Copy ByteReader to BufferReader and add some error handling

media/libstagefright/binding/include/mp4_demuxer/BufferReader.h

@@ -0,0 +1,225 @@
+/* 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/. */
+
+#ifndef BUFFER_READER_H_
+#define BUFFER_READER_H_
+
+#include "mozilla/EndianUtils.h"
+#include "mozilla/Vector.h"
+#include "nsTArray.h"
+#include "MediaData.h"
+
+namespace mp4_demuxer {
+
+class MOZ_RAII BufferReader
+{
+public:
+  BufferReader() : mPtr(nullptr), mRemaining(0) {}
+  explicit BufferReader(const mozilla::Vector<uint8_t>& aData)
+    : mPtr(aData.begin()), mRemaining(aData.length()), mLength(aData.length())
+  {
+  }
+  BufferReader(const uint8_t* aData, size_t aSize)
+    : mPtr(aData), mRemaining(aSize), mLength(aSize)
+  {
+  }
+  template<size_t S>
+  explicit BufferReader(const AutoTArray<uint8_t, S>& aData)
+    : mPtr(aData.Elements()), mRemaining(aData.Length()), mLength(aData.Length())
+  {
+  }
+  explicit BufferReader(const nsTArray<uint8_t>& aData)
+    : mPtr(aData.Elements()), mRemaining(aData.Length()), mLength(aData.Length())
+  {
+  }
+  explicit BufferReader(const mozilla::MediaByteBuffer* aData)
+    : mPtr(aData->Elements()), mRemaining(aData->Length()), mLength(aData->Length())
+  {
+  }
+
+  void SetData(const nsTArray<uint8_t>& aData)
+  {
+    MOZ_ASSERT(!mPtr && !mRemaining);
+    mPtr = aData.Elements();
+    mRemaining = aData.Length();
+    mLength = mRemaining;
+  }
+
+  ~BufferReader()
+  {
+  }
+
+  size_t Offset() const
+  {
+    return mLength - mRemaining;
+  }
+
+  size_t Remaining() const { return mRemaining; }
+
+  bool CanRead8() const { return mRemaining >= 1; }
+
+  bool ReadU8(uint8_t& aU8)
+  {
+    const uint8_t* ptr;
+    if (!Read(1, &ptr)) {
+      NS_WARNING("Failed to read data");
+      return false;
+    }
+    aU8 = *ptr;
+    return true;
+  }
+
+  bool CanRead16() { return mRemaining >= 2; }
+
+  bool ReadU16(uint16_t& u16)
+  {
+    const uint8_t* ptr;
+    if (!Read(2, &ptr)) {
+      NS_WARNING("Failed to read data");
+      return false;
+    }
+    u16 = mozilla::BigEndian::readUint16(ptr);
+    return true;
+  }
+
+  bool CanRead32() { return mRemaining >= 4; }
+
+  bool ReadU32(uint32_t& u32)
+  {
+    const uint8_t* ptr;
+    if (!Read(4, &ptr)) {
+      NS_WARNING("Failed to read data");
+      return false;
+    }
+    u32 = mozilla::BigEndian::readUint32(ptr);
+    return true;
+  }
+
+  bool Read32(int32_t& i32)
+  {
+    const uint8_t* ptr;
+    if (!Read(4, &ptr)) {
+      NS_WARNING("Failed to read data");
+      return 0;
+    }
+    i32 = mozilla::BigEndian::readInt32(ptr);
+    return true;
+  }
+
+  bool ReadU64(uint64_t& u64)
+  {
+    const uint8_t* ptr;
+    if (!Read(8, &ptr)) {
+      NS_WARNING("Failed to read data");
+      return false;
+    }
+    u64 = mozilla::BigEndian::readUint64(ptr);
+    return true;
+  }
+
+  bool Read64(int64_t& i64)
+  {
+    const uint8_t* ptr;
+    if (!Read(8, &ptr)) {
+      NS_WARNING("Failed to read data");
+      return false;
+    }
+    i64 = mozilla::BigEndian::readInt64(ptr);
+    return true;
+  }
+
+  bool ReadU24(uint32_t& u32)
+  {
+    const uint8_t* ptr;
+    if (!Read(3, &ptr)) {
+      NS_WARNING("Failed to read data");
+      return false;
+    }
+    u32 = ptr[0] << 16 | ptr[1] << 8 | ptr[2];
+    return true;
+  }
+
+  bool Skip(size_t aCount)
+  {
+    const uint8_t* ptr;
+    if (!Read(aCount, &ptr)) {
+      NS_WARNING("Failed to skip data");
+      return false;
+    }
+    return true;
+  }
+
+  bool Read(size_t aCount, const uint8_t** aPtr)
+  {
+    if (aCount > mRemaining) {
+      mRemaining = 0;
+      return false;
+    }
+    mRemaining -= aCount;
+
+    *aPtr = mPtr;
+    mPtr += aCount;
+
+    return true;
+  }
+
+  uint32_t Align() const
+  {
+    return 4 - ((intptr_t)mPtr & 3);
+  }
+
+  template <typename T> bool CanReadType() const { return mRemaining >= sizeof(T); }
+
+  template <typename T> T ReadType()
+  {
+    const uint8_t* ptr;
+    if (!Read(sizeof(T), &ptr)) {
+      NS_WARNING("ReadType failed");
+      return 0;
+    }
+    return *reinterpret_cast<const T*>(ptr);
+  }
+
+  template <typename T>
+  MOZ_MUST_USE bool ReadArray(nsTArray<T>& aDest, size_t aLength)
+  {
+    const uint8_t* ptr;
+    if (!Read(aLength * sizeof(T), &ptr)) {
+      NS_WARNING("ReadArray failed");
+      return false;
+    }
+
+    aDest.Clear();
+    aDest.AppendElements(reinterpret_cast<const T*>(ptr), aLength);
+    return true;
+  }
+
+  template <typename T>
+  MOZ_MUST_USE bool ReadArray(FallibleTArray<T>& aDest, size_t aLength)
+  {
+    const uint8_t* ptr;
+    if (!Read(aLength * sizeof(T), &ptr)) {
+      NS_WARNING("ReadArray failed");
+      return false;
+    }
+
+    aDest.Clear();
+    if (!aDest.SetCapacity(aLength, mozilla::fallible)) {
+      return false;
+    }
+    MOZ_ALWAYS_TRUE(aDest.AppendElements(reinterpret_cast<const T*>(ptr),
+                                         aLength,
+                                         mozilla::fallible));
+    return true;
+  }
+
+private:
+  const uint8_t* mPtr;
+  size_t mRemaining;
+  size_t mLength;
+};
+
+} // namespace mp4_demuxer
+
+#endif

media/libstagefright/moz.build

@@ -53,6 +53,7 @@ EXPORTS.mp4_demuxer += [
     'binding/include/mp4_demuxer/Atom.h',
     'binding/include/mp4_demuxer/AtomType.h',
     'binding/include/mp4_demuxer/BitReader.h',
+    'binding/include/mp4_demuxer/BufferReader.h',
     'binding/include/mp4_demuxer/BufferStream.h',
     'binding/include/mp4_demuxer/ByteReader.h',
     'binding/include/mp4_demuxer/ByteWriter.h',