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gunzip.hh
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gunzip.hh
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/* My tiny gzip decompressor without using zlib. - Joel Yliluoma
* http://iki.fi/bisqwit/ , http://youtube.com/user/Bisqwit
* Inspired and influenced by a 13th IOCCC winner program by Ron McFarland */
/* Further optimized based on ideas from tinf library by Joergen Ibsen */
/** @file gunzip.hh @brief TinyDeflate */
/* Fun fact: Contains zero new/delete, and no STL data structures */
/* Distributed under the terms of the Zlib license:
Copyright (C) 2018 Joel Yliluoma
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
#include <assert.h>
#include <utility> // std::forward
#include <cstdint> // integer sizes
#include <type_traits>
#include <iterator>
#if !1 //Documentation purposes only; the actual prototypes are littered with std::enable_ifs.
/// Deflate(): This is the public method declared (later) in this file.
/// Decompresses (inflates) deflate-compressed data, with a gzip or deflate header.
/// User-supplied functors:
/// @param input() returns the next byte from the (compressed) input.
/// @param output(byte) outputs one uncompressed byte.
/// @param outputcopy(length, offset) copies length uncompressed bytes from offset,
/// Offset is always >= 1.
/// offset 1 means previous byte,
/// offset 2 means previous before that and so on.
/// Note that (offset < length) is not an error and in fact happens frequently.
/// If length=0, offset indicates the largest look-behind window length that
/// you need to be prepared for. The length is a power-of-two in range 256..32768.
//
/// If you want to implement range checking in input, return a negative value
/// from input() when there is no more input.
//
/// If you want to implement range checking in output, add a return value
/// in output(): false=ok, true=abort; and a return value in outputcopy():
/// 0=ok, nonzero=one or more bytes were not writable.
//
/// @returns:
/// 0 = decompression complete
/// -1 = data error
/// -2 = input functor returned a value outside 0x00..0xFF range
/// -3 = output functor returned nonzero / bool true value
/// -4 = outputcopy functor returned nonzero remaining length value
//
template<typename InputFunctor, typename OutputFunctor, typename WindowFunctor>
int Deflate(InputFunctor&& input, OutputFunctor&& output, WindowFunctor&& outputcopy);
/// Check README.md for the full list of versions of Deflate() available.
#endif
struct DeflateTrackTagBase{};
struct DeflateTrackNoSize: public DeflateTrackTagBase{};
struct DeflateTrackInSize: public DeflateTrackTagBase{};
struct DeflateTrackOutSize: public DeflateTrackTagBase{};
struct DeflateTrackBothSize: public DeflateTrackTagBase{};
/// The rest of the file is just for the curious about implementation.
#ifndef DOXYGEN_SHOULD_SKIP_THIS
namespace gunzip_ns
{
//#define DO_DEFDB_DUMPING
// If you want more performance at the expense of RAM use,
// Turn one or more of these settings to false:
static constexpr bool USE_BITARRAY_TEMPORARY_IN_HUFFMAN_CREATION = false; /* 8 bytes save */
static constexpr bool USE_BITARRAY_FOR_LENGTHS = false; /* 160 bytes save */
static constexpr bool USE_BITARRAY_FOR_HUFFNODES = false; /* 392 bytes save */
static constexpr unsigned MAX_WINDOW_SIZE = 32768u;
static_assert(MAX_WINDOW_SIZE >= 1, "Max window size should be >= 1");
static_assert(MAX_WINDOW_SIZE <= 32768u, "Window sizes larger than 32768 are not supported by deflate standard. Edit the source code to remove this assert if you need it.");
//
#define DEFLATE_USE_DATA_TABLES
#if !defined(DEFLATE_ALLOCATION_AUTOMATIC) && !defined(DEFLATE_ALLOCATION_STATIC) && !defined(DEFLATE_ALLOCATION_DYNAMIC)
// Choose one:
#define DEFLATE_ALLOCATION_AUTOMATIC
//#define DEFLATE_ALLOCATION_STATIC
//#define DEFLATE_ALLOCATION_DYNAMIC
#endif
constexpr unsigned Flag_InputAbortable = 0x01;
constexpr unsigned Flag_OutputAbortable = 0x02;
constexpr unsigned Flag_TrackIn = 0x40;
constexpr unsigned Flag_TrackOut = 0x80;
constexpr unsigned Flag_NoTrackFlagMask = 0x03;
}
#ifdef DEFLATE_ALLOCATION_DYNAMIC
# include <memory>
#endif
// RandomAccessBitArray: An engine for arrays of data items that are not byte-aligned
template<typename U = std::uint_least64_t>
struct RandomAccessBitArrayBase
{
private:
static constexpr unsigned Ubytes = sizeof(U), Ubits = Ubytes*8;
static std::uint_fast64_t Get_Unclean(unsigned Size, const U* data, unsigned index) throw()
{
unsigned bitpos = index*Size, unitpos = bitpos / Ubits, shift = bitpos % Ubits;
std::uint_fast64_t result = data[unitpos] >> shift;
//assert(Size <= sizeof(result)*8);
unsigned acquired = Ubits - shift;
for(; acquired < Size; acquired += Ubits)
{
result += (std::uint_fast64_t)data[++unitpos] << acquired;
}
return result;
}
public:
template<unsigned Size>
static std::uint_fast64_t Get(const U* data, unsigned index) throw()
{
std::uint_fast64_t result = Get_Unclean(Size,data,index);
return (Size >= sizeof(result)*8) ? result : (result & ((std::uint64_t(1) << Size)-1));
}
template<unsigned Size, bool update = false>
static void Set(U* data, unsigned index, std::uint_fast64_t value) throw()
{
unsigned bitpos = index*Size, unitpos = bitpos / Ubits, eat = 0;
// Make sure our storage unit is at least as bit as value
//assert(Ubits >= sizeof(value)*8);
//assert(Size >= sizeof(value)*8 || value < (std::uint64_t(1) << Size));
if(Size % Ubits != 0)
{
unsigned shift = bitpos % Ubits;
eat = Ubits - shift; if(eat > Size) eat = Size;
//assert(eat < sizeof(std::uint_fast64_t)*8);
//assert(shift + eat <= Ubits);
std::uint_fast64_t vmask = (std::uint64_t(1) << eat)-1;
if(update)
data[unitpos] = (data[unitpos] & ~(vmask << shift)) | (value << shift);
else
data[unitpos] |= value << shift;
//assert(eat < sizeof(value)*8);
value >>= eat;
++unitpos;
}
if(eat < Size)
for(unsigned remain = Size-eat; ; ++unitpos)
{
eat = Ubits;
if(eat > remain)
{
eat = remain;
if(update)
{
std::uint_fast64_t vmask = ((std::uint64_t(1) << eat)-1);
data[unitpos] = (data[unitpos] & ~vmask) | value;
}
else
{
data[unitpos] |= value;
}
break;
}
else
{
data[unitpos] = value;
value >>= Ubits/2; value >>= Ubits/2;
remain -= Ubits;
if(!remain) break;
}
}
}
};
template<unsigned Nbits, typename U = std::uint_least64_t>
struct RandomAccessBitArray
{
static constexpr unsigned Ubytes = sizeof(U), Ubits = Ubytes*8, Nunits = (Nbits+Ubits-1)/Ubits;
U data[Nunits];
template<unsigned Size>
inline std::uint_fast64_t Get(unsigned index) const throw()
{
return RandomAccessBitArrayBase<U>::template Get<Size>(data, index);
}
template<unsigned Size, bool update = false>
inline void Set(unsigned index, std::uint_fast64_t value) throw()
{
RandomAccessBitArrayBase<U>::template Set<Size,update>(data, index, value);
}
};
namespace gunzip_ns
{
struct dummy{};
/// Utility: ceil(log2(n))
template<unsigned long N> struct CeilLog2_s{ static constexpr unsigned result = 1+CeilLog2_s<(N+1)/2>::result; };
template<> struct CeilLog2_s<0> { static constexpr unsigned result = 0; };
template<> struct CeilLog2_s<1> { static constexpr unsigned result = 0; };
template<unsigned long N> static constexpr unsigned CeilLog2 = CeilLog2_s<N>::result;
/// Utility: floor(log2(n))
template<unsigned long N> struct FloorLog2_s{ static constexpr unsigned result = 1+FloorLog2_s<N/2>::result; };
template<> struct FloorLog2_s<0> { static constexpr unsigned result = 0; };
template<> struct FloorLog2_s<1> { static constexpr unsigned result = 0; };
template<unsigned long N> static constexpr unsigned FloorLog2 = FloorLog2_s<N>::result;
/// Utility: smallest unsigned integer type that can store n-bit value
template<unsigned bits>
using SmallestType = std::conditional_t< (bits<=16),
std::conditional_t< (bits<= 8), std::uint_least8_t, std::uint_least16_t>,
std::conditional_t< (bits<=32), std::uint_least32_t, std::uint_least64_t>>;
/// testcases
static_assert(FloorLog2<1> == 0, "FloorLog2 fail"); static_assert(CeilLog2<1> == 0, "CeilLog2 fail");
static_assert(FloorLog2<2> == 1, "FloorLog2 fail"); static_assert(CeilLog2<2> == 1, "CeilLog2 fail");
static_assert(FloorLog2<3> == 1, "FloorLog2 fail"); static_assert(CeilLog2<3> == 2, "CeilLog2 fail");
static_assert(FloorLog2<4> == 2, "FloorLog2 fail"); static_assert(CeilLog2<4> == 2, "CeilLog2 fail");
static_assert(FloorLog2<5> == 2, "FloorLog2 fail"); static_assert(CeilLog2<5> == 3, "CeilLog2 fail");
static_assert(FloorLog2<6> == 2, "FloorLog2 fail"); static_assert(CeilLog2<6> == 3, "CeilLog2 fail");
static_assert(FloorLog2<7> == 2, "FloorLog2 fail"); static_assert(CeilLog2<7> == 3, "CeilLog2 fail");
static_assert(FloorLog2<8> == 3, "FloorLog2 fail"); static_assert(CeilLog2<8> == 3, "CeilLog2 fail");
static_assert(FloorLog2<9> == 3, "FloorLog2 fail"); static_assert(CeilLog2<9> == 4, "CeilLog2 fail");
template<bool packed, unsigned Dimension, unsigned ElementSize>
struct RandomAccessArray {};
template<unsigned Dim, unsigned Elem>
struct RandomAccessArray<true, Dim, Elem>
{
RandomAccessBitArray<Dim*Elem> impl;
inline std::uint_fast64_t Get(unsigned index) const { return impl.template Get<Elem>(index); }
inline void Set(unsigned index, std::uint_fast32_t value) { impl.template Set<Elem,true>(index, value); }
inline void QSet(unsigned index, std::uint_fast32_t value) { impl.template Set<Elem,false>(index, value); }
template<unsigned Bits>
inline void WSet(unsigned index, std::uint_fast64_t value) { impl.template Set<Bits,true>(index, value); }
};
template<unsigned Dim, unsigned Elem>
struct RandomAccessArray<false, Dim, Elem>
{
typedef SmallestType<Elem> E;
E data[Dim];
inline E Get(unsigned index) const { return data[index]; }
inline void Set(unsigned index, E value) { data[index] = value; }
inline void QSet(unsigned index, E value) { data[index] = value; }
template<unsigned Bits>
inline void WSet(unsigned index, std::uint_fast64_t value)
{
index *= Bits/Elem;
for(unsigned b=0; b<Bits; b+=Elem, value>>=Elem)
QSet(index++, (value % (1u << Elem)));
}
};
}
namespace gunzip_ns
{
//#define DEFL_DO_HUFF_STATS
template<bool Abortable, unsigned A,unsigned B, typename LengthFunctor>
bool CreateHuffmanTree(const char*
#ifdef DEFL_DO_HUFF_STATS
why
#endif
, RandomAccessArray<USE_BITARRAY_FOR_HUFFNODES,A,B>& tree,
unsigned num_values,
LengthFunctor&& ReadLength) throw()
{
/* Lengths[] needs to be scanned exactly twice, in forward order.
* Technically we could use a functor instead of a table,
* but this would require that the dynamic tree generator
* can read sections of the compressed data twice,
* which we currently do not support.
*/
constexpr unsigned ElemBits = CeilLog2<A-15>; // ceil(log2(A-15)) where A-15 is max value of num_values
static_assert((1u << B) >= (A-15), "B is too small");
assert(num_values <= (A-15));
RandomAccessArray<USE_BITARRAY_TEMPORARY_IN_HUFFMAN_CREATION, 15, ElemBits> offs{}; // 24 or 16 bytes.
// Theoretically 15.32 bytes for 288 num_values, 9.375 for 32 num_values, 7.97 for 19 num_values.
// Clear code length count table
tree.template WSet<(15*B + 63) & ~63>(0, 0); // First 15 needed, but round to nice unit
// Scan symbol length, and sum code length counts
#ifdef DEFL_DO_HUFF_STATS
unsigned largest_treetable_value = 0, largest_offs = 0, smallest_treetable_value = ~0u;
unsigned largest_treetrans_index=0, largest_treetrans_value=0;
unsigned longest_length = 0;
#endif
for(unsigned a = 0; a < num_values; ++a)
{
int length = ReadLength(a); // Note: Can be zero.
if(Abortable && length < 0) return true;
if(length)
{
unsigned v = tree.Get(0 + length-1)+1;
#ifdef DEFL_DO_HUFF_STATS
largest_treetable_value = std::max(largest_treetable_value, v);
longest_length = std::max(longest_length, unsigned(length));
#endif
//fprintf(stderr, " [%d]%3d CLL (val: %d)\n", length, v, v);
tree.Set(0 + length-1, v);
}
else
{
//fprintf(stderr, " [_]%3d CLL (val: 0)\n", 0);
}
}
// Compute offset table for distribution sort
for(unsigned sum=0, a = 1; a < 16; ++a)
{
offs.QSet(a-1, sum); // starting offset for values that have length "a"
sum += tree.Get(0 + a-1); // number of values that have length "a"
}
#ifdef DEFL_DO_HUFF_STATS
for(unsigned a=1; a<=longest_length; ++a)
smallest_treetable_value = std::min(smallest_treetable_value, (unsigned)tree.Get(0 + a-1));
#endif
// Create code->symbol translation table (symbols sorted by code)
for(unsigned value = 0; value < num_values; ++value)
{
int length = ReadLength(value); // Note: Can be zero.
if(Abortable && length < 0) return true;
if(length)
{
unsigned q = offs.Get(length-1); offs.Set(length-1, q+1); // q = offset[length]++;
#ifdef DEFL_DO_HUFF_STATS
largest_offs = std::max(q, largest_offs);
largest_treetrans_index = std::max(largest_treetrans_index, q);
largest_treetrans_value = std::max(largest_treetrans_value, value);
#endif
assert(q < num_values /*&& value < num_values*/);
//fprintf(stderr, " [x]%3d CLL %d\n", 15+q, value);
tree.Set(15 + q, value);
}
}
#ifdef DEFL_DO_HUFF_STATS
std::fprintf(stderr, "Largest \"%12s\"(treetable_value=%4u..%4u, offs=%4u, treetrans_index=%4u, treetrans_value=%4u)\n",
why, smallest_treetable_value,largest_treetable_value,
largest_offs, largest_treetrans_index, largest_treetrans_value);
#endif
// Largest values observed in the wild:
// Dyn Lengths: Max treetable_value =255, max offs =285, max treetrans_index =285, max treetrans_value =285
// Stat Lengths:Max treetable_value =152, max offs =287, max treetrans_index =287, max treetrans_value =287
// Len Lengths: Max treetable_value = 13, max offs = 18, max treetrans_index = 18, max treetrans_value = 18
// Dyn Dists: Max treetable_value = 19, max offs = 29, max treetrans_index = 29, max treetrans_value = 29
// Stat Dists: Max treetable_value = 32, max offs = 31, max treetrans_index = 31, max treetrans_value = 31
return false;
}
#ifdef DEFLATE_USE_DATA_TABLES
template<bool=0> // Using a dummy template parameter makes this function and its data weak,
inline const std::uint_least8_t* GetBTable() throw() // removing linker problems in multi-module use
{
static const std::uint_least8_t data[] {
// Length bases (0-31)
0,1,2,3,4,5,6,7,8,10,12,14,16,20,24,28,32,40,48,56,64,80,96,112,128,160,192,224,255, 0,0,0,
// Length bits and distance bits (29-60) (overlap 3 bytes)
// 0x00,0x01,0x01,0x02,0x02,0x13,0x13,0x14,0x14,0x25,0x25,0x26,0x26,
//0x37,0x37,0x38,0x38,0x49,0x49,0x4A,0x4A,0x5B,0x5B,0x5C,0x5C,0x0D,0x0D,0x00,0x00
// Reverse-order table
3*3,17*3,15*3,13*3,11*3,9*3,7*3,5*3,4*3,6*3,8*3,10*3,12*3,14*3,16*3,18*3,0*3,1*3,2*3
};
return data;
}
//template<bool=0>
//inline const std::uint_least16_t* GetWTable() throw()
//{
// static const std::uint_least16_t data[32] {
// 1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577, 0,0 };
// return data;
//}
//inline unsigned dbase(unsigned distcode) { return GetWTable<>()[distcode]; }
inline unsigned lbase(unsigned lencode) { return GetBTable<>()[lencode-257+0] + 3; }
//inline unsigned dbits(unsigned distcode) { return GetBTable<>()[distcode+29] & 0xF; }
//inline unsigned lbits(unsigned lencode) { return GetBTable<>()[lencode-257+29] >> 4; }
inline unsigned rshift(unsigned a) { return GetBTable<>()[a + 32]; }
#else
inline unsigned lbase(unsigned lencode) { return (lencode > 285 ? 3 : ((lencode >= 265) ? (((lencode-257)%4+4) << ((lencode-257)/4-1)) + (lencode==285 ? 2 : 3) : (lencode-254))); }
inline unsigned rshift(unsigned a) { if(!a) return 3*3; else if(a>=16) return (a-16)*3; int r = 12 + 7*(a<8) - a*2; return (r<0 ? -r : r)*3; }
#endif
inline unsigned dbase(unsigned distcode) { return (1 + (distcode>=4 ? ((2+distcode%2) << (distcode/2-1)) : distcode)); }
inline unsigned dbits(unsigned distcode) { return distcode>=4 ? distcode/2-1 : 0; }
inline unsigned lbits(unsigned lencode) { return ((lencode>=265 && lencode<285) ? ((lencode-265)/4+1) : 0); }
//inline unsigned order(unsigned index) { return index<3 ? (index+16) : ((index%2) ? (1-index/2)&7 : (6+index/2)); }
// Cortex-M0+ Cortex-M4 x86_64
// dbase with table 12+64 = 76 12+64 = 76 14+64 = 78
// dbase with func 24 22 26
// lbase with table 12+32 = 48 12+32 = 48 21+64 = 76
// lbase with func 54 56 64
// dbits+lbits with table 12+16+29 = 57 12+16+29 = 57 17+21+29 = 67
// dbits+lbits with func 14+18 = 32 14+18 = 32 13+20 = 33
// Support for pre-c++20
template<typename T>
using remove_cvref_t = std::remove_reference_t<std::remove_cv_t<T>>;
// Support for pre-c++20 (result_of is removed in c++20, invoke_result is added in c++17, so neither can be used exclusively)
template <class T>
struct result_of { // explain usage
static_assert((T)false, "result_of<CallableType> is invalid; use "
"result_of<CallableType(zero or more argument types)> instead.");
};
#if __cplusplus > 202000UL
template <typename F, typename... Args>
struct result_of<F(Args...)> : std::invoke_result<F, Args...> {};
#else
template <typename F, typename... Args>
struct result_of<F(Args...)> : std::result_of<F(Args...)> {};
#endif
template <class T>
using result_of_t = typename result_of<T>::type;
#define BEGIN_COND(name) \
template<typename T, typename=void> struct name : public std::false_type {}; \
template<typename T> struct name<T, std::enable_if_t<
#define END_COND(name) \
, void>> : public std::true_type {}; \
template<typename T> \
inline constexpr bool name ## _v = name<T>::value; \
// Input parameter condition testers:
BEGIN_COND(is_input_functor)
std::is_convertible_v<result_of_t<remove_cvref_t<T>()>,int>
END_COND(is_input_functor)
BEGIN_COND(is_input_iterator)
std::is_convertible_v<typename std::iterator_traits<remove_cvref_t<T>>::value_type, unsigned char>
&& std::is_same_v<typename std::iterator_traits<remove_cvref_t<T>>::iterator_category, std::input_iterator_tag>
END_COND(is_input_iterator)
BEGIN_COND(is_bidir_input)
std::is_convertible_v<typename std::iterator_traits<remove_cvref_t<T>>::value_type, unsigned char>
&& (std::is_same_v<typename std::iterator_traits<remove_cvref_t<T>>::iterator_category, std::forward_iterator_tag>
|| std::is_same_v<typename std::iterator_traits<remove_cvref_t<T>>::iterator_category, std::bidirectional_iterator_tag>
|| std::is_same_v<typename std::iterator_traits<remove_cvref_t<T>>::iterator_category, std::random_access_iterator_tag>)
END_COND(is_bidir_input)
BEGIN_COND(is_size_type)
std::is_convertible_v<remove_cvref_t<T>, std::size_t> && !std::is_pointer_v<remove_cvref_t<T>>
END_COND(is_size_type)
// Output parameter condition testers:
BEGIN_COND(is_random_iterator)
std::is_convertible_v<typename std::iterator_traits<remove_cvref_t<T>>::value_type, unsigned char>
&& !std::is_const_v<typename std::iterator_traits<remove_cvref_t<T>>::reference>
&& std::is_same_v<typename std::iterator_traits<remove_cvref_t<T>>::iterator_category, std::random_access_iterator_tag>
END_COND(is_random_iterator)
BEGIN_COND(is_output_iterator)
std::is_convertible_v<typename std::iterator_traits<remove_cvref_t<T>>::value_type, unsigned char>
&& !std::is_const_v<typename std::iterator_traits<remove_cvref_t<T>>::reference>
&& !std::is_pointer_v<remove_cvref_t<T>>
&& (std::is_same_v<typename std::iterator_traits<remove_cvref_t<T>>::iterator_category, std::output_iterator_tag>
|| std::is_same_v<typename std::iterator_traits<remove_cvref_t<T>>::iterator_category, std::forward_iterator_tag>
|| std::is_same_v<typename std::iterator_traits<remove_cvref_t<T>>::iterator_category, std::bidirectional_iterator_tag>)
END_COND(is_output_iterator)
// Output functor & window functor: Returns void or something that can be converted to bool
BEGIN_COND(is_output_functor)
std::is_same_v<result_of_t<remove_cvref_t<T>(int)>,void> || std::is_convertible_v<result_of_t<remove_cvref_t<T>(int)>,bool>
END_COND(is_output_functor)
BEGIN_COND(is_window_functor)
std::is_same_v<result_of_t<remove_cvref_t<T>(int,int)>,void> || std::is_convertible_v<result_of_t<remove_cvref_t<T>(int,int)>,int>
END_COND(is_window_functor)
BEGIN_COND(is_abortable_input_type)
!(std::is_same_v<T, unsigned char> || std::is_same_v<T, signed char> || std::is_same_v<T, char>)
END_COND(is_abortable_input_type)
#undef END_COND
#undef BEGIN_COND
template<typename T>
constexpr bool DeflAbortable_InFun = is_abortable_input_type_v<remove_cvref_t<result_of_t<T()>>>;
template<typename T>
constexpr bool DeflAbortable_OutFun = std::is_same_v<result_of_t<T(int)>, bool>;
template<typename T>
constexpr bool DeflAbortable_WinFun = std::is_convertible_v<remove_cvref_t<result_of_t<T(int,int)>>, int>;
template<bool Abortable>
struct OutputHelper
{
template<typename OutputFunctor>
static inline bool output(OutputFunctor&& output, unsigned char byte)
{
output(byte);
return false;
}
template<typename WindowFunctor>
static inline bool outputcopy(WindowFunctor&& outputcopy, std::uint_least16_t length, std::uint_fast32_t offset)
{
outputcopy(length, offset);
return false;
}
};
template<>
struct OutputHelper<true>
{
template<typename OutputFunctor>
static inline bool output(OutputFunctor&& output, unsigned char byte)
{
return output(byte);
}
template<typename WindowFunctor>
static inline bool outputcopy(WindowFunctor&& outputcopy, std::uint_least16_t& length, std::uint_fast32_t offset)
{
length = outputcopy(length, offset);
return length != 0;
}
};
struct SizeTracker_NoOutput
{
inline void OutByte() { }
inline void OutBytes(std::uint_fast64_t) { }
// Dummy forwarders. Do the same as std::forward.
template<typename T>
static inline constexpr T&& ForwardOutput(std::remove_reference_t<T>& fun) { return static_cast<T&&>(fun); }
template<typename T>
static inline constexpr T&& ForwardOutput(std::remove_reference_t<T>&& fun) { return static_cast<T&&>(fun); }
template<typename T>
static inline constexpr T&& ForwardWindow(std::remove_reference_t<T>& fun) { return static_cast<T&&>(fun); }
template<typename T>
static inline constexpr T&& ForwardWindow(std::remove_reference_t<T>&& fun) { return static_cast<T&&>(fun); }
};
struct SizeTracker_NoInput
{
inline void InByte() { }
inline void InBytes(std::uint_fast64_t) { }
template<typename T>
static inline constexpr T&& ForwardInput(std::remove_reference_t<T>& fun) { return static_cast<T&&>(fun); }
template<typename T>
static inline constexpr T&& ForwardInput(std::remove_reference_t<T>&& fun) { return static_cast<T&&>(fun); }
};
struct SizeTracker_DoInput
{
std::uint_fast64_t insize=0;
inline void InByte() { ++insize; }
inline void InBytes(std::uint_fast64_t n) { insize += n; }
template<typename InputFunctor, std::enable_if_t<!DeflAbortable_InFun<InputFunctor>,gunzip_ns::dummy>...>
auto ForwardInput(const InputFunctor& input)
{
return [&]() { InByte(); return input(); };
}
template<typename InputFunctor, std::enable_if_t<DeflAbortable_InFun<InputFunctor>,gunzip_ns::dummy>...>
auto ForwardInput(const InputFunctor& input)
{
return [&]() { auto r = input(); if(!(r & ~0xFF)) { InByte(); } return r; };
}
};
struct SizeTracker_DoOutput
{
std::uint_fast64_t outsize=0;
inline void OutByte() { ++outsize; }
inline void OutBytes(std::uint_fast64_t n) { outsize += n; }
template<typename OutputFunctor, std::enable_if_t<!DeflAbortable_OutFun<OutputFunctor>,gunzip_ns::dummy>...>
auto ForwardOutput(const OutputFunctor& output)
{
return [&](unsigned char byte) { OutByte(); return output(byte); };
}
template<typename OutputFunctor, std::enable_if_t<DeflAbortable_OutFun<OutputFunctor>,gunzip_ns::dummy>...>
auto ForwardOutput(const OutputFunctor& output)
{
return [&](unsigned char byte) { auto r = output(byte); if(!r) { OutByte(); } return r; };
}
template<typename WindowFunctor, std::enable_if_t<!DeflAbortable_WinFun<WindowFunctor>,gunzip_ns::dummy>...>
auto ForwardWindow(const WindowFunctor& outputcopy)
{
return [&](std::uint_least16_t length, std::uint_fast32_t offset)
{
OutBytes(length);
return outputcopy(length, offset);
};
}
template<typename WindowFunctor, std::enable_if_t<DeflAbortable_WinFun<WindowFunctor>,gunzip_ns::dummy>...>
auto ForwardWindow(const WindowFunctor& outputcopy)
{
return [&](std::uint_least16_t length, std::uint_fast32_t offset)
{
auto remain = outputcopy(length, offset);
OutBytes(length - remain);
return remain;
};
}
};
template<typename TrackType>
struct SizeTracker: public SizeTracker_NoOutput, public SizeTracker_NoInput
{
inline int operator() (int returncode) const { return returncode; }
};
template<>
struct SizeTracker<DeflateTrackOutSize>: public SizeTracker_NoInput, public SizeTracker_DoOutput
{
typedef std::pair<int,std::uint_fast64_t> result;
inline result operator() (int returncode) const { return result{returncode,outsize}; }
};
template<>
struct SizeTracker<DeflateTrackInSize>: public SizeTracker_NoOutput, public SizeTracker_DoInput
{
typedef std::pair<int,std::uint_fast64_t> result;
inline result operator() (int returncode) const { return result{returncode,insize}; }
};
template<>
struct SizeTracker<DeflateTrackBothSize>: public SizeTracker_DoInput, public SizeTracker_DoOutput
{
typedef std::pair<int, std::pair<std::uint_fast64_t,std::uint_fast64_t>> result;
inline result operator() (int returncode) const { return result{returncode,std::make_pair(insize,outsize)}; }
};
#ifdef DO_DEFDB_DUMPING
unsigned bitcounter=0;
#endif
struct DeflateBitCache
{
std::uint_least8_t BitCache = 0, BitCount = 0;
template<bool Abortable, typename InputFunctor>
std::uint_least64_t GetBits(InputFunctor&& input, unsigned numbits)
{
#ifdef DO_DEFDB_DUMPING
bitcounter += numbits;
#endif
std::uint_fast64_t result = BitCache;
if(numbits <= BitCount)
{
BitCount -= numbits;
BitCache >>= numbits;
result &= ((1u << numbits)-1); // 0-8
return result;
}
for(unsigned acquired = BitCount; ; acquired += 8)
{
unsigned byte = input();
if(Abortable && (byte & ~0xFFu))
{
// Note: Throws away bits already eaten from BitCache
return ~std::uint_least64_t(0); // error
}
unsigned eat = numbits-acquired;
byte &= 0xFF;
if(eat <= 8)
{
result |= ((std::uint_fast64_t)(byte & ((1u << eat)-1))) << acquired;
BitCount = 8-eat;
BitCache = byte >> eat;
return result;
}
result |= ((std::uint_fast64_t)(byte)) << acquired;
}
}
template<bool Abortable, typename InputFunctor, unsigned A,unsigned B>
std::uint_least32_t HuffRead(InputFunctor&& input,
RandomAccessArray<USE_BITARRAY_FOR_HUFFNODES,A,B>& tree)
{
int sum=0, cur=0, len=0;
#ifdef DEFL_DO_HUFF_STATS
static int maxlen = 0;
#endif
// Get more bits while code value is above sum
do {
auto p = GetBits<Abortable>(std::forward<InputFunctor>(input), 1);
if(Abortable && !~p)
{
// Note: Throws away progress already made traversing the tree
return ~std::uint_least32_t(0); // error flag
}
cur = (unsigned(cur) << 1) | bool(p);
#ifdef DEFL_DO_HUFF_STATS
if(len > maxlen)
{
maxlen = len;
std::fprintf(stderr, "maxlen access: %d (%d)\n", maxlen, (int)tree.Get(0 + len));
}
#endif
auto v = tree.Get(0 + len++);
sum += v;
cur -= v;
} while(cur >= 0);
return tree.Get(15 + sum + cur);
}
};
template<bool Backtrackable>
struct DeflateState: public DeflateBitCache
{
std::uint_least8_t lencode = 0, num = 0; // used in DynTreeFunc
// Lengths are in 0..15 range.
RandomAccessArray<USE_BITARRAY_FOR_LENGTHS, 288, CeilLog2<16>> Lengths; // 144 bytes
// Length tree
// Values up to 288 in indexes 0-14. (Table) (255 is max observed in wild)
// Values up to 287 in indexes 15-302. (Trans)
RandomAccessArray<USE_BITARRAY_FOR_HUFFNODES, 15+288, CeilLog2<289>> ltree; // 341->344 bytes
// Distance tree
// Values up to 32 in indexes 0-14. (Table)
// Values up to 31 in indexes 15-46. (Trans)
RandomAccessArray<USE_BITARRAY_FOR_HUFFNODES, 15+32, CeilLog2<33>> dtree; // 36->40 bytes
RandomAccessArray<USE_BITARRAY_FOR_HUFFNODES, 15+32, CeilLog2<33>>& lltree = dtree;
// Theoretical minimum memory use:
// (15*log2(289) + 288*log2(288))/8 = 309.45 bytes for ltree
// (15*log2(33) + 32 *log2(32))/8 = 29.46 bytes for dtree
// 144.00 bytes for lengths
// total 482.91 bytes
template<bool Abortable, typename InputFunctor, typename BacktrackFunctor>
auto DynTreeFunc(InputFunctor&& input, std::uint_fast16_t length, BacktrackFunctor&& /*backtrack*/,
bool
#ifdef DO_DEFDB_DUMPING
dists
#endif
)
{
Lengths = {}; // clear at least length nibbles; easiest to clear it all
bool error = false;
for(std::uint_fast16_t code = 0; ; )
{
#ifdef DO_DEFDB_DUMPING
unsigned bits_before=bitcounter;
#endif
if(!num)
{
auto p = HuffRead<Abortable>(std::forward<InputFunctor>(input), lltree);
if(Abortable && !~p) { error = true; goto done; }
std::uint_least8_t what = p; // 0-18
if(!(what & 16)) { lencode = what * 0x11u; what = 0x01; } // 1 times (what < 16) (use what, set prev)
else if(what < 17) { lencode = (lencode >> 4) * 0x11u; what = 0x23; } // 3..6 (use prev)
else if(what == 17) { lencode = 0; what = 0x33; } // 3..10 (use 0, set prev)
else { lencode = 0; what = 0x7B; } // 11..138 (use 0, set prev)
p = GetBits<Abortable>(std::forward<InputFunctor>(input), what >> 4); // 0, 2, 3 or 7 bits
#ifdef DO_DEFDB_DUMPING
if(what>>4)
{
char tmp[64]="[_]"; sprintf(tmp, "[%d]", int(bitcounter-bits_before));
fprintf(stderr, "%4s %cREP (%d times)\n", tmp, (lencode&0xF)?'L':'Z', p+(what&0xF));
}
#endif
if(Abortable && !~p) { error = true; goto done; }
num = p + (what & 0xF); // 1..138
}
#ifdef DO_DEFDB_DUMPING
bool rep=num>1;
#endif
do {
#ifdef DO_DEFDB_DUMPING
char tmp[64]="[_]"; if(!rep) sprintf(tmp, "[%d]", int(bitcounter-bits_before));
if(code == 0x100)
fprintf(stderr, "%4s EofB CL (val:%2d)\n", tmp, int(lencode&0xF));
else if(dists)
fprintf(stderr, "%4s d_%02d CL (val:%2d)\n", tmp, int(code), int(lencode&0xF));
else if(code > 0x100)
fprintf(stderr, "%4s l_%02d CL (val:%2d)\n", tmp, int(code- 0x101), int(lencode&0xF));
else
fprintf(stderr, "%4s 0x%02X CL (val:%2d)\n", tmp, (int)code, int(lencode&0xF));
#endif
--num;
Lengths.QSet(code++, lencode & 0xF);
if(code == length) { goto done; }
} while(num > 0);
}
done:;
return [this,error](unsigned index) -> std::conditional_t<Abortable, int, unsigned char>
{
if(Abortable && error) return -1;
return Lengths.Get(index);
};
}
};
template<>
struct DeflateState<true>: public DeflateBitCache
{
// Length tree
// Values up to 288 in indexes 0-14. (Table) (255 is max observed in wild)
// Values up to 287 in indexes 15-302. (Trans)
RandomAccessArray<USE_BITARRAY_FOR_HUFFNODES, 15+288, CeilLog2<289>> ltree; // 341->344 bytes
// Distance tree
// Values up to 32 in indexes 0-14. (Table)
// Values up to 31 in indexes 15-46. (Trans)
RandomAccessArray<USE_BITARRAY_FOR_HUFFNODES, 15+32, CeilLog2<33>> dtree; // 36->40 bytes
// Length-lengths tree
// Values up to 19 in indexes 0-14. (Table) (13 is max observed in wild)
// Values up to 18 in indexes 15-33. (Trans)
RandomAccessArray<USE_BITARRAY_FOR_HUFFNODES, 15+19, CeilLog2<20>> lltree; // 22->24 bytes
// Theoretical minimum memory use:
// (15*log2(289) + 288*log2(288))/8 = 309.45 bytes for ltree
// (15*log2(33) + 32 *log2(32))/8 = 29.46 bytes for dtree
// (15*log2(20) + 19 *log2(19))/8 = 18.19 bytes for lltree
// total 357.10 bytes
std::uint_least8_t lencode, num; // used in DynTreeFunc
std::uint_least8_t checkpoint_lencode, checkpoint_num;
std::uint_least8_t checkpoint_BitCache, checkpoint_BitCount;
template<bool Abortable, typename InputFunctor, typename BacktrackFunctor>
auto DynTreeFunc(InputFunctor&& input, std::uint_fast16_t /*length*/, BacktrackFunctor&& backtrack,
bool
#ifdef DO_DEFDB_DUMPING
dists
#endif
)
{
// Create checkpoint
checkpoint_lencode = 0;
checkpoint_num = 0;
checkpoint_BitCache = BitCache;
checkpoint_BitCount = BitCount;
backtrack(false);
return [this,&input,&backtrack](unsigned index) -> std::conditional_t<Abortable, int, unsigned char>
{
if(index == 0)
{
// Restore checkpoint
lencode = checkpoint_lencode;
num = checkpoint_num;
BitCache = checkpoint_BitCache;
BitCount = checkpoint_BitCount;
backtrack(true);
}
if(Abortable && (num==0xFF)) return -1;
if(!num)
{
auto p = HuffRead<Abortable>(std::forward<InputFunctor>(input), lltree);
if(Abortable && !~p) { num = 0xFF; return -1; } // If p== ~uint64_t()
std::uint_least8_t what = p; // 0-18
if(!(what & 16)) { lencode = what * 0x11u; what = 0x01; } // 1 times (what < 16) (use what, set prev)
else if(what < 17) { lencode = (lencode >> 4) * 0x11u; what = 0x23; } // 3..6 (use prev)
else if(what == 17) { lencode = 0; what = 0x33; } // 3..10 (use 0, set prev)
else { lencode = 0; what = 0x7B; } // 11..138 (use 0, set prev)
p = GetBits<Abortable>(std::forward<InputFunctor>(input), what >> 4); // 0, 2, 3 or 7 bits
if(Abortable && !~p) { num = 0xFF; return -1; } // If p== ~uint64_t()
num = p + (what & 0xF); // 1..138
}
--num;
return (lencode & 0xF);
};
}
};
struct DeflateWindow
{
unsigned char Data[gunzip_ns::MAX_WINDOW_SIZE];
SmallestType<CeilLog2<gunzip_ns::MAX_WINDOW_SIZE>> Head = 0;
};
#ifdef DEFLATE_ALLOCATION_STATIC
template<typename ObjectType>
ObjectType& GetStaticObj()
{
static thread_local ObjectType obj;
obj.~ObjectType();
new(&obj) ObjectType();
return obj;
}
#endif
/* Values of Abortable:
* Input abortable = &1
* Output abortable = &2
* Resumable = &4
*
* Input abortable Output abortable Resumable Value
* no no no 0
* yes no no 1
* no yes no 2
* yes yes no 3
* 4 = invalid
* yes no yes 5
* no yes yes 6
* yes yes yes 7
*/
template<unsigned char Abortable,
typename InputFunctor, typename OutputFunctor, typename WindowFunctor,
typename BacktrackFunctor>
int Gunzip(InputFunctor&& input,
OutputFunctor&& output,
WindowFunctor&& outputcopy,
BacktrackFunctor&& backtrack)
{
using namespace gunzip_ns;
typedef DeflateState<!std::is_same_v<remove_cvref_t<BacktrackFunctor>,dummy>> StateType;
#ifdef DEFLATE_ALLOCATION_AUTOMATIC
StateType state;
#elif defined(DEFLATE_ALLOCATION_STATIC)
auto& state = gunzip_ns::GetStaticObj<StateType>();
#elif defined(DEFLATE_ALLOCATION_DYNAMIC)
std::unique_ptr<StateType> stateptr(new StateType);
auto& state = *stateptr;
#endif
// The following routines are macros rather than e.g. lambda functions,
// in order to make them inlined in the function structure, and breakable/resumable.
// Bit-by-bit input routine
#define DummyGetBits(numbits) do { \
auto p = state.template GetBits<bool(Abortable&Flag_InputAbortable)>(std::forward<InputFunctor>(input), numbits); \
if((Abortable & Flag_InputAbortable) && !~p) return -2; \
} while(0)
#define GetBits(numbits, target) \
auto p = state.template GetBits<bool(Abortable&Flag_InputAbortable)>(std::forward<InputFunctor>(input), numbits); \
if((Abortable & Flag_InputAbortable) && !~p) return -2; \
target = p
// Huffman tree read routine.
#define HuffRead(tree, target) \
auto p = state.template HuffRead<bool(Abortable&Flag_InputAbortable)>(std::forward<InputFunctor>(input), tree); \
if((Abortable & Flag_InputAbortable) && !~p) return -2; \
target = p
#define Fail_If(condition) do { \
/*assert(!(condition));*/ \
if(condition) return -1; \
} while(0)
// Read stream header
GetBits(16, std::uint_least16_t header);
// ^ Read deflate header: method[4] ; winsize[4] ; checksum[8]
if(header == 0x8B1F) // Is it actually a gzip header?
{
// Get format identifier, flags, MTIME, XFL and OS
GetBits(64, header); Fail_If((header & 0xFF) != 8); // Format identifier should be 8
if(header&0x0400) // Skip extra fields as indicated by FEXTRA
{ GetBits(16, std::uint_fast16_t q); DummyGetBits(8*q); }
if(header&0x0800) for(;;) { GetBits(8, bool q); if(!q) break; } // NAME: Skip filename if FNAME was present
if(header&0x1000) for(;;) { GetBits(8, bool q); if(!q) break; } // COMMENT: Skip comment if FCOMMENT was present
if(header&0x0200) { DummyGetBits(16); } // HCRC: Skip FCRC if was present
outputcopy(0, 32768u); // GZIP always uses 32k window
}
else // No. Deflate header?
{
Fail_If((header & 0x208F) != 0x0008 || ((((header<<8)+(header>>8))&0xFFFF)%31) != 0);
outputcopy(0, 256 << ((header >> 4) & 0xF)); // Preset dictionary (0x2000) is not supported
}
// Read compressed blocks
for(;;)
{
GetBits(3, header);
//fprintf(stderr, "header=%d\n", header);
if(header & 4) // Dynamic block
{
Fail_If(header & 2);
std::uint_least16_t nlen_ndist_ncode;
GetBits(14, nlen_ndist_ncode);