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Add zlib module:

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The zlib module is a port of ZLib's raw deflate
algorithm to header-only C++11.
This commit is contained in:
Vinnie Falco
2016-11-15 12:04:59 -05:00
parent a0a335972f
commit 9ff1a27160
265 changed files with 76497 additions and 16 deletions
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include/beast/zlib.hpp
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//
// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef BEAST_ZLIB_HPP
#define BEAST_ZLIB_HPP
#include <beast/zlib/deflate_stream.hpp>
#include <beast/zlib/inflate_stream.hpp>
#endif
include/beast/zlib/deflate_stream.hpp
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//
// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// This is a derivative work based on Zlib, copyright below:
/*
Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
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.
Jean-loup Gailly Mark Adler
jloup@gzip.org madler@alumni.caltech.edu
The data format used by the zlib library is described by RFCs (Request for
Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
(zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
*/
#ifndef BEAST_ZLIB_DEFLATE_STREAM_HPP
#define BEAST_ZLIB_DEFLATE_STREAM_HPP
#include <beast/zlib/error.hpp>
#include <beast/zlib/zlib.hpp>
#include <beast/zlib/detail/deflate_stream.hpp>
#include <algorithm>
#include <cstdlib>
#include <cstdint>
#include <cstring>
#include <memory>
namespace beast {
namespace zlib {
/** Raw deflate compressor.
This is a port of zlib's "deflate" functionality to C++.
*/
class deflate_stream
: private detail::deflate_stream
{
public:
/** Construct a default deflate stream.
Upon construction, the stream settings will be set
to these default values:
@li `level = 6`
@li `windowBits = 15`
@li `memLevel = 8`
@li `strategy = Strategy::normal`
Although the stream is ready to be used immediately
after construction, any required internal buffers are
not dynamically allocated until needed.
*/
deflate_stream()
{
reset(6, 15, DEF_MEM_LEVEL, Strategy::normal);
}
/** Reset the stream and compression settings.
This function initializes the stream to the specified
compression settings.
Although the stream is ready to be used immediately
after a reset, any required internal buffers are not
dynamically allocated until needed.
@note Any unprocessed input or pending output from
previous calls are discarded.
*/
void
reset(
int level,
int windowBits,
int memLevel,
Strategy strategy)
{
doReset(level, windowBits, memLevel, strategy);
}
/** Reset the stream without deallocating memory.
This function performs the equivalent of calling `clear`
followed by `reset` with the same compression settings,
without deallocating the internal buffers.
@note Any unprocessed input or pending output from
previous calls are discarded.
*/
void
reset()
{
doReset();
}
/** Clear the stream.
This function resets the stream and frees all dynamically
allocated internal buffers. The compression settings are
left unchanged.
@note Any unprocessed input or pending output from
previous calls are discarded.
*/
void
clear()
{
doClear();
}
/** Returns the upper limit on the size of a compressed block.
This function makes a conservative estimate of the maximum number
of bytes needed to store the result of compressing a block of
data based on the current compression level and strategy.
@param bytes The size of the uncompressed data.
@return The maximum number of resulting compressed bytes.
*/
std::size_t
upper_bound(std::size_t sourceLen) const
{
return doUpperBound(sourceLen);
}
/** Fine tune internal compression parameters.
Compression parameters should only be tuned by someone who
understands the algorithm used by zlib's deflate for searching
for the best matching string, and even then only by the most
fanatic optimizer trying to squeeze out the last compressed bit
for their specific input data. Read the deflate.c source code
(ZLib) for the meaning of the max_lazy, good_length, nice_length,
and max_chain parameters.
*/
void
tune(
int good_length,
int max_lazy,
int nice_length,
int max_chain)
{
doTune(good_length, max_lazy, nice_length, max_chain);
}
/** Compress input and write output.
This function compresses as much data as possible, and stops when
the input buffer becomes empty or the output buffer becomes full.
It may introduce some output latency (reading input without
producing any output) except when forced to flush.
In each call, one or both of these actions are performed:
@li Compress more input starting at `zs.next_in` and update
`zs.next_in` and `zs.avail_in` accordingly. If not all
input can be processed (because there is not enough room in
the output buffer), `zs.next_in` and `zs.avail_in` are updated
and processing will resume at this point for the next call.
@li Provide more output starting at `zs.next_out` and update
`zs.next_out` and `zs.avail_out` accordingly. This action is
forced if the parameter flush is not `Flush::none`. Forcing
flush frequently degrades the compression ratio, so this parameter
should be set only when necessary (in interactive applications).
Some output may be provided even if flush is not set.
Before the call, the application must ensure that at least one
of the actions is possible, by providing more input and/or
consuming more output, and updating `zs.avail_in` or `zs.avail_out`
accordingly; `zs.avail_out` should never be zero before the call.
The application can consume the compressed output when it wants,
for example when the output buffer is full (`zs.avail_out == 0`),
or after each call of `write`. If `write` returns no error
with zero `zs.avail_out`, it must be called again after making
room in the output buffer because there might be more output
pending.
Normally the parameter flush is set to `Flush::none`, which allows
deflate to decide how much data to accumulate before producing
output, in order to maximize compression.
If the parameter flush is set to `Flush::sync`, all pending output
is flushed to the output buffer and the output is aligned on a
byte boundary, so that the decompressor can get all input data
available so far. In particular `zs.avail_in` is zero after the
call if enough output space has been provided before the call.
Flushing may degrade compression for some compression algorithms
and so it should be used only when necessary. This completes the
current deflate block and follows it with an empty stored block
that is three bits plus filler bits to the next byte, followed
by the four bytes `{ 0x00, 0x00 0xff 0xff }`.
If flush is set to `Flush::partial`, all pending output is flushed
to the output buffer, but the output is not aligned to a byte
boundary. All of the input data so far will be available to the
decompressor, as for Z_SYNC_FLUSH. This completes the current
deflate block and follows it with an empty fixed codes block that
is 10 bits long. This assures that enough bytes are output in order
for the decompressor to finish the block before the empty fixed
code block.
If flush is set to `Flush::block`, a deflate block is completed
and emitted, as for `Flush::sync`, but the output is not aligned
on a byte boundary, and up to seven bits of the current block are
held to be written as the next byte after the next deflate block
is completed. In this case, the decompressor may not be provided
enough bits at this point in order to complete decompression of
the data provided so far to the compressor. It may need to wait
for the next block to be emitted. This is for advanced applications
that need to control the emission of deflate blocks.
If flush is set to `Flush::full`, all output is flushed as with
`Flush::sync`, and the compression state is reset so that
decompression can restart from this point if previous compressed
data has been damaged or if random access is desired. Using
`Flush::full` too often can seriously degrade compression.
If `write` returns with `zs.avail_out == 0`, this function must
be called again with the same value of the flush parameter and
more output space (updated `zs.avail_out`), until the flush is
complete (`write` returns with non-zero `zs.avail_out`). In the
case of a `Flush::full`or `Flush::sync`, make sure that
`zs.avail_out` is greater than six to avoid repeated flush markers
due to `zs.avail_out == 0` on return.
If the parameter flush is set to `Flush::finish`, pending input
is processed, pending output is flushed and deflate returns the
error `error::end_of_stream` if there was enough output space;
if deflate returns with no error, this function must be called
again with `Flush::finish` and more output space (updated
`zs.avail_out`) but no more input data, until it returns the
error `error::end_of_stream` or another error. After `write` has
returned the `error::end_of_stream` error, the only possible
operations on the stream are to reset or destroy.
`Flush::finish` can be used immediately after initialization
if all the compression is to be done in a single step. In this
case, `zs.avail_out` must be at least value returned by
`upper_bound` (see below). Then `write` is guaranteed to return
the `error::end_of_stream` error. If not enough output space
is provided, deflate will not return `error::end_of_stream`,
and it must be called again as described above.
`write` returns no error if some progress has been made (more
input processed or more output produced), `error::end_of_stream`
if all input has been consumed and all output has been produced
(only when flush is set to `Flush::finish`), `error::stream_error`
if the stream state was inconsistent (for example if `zs.next_in`
or `zs.next_out` was `nullptr`), `error::need_buffers` if no
progress is possible (for example `zs.avail_in` or `zs.avail_out`
was zero). Note that `error::need_buffers` is not fatal, and
`write` can be called again with more input and more output space
to continue compressing.
*/
void
write(
z_params& zs,
Flush flush,
error_code& ec)
{
doWrite(zs, flush, ec);
}
/** Update the compression level and strategy.
This function dynamically updates the compression level and
compression strategy. The interpretation of level and strategy
is as in @ref reset. This can be used to switch between compression
and straight copy of the input data, or to switch to a different kind
of input data requiring a different strategy. If the compression level
is changed, the input available so far is compressed with the old level
(and may be flushed); the new level will take effect only at the next
call of @ref write.
Before the call of `params`, the stream state must be set as for a
call of @ref write, since the currently available input may have to be
compressed and flushed. In particular, `zs.avail_out` must be non-zero.
@return `Z_OK` if success, `Z_STREAM_ERROR` if the source stream state
was inconsistent or if a parameter was invalid, `error::need_buffers`
if `zs.avail_out` was zero.
*/
void
params(
z_params& zs,
int level,
Strategy strategy,
error_code& ec)
{
doParams(zs, level, strategy, ec);
}
/** Return bits pending in the output.
This function returns the number of bytes and bits of output
that have been generated, but not yet provided in the available
output. The bytes not provided would be due to the available
output space having being consumed. The number of bits of output
not provided are between 0 and 7, where they await more bits to
join them in order to fill out a full byte. If pending or bits
are `nullptr`, then those values are not set.
@return `Z_OK` if success, or `Z_STREAM_ERROR` if the source
stream state was inconsistent.
*/
void
pending(unsigned *value, int *bits)
{
doPending(value, bits);
}
/** Insert bits into the compressed output stream.
This function inserts bits in the deflate output stream. The
intent is that this function is used to start off the deflate
output with the bits leftover from a previous deflate stream when
appending to it. As such, this function can only be used for raw
deflate, and must be used before the first `write` call after an
initialization. `bits` must be less than or equal to 16, and that
many of the least significant bits of `value` will be inserted in
the output.
@return `error::need_buffers` if there was not enough room in
the internal buffer to insert the bits.
*/
void
prime(int bits, int value, error_code& ec)
{
return doPrime(bits, value, ec);
}
};
/** Returns the upper limit on the size of a compressed block.
This function makes a conservative estimate of the maximum number
of bytes needed to store the result of compressing a block of
data.
@param bytes The size of the uncompressed data.
@return The maximum number of resulting compressed bytes.
*/
std::size_t
deflate_upper_bound(std::size_t bytes);
/* For the default windowBits of 15 and memLevel of 8, this function returns
a close to exact, as well as small, upper bound on the compressed size.
They are coded as constants here for a reason--if the #define's are
changed, then this function needs to be changed as well. The return
value for 15 and 8 only works for those exact settings.
For any setting other than those defaults for windowBits and memLevel,
the value returned is a conservative worst case for the maximum expansion
resulting from using fixed blocks instead of stored blocks, which deflate
can emit on compressed data for some combinations of the parameters.
This function could be more sophisticated to provide closer upper bounds for
every combination of windowBits and memLevel. But even the conservative
upper bound of about 14% expansion does not seem onerous for output buffer
allocation.
*/
inline
std::size_t
deflate_upper_bound(std::size_t bytes)
{
return bytes +
((bytes + 7) >> 3) +
((bytes + 63) >> 6) + 5 +
6;
}
} // zlib
} // beast
#endif
include/beast/zlib/detail/bitstream.hpp
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//
// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// This is a derivative work based on Zlib, copyright below:
/*
Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
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.
Jean-loup Gailly Mark Adler
jloup@gzip.org madler@alumni.caltech.edu
The data format used by the zlib library is described by RFCs (Request for
Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
(zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
*/
#ifndef BEAST_ZLIB_DETAIL_BITSTREAM_HPP
#define BEAST_ZLIB_DETAIL_BITSTREAM_HPP
#include <boost/assert.hpp>
#include <cstdint>
#include <iterator>
namespace beast {
namespace zlib {
namespace detail {
class bitstream
{
using value_type = std::uint32_t;
value_type v_ = 0;
unsigned n_ = 0;
public:
// returns the number of bits in the reservoir
unsigned
size() const
{
return n_;
}
// discard n bits
void
drop(std::size_t n)
{
BOOST_ASSERT(n <= n_);
n_ -= static_cast<unsigned>(n);
v_ >>= n;
}
// flush everything
void
flush()
{
n_ = 0;
v_ = 0;
}
// flush to the next byte boundary
void
flush_byte()
{
drop(n_ % 8);
}
// ensure at least n bits
template<class FwdIt>
bool
fill(std::size_t n, FwdIt& first, FwdIt const& last);
// fill 8 bits, unchecked
template<class FwdIt>
void
fill_8(FwdIt& it);
// fill 16 bits, unchecked
template<class FwdIt>
void
fill_16(FwdIt& it);
// return n bits
template<class Unsigned>
void
peek(Unsigned& value, std::size_t n);
// return everything in the reservoir
value_type
peek_fast() const
{
return v_;
}
// return n bits, and consume
template<class Unsigned>
void
read(Unsigned& value, std::size_t n);
// rewind by the number of whole bytes stored (unchecked)
template<class BidirIt>
void
rewind(BidirIt& it);
};
template<class FwdIt>
inline
bool
bitstream::
fill(std::size_t n, FwdIt& first, FwdIt const& last)
{
while(n_ < n)
{
if(first == last)
return false;
v_ += static_cast<value_type>(*first++) << n_;
n_ += 8;
}
return true;
}
template<class FwdIt>
inline
void
bitstream::
fill_8(FwdIt& it)
{
v_ += static_cast<value_type>(*it++) << n_;
n_ += 8;
}
template<class FwdIt>
inline
void
bitstream::
fill_16(FwdIt& it)
{
v_ += static_cast<value_type>(*it++) << n_;
n_ += 8;
v_ += static_cast<value_type>(*it++) << n_;
n_ += 8;
}
template<class Unsigned>
inline
void
bitstream::
peek(Unsigned& value, std::size_t n)
{
BOOST_ASSERT(n <= sizeof(value)*8);
BOOST_ASSERT(n <= n_);
value = static_cast<Unsigned>(
v_ & ((1ULL << n) - 1));
}
template<class Unsigned>
inline
void
bitstream::
read(Unsigned& value, std::size_t n)
{
BOOST_ASSERT(n < sizeof(v_)*8);
BOOST_ASSERT(n <= n_);
value = static_cast<Unsigned>(
v_ & ((1ULL << n) - 1));
v_ >>= n;
n_ -= static_cast<unsigned>(n);
}
template<class BidirIt>
inline
void
bitstream::
rewind(BidirIt& it)
{
auto len = n_ >> 3;
it = std::prev(it, len);
n_ &= 7;
v_ &= (1U << n_) - 1;
}
} // detail
} // zlib
} // beast
#endif
include/beast/zlib/detail/deflate_stream.hpp
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include/beast/zlib/detail/inflate_stream.hpp
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include/beast/zlib/detail/ranges.hpp
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//
// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// This is a derivative work based on Zlib, copyright below:
/*
Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
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.
Jean-loup Gailly Mark Adler
jloup@gzip.org madler@alumni.caltech.edu
The data format used by the zlib library is described by RFCs (Request for
Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
(zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
*/
#ifndef BEAST_ZLIB_DETAIL_RANGES_HPP
#define BEAST_ZLIB_DETAIL_RANGES_HPP
#include <cstdint>
#include <type_traits>
namespace beast {
namespace zlib {
namespace detail {
struct ranges
{
template<bool isConst>
struct range
{
using iter_t =
typename std::conditional<isConst,
std::uint8_t const*,
std::uint8_t*>::type;
iter_t first;
iter_t last;
iter_t next;
// total bytes in range
std::size_t
size() const
{
return last - first;
}
// bytes consumed
std::size_t
used() const
{
return next - first;
}
// bytes remaining
std::size_t
avail() const
{
return last - next;
}
};
range<true> in;
range<false> out;
};
// Clamp u to v where u and v are different types
template<class U, class V>
inline
U
clamp(U u, V v)
{
if(u > v)
u = static_cast<U>(v);
return u;
}
} // detail
} // zlib
} // beast
#endif
include/beast/zlib/detail/window.hpp
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//
// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// This is a derivative work based on Zlib, copyright below:
/*
Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
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.
Jean-loup Gailly Mark Adler
jloup@gzip.org madler@alumni.caltech.edu
The data format used by the zlib library is described by RFCs (Request for
Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
(zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
*/
#ifndef BEAST_ZLIB_DETAIL_WINDOW_HPP
#define BEAST_ZLIB_DETAIL_WINDOW_HPP
#include <boost/assert.hpp>
#include <cstdint>
#include <cstring>
#include <memory>
namespace beast {
namespace zlib {
namespace detail {
class window
{
std::unique_ptr<std::uint8_t[]> p_;
std::uint16_t i_ = 0;
std::uint16_t size_ = 0;
std::uint16_t capacity_ = 0;
std::uint8_t bits_ = 0;
public:
int
bits() const
{
return bits_;
}
unsigned
capacity() const
{
return capacity_;
}
unsigned
size() const
{
return size_;
}
void
reset(int bits);
void
read(std::uint8_t* out, std::size_t pos, std::size_t n);
template<class = void>
void
write(std::uint8_t const* in, std::size_t n);
};
inline
void
window::
reset(int bits)
{
if(bits_ != bits)
{
p_.reset();
bits_ = static_cast<std::uint8_t>(bits);
capacity_ = 1U << bits_;
}
i_ = 0;
size_ = 0;
}
inline
void
window::
read(std::uint8_t* out, std::size_t pos, std::size_t n)
{
if(i_ >= size_)
{
// window is contiguous
std::memcpy(out, &p_[i_ - pos], n);
return;
}
auto i = ((i_ - pos) + capacity_) % capacity_;
auto m = capacity_ - i;
if(n <= m)
{
std::memcpy(out, &p_[i], n);
return;
}
std::memcpy(out, &p_[i], m);
out += m;
std::memcpy(out, &p_[0], n - m);
}
template<class>
void
window::
write(std::uint8_t const* in, std::size_t n)
{
if(! p_)
p_.reset(new std::uint8_t[capacity_]);
if(n >= capacity_)
{
i_ = 0;
size_ = capacity_;
std::memcpy(&p_[0], in + (n - size_), size_);
return;
}
if(i_ + n <= capacity_)
{
std::memcpy(&p_[i_], in, n);
if(size_ >= capacity_ - n)
size_ = capacity_;
else
size_ = static_cast<std::uint16_t>(size_ + n);
i_ = static_cast<std::uint16_t>(
(i_ + n) % capacity_);
return;
}
auto m = capacity_ - i_;
std::memcpy(&p_[i_], in, m);
in += m;
i_ = static_cast<std::uint16_t>(n - m);
std::memcpy(&p_[0], in, i_);
size_ = capacity_;
}
} // detail
} // zlib
} // beast
#endif
include/beast/zlib/error.hpp
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//
// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// This is a derivative work based on Zlib, copyright below:
/*
Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
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.
Jean-loup Gailly Mark Adler
jloup@gzip.org madler@alumni.caltech.edu
The data format used by the zlib library is described by RFCs (Request for
Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
(zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
*/
#ifndef BEAST_ZLIB_ERROR_HPP
#define BEAST_ZLIB_ERROR_HPP
#include <beast/core/error.hpp>
namespace beast {
namespace zlib {
/** Error codes returned by the codec.
*/
enum class error
{
/** Additional buffers are required.
This error indicates that one or both of the buffers
provided buffers do not have sufficient available bytes
to make forward progress.
This does not always indicate a failure condition.
@note This is the same as `Z_BUF_ERROR` returned by ZLib.
*/
need_buffers = 1,
/** End of stream reached.
@note This is the same as `Z_STREAM_END` returned by ZLib.
*/
end_of_stream,
/** Invalid stream or parameters.
This error is returned when invalid parameters are passed,
or the operation being performed is not consistent with the
state of the stream. For example, attempting to write data
when the end of stream is already reached.
@note This is the same as `Z_STREAM_ERROR` returned by ZLib.
*/
stream_error,
//
// Errors generated by basic_deflate_stream
//
//
// Errors generated by basic_inflate_stream
//
/// Invalid block type
invalid_block_type,
/// Invalid stored block length
invalid_stored_length,
/// Too many length or distance symbols
too_many_symbols,
/// Invalid code lengths
invalid_code_lenths,
/// Invalid bit length repeat
invalid_bit_length_repeat,
/// Missing end of block code
missing_eob,
/// Invalid literal/length code
invalid_literal_length,
/// Invalid distance code
invalid_distance_code,
/// Invalid distance too far back
invalid_distance,
//
// Errors generated by inflate_table
//
/// Over-subscribed length code
over_subscribed_length,
/// Incomplete length set
incomplete_length_set,
/// general error
general
};
} // zlib
} // beast
#include <beast/zlib/impl/error.ipp>
#endif
include/beast/zlib/impl/error.ipp
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//
// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// This is a derivative work based on Zlib, copyright below:
/*
Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
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.
Jean-loup Gailly Mark Adler
jloup@gzip.org madler@alumni.caltech.edu
The data format used by the zlib library is described by RFCs (Request for
Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
(zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
*/
#ifndef BEAST_ZLIB_IMPL_ERROR_IPP
#define BEAST_ZLIB_IMPL_ERROR_IPP
#include <beast/core/error.hpp>
#include <type_traits>
namespace boost {
namespace system {
template<>
struct is_error_code_enum<beast::zlib::error>
{
static bool const value = true;
};
} // system
} // boost
namespace beast {
namespace zlib {
namespace detail {
class zlib_error_category : public error_category
{
public:
const char*
name() const noexcept override
{
return "zlib";
}
std::string
message(int ev) const override
{
switch(static_cast<error>(ev))
{
case error::need_buffers: return "need buffers";
case error::end_of_stream: return "end of stream";
case error::stream_error: return "stream error";
case error::invalid_block_type: return "invalid block type";
case error::invalid_stored_length: return "invalid stored block length";
case error::too_many_symbols: return "too many symbols";
case error::invalid_code_lenths: return "invalid code lengths";
case error::invalid_bit_length_repeat: return "invalid bit length repeat";
case error::missing_eob: return "missing end of block code";
case error::invalid_literal_length: return "invalid literal/length code";
case error::invalid_distance_code: return "invalid distance code";
case error::invalid_distance: return "invalid distance";
case error::over_subscribed_length: return "over-subscribed length";
case error::incomplete_length_set: return "incomplete length set";
case error::general:
default:
return "zlib error";
}
}
error_condition
default_error_condition(int ev) const noexcept override
{
return error_condition{ev, *this};
}
bool
equivalent(int ev,
error_condition const& condition
) const noexcept override
{
return condition.value() == ev &&
&condition.category() == this;
}
bool
equivalent(error_code const& error, int ev) const noexcept override
{
return error.value() == ev &&
&error.category() == this;
}
};
inline
error_category const&
get_error_category()
{
static zlib_error_category const cat{};
return cat;
}
} // detail
inline
error_code
make_error_code(error ev)
{
return error_code{
static_cast<std::underlying_type<error>::type>(ev),
detail::get_error_category()};
}
} // zlib
} // beast
#endif
include/beast/zlib/inflate_stream.hpp
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//
// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// This is a derivative work based on Zlib, copyright below:
/*
Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
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.
Jean-loup Gailly Mark Adler
jloup@gzip.org madler@alumni.caltech.edu
The data format used by the zlib library is described by RFCs (Request for
Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
(zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
*/
#ifndef BEAST_ZLIB_INFLATE_STREAM_HPP
#define BEAST_ZLIB_INFLATE_STREAM_HPP
#include <beast/zlib/detail/inflate_stream.hpp>
namespace beast {
namespace zlib {
/** Raw deflate stream decompressor.
This implements a raw deflate stream decompressor. The deflate
protocol is a compression protocol described in
"DEFLATE Compressed Data Format Specification version 1.3"
located here: https://tools.ietf.org/html/rfc1951
The implementation is a refactored port to C++ of ZLib's "inflate".
A more detailed description of ZLib is at http://zlib.net/.
Compression can be done in a single step if the buffers are large
enough (for example if an input file is memory mapped), or can be done
by repeated calls of the compression function. In the latter case, the
application must provide more input and/or consume the output (providing
more output space) before each call.
*/
class inflate_stream
: private detail::inflate_stream
{
public:
/** Construct a raw deflate decompression stream.
The window size is set to the default of 15 bits.
*/
inflate_stream() = default;
/** Reset the stream.
This puts the stream in a newly constructed state with
the previously specified window size, but without de-allocating
any dynamically created structures.
*/
void
reset()
{
doReset();
}
/** Reset the stream.
This puts the stream in a newly constructed state with the
specified window size, but without de-allocating any dynamically
created structures.
*/
void
reset(int windowBits)
{
doReset(windowBits);
}
/** Put the stream in a newly constructed state.
All dynamically allocated memory is de-allocated.
*/
void
clear()
{
doClear();
}
/** Decompress input and produce output.
This function decompresses as much data as possible, and stops when
the input buffer becomes empty or the output buffer becomes full. It
may introduce some output latency (reading input without producing any
output) except when forced to flush.
One or both of the following actions are performed:
@li Decompress more input starting at `zs.next_in` and update `zs.next_in`
and `zs.avail_in` accordingly. If not all input can be processed (because
there is not enough room in the output buffer), `zs.next_in` is updated
and processing will resume at this point for the next call.
@li Provide more output starting at `zs.next_out` and update `zs.next_out`
and `zs.avail_out` accordingly. `write` provides as much output as
possible, until there is no more input data or no more space in the output
buffer (see below about the flush parameter).
Before the call, the application should ensure that at least one of the
actions is possible, by providing more input and/or consuming more output,
and updating the values in `zs` accordingly. The application can consume
the uncompressed output when it wants, for example when the output buffer
is full (`zs.avail_out == 0`), or after each call. If `write` returns no
error and with zero `zs.avail_out`, it must be called again after making
room in the output buffer because there might be more output pending.
The flush parameter may be `Flush::none`, `Flush::sync`, `Flush::finish`,
`Flush::block`, or `Flush::trees`. `Flush::sync` requests to flush as much
output as possible to the output buffer. `Flush::block` requests to stop if
and when it gets to the next deflate block boundary. When decoding the
zlib or gzip format, this will cause `write` to return immediately after
the header and before the first block. When doing a raw inflate, `write` will
go ahead and process the first block, and will return when it gets to the
end of that block, or when it runs out of data.
The `Flush::block` option assists in appending to or combining deflate
streams. Also to assist in this, on return `write` will set `zs.data_type`
to the number of unused bits in the last byte taken from `zs.next_in`, plus
64 if `write` is currently decoding the last block in the deflate stream,
plus 128 if `write` returned immediately after decoding an end-of-block code
or decoding the complete header up to just before the first byte of the
deflate stream. The end-of-block will not be indicated until all of the
uncompressed data from that block has been written to `zs.next_out`. The
number of unused bits may in general be greater than seven, except when
bit 7 of `zs.data_type` is set, in which case the number of unused bits
will be less than eight. `zs.data_type` is set as noted here every time
`write` returns for all flush options, and so can be used to determine the
amount of currently consumed input in bits.
The `Flush::trees` option behaves as `Flush::block` does, but it also returns
when the end of each deflate block header is reached, before any actual data
in that block is decoded. This allows the caller to determine the length of
the deflate block header for later use in random access within a deflate block.
256 is added to the value of `zs.data_type` when `write` returns immediately
after reaching the end of the deflate block header.
`write` should normally be called until it returns `error::end_of_stream` or
another error. However if all decompression is to be performed in a single
step (a single call of `write`), the parameter flush should be set to
`Flush::finish`. In this case all pending input is processed and all pending
output is flushed; `zs.avail_out` must be large enough to hold all of the
uncompressed data for the operation to complete. (The size of the uncompressed
data may have been saved by the compressor for this purpose.) The use of
`Flush::finish` is not required to perform an inflation in one step. However
it may be used to inform inflate that a faster approach can be used for the
single call. `Flush::finish` also informs inflate to not maintain a sliding
window if the stream completes, which reduces inflate's memory footprint.
If the stream does not complete, either because not all of the stream is
provided or not enough output space is provided, then a sliding window will be
allocated and `write` can be called again to continue the operation as if
`Flush::none` had been used.
In this implementation, `write` always flushes as much output as possible to
the output buffer, and always uses the faster approach on the first call. So
the effects of the flush parameter in this implementation are on the return value
of `write` as noted below, when `write` returns early when `Flush::block` or
`Flush::trees` is used, and when `write` avoids the allocation of memory for a
sliding window when `Flush::finsih` is used.
If a preset dictionary is needed after this call (see @ref dictionary below),
`write` sets `zs.adler` to the Adler-32 checksum of the dictionary chosen by
the compressor and returns `error::need_dictionary`; otherwise it sets
`zs.adler` to the Adler-32 checksum of all output produced so far (that is,
`zs.total_out bytes`) and returns no error, `error::end_of_stream`, or an
error code as described below. At the end of the stream, `write` checks that
its computed adler32 checksum is equal to that saved by the compressor and
returns `error::end_of_stream` only if the checksum is correct.
This function returns no error if some progress has been made (more input
processed or more output produced), `error::end_of_stream` if the end of the
compressed data has been reached and all uncompressed output has been produced,
`error::need_dictionary` if a preset dictionary is needed at this point,
`error::invalid_data` if the input data was corrupted (input stream not
conforming to the zlib format or incorrect check value), `error::stream_error`
if the stream structure was inconsistent (for example if `zs.next_in` or
`zs.next_out` was null), `error::need_buffers` if no progress is possible or
if there was not enough room in the output buffer when `Flush::finish` is
used. Note that `error::need_buffers` is not fatal, and `write` can be called
again with more input and more output space to continue decompressing.
*/
void
write(z_params& zs, Flush flush, error_code& ec)
{
doWrite(zs, flush, ec);
}
};
} // zlib
} // beast
#endif
include/beast/zlib/zlib.hpp
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//
// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// This is a derivative work based on Zlib, copyright below:
/*
Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
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.
Jean-loup Gailly Mark Adler
jloup@gzip.org madler@alumni.caltech.edu
The data format used by the zlib library is described by RFCs (Request for
Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
(zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
*/
#ifndef BEAST_ZLIB_ZLIB_HPP
#define BEAST_ZLIB_ZLIB_HPP
#include <cstdint>
#include <cstdlib>
namespace beast {
namespace zlib {
#if !defined(__MACTYPES__)
typedef unsigned char Byte; /* 8 bits */
#endif
typedef unsigned int uInt; /* 16 bits or more */
/* Possible values of the data_type field (though see inflate()) */
enum z_Type
{
Z_BINARY = 0,
Z_TEXT = 1,
Z_UNKNOWN = 2
};
/** Deflate codec parameters.
Objects of this type are filled in by callers and provided to the
deflate codec to define the input and output areas for the next
compress or decompress operation.
The application must update next_in and avail_in when avail_in has dropped
to zero. It must update next_out and avail_out when avail_out has dropped
to zero. The application must initialize zalloc, zfree and opaque before
calling the init function. All other fields are set by the compression
library and must not be updated by the application.
The fields total_in and total_out can be used for statistics or progress
reports. After compression, total_in holds the total size of the
uncompressed data and may be saved for use in the decompressor (particularly
if the decompressor wants to decompress everything in a single step).
*/
struct z_params
{
/** A pointer to the next input byte.
If there is no more input, this may be set to `nullptr`.
*/
void const* next_in;
/** The number of bytes of input available at `next_in`.
If there is no more input, this should be set to zero.
*/
std::size_t avail_in;
/** The total number of input bytes read so far.
*/
std::size_t total_in = 0;
/** A pointer to the next output byte.
*/
void* next_out;
/** The remaining bytes of space at `next_out`.
*/
std::size_t avail_out;
/** The total number of bytes output so far.
*/
std::size_t total_out = 0;
int data_type = Z_UNKNOWN; // best guess about the data type: binary or text
};
/** Flush option.
*/
enum class Flush
{
// order matters
none,
block,
partial,
sync,
full,
finish,
trees
};
/* compression levels */
enum z_Compression
{
Z_NO_COMPRESSION = 0,
Z_BEST_SPEED = 1,
Z_BEST_COMPRESSION = 9,
Z_DEFAULT_COMPRESSION = -1
};
/** Compression strategy.
These are used when compressing streams.
*/
enum class Strategy
{
/** Default strategy.
This is suitable for general purpose compression, and works
well in the majority of cases.
*/
normal,
/** Filtered strategy.
This strategy should be used when the data be compressed
is produced by a filter or predictor.
*/
filtered,
/** Huffman-only strategy.
This strategy only performs Huffman encoding, without doing
any string matching.
*/
huffman,
/** Run Length Encoding strategy.
This strategy limits match distances to one, making it
equivalent to run length encoding. This can give better
performance for things like PNG image data.
*/
rle,
/** Fixed table strategy.
This strategy prevents the use of dynamic Huffman codes,
allowing for a simpler decoder for special applications.
*/
fixed
};
} // zlib
} // beast
#endif