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 "nsPrintfCString.h"
  13 #include "nsRFPService.h"
  14 #include "nsStringStream.h"
  15 #include "prtime.h"
  16
  17 namespace mozilla::dom {
  18
  19 // static
  20 already_AddRefed<MemoryBlobImpl> MemoryBlobImpl::CreateWithCustomLastModified(
  21     void* aMemoryBuffer, uint64_t aLength, const nsAString& aName,
  22     const nsAString& aContentType, int64_t aLastModifiedDate) {
  23   RefPtr<MemoryBlobImpl> blobImpl = new MemoryBlobImpl(
  24       aMemoryBuffer, aLength, aName, aContentType, aLastModifiedDate);
  25   return blobImpl.forget();
  26 }
  27
  28 // static
  29 already_AddRefed<MemoryBlobImpl> MemoryBlobImpl::CreateWithLastModifiedNow(
  30     void* aMemoryBuffer, uint64_t aLength, const nsAString& aName,
  31     const nsAString& aContentType, RTPCallerType aRTPCallerType) {
  32   int64_t lastModificationDate =
  33       nsRFPService::ReduceTimePrecisionAsUSecs(PR_Now(), 0, aRTPCallerType);
  34   return CreateWithCustomLastModified(aMemoryBuffer, aLength, aName,
  35                                       aContentType, lastModificationDate);
  36 }
  37
  38 nsresult MemoryBlobImpl::DataOwnerAdapter::Create(DataOwner* aDataOwner,
  39                                                   size_t aStart, size_t aLength,
  40                                                   nsIInputStream** _retval) {
  41   MOZ_ASSERT(aDataOwner, "Uh ...");
  42   Span data{static_cast<const char*>(aDataOwner->mData) + aStart, aLength};
  43   RefPtr adapter = new MemoryBlobImpl::DataOwnerAdapter(aDataOwner, data);
  44   return NS_NewByteInputStream(_retval, adapter);
  45 }
  46
  47 already_AddRefed<BlobImpl> MemoryBlobImpl::CreateSlice(
  48     uint64_t aStart, uint64_t aLength, const nsAString& aContentType,
  49     ErrorResult& aRv) const {
  50   RefPtr<BlobImpl> impl =
  51       new MemoryBlobImpl(this, aStart, aLength, aContentType);
  52   return impl.forget();
  53 }
  54
  55 void MemoryBlobImpl::CreateInputStream(nsIInputStream** aStream,
  56                                        ErrorResult& aRv) const {
  57   if (mLength >= INT32_MAX) {
  58     aRv.Throw(NS_ERROR_FAILURE);
  59     return;
  60   }
  61
  62   aRv = MemoryBlobImpl::DataOwnerAdapter::Create(mDataOwner, mStart, mLength,
  63                                                  aStream);
  64 }
  65
  66 /* static */
  67 StaticMutex MemoryBlobImpl::DataOwner::sDataOwnerMutex;
  68
  69 /* static */ StaticAutoPtr<LinkedList<MemoryBlobImpl::DataOwner>>
  70     MemoryBlobImpl::DataOwner::sDataOwners;
  71
  72 /* static */
  73 bool MemoryBlobImpl::DataOwner::sMemoryReporterRegistered = false;
  74
  75 MOZ_DEFINE_MALLOC_SIZE_OF(MemoryFileDataOwnerMallocSizeOf)
  76
  77 class MemoryBlobImplDataOwnerMemoryReporter final : public nsIMemoryReporter {
  78   ~MemoryBlobImplDataOwnerMemoryReporter() = default;
  79
  80  public:
  81   NS_DECL_THREADSAFE_ISUPPORTS
  82
  83   NS_IMETHOD CollectReports(nsIHandleReportCallback* aHandleReport,
  84                             nsISupports* aData, bool aAnonymize) override {
  85     using DataOwner = MemoryBlobImpl::DataOwner;
  86
  87     StaticMutexAutoLock lock(DataOwner::sDataOwnerMutex);
  88
  89     if (!DataOwner::sDataOwners) {
  90       return NS_OK;
  91     }
  92
  93     const size_t LARGE_OBJECT_MIN_SIZE = 8 * 1024;
  94     size_t smallObjectsTotal = 0;
  95
  96     for (DataOwner* owner = DataOwner::sDataOwners->getFirst(); owner;
  97          owner = owner->getNext()) {
  98       size_t size = MemoryFileDataOwnerMallocSizeOf(owner->mData);
  99
 100       if (size < LARGE_OBJECT_MIN_SIZE) {
 101         smallObjectsTotal += size;
 102       } else {
 103         SHA1Sum sha1;
 104         sha1.update(owner->mData, owner->mLength);
 105         uint8_t digest[SHA1Sum::kHashSize];  // SHA1 digests are 20 bytes long.
 106         sha1.finish(digest);
 107
 108         nsAutoCString digestString;
 109         for (size_t i = 0; i < sizeof(digest); i++) {
 110           digestString.AppendPrintf("%02x", digest[i]);
 111         }
 112
 113         aHandleReport->Callback(
 114             /* process */ ""_ns,
 115             nsPrintfCString(
 116                 "explicit/dom/memory-file-data/large/file(length=%" PRIu64
 117                 ", sha1=%s)",
 118                 owner->mLength,
 119                 aAnonymize ? "<anonymized>" : digestString.get()),
 120             KIND_HEAP, UNITS_BYTES, size,
 121             nsPrintfCString(
 122                 "Memory used to back a memory file of length %" PRIu64
 123                 " bytes.  The file "
 124                 "has a sha1 of %s.\n\n"
 125                 "Note that the allocator may round up a memory file's length "
 126                 "-- "
 127                 "that is, an N-byte memory file may take up more than N bytes "
 128                 "of "
 129                 "memory.",
 130                 owner->mLength, digestString.get()),
 131             aData);
 132       }
 133     }
 134
 135     if (smallObjectsTotal > 0) {
 136       aHandleReport->Callback(
 137           /* process */ ""_ns, "explicit/dom/memory-file-data/small"_ns,
 138           KIND_HEAP, UNITS_BYTES, smallObjectsTotal,
 139           nsPrintfCString(
 140               "Memory used to back small memory files (i.e. those taking up "
 141               "less "
 142               "than %zu bytes of memory each).\n\n"
 143               "Note that the allocator may round up a memory file's length -- "
 144               "that is, an N-byte memory file may take up more than N bytes of "
 145               "memory.",
 146               LARGE_OBJECT_MIN_SIZE),
 147           aData);
 148     }
 149
 150     return NS_OK;
 151   }
 152 };
 153
 154 NS_IMPL_ISUPPORTS(MemoryBlobImplDataOwnerMemoryReporter, nsIMemoryReporter)
 155
 156 /* static */
 157 void MemoryBlobImpl::DataOwner::EnsureMemoryReporterRegistered() {
 158   sDataOwnerMutex.AssertCurrentThreadOwns();
 159   if (sMemoryReporterRegistered) {
 160     return;
 161   }
 162
 163   RegisterStrongMemoryReporter(new MemoryBlobImplDataOwnerMemoryReporter());
 164
 165   sMemoryReporterRegistered = true;
 166 }
 167
 168 }  // namespace mozilla::dom