(request && result);
nsCacheEntryDescriptor * descriptor =
new nsCacheEntryDescriptor(this, accessGranted);
// XXX check request is on q
PR_REMOVE_AND_INIT_LINK(request); // remove request regardless of success
if (descriptor == nullptr)
return NS_ERROR_OUT_OF_MEMORY;
PR_APPEND_LINK(descriptor, &mDescriptorQ);
CACHE_LOG_DEBUG((" descriptor %p created for request %p on entry %p\n",
descriptor, request, this));
NS_ADDREF(*result = descriptor);
return NS_OK;
}
bool
nsCacheEntry::RemoveRequest(nsCacheRequest * request)
{
// XXX if debug: verify this request belongs to this entry
PR_REMOVE_AND_INIT_LINK(request);
// return true if this entry should stay active
return !((PR_CLIST_IS_EMPTY(&mRequestQ)) &&
(PR_CLIST_IS_EMPTY(&mDescriptorQ)));
}
bool
nsCacheEntry::RemoveDescriptor(nsCacheEntryDescriptor * descriptor,
bool * doomEntry)
{
NS_ASSERTION(descriptor->CacheEntry() == this, "### Wrong cache entry!!");
*doomEntry = descriptor->ClearCacheEntry();
PR_REMOVE_AND_INIT_LINK(descriptor);
if (!PR_CLIST_IS_EMPTY(&mDescriptorQ))
return true; // stay active if we still have open descriptors
if (PR_CLIST_IS_EMPTY(&mRequestQ))
return false; // no descriptors or requests, we can deactivate
return true; // find next best request to give a descriptor to
}
void
nsCacheEntry::DetachDescriptors()
{
nsCacheEntryDescriptor * descriptor =
(nsCacheEntryDescriptor *)PR_LIST_HEAD(&mDescriptorQ);
while (descriptor != &mDescriptorQ) {
nsCacheEntryDescriptor * nextDescriptor =
(nsCacheEntryDescriptor *)PR_NEXT_LINK(descriptor);
descriptor->ClearCacheEntry();
PR_REMOVE_AND_INIT_LINK(descriptor);
descriptor = nextDescriptor;
}
}
void
nsCacheEntry::GetDescriptors(
nsTArray<nsRefPtr<nsCacheEntryDescriptor> > &outDescriptors)
{
nsCacheEntryDescriptor * descriptor =
(nsCacheEntryDescriptor *)PR_LIST_HEAD(&mDescriptorQ);
while (descriptor != &mDescriptorQ) {
nsCacheEntryDescriptor * nextDescriptor =
(nsCacheEntryDescriptor *)PR_NEXT_LINK(descriptor);
outDescriptors.AppendElement(descriptor);
descriptor = nextDescriptor;
}
}
/******************************************************************************
* nsCacheEntryInfo - for implementing about:cache
*****************************************************************************/
NS_IMPL_ISUPPORTS(nsCacheEntryInfo, nsICacheEntryInfo)
NS_IMETHODIMP
nsCacheEntryInfo::GetClientID(char ** clientID)
{
NS_ENSURE_ARG_POINTER(clientID);
if (!mCacheEntry) return NS_ERROR_NOT_AVAILABLE;
return ClientIDFromCacheKey(*mCacheEntry->Key(), clientID);
}
NS_IMETHODIMP
nsCacheEntryInfo::GetDeviceID(char ** deviceID)
{
NS_ENSURE_ARG_POINTER(deviceID);
if (!mCacheEntry) return NS_ERROR_NOT_AVAILABLE;
*deviceID = NS_strdup(mCacheEntry->GetDeviceID());
return *deviceID ? NS_OK : NS_ERROR_OUT_OF_MEMORY;
}
NS_IMETHODIMP
nsCacheEntryInfo::GetKey(nsACString &key)
{
if (!mCacheEntry) return NS_ERROR_NOT_AVAILABLE;
return ClientKeyFromCacheKey(*mCacheEntry->Key(), key);
}
NS_IMETHODIMP
nsCacheEntryInfo::GetFetchCount(int32_t * fetchCount)
{
NS_ENSURE_ARG_POINTER(fetchCount);
if (!mCacheEntry) return NS_ERROR_NOT_AVAILABLE;
*fetchCount = mCacheEntry->FetchCount();
return NS_OK;
}
NS_IMETHODIMP
nsCacheEntryInfo::GetLastFetched(uint32_t * lastFetched)
{
NS_ENSURE_ARG_POINTER(lastFetched);
if (!mCacheEntry) return NS_ERROR_NOT_AVAILABLE;
*lastFetched = mCacheEntry->LastFetched();
return NS_OK;
}
NS_IMETHODIMP
nsCacheEntryInfo::GetLastModified(uint32_t * lastModified)
{
NS_ENSURE_ARG_POINTER(lastModified);
if (!mCacheEntry) return NS_ERROR_NOT_AVAILABLE;
*lastModified = mCacheEntry->LastModified();
return NS_OK;
}
NS_IMETHODIMP
nsCacheEntryInfo::GetExpirationTime(uint32_t * expirationTime)
{
NS_ENSURE_ARG_POINTER(expirationTime);
if (!mCacheEntry) return NS_ERROR_NOT_AVAILABLE;
*expirationTime = mCacheEntry->ExpirationTime();
return NS_OK;
}
NS_IMETHODIMP
nsCacheEntryInfo::GetDataSize(uint32_t * dataSize)
{
NS_ENSURE_ARG_POINTER(dataSize);
if (!mCacheEntry) return NS_ERROR_NOT_AVAILABLE;
*dataSize = mCacheEntry->DataSize();
return NS_OK;
}
NS_IMETHODIMP
nsCacheEntryInfo::IsStreamBased(bool * result)
{
NS_ENSURE_ARG_POINTER(result);
if (!mCacheEntry) return NS_ERROR_NOT_AVAILABLE;
*result = mCacheEntry->IsStreamData();
return NS_OK;
}
/******************************************************************************
* nsCacheEntryHashTable
*****************************************************************************/
const PLDHashTableOps
nsCacheEntryHashTable::ops =
{
HashKey,
MatchEntry,
MoveEntry,
ClearEntry
};
nsCacheEntryHashTable::nsCacheEntryHashTable()
: table(&ops, sizeof(nsCacheEntryHashTableEntry), kInitialTableLength)
, initialized(false)
{
MOZ_COUNT_CTOR(nsCacheEntryHashTable);
}
nsCacheEntryHashTable::~nsCacheEntryHashTable()
{
MOZ_COUNT_DTOR(nsCacheEntryHashTable);
if (initialized)
Shutdown();
}
void
nsCacheEntryHashTable::Init()
{
table.ClearAndPrepareForLength(kInitialTableLength);
initialized = true;
}
void
nsCacheEntryHashTable::Shutdown()
{
if (initialized) {
table.ClearAndPrepareForLength(kInitialTableLength);
initialized = false;
}
}
nsCacheEntry *
nsCacheEntryHashTable::GetEntry( const nsCString * key)
{
NS_ASSERTION(initialized, "nsCacheEntryHashTable not initialized");
if (!initialized) return nullptr;
PLDHashEntryHdr *hashEntry = PL_DHashTableSearch(&table, key);
return hashEntry ? ((nsCacheEntryHashTableEntry *)hashEntry)->cacheEntry
: nullptr;
}
nsresult
nsCacheEntryHashTable::AddEntry( nsCacheEntry *cacheEntry)
{
PLDHashEntryHdr *hashEntry;
NS_ASSERTION(initialized, "nsCacheEntryHashTable not initialized");
if (!initialized) return NS_ERROR_NOT_INITIALIZED;
if (!cacheEntry) return NS_ERROR_NULL_POINTER;
hashEntry = PL_DHashTableAdd(&table, &(cacheEntry->mKey), fallible);
#ifndef DEBUG_dougt
NS_ASSERTION(((nsCacheEntryHashTableEntry *)hashEntry)->cacheEntry == 0,
"### nsCacheEntryHashTable::AddEntry - entry already used");
#endif
((nsCacheEntryHashTableEntry *)hashEntry)->cacheEntry = cacheEntry;
return NS_OK;
}
void
nsCacheEntryHashTable::RemoveEntry( nsCacheEntry *cacheEntry)
{
NS_ASSERTION(initialized, "nsCacheEntryHashTable not initialized");
NS_ASSERTION(cacheEntry, "### cacheEntry == nullptr");
if (!initialized) return; // NS_ERROR_NOT_INITIALIZED
#if DEBUG
// XXX debug code to make sure we have the entry we're trying to remove
nsCacheEntry *check = GetEntry(&(cacheEntry->mKey));
NS_ASSERTION(check == cacheEntry, "### Attempting to remove unknown cache entry!!!");
#endif
PL_DHashTableRemove(&table, &(cacheEntry->mKey));
}
PLDHashTable::Iterator
nsCacheEntryHashTable::Iter()
{
return PLDHashTable::Iterator(&table);
}
/**
* hash table operation callback functions
*/
PLDHashNumber
nsCacheEntryHashTable::HashKey( PLDHashTable *table, const void *key)
{
return HashString(*static_cast<const nsCString *>(key));
}
bool
nsCacheEntryHashTable::MatchEntry(PLDHashTable * /* table */,
const PLDHashEntryHdr * hashEntry,
const void * key)
{
NS_ASSERTION(key != nullptr, "### nsCacheEntryHashTable::MatchEntry : null key");
nsCacheEntry *cacheEntry = ((nsCacheEntryHashTableEntry *)hashEntry)->cacheEntry;
return cacheEntry->mKey.Equals(*(nsCString *)key);
}
void
nsCacheEntryHashTable::MoveEntry(PLDHashTable * /* table */,
const PLDHashEntryHdr *from,
PLDHashEntryHdr *to)
{
((nsCacheEntryHashTableEntry *)to)->cacheEntry =
((nsCacheEntryHashTableEntry *)from)->cacheEntry;
}
void
nsCacheEntryHashTable::ClearEntry(PLDHashTable * /* table */,
PLDHashEntryHdr * hashEntry)
{
((nsCacheEntryHashTableEntry *)hashEntry)->cacheEntry = 0;
}