The Tor Browser: netwerk/cache2/CacheFileContextEvictor.cpp@7e26c7da4463 (annotated)

netwerk/cache2/CacheFileContextEvictor.cpp@7e26c7da4463 (annotated)

netwerk/cache2/CacheFileContextEvictor.cpp

Wed, 31 Dec 2014 06:55:50 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:55:50 +0100
changeset 2: 7e26c7da4463
permissions: -rw-r--r--

Added tag UPSTREAM_283F7C6 for changeset ca08bd8f51b2

 /* 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 "CacheFileContextEvictor.h"
 #include "CacheFileIOManager.h"
 #include "CacheIndex.h"
 #include "CacheIndexIterator.h"
 #include "CacheFileUtils.h"
 #include "nsIFile.h"
 #include "LoadContextInfo.h"
 #include "nsThreadUtils.h"
 #include "nsString.h"
 #include "nsISimpleEnumerator.h"
 #include "nsIDirectoryEnumerator.h"
 #include "mozilla/Base64.h"
 namespace mozilla {
 namespace net {
 const char kContextEvictionPrefix[] = "ce_";
 const uint32_t kContextEvictionPrefixLength =
   sizeof(kContextEvictionPrefix) - 1;
 bool CacheFileContextEvictor::sDiskAlreadySearched = false;
 CacheFileContextEvictor::CacheFileContextEvictor()
   : mEvicting(false)
   , mIndexIsUpToDate(false)
 {
   LOG(("CacheFileContextEvictor::CacheFileContextEvictor() [this=%p]", this));
 }
 CacheFileContextEvictor::~CacheFileContextEvictor()
 {
   LOG(("CacheFileContextEvictor::~CacheFileContextEvictor() [this=%p]", this));
 }
 nsresult
 CacheFileContextEvictor::Init(nsIFile *aCacheDirectory)
 {
   LOG(("CacheFileContextEvictor::Init()"));
   nsresult rv;
   MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
   CacheIndex::IsUpToDate(&mIndexIsUpToDate);
   mCacheDirectory = aCacheDirectory;
   rv = aCacheDirectory->Clone(getter_AddRefs(mEntriesDir));
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
   rv = mEntriesDir->AppendNative(NS_LITERAL_CSTRING(kEntriesDir));
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
   if (!sDiskAlreadySearched) {
     LoadEvictInfoFromDisk();
     if ((mEntries.Length() != 0) && mIndexIsUpToDate) {
       CreateIterators();
       StartEvicting();
     }
   }
   return NS_OK;
 }
 uint32_t
 CacheFileContextEvictor::ContextsCount()
 {
   MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
   return mEntries.Length();
 }
 nsresult
 CacheFileContextEvictor::AddContext(nsILoadContextInfo *aLoadContextInfo)
 {
   LOG(("CacheFileContextEvictor::AddContext() [this=%p, loadContextInfo=%p]",
        this, aLoadContextInfo));
   nsresult rv;
   MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
   CacheFileContextEvictorEntry *entry = nullptr;
   for (uint32_t i = 0; i < mEntries.Length(); ++i) {
     if (mEntries[i]->mInfo->Equals(aLoadContextInfo)) {
       entry = mEntries[i];
       break;
     }
   }
   if (!entry) {
     entry = new CacheFileContextEvictorEntry();
     entry->mInfo = aLoadContextInfo;
     mEntries.AppendElement(entry);
   }
   entry->mTimeStamp = PR_Now() / PR_USEC_PER_MSEC;
   PersistEvictionInfoToDisk(aLoadContextInfo);
   if (mIndexIsUpToDate) {
     // Already existing context could be added again, in this case the iterator
     // would be recreated. Close the old iterator explicitely.
     if (entry->mIterator) {
       entry->mIterator->Close();
       entry->mIterator = nullptr;
     }
     rv = CacheIndex::GetIterator(aLoadContextInfo, false,
                                  getter_AddRefs(entry->mIterator));
     if (NS_FAILED(rv)) {
       // This could probably happen during shutdown. Remove the entry from
       // the array, but leave the info on the disk. No entry can be opened
       // during shutdown and we'll load the eviction info on next start.
       LOG(("CacheFileContextEvictor::AddContext() - Cannot get an iterator. "
            "[rv=0x%08x]", rv));
       mEntries.RemoveElement(entry);
       return rv;
     }
     StartEvicting();
   }
   return NS_OK;
 }
 nsresult
 CacheFileContextEvictor::CacheIndexStateChanged()
 {
   LOG(("CacheFileContextEvictor::CacheIndexStateChanged() [this=%p]", this));
   MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
   bool isUpToDate = false;
   CacheIndex::IsUpToDate(&isUpToDate);
   if (mEntries.Length() == 0) {
     // Just save the state and exit, since there is nothing to do
     mIndexIsUpToDate = isUpToDate;
     return NS_OK;
   }
   if (!isUpToDate && !mIndexIsUpToDate) {
     // Index is outdated and status has not changed, nothing to do.
     return NS_OK;
   }
   if (isUpToDate && mIndexIsUpToDate) {
     // Status has not changed, but make sure the eviction is running.
     if (mEvicting) {
       return NS_OK;
     }
     // We're not evicting, but we should be evicting?!
     LOG(("CacheFileContextEvictor::CacheIndexStateChanged() - Index is up to "
          "date, we have some context to evict but eviction is not running! "
          "Starting now."));
   }
   mIndexIsUpToDate = isUpToDate;
   if (mIndexIsUpToDate) {
     CreateIterators();
     StartEvicting();
   } else {
     CloseIterators();
   }
   return NS_OK;
 }
 nsresult
 CacheFileContextEvictor::WasEvicted(const nsACString &aKey, nsIFile *aFile,
                                     bool *_retval)
 {
   LOG(("CacheFileContextEvictor::WasEvicted() [key=%s]",
        PromiseFlatCString(aKey).get()));
   nsresult rv;
   MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
   nsCOMPtr<nsILoadContextInfo> info = CacheFileUtils::ParseKey(aKey);
   MOZ_ASSERT(info);
   if (!info) {
     LOG(("CacheFileContextEvictor::WasEvicted() - Cannot parse key!"));
     *_retval = false;
     return NS_OK;
   }
   CacheFileContextEvictorEntry *entry = nullptr;
   for (uint32_t i = 0; i < mEntries.Length(); ++i) {
     if (info->Equals(mEntries[i]->mInfo)) {
       entry = mEntries[i];
       break;
     }
   }
   if (!entry) {
     LOG(("CacheFileContextEvictor::WasEvicted() - Didn't find equal context, "
          "returning false."));
     *_retval = false;
     return NS_OK;
   }
   PRTime lastModifiedTime;
   rv = aFile->GetLastModifiedTime(&lastModifiedTime);
   if (NS_FAILED(rv)) {
     LOG(("CacheFileContextEvictor::WasEvicted() - Cannot get last modified time"
          ", returning false."));
     *_retval = false;
     return NS_OK;
   }
   *_retval = !(lastModifiedTime > entry->mTimeStamp);
   LOG(("CacheFileContextEvictor::WasEvicted() - returning %s. [mTimeStamp=%lld,"
        " lastModifiedTime=%lld]", *_retval ? "true" : "false",
        mEntries[0]->mTimeStamp, lastModifiedTime));
   return NS_OK;
 }
 nsresult
 CacheFileContextEvictor::PersistEvictionInfoToDisk(
   nsILoadContextInfo *aLoadContextInfo)
 {
   LOG(("CacheFileContextEvictor::PersistEvictionInfoToDisk() [this=%p, "
        "loadContextInfo=%p]", this, aLoadContextInfo));
   nsresult rv;
   MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
   nsCOMPtr<nsIFile> file;
   rv = GetContextFile(aLoadContextInfo, getter_AddRefs(file));
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
 #ifdef PR_LOGGING
   nsAutoCString path;
   file->GetNativePath(path);
 #endif
   PRFileDesc *fd;
   rv = file->OpenNSPRFileDesc(PR_RDWR | PR_CREATE_FILE | PR_TRUNCATE, 0600,
                               &fd);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     LOG(("CacheFileContextEvictor::PersistEvictionInfoToDisk() - Creating file "
          "failed! [path=%s, rv=0x%08x]", path.get(), rv));
     return rv;
   }
   PR_Close(fd);
   LOG(("CacheFileContextEvictor::PersistEvictionInfoToDisk() - Successfully "
        "created file. [path=%s]", path.get()));
   return NS_OK;
 }
 nsresult
 CacheFileContextEvictor::RemoveEvictInfoFromDisk(
   nsILoadContextInfo *aLoadContextInfo)
 {
   LOG(("CacheFileContextEvictor::RemoveEvictInfoFromDisk() [this=%p, "
        "loadContextInfo=%p]", this, aLoadContextInfo));
   nsresult rv;
   MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
   nsCOMPtr<nsIFile> file;
   rv = GetContextFile(aLoadContextInfo, getter_AddRefs(file));
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
 #ifdef PR_LOGGING
   nsAutoCString path;
   file->GetNativePath(path);
 #endif
   rv = file->Remove(false);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     LOG(("CacheFileContextEvictor::RemoveEvictionInfoFromDisk() - Removing file"
          " failed! [path=%s, rv=0x%08x]", path.get(), rv));
     return rv;
   }
   LOG(("CacheFileContextEvictor::RemoveEvictionInfoFromDisk() - Successfully "
        "removed file. [path=%s]", path.get()));
   return NS_OK;
 }
 nsresult
 CacheFileContextEvictor::LoadEvictInfoFromDisk()
 {
   LOG(("CacheFileContextEvictor::LoadEvictInfoFromDisk() [this=%p]", this));
   nsresult rv;
   MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
   sDiskAlreadySearched = true;
   nsCOMPtr<nsISimpleEnumerator> enumerator;
   rv = mCacheDirectory->GetDirectoryEntries(getter_AddRefs(enumerator));
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
   nsCOMPtr<nsIDirectoryEnumerator> dirEnum = do_QueryInterface(enumerator, &rv);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
   while (true) {
     nsCOMPtr<nsIFile> file;
     rv = dirEnum->GetNextFile(getter_AddRefs(file));
     if (!file) {
       break;
     }
     bool isDir = false;
     file->IsDirectory(&isDir);
     if (isDir) {
       continue;
     }
     nsAutoCString leaf;
     rv = file->GetNativeLeafName(leaf);
     if (NS_FAILED(rv)) {
       LOG(("CacheFileContextEvictor::LoadEvictInfoFromDisk() - "
            "GetNativeLeafName() failed! Skipping file."));
       continue;
     }
     if (leaf.Length() < kContextEvictionPrefixLength) {
       continue;
     }
     if (!StringBeginsWith(leaf, NS_LITERAL_CSTRING(kContextEvictionPrefix))) {
       continue;
     }
     nsAutoCString encoded;
     encoded = Substring(leaf, kContextEvictionPrefixLength);
     encoded.ReplaceChar('-', '/');
     nsAutoCString decoded;
     rv = Base64Decode(encoded, decoded);
     if (NS_FAILED(rv)) {
       LOG(("CacheFileContextEvictor::LoadEvictInfoFromDisk() - Base64 decoding "
            "failed. Removing the file. [file=%s]", leaf.get()));
       file->Remove(false);
       continue;
     }
     nsCOMPtr<nsILoadContextInfo> info = CacheFileUtils::ParseKey(decoded);
     if (!info) {
       LOG(("CacheFileContextEvictor::LoadEvictInfoFromDisk() - Cannot parse "
            "context key, removing file. [contextKey=%s, file=%s]",
            decoded.get(), leaf.get()));
       file->Remove(false);
       continue;
     }
     PRTime lastModifiedTime;
     rv = file->GetLastModifiedTime(&lastModifiedTime);
     if (NS_FAILED(rv)) {
       continue;
     }
     CacheFileContextEvictorEntry *entry = new CacheFileContextEvictorEntry();
     entry->mInfo = info;
     entry->mTimeStamp = lastModifiedTime;
     mEntries.AppendElement(entry);
   }
   return NS_OK;
 }
 nsresult
 CacheFileContextEvictor::GetContextFile(nsILoadContextInfo *aLoadContextInfo,
                                         nsIFile **_retval)
 {
   nsresult rv;
   nsAutoCString leafName;
   leafName.Assign(NS_LITERAL_CSTRING(kContextEvictionPrefix));
   nsAutoCString keyPrefix;
   CacheFileUtils::AppendKeyPrefix(aLoadContextInfo, keyPrefix);
   // TODO: This hack is needed because current CacheFileUtils::ParseKey() can
   // parse only the whole key and not just the key prefix generated by
   // CacheFileUtils::CreateKeyPrefix(). This should be removed once bug #968593
   // is fixed.
   keyPrefix.Append(":foo");
   nsAutoCString data64;
   rv = Base64Encode(keyPrefix, data64);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
   // Replace '/' with '-' since '/' cannot be part of the filename.
   data64.ReplaceChar('/', '-');
   leafName.Append(data64);
   nsCOMPtr<nsIFile> file;
   rv = mCacheDirectory->Clone(getter_AddRefs(file));
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
   rv = file->AppendNative(leafName);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
   file.swap(*_retval);
   return NS_OK;
 }
 void
 CacheFileContextEvictor::CreateIterators()
 {
   LOG(("CacheFileContextEvictor::CreateIterators() [this=%p]", this));
   CloseIterators();
   nsresult rv;
   for (uint32_t i = 0; i < mEntries.Length(); ) {
     rv = CacheIndex::GetIterator(mEntries[i]->mInfo, false,
                                  getter_AddRefs(mEntries[i]->mIterator));
     if (NS_FAILED(rv)) {
       LOG(("CacheFileContextEvictor::CreateIterators() - Cannot get an iterator"
            ". [rv=0x%08x]", rv));
       mEntries.RemoveElementAt(i);
       continue;
     }
     ++i;
   }
 }
 void
 CacheFileContextEvictor::CloseIterators()
 {
   LOG(("CacheFileContextEvictor::CloseIterators() [this=%p]", this));
   for (uint32_t i = 0; i < mEntries.Length(); ++i) {
     if (mEntries[i]->mIterator) {
       mEntries[i]->mIterator->Close();
       mEntries[i]->mIterator = nullptr;
     }
   }
 }
 void
 CacheFileContextEvictor::StartEvicting()
 {
   LOG(("CacheFileContextEvictor::StartEvicting() [this=%p]", this));
   MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
   if (mEvicting) {
     LOG(("CacheFileContextEvictor::StartEvicting() - already evicintg."));
     return;
   }
   if (mEntries.Length() == 0) {
     LOG(("CacheFileContextEvictor::StartEvicting() - no context to evict."));
     return;
   }
   nsCOMPtr<nsIRunnable> ev;
   ev = NS_NewRunnableMethod(this, &CacheFileContextEvictor::EvictEntries);
   nsRefPtr<CacheIOThread> ioThread = CacheFileIOManager::IOThread();
   nsresult rv = ioThread->Dispatch(ev, CacheIOThread::EVICT);
   if (NS_FAILED(rv)) {
     LOG(("CacheFileContextEvictor::StartEvicting() - Cannot dispatch event to "
          "IO thread. [rv=0x%08x]", rv));
   }
   mEvicting = true;
 }
 nsresult
 CacheFileContextEvictor::EvictEntries()
 {
   LOG(("CacheFileContextEvictor::EvictEntries()"));
   nsresult rv;
   MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
   mEvicting = false;
   if (!mIndexIsUpToDate) {
     LOG(("CacheFileContextEvictor::EvictEntries() - Stopping evicting due to "
          "outdated index."));
     return NS_OK;
   }
   while (true) {
     if (CacheIOThread::YieldAndRerun()) {
       LOG(("CacheFileContextEvictor::EvictEntries() - Breaking loop for higher "
            "level events."));
       mEvicting = true;
       return NS_OK;
     }
     if (mEntries.Length() == 0) {
       LOG(("CacheFileContextEvictor::EvictEntries() - Stopping evicting, there "
            "is no context to evict."));
       return NS_OK;
     }
     SHA1Sum::Hash hash;
     rv = mEntries[0]->mIterator->GetNextHash(&hash);
     if (rv == NS_ERROR_NOT_AVAILABLE) {
       LOG(("CacheFileContextEvictor::EvictEntries() - No more entries left in "
            "iterator. [iterator=%p, info=%p]", mEntries[0]->mIterator.get(),
            mEntries[0]->mInfo.get()));
       RemoveEvictInfoFromDisk(mEntries[0]->mInfo);
       mEntries.RemoveElementAt(0);
       continue;
     } else if (NS_FAILED(rv)) {
       LOG(("CacheFileContextEvictor::EvictEntries() - Iterator failed to "
            "provide next hash (shutdown?), keeping eviction info on disk."
            " [iterator=%p, info=%p]", mEntries[0]->mIterator.get(),
            mEntries[0]->mInfo.get()));
       mEntries.RemoveElementAt(0);
       continue;
     }
     LOG(("CacheFileContextEvictor::EvictEntries() - Processing hash. "
          "[hash=%08x%08x%08x%08x%08x, iterator=%p, info=%p]", LOGSHA1(&hash),
          mEntries[0]->mIterator.get(), mEntries[0]->mInfo.get()));
     nsRefPtr<CacheFileHandle> handle;
     CacheFileIOManager::gInstance->mHandles.GetHandle(&hash, false,
                                                       getter_AddRefs(handle));
     if (handle) {
       // We doom any active handle in CacheFileIOManager::EvictByContext(), so
       // this must be a new one. Skip it.
       LOG(("CacheFileContextEvictor::EvictEntries() - Skipping entry since we "
            "found an active handle. [handle=%p]", handle.get()));
       continue;
     }
     nsAutoCString leafName;
     CacheFileIOManager::HashToStr(&hash, leafName);
     PRTime lastModifiedTime;
     nsCOMPtr<nsIFile> file;
     rv = mEntriesDir->Clone(getter_AddRefs(file));
     if (NS_SUCCEEDED(rv)) {
       rv = file->AppendNative(leafName);
     }
     if (NS_SUCCEEDED(rv)) {
       rv = file->GetLastModifiedTime(&lastModifiedTime);
     }
     if (NS_FAILED(rv)) {
       LOG(("CacheFileContextEvictor::EvictEntries() - Cannot get last modified "
            "time, skipping entry."));
       continue;
     }
     if (lastModifiedTime > mEntries[0]->mTimeStamp) {
       LOG(("CacheFileContextEvictor::EvictEntries() - Skipping newer entry. "
            "[mTimeStamp=%lld, lastModifiedTime=%lld]", mEntries[0]->mTimeStamp,
            lastModifiedTime));
       continue;
     }
     LOG(("CacheFileContextEvictor::EvictEntries - Removing entry."));
     file->Remove(false);
     CacheIndex::RemoveEntry(&hash);
   }
   NS_NOTREACHED("We should never get here");
   return NS_OK;
 }
 } // net
 } // mozilla

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netwerk/cache2/CacheFileContextEvictor.cpp@7e26c7da4463 (annotated)

netwerk/cache2/CacheFileContextEvictor.cpp