dom/file/MemoryBlobImpl.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "MemoryBlobImpl.h"
   8 #include "mozilla/ipc/InputStreamUtils.h"
   9 #include "mozilla/IntegerPrintfMacros.h"
  10 #include "mozilla/SHA1.h"
  11 #include "nsIMemoryReporter.h"
  12 #include "nsMemory.h"
  13 #include "nsPrintfCString.h"
  14 #include "nsRFPService.h"
  15 #include "nsStringStream.h"
  16 #include "prtime.h"
  17
  18 namespace mozilla::dom {
  19
  20 // static
  21 already_AddRefed<MemoryBlobImpl> MemoryBlobImpl::CreateWithCustomLastModified(
  22     void* aMemoryBuffer, uint64_t aLength, const nsAString& aName,
  23     const nsAString& aContentType, int64_t aLastModifiedDate) {
  24   RefPtr<MemoryBlobImpl> blobImpl = new MemoryBlobImpl(
  25       aMemoryBuffer, aLength, aName, aContentType, aLastModifiedDate);
  26   return blobImpl.forget();
  27 }
  28
  29 // static
  30 already_AddRefed<MemoryBlobImpl> MemoryBlobImpl::CreateWithLastModifiedNow(
  31     void* aMemoryBuffer, uint64_t aLength, const nsAString& aName,
  32     const nsAString& aContentType, bool aCrossOriginIsolated) {
  33   int64_t lastModificationDate = nsRFPService::ReduceTimePrecisionAsUSecs(
  34       PR_Now(), 0,
  35       /* aIsSystemPrincipal */ false, aCrossOriginIsolated);
  36   return CreateWithCustomLastModified(aMemoryBuffer, aLength, aName,
  37                                       aContentType, lastModificationDate);
  38 }
  39
  40 nsresult MemoryBlobImpl::DataOwnerAdapter::Create(DataOwner* aDataOwner,
  41                                                   size_t aStart, size_t aLength,
  42                                                   nsIInputStream** _retval) {
  43   MOZ_ASSERT(aDataOwner, "Uh ...");
  44   Span data{static_cast<const char*>(aDataOwner->mData) + aStart, aLength};
  45   RefPtr adapter = new MemoryBlobImpl::DataOwnerAdapter(aDataOwner, data);
  46   return NS_NewByteInputStream(_retval, adapter);
  47 }
  48
  49 already_AddRefed<BlobImpl> MemoryBlobImpl::CreateSlice(
  50     uint64_t aStart, uint64_t aLength, const nsAString& aContentType,
  51     ErrorResult& aRv) {
  52   RefPtr<BlobImpl> impl =
  53       new MemoryBlobImpl(this, aStart, aLength, aContentType);
  54   return impl.forget();
  55 }
  56
  57 void MemoryBlobImpl::CreateInputStream(nsIInputStream** aStream,
  58                                        ErrorResult& aRv) {
  59   if (mLength >= INT32_MAX) {
  60     aRv.Throw(NS_ERROR_FAILURE);
  61     return;
  62   }
  63
  64   aRv = MemoryBlobImpl::DataOwnerAdapter::Create(mDataOwner, mStart, mLength,
  65                                                  aStream);
  66 }
  67
  68 /* static */
  69 StaticMutex MemoryBlobImpl::DataOwner::sDataOwnerMutex;
  70
  71 /* static */ StaticAutoPtr<LinkedList<MemoryBlobImpl::DataOwner>>
  72     MemoryBlobImpl::DataOwner::sDataOwners;
  73
  74 /* static */
  75 bool MemoryBlobImpl::DataOwner::sMemoryReporterRegistered = false;
  76
  77 MOZ_DEFINE_MALLOC_SIZE_OF(MemoryFileDataOwnerMallocSizeOf)
  78
  79 class MemoryBlobImplDataOwnerMemoryReporter final : public nsIMemoryReporter {
  80   ~MemoryBlobImplDataOwnerMemoryReporter() = default;
  81
  82  public:
  83   NS_DECL_THREADSAFE_ISUPPORTS
  84
  85   NS_IMETHOD CollectReports(nsIHandleReportCallback* aHandleReport,
  86                             nsISupports* aData, bool aAnonymize) override {
  87     using DataOwner = MemoryBlobImpl::DataOwner;
  88
  89     StaticMutexAutoLock lock(DataOwner::sDataOwnerMutex);
  90
  91     if (!DataOwner::sDataOwners) {
  92       return NS_OK;
  93     }
  94
  95     const size_t LARGE_OBJECT_MIN_SIZE = 8 * 1024;
  96     size_t smallObjectsTotal = 0;
  97
  98     for (DataOwner* owner = DataOwner::sDataOwners->getFirst(); owner;
  99          owner = owner->getNext()) {
 100       size_t size = MemoryFileDataOwnerMallocSizeOf(owner->mData);
 101
 102       if (size < LARGE_OBJECT_MIN_SIZE) {
 103         smallObjectsTotal += size;
 104       } else {
 105         SHA1Sum sha1;
 106         sha1.update(owner->mData, owner->mLength);
 107         uint8_t digest[SHA1Sum::kHashSize];  // SHA1 digests are 20 bytes long.
 108         sha1.finish(digest);
 109
 110         nsAutoCString digestString;
 111         for (size_t i = 0; i < sizeof(digest); i++) {
 112           digestString.AppendPrintf("%02x", digest[i]);
 113         }
 114
 115         aHandleReport->Callback(
 116             /* process */ ""_ns,
 117             nsPrintfCString(
 118                 "explicit/dom/memory-file-data/large/file(length=%" PRIu64
 119                 ", sha1=%s)",
 120                 owner->mLength,
 121                 aAnonymize ? "<anonymized>" : digestString.get()),
 122             KIND_HEAP, UNITS_BYTES, size,
 123             nsPrintfCString(
 124                 "Memory used to back a memory file of length %" PRIu64
 125                 " bytes.  The file "
 126                 "has a sha1 of %s.\n\n"
 127                 "Note that the allocator may round up a memory file's length "
 128                 "-- "
 129                 "that is, an N-byte memory file may take up more than N bytes "
 130                 "of "
 131                 "memory.",
 132                 owner->mLength, digestString.get()),
 133             aData);
 134       }
 135     }
 136
 137     if (smallObjectsTotal > 0) {
 138       aHandleReport->Callback(
 139           /* process */ ""_ns, "explicit/dom/memory-file-data/small"_ns,
 140           KIND_HEAP, UNITS_BYTES, smallObjectsTotal,
 141           nsPrintfCString(
 142               "Memory used to back small memory files (i.e. those taking up "
 143               "less "
 144               "than %zu bytes of memory each).\n\n"
 145               "Note that the allocator may round up a memory file's length -- "
 146               "that is, an N-byte memory file may take up more than N bytes of "
 147               "memory.",
 148               LARGE_OBJECT_MIN_SIZE),
 149           aData);
 150     }
 151
 152     return NS_OK;
 153   }
 154 };
 155
 156 NS_IMPL_ISUPPORTS(MemoryBlobImplDataOwnerMemoryReporter, nsIMemoryReporter)
 157
 158 /* static */
 159 void MemoryBlobImpl::DataOwner::EnsureMemoryReporterRegistered() {
 160   sDataOwnerMutex.AssertCurrentThreadOwns();
 161   if (sMemoryReporterRegistered) {
 162     return;
 163   }
 164
 165   RegisterStrongMemoryReporter(new MemoryBlobImplDataOwnerMemoryReporter());
 166
 167   sMemoryReporterRegistered = true;
 168 }
 169
 170 }  // namespace mozilla::dom