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/* 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
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