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[coding] Added a version with exceptions to MemReader.

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This commit is contained in:
Maxim Pimenov 2016-12-09 14:15:28 +03:00
parent ef16507945
commit cbc1d46553
2 changed files with 33 additions and 26 deletions
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16
coding/reader.cpp
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@ -19,19 +19,3 @@ bool Reader::IsEqual(string const & name1, string const & name2)
return (name1 == name2);
#endif
}
namespace
{
bool AssertPosAndSizeImpl(uint64_t pos, uint64_t size, uint64_t readerSize)
{
bool const ret1 = (pos + size <= readerSize);
bool const ret2 = (size <= static_cast<size_t>(-1));
ASSERT ( ret1 && ret2, (pos, size, readerSize) );
return (ret1 && ret2);
}
}
bool MemReader::AssertPosAndSize(uint64_t pos, uint64_t size) const
{
return AssertPosAndSizeImpl(pos, size, Size());
}

43
coding/reader.hpp
View file

@ -32,13 +32,12 @@ public:
};
// Reader from memory.
class MemReader : public Reader
template <bool WithExceptions>
class MemReaderTemplate : public Reader
{
bool AssertPosAndSize(uint64_t pos, uint64_t size) const;
public:
// Construct from block of memory.
MemReader(void const * pData, size_t size)
MemReaderTemplate(void const * pData, size_t size)
: m_pData(static_cast<char const *>(pData)), m_size(size)
{
}
@ -50,27 +49,51 @@ public:
inline void Read(uint64_t pos, void * p, size_t size) const override
{
ASSERT ( AssertPosAndSize(pos, size), () );
AssertPosAndSize(pos, size);
memcpy(p, m_pData + pos, size);
}
inline MemReader SubReader(uint64_t pos, uint64_t size) const
inline MemReaderTemplate SubReader(uint64_t pos, uint64_t size) const
{
ASSERT ( AssertPosAndSize(pos, size), () );
return MemReader(m_pData + pos, static_cast<size_t>(size));
AssertPosAndSize(pos, size);
return MemReaderTemplate(m_pData + pos, static_cast<size_t>(size));
}
inline unique_ptr<Reader> CreateSubReader(uint64_t pos, uint64_t size) const override
{
ASSERT ( AssertPosAndSize(pos, size), () );
return make_unique<MemReader>(m_pData + pos, static_cast<size_t>(size));
AssertPosAndSize(pos, size);
return make_unique<MemReaderTemplate>(m_pData + pos, static_cast<size_t>(size));
}
private:
bool GoodPosAndSize(uint64_t pos, uint64_t size) const
{
uint64_t const readerSize = Size();
bool const ret1 = (pos + size <= readerSize);
bool const ret2 = (size <= static_cast<size_t>(-1));
return ret1 && ret2;
}
void AssertPosAndSize(uint64_t pos, uint64_t size) const
{
if (WithExceptions)
{
if (!GoodPosAndSize(pos, size))
MYTHROW(Reader::SizeException, (pos, size, Size()));
}
else
{
ASSERT(GoodPosAndSize(pos, size), (pos, size, Size()));
}
}
char const * m_pData;
size_t m_size;
};
using MemReader = MemReaderTemplate<false>;
using MemReaderWithExceptions = MemReaderTemplate<true>;
// Reader wrapper to hold the pointer to a polymorfic reader.
// Common use: ReaderSource<ReaderPtr<Reader> >.
// Note! It takes the ownership of Reader.