The Tor Browser: toolkit/components/url-classifier/nsUrlClassifierPrefixSet.cpp@925c144e1f1f (annotated)

toolkit/components/url-classifier/nsUrlClassifierPrefixSet.cpp@925c144e1f1f (annotated)

toolkit/components/url-classifier/nsUrlClassifierPrefixSet.cpp

Fri, 16 Jan 2015 18:13:44 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Fri, 16 Jan 2015 18:13:44 +0100
branch: TOR_BUG_9701
changeset 14: 925c144e1f1f
permissions: -rw-r--r--

Integrate suggestion from review to improve consistency with existing code.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 /* 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 "nsAutoPtr.h"
 #include "nsCOMPtr.h"
 #include "nsDebug.h"
 #include "nsPrintfCString.h"
 #include "nsTArray.h"
 #include "nsString.h"
 #include "nsUrlClassifierPrefixSet.h"
 #include "nsIUrlClassifierPrefixSet.h"
 #include "nsIRandomGenerator.h"
 #include "nsIFile.h"
 #include "nsToolkitCompsCID.h"
 #include "nsTArray.h"
 #include "nsThreadUtils.h"
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/Mutex.h"
 #include "mozilla/Telemetry.h"
 #include "mozilla/FileUtils.h"
 #include "prlog.h"
 using namespace mozilla;
 // NSPR_LOG_MODULES=UrlClassifierPrefixSet:5
 #if defined(PR_LOGGING)
 static const PRLogModuleInfo *gUrlClassifierPrefixSetLog = nullptr;
 #define LOG(args) PR_LOG(gUrlClassifierPrefixSetLog, PR_LOG_DEBUG, args)
 #define LOG_ENABLED() PR_LOG_TEST(gUrlClassifierPrefixSetLog, 4)
 #else
 #define LOG(args)
 #define LOG_ENABLED() (false)
 #endif
 NS_IMPL_ISUPPORTS(
   nsUrlClassifierPrefixSet, nsIUrlClassifierPrefixSet, nsIMemoryReporter)
 nsUrlClassifierPrefixSet::nsUrlClassifierPrefixSet()
   : mHasPrefixes(false)
   , mMemoryReportPath()
 {
 #if defined(PR_LOGGING)
   if (!gUrlClassifierPrefixSetLog)
     gUrlClassifierPrefixSetLog = PR_NewLogModule("UrlClassifierPrefixSet");
 #endif
 }
 NS_IMETHODIMP
 nsUrlClassifierPrefixSet::Init(const nsACString& aName)
 {
   mMemoryReportPath =
     nsPrintfCString(
       "explicit/storage/prefix-set/%s",
       (!aName.IsEmpty() ? PromiseFlatCString(aName).get() : "?!")
     );
   RegisterWeakMemoryReporter(this);
   return NS_OK;
 }
 nsUrlClassifierPrefixSet::~nsUrlClassifierPrefixSet()
 {
   UnregisterWeakMemoryReporter(this);
 }
 NS_IMETHODIMP
 nsUrlClassifierPrefixSet::SetPrefixes(const uint32_t* aArray, uint32_t aLength)
 {
   if (aLength <= 0) {
     if (mHasPrefixes) {
       LOG(("Clearing PrefixSet"));
       mDeltas.Clear();
       mIndexPrefixes.Clear();
       mIndexStarts.Clear();
       mHasPrefixes = false;
     }
   } else {
     return MakePrefixSet(aArray, aLength);
   }
   return NS_OK;
 }
 nsresult
 nsUrlClassifierPrefixSet::MakePrefixSet(const uint32_t* aPrefixes, uint32_t aLength)
 {
   if (aLength == 0) {
     return NS_OK;
   }
 #ifdef DEBUG
   for (uint32_t i = 1; i < aLength; i++) {
     MOZ_ASSERT(aPrefixes[i] >= aPrefixes[i-1]);
   }
 #endif
   mIndexPrefixes.Clear();
   mIndexStarts.Clear();
   mDeltas.Clear();
   mIndexPrefixes.AppendElement(aPrefixes[0]);
   mIndexStarts.AppendElement(mDeltas.Length());
   uint32_t numOfDeltas = 0;
   uint32_t currentItem = aPrefixes[0];
   for (uint32_t i = 1; i < aLength; i++) {
     if ((numOfDeltas >= DELTAS_LIMIT) ||
           (aPrefixes[i] - currentItem >= MAX_INDEX_DIFF)) {
       mIndexStarts.AppendElement(mDeltas.Length());
       mIndexPrefixes.AppendElement(aPrefixes[i]);
       numOfDeltas = 0;
     } else {
       uint16_t delta = aPrefixes[i] - currentItem;
       mDeltas.AppendElement(delta);
       numOfDeltas++;
     }
     currentItem = aPrefixes[i];
   }
   mIndexPrefixes.Compact();
   mIndexStarts.Compact();
   mDeltas.Compact();
   LOG(("Total number of indices: %d", mIndexPrefixes.Length()));
   LOG(("Total number of deltas: %d", mDeltas.Length()));
   mHasPrefixes = true;
   return NS_OK;
 }
 NS_IMETHODIMP
 nsUrlClassifierPrefixSet::GetPrefixes(uint32_t* aCount,
                                       uint32_t** aPrefixes)
 {
   NS_ENSURE_ARG_POINTER(aCount);
   *aCount = 0;
   NS_ENSURE_ARG_POINTER(aPrefixes);
   *aPrefixes = nullptr;
   nsTArray<uint32_t> aArray;
   uint32_t prefixLength = mIndexPrefixes.Length();
   for (uint32_t i = 0; i < prefixLength; i++) {
     uint32_t prefix = mIndexPrefixes[i];
     uint32_t start = mIndexStarts[i];
     uint32_t end = (i == (prefixLength - 1)) ? mDeltas.Length()
                                              : mIndexStarts[i + 1];
     if (end > mDeltas.Length()) {
       return NS_ERROR_FILE_CORRUPTED;
     }
     aArray.AppendElement(prefix);
     for (uint32_t j = start; j < end; j++) {
       prefix += mDeltas[j];
       aArray.AppendElement(prefix);
     }
   }
   NS_ASSERTION(mIndexStarts.Length() + mDeltas.Length() == aArray.Length(),
                "Lengths are inconsistent");
   uint32_t itemCount = aArray.Length();
   uint32_t* retval = static_cast<uint32_t*>(nsMemory::Alloc(itemCount * sizeof(uint32_t)));
   NS_ENSURE_TRUE(retval, NS_ERROR_OUT_OF_MEMORY);
   for (uint32_t i = 0; i < itemCount; i++) {
     retval[i] = aArray[i];
   }
   *aCount = itemCount;
   *aPrefixes = retval;
   return NS_OK;
 }
 uint32_t nsUrlClassifierPrefixSet::BinSearch(uint32_t start,
                                              uint32_t end,
                                              uint32_t target)
 {
   while (start != end && end >= start) {
     uint32_t i = start + ((end - start) >> 1);
     uint32_t value = mIndexPrefixes[i];
     if (value < target) {
       start = i + 1;
     } else if (value > target) {
       end = i - 1;
     } else {
       return i;
     }
   }
   return end;
 }
 NS_IMETHODIMP
 nsUrlClassifierPrefixSet::Contains(uint32_t aPrefix, bool* aFound)
 {
   *aFound = false;
   if (!mHasPrefixes) {
     return NS_OK;
   }
   uint32_t target = aPrefix;
   // We want to do a "Price is Right" binary search, that is, we want to find
   // the index of the value either equal to the target or the closest value
   // that is less than the target.
   //
   if (target < mIndexPrefixes[0]) {
     return NS_OK;
   }
   // |binsearch| does not necessarily return the correct index (when the
   // target is not found) but rather it returns an index at least one away
   // from the correct index.
   // Because of this, we need to check if the target lies before the beginning
   // of the indices.
   uint32_t i = BinSearch(0, mIndexPrefixes.Length() - 1, target);
   if (mIndexPrefixes[i] > target && i > 0) {
     i--;
   }
   // Now search through the deltas for the target.
   uint32_t diff = target - mIndexPrefixes[i];
   uint32_t deltaIndex = mIndexStarts[i];
   uint32_t deltaSize  = mDeltas.Length();
   uint32_t end = (i + 1 < mIndexStarts.Length()) ? mIndexStarts[i+1]
                                                  : deltaSize;
   // Sanity check the read values
   if (end > deltaSize) {
     return NS_ERROR_FILE_CORRUPTED;
   }
   while (diff > 0 && deltaIndex < end) {
     diff -= mDeltas[deltaIndex];
     deltaIndex++;
   }
   if (diff == 0) {
     *aFound = true;
   }
   return NS_OK;
 }
 MOZ_DEFINE_MALLOC_SIZE_OF(UrlClassifierMallocSizeOf)
 NS_IMETHODIMP
 nsUrlClassifierPrefixSet::CollectReports(nsIHandleReportCallback* aHandleReport,
                                          nsISupports* aData)
 {
   return aHandleReport->Callback(
     EmptyCString(), mMemoryReportPath, KIND_HEAP, UNITS_BYTES,
     SizeOfIncludingThis(UrlClassifierMallocSizeOf),
     NS_LITERAL_CSTRING("Memory used by the prefix set for a URL classifier."),
     aData);
 }
 size_t
 nsUrlClassifierPrefixSet::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf)
 {
   size_t n = 0;
   n += aMallocSizeOf(this);
   n += mDeltas.SizeOfExcludingThis(aMallocSizeOf);
   n += mIndexPrefixes.SizeOfExcludingThis(aMallocSizeOf);
   n += mIndexStarts.SizeOfExcludingThis(aMallocSizeOf);
   return n;
 }
 NS_IMETHODIMP
 nsUrlClassifierPrefixSet::IsEmpty(bool * aEmpty)
 {
   *aEmpty = !mHasPrefixes;
   return NS_OK;
 }
 nsresult
 nsUrlClassifierPrefixSet::LoadFromFd(AutoFDClose& fileFd)
 {
   uint32_t magic;
   int32_t read;
   read = PR_Read(fileFd, &magic, sizeof(uint32_t));
   NS_ENSURE_TRUE(read == sizeof(uint32_t), NS_ERROR_FAILURE);
   if (magic == PREFIXSET_VERSION_MAGIC) {
     uint32_t indexSize;
     uint32_t deltaSize;
     read = PR_Read(fileFd, &indexSize, sizeof(uint32_t));
     NS_ENSURE_TRUE(read == sizeof(uint32_t), NS_ERROR_FILE_CORRUPTED);
     read = PR_Read(fileFd, &deltaSize, sizeof(uint32_t));
     NS_ENSURE_TRUE(read == sizeof(uint32_t), NS_ERROR_FILE_CORRUPTED);
     if (indexSize == 0) {
       LOG(("stored PrefixSet is empty!"));
       return NS_OK;
     }
     if (deltaSize > (indexSize * DELTAS_LIMIT)) {
       return NS_ERROR_FILE_CORRUPTED;
     }
     mIndexStarts.SetLength(indexSize);
     mIndexPrefixes.SetLength(indexSize);
     mDeltas.SetLength(deltaSize);
     int32_t toRead = indexSize*sizeof(uint32_t);
     read = PR_Read(fileFd, mIndexPrefixes.Elements(), toRead);
     NS_ENSURE_TRUE(read == toRead, NS_ERROR_FILE_CORRUPTED);
     read = PR_Read(fileFd, mIndexStarts.Elements(), toRead);
     NS_ENSURE_TRUE(read == toRead, NS_ERROR_FILE_CORRUPTED);
     if (deltaSize > 0) {
       toRead = deltaSize*sizeof(uint16_t);
       read = PR_Read(fileFd, mDeltas.Elements(), toRead);
       NS_ENSURE_TRUE(read == toRead, NS_ERROR_FILE_CORRUPTED);
     }
     mHasPrefixes = true;
   } else {
     LOG(("Version magic mismatch, not loading"));
     return NS_ERROR_FILE_CORRUPTED;
   }
   LOG(("Loading PrefixSet successful"));
   return NS_OK;
 }
 NS_IMETHODIMP
 nsUrlClassifierPrefixSet::LoadFromFile(nsIFile* aFile)
 {
   Telemetry::AutoTimer<Telemetry::URLCLASSIFIER_PS_FILELOAD_TIME> timer;
   nsresult rv;
   AutoFDClose fileFd;
   rv = aFile->OpenNSPRFileDesc(PR_RDONLY | nsIFile::OS_READAHEAD,
 , &fileFd.rwget());
   NS_ENSURE_SUCCESS(rv, rv);
   return LoadFromFd(fileFd);
 }
 nsresult
 nsUrlClassifierPrefixSet::StoreToFd(AutoFDClose& fileFd)
 {
   {
       Telemetry::AutoTimer<Telemetry::URLCLASSIFIER_PS_FALLOCATE_TIME> timer;
       int64_t size = 4 * sizeof(uint32_t);
       size += 2 * mIndexStarts.Length() * sizeof(uint32_t);
       size +=     mDeltas.Length() * sizeof(uint16_t);
       mozilla::fallocate(fileFd, size);
   }
   int32_t written;
   int32_t writelen = sizeof(uint32_t);
   uint32_t magic = PREFIXSET_VERSION_MAGIC;
   written = PR_Write(fileFd, &magic, writelen);
   NS_ENSURE_TRUE(written == writelen, NS_ERROR_FAILURE);
   uint32_t indexSize = mIndexStarts.Length();
   uint32_t deltaSize = mDeltas.Length();
   written = PR_Write(fileFd, &indexSize, writelen);
   NS_ENSURE_TRUE(written == writelen, NS_ERROR_FAILURE);
   written = PR_Write(fileFd, &deltaSize, writelen);
   NS_ENSURE_TRUE(written == writelen, NS_ERROR_FAILURE);
   writelen = indexSize * sizeof(uint32_t);
   written = PR_Write(fileFd, mIndexPrefixes.Elements(), writelen);
   NS_ENSURE_TRUE(written == writelen, NS_ERROR_FAILURE);
   written = PR_Write(fileFd, mIndexStarts.Elements(), writelen);
   NS_ENSURE_TRUE(written == writelen, NS_ERROR_FAILURE);
   if (deltaSize > 0) {
     writelen = deltaSize * sizeof(uint16_t);
     written = PR_Write(fileFd, mDeltas.Elements(), writelen);
     NS_ENSURE_TRUE(written == writelen, NS_ERROR_FAILURE);
   }
   LOG(("Saving PrefixSet successful\n"));
   return NS_OK;
 }
 NS_IMETHODIMP
 nsUrlClassifierPrefixSet::StoreToFile(nsIFile* aFile)
 {
   AutoFDClose fileFd;
   nsresult rv = aFile->OpenNSPRFileDesc(PR_RDWR | PR_TRUNCATE | PR_CREATE_FILE,
 , &fileFd.rwget());
   NS_ENSURE_SUCCESS(rv, rv);
   return StoreToFd(fileFd);
 }

The Tor Browser / annotate

toolkit/components/url-classifier/nsUrlClassifierPrefixSet.cpp@925c144e1f1f (annotated)

toolkit/components/url-classifier/nsUrlClassifierPrefixSet.cpp