1 // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
2 // (C) Copyright 2003-2007 Jonathan Turkanis
3 // Distributed under the Boost Software License, Version 1.0. (See accompanying
4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
5
6 // See http://www.boost.org/libs/iostreams for documentation.
7
8 // Note: custom allocators are not supported on VC6, since that compiler
9 // had trouble finding the function zlib_base::do_init.
10
11 #ifndef BOOST_IOSTREAMS_ZLIB_HPP_INCLUDED
12 #define BOOST_IOSTREAMS_ZLIB_HPP_INCLUDED
13
14 #if defined(_MSC_VER)
15 # pragma once
16 #endif
17
18 #include <cassert>
19 #include <iosfwd> // streamsize.
20 #include <memory> // allocator, bad_alloc.
21 #include <new>
22 #include <boost/config.hpp> // MSVC, STATIC_CONSTANT, DEDUCED_TYPENAME, DINKUM.
23 #include <boost/cstdint.hpp> // uint*_t
24 #include <boost/detail/workaround.hpp>
25 #include <boost/iostreams/constants.hpp> // buffer size.
26 #include <boost/iostreams/detail/config/auto_link.hpp>
27 #include <boost/iostreams/detail/config/dyn_link.hpp>
28 #include <boost/iostreams/detail/config/wide_streams.hpp>
29 #include <boost/iostreams/detail/config/zlib.hpp>
30 #include <boost/iostreams/detail/ios.hpp> // failure, streamsize.
31 #include <boost/iostreams/filter/symmetric.hpp>
32 #include <boost/iostreams/pipeline.hpp>
33 #include <boost/type_traits/is_same.hpp>
34
35 // Must come last.
36 #ifdef BOOST_MSVC
37 # pragma warning(push)
38 # pragma warning(disable:4251 4275 4231 4660) // Dependencies not exported.
39 #endif
40 #include <boost/config/abi_prefix.hpp>
41
42 namespace boost { namespace iostreams {
43
44 namespace zlib {
45 // Typedefs
46
47 typedef uint32_t uint;
48 typedef uint8_t byte;
49 typedef uint32_t ulong;
50
51 // Prefix 'x' prevents symbols from being redefined when Z_PREFIX is defined
52 typedef void* (*xalloc_func)(void*, zlib::uint, zlib::uint);
53 typedef void (*xfree_func)(void*, void*);
54
55 // Compression levels
56
57 BOOST_IOSTREAMS_DECL extern const int no_compression;
58 BOOST_IOSTREAMS_DECL extern const int best_speed;
59 BOOST_IOSTREAMS_DECL extern const int best_compression;
60 BOOST_IOSTREAMS_DECL extern const int default_compression;
61
62 // Compression methods
63
64 BOOST_IOSTREAMS_DECL extern const int deflated;
65
66 // Compression strategies
67
68 BOOST_IOSTREAMS_DECL extern const int default_strategy;
69 BOOST_IOSTREAMS_DECL extern const int filtered;
70 BOOST_IOSTREAMS_DECL extern const int huffman_only;
71
72 // Status codes
73
74 BOOST_IOSTREAMS_DECL extern const int okay;
75 BOOST_IOSTREAMS_DECL extern const int stream_end;
76 BOOST_IOSTREAMS_DECL extern const int stream_error;
77 BOOST_IOSTREAMS_DECL extern const int version_error;
78 BOOST_IOSTREAMS_DECL extern const int data_error;
79 BOOST_IOSTREAMS_DECL extern const int mem_error;
80 BOOST_IOSTREAMS_DECL extern const int buf_error;
81
82 // Flush codes
83
84 BOOST_IOSTREAMS_DECL extern const int finish;
85 BOOST_IOSTREAMS_DECL extern const int no_flush;
86 BOOST_IOSTREAMS_DECL extern const int sync_flush;
87
88 // Code for current OS
89
90 //BOOST_IOSTREAMS_DECL extern const int os_code;
91
92 // Null pointer constant.
93
94 const int null = 0;
95
96 // Default values
97
98 const int default_window_bits = 15;
99 const int default_mem_level = 8;
100 const bool default_crc = false;
101 const bool default_noheader = false;
102
103 } // End namespace zlib.
104
105 //
106 // Class name: zlib_params.
107 // Description: Encapsulates the parameters passed to deflateInit2
108 // and inflateInit2 to customize compression and decompression.
109 //
110 struct zlib_params {
111
112 // Non-explicit constructor.
113 zlib_params( int level_ = zlib::default_compression,
114 int method_ = zlib::deflated,
115 int window_bits_ = zlib::default_window_bits,
116 int mem_level_ = zlib::default_mem_level,
117 int strategy_ = zlib::default_strategy,
118 bool noheader_ = zlib::default_noheader,
119 bool calculate_crc_ = zlib::default_crc )
120 : level(level_), method(method_), window_bits(window_bits_),
121 mem_level(mem_level_), strategy(strategy_),
122 noheader(noheader_), calculate_crc(calculate_crc_)
123 { }
124 int level;
125 int method;
126 int window_bits;
127 int mem_level;
128 int strategy;
129 bool noheader;
130 bool calculate_crc;
131 };
132
133 //
134 // Class name: zlib_error.
135 // Description: Subclass of std::ios::failure thrown to indicate
136 // zlib errors other than out-of-memory conditions.
137 //
138 class BOOST_IOSTREAMS_DECL zlib_error : public BOOST_IOSTREAMS_FAILURE {
139 public:
140 explicit zlib_error(int error);
141 int error() const { return error_; }
142 static void check BOOST_PREVENT_MACRO_SUBSTITUTION(int error);
143 private:
144 int error_;
145 };
146
147 namespace detail {
148
149 template<typename Alloc>
150 struct zlib_allocator_traits {
151 #ifndef BOOST_NO_STD_ALLOCATOR
152 #if defined(BOOST_NO_CXX11_ALLOCATOR)
153 typedef typename Alloc::template rebind<char>::other type;
154 #else
155 typedef typename std::allocator_traits<Alloc>::template rebind_alloc<char> type;
156 #endif
157 #else
158 typedef std::allocator<char> type;
159 #endif
160 };
161
162 template< typename Alloc,
163 typename Base = // VC6 workaround (C2516)
164 BOOST_DEDUCED_TYPENAME zlib_allocator_traits<Alloc>::type >
165 struct zlib_allocator : private Base {
166 private:
167 #if defined(BOOST_NO_CXX11_ALLOCATOR) || defined(BOOST_NO_STD_ALLOCATOR)
168 typedef typename Base::size_type size_type;
169 #else
170 typedef typename std::allocator_traits<Base>::size_type size_type;
171 #endif
172 public:
173 BOOST_STATIC_CONSTANT(bool, custom =
174 (!is_same<std::allocator<char>, Base>::value));
175 typedef typename zlib_allocator_traits<Alloc>::type allocator_type;
176 static void* allocate(void* self, zlib::uint items, zlib::uint size);
177 static void deallocate(void* self, void* address);
178 };
179
180 class BOOST_IOSTREAMS_DECL zlib_base {
181 public:
182 typedef char char_type;
183 protected:
184 zlib_base();
185 ~zlib_base();
186 void* stream() { return stream_; }
187 template<typename Alloc>
188 void init( const zlib_params& p,
189 bool compress,
190 zlib_allocator<Alloc>& zalloc )
191 {
192 bool custom = zlib_allocator<Alloc>::custom;
|
(3) Event dead_error_condition: |
The condition "custom" cannot be true. |
|
(4) Event dead_error_line: |
Execution cannot reach the expression "allocate" inside this statement: "this->do_init(p, compress, ...". |
|
(5) Event effectively_constant: |
Local variable "custom" is assigned only once, to a constant value, making it effectively constant throughout its scope. If this is not the intent, examine the logic to see if there is a missing assignment that would make "custom" not remain constant. Otherwise, declaring "custom" as "const" will suppress this defect. |
| Also see events: |
[assignment][const] |
193 do_init( p, compress,
194 custom ? zlib_allocator<Alloc>::allocate : 0,
195 custom ? zlib_allocator<Alloc>::deallocate : 0,
196 &zalloc );
197 }
198 void before( const char*& src_begin, const char* src_end,
199 char*& dest_begin, char* dest_end );
200 void after( const char*& src_begin, char*& dest_begin,
201 bool compress );
202 int xdeflate(int flush); // Prefix 'x' prevents symbols from being
203 int xinflate(int flush); // redefined when Z_PREFIX is defined
204 void reset(bool compress, bool realloc);
205 public:
206 zlib::ulong crc() const { return crc_; }
207 int total_in() const { return total_in_; }
208 int total_out() const { return total_out_; }
209 private:
210 void do_init( const zlib_params& p, bool compress,
211 zlib::xalloc_func,
212 zlib::xfree_func,
213 void* derived );
214 void* stream_; // Actual type: z_stream*.
215 bool calculate_crc_;
216 zlib::ulong crc_;
217 zlib::ulong crc_imp_;
218 int total_in_;
219 int total_out_;
220 };
221
222 //
223 // Template name: zlib_compressor_impl
224 // Description: Model of C-Style Filte implementing compression by
225 // delegating to the zlib function deflate.
226 //
227 template<typename Alloc = std::allocator<char> >
228 class zlib_compressor_impl : public zlib_base, public zlib_allocator<Alloc> {
229 public:
230 zlib_compressor_impl(const zlib_params& = zlib::default_compression);
231 ~zlib_compressor_impl();
232 bool filter( const char*& src_begin, const char* src_end,
233 char*& dest_begin, char* dest_end, bool flush );
234 void close();
235 };
236
237 //
238 // Template name: zlib_compressor
239 // Description: Model of C-Style Filte implementing decompression by
240 // delegating to the zlib function inflate.
241 //
242 template<typename Alloc = std::allocator<char> >
243 class zlib_decompressor_impl : public zlib_base, public zlib_allocator<Alloc> {
244 public:
245 zlib_decompressor_impl(const zlib_params&);
246 zlib_decompressor_impl(int window_bits = zlib::default_window_bits);
247 ~zlib_decompressor_impl();
248 bool filter( const char*& begin_in, const char* end_in,
249 char*& begin_out, char* end_out, bool flush );
250 void close();
251 bool eof() const { return eof_; }
252 private:
253 bool eof_;
254 };
255
256 } // End namespace detail.
257
258 //
259 // Template name: zlib_compressor
260 // Description: Model of InputFilter and OutputFilter implementing
261 // compression using zlib.
262 //
263 template<typename Alloc = std::allocator<char> >
264 struct basic_zlib_compressor
265 : symmetric_filter<detail::zlib_compressor_impl<Alloc>, Alloc>
266 {
267 private:
268 typedef detail::zlib_compressor_impl<Alloc> impl_type;
269 typedef symmetric_filter<impl_type, Alloc> base_type;
270 public:
271 typedef typename base_type::char_type char_type;
272 typedef typename base_type::category category;
273 basic_zlib_compressor( const zlib_params& = zlib::default_compression,
274 std::streamsize buffer_size = default_device_buffer_size );
275 zlib::ulong crc() { return this->filter().crc(); }
276 int total_in() { return this->filter().total_in(); }
277 };
278 BOOST_IOSTREAMS_PIPABLE(basic_zlib_compressor, 1)
279
280 typedef basic_zlib_compressor<> zlib_compressor;
281
282 //
283 // Template name: zlib_decompressor
284 // Description: Model of InputFilter and OutputFilter implementing
285 // decompression using zlib.
286 //
287 template<typename Alloc = std::allocator<char> >
288 struct basic_zlib_decompressor
289 : symmetric_filter<detail::zlib_decompressor_impl<Alloc>, Alloc>
290 {
291 private:
292 typedef detail::zlib_decompressor_impl<Alloc> impl_type;
293 typedef symmetric_filter<impl_type, Alloc> base_type;
294 public:
295 typedef typename base_type::char_type char_type;
296 typedef typename base_type::category category;
297 basic_zlib_decompressor( int window_bits = zlib::default_window_bits,
298 std::streamsize buffer_size = default_device_buffer_size );
299 basic_zlib_decompressor( const zlib_params& p,
300 std::streamsize buffer_size = default_device_buffer_size );
301 zlib::ulong crc() { return this->filter().crc(); }
302 int total_out() { return this->filter().total_out(); }
303 bool eof() { return this->filter().eof(); }
304 };
305 BOOST_IOSTREAMS_PIPABLE(basic_zlib_decompressor, 1)
306
307 typedef basic_zlib_decompressor<> zlib_decompressor;
308
309 //----------------------------------------------------------------------------//
310
311 //------------------Implementation of zlib_allocator--------------------------//
312
313 namespace detail {
314
315 template<typename Alloc, typename Base>
316 void* zlib_allocator<Alloc, Base>::allocate
317 (void* self, zlib::uint items, zlib::uint size)
318 {
319 size_type len = items * size;
320 char* ptr =
321 static_cast<allocator_type*>(self)->allocate
322 (len + sizeof(size_type)
323 #if BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, == 1)
324 , (char*)0
325 #endif
326 );
327 *reinterpret_cast<size_type*>(ptr) = len;
328 return ptr + sizeof(size_type);
329 }
330
331 template<typename Alloc, typename Base>
332 void zlib_allocator<Alloc, Base>::deallocate(void* self, void* address)
333 {
334 char* ptr = reinterpret_cast<char*>(address) - sizeof(size_type);
335 size_type len = *reinterpret_cast<size_type*>(ptr) + sizeof(size_type);
336 static_cast<allocator_type*>(self)->deallocate(ptr, len);
337 }
338
339 //------------------Implementation of zlib_compressor_impl--------------------//
340
341 template<typename Alloc>
342 zlib_compressor_impl<Alloc>::zlib_compressor_impl(const zlib_params& p)
343 { init(p, true, static_cast<zlib_allocator<Alloc>&>(*this)); }
344
345 template<typename Alloc>
346 zlib_compressor_impl<Alloc>::~zlib_compressor_impl()
347 { reset(true, false); }
348
349 template<typename Alloc>
350 bool zlib_compressor_impl<Alloc>::filter
351 ( const char*& src_begin, const char* src_end,
352 char*& dest_begin, char* dest_end, bool flush )
353 {
354 before(src_begin, src_end, dest_begin, dest_end);
355 int result = xdeflate(flush ? zlib::finish : zlib::no_flush);
356 after(src_begin, dest_begin, true);
357 zlib_error::check BOOST_PREVENT_MACRO_SUBSTITUTION(result);
358 return result != zlib::stream_end;
359 }
360
361 template<typename Alloc>
362 void zlib_compressor_impl<Alloc>::close() { reset(true, true); }
363
364 //------------------Implementation of zlib_decompressor_impl------------------//
365
366 template<typename Alloc>
367 zlib_decompressor_impl<Alloc>::zlib_decompressor_impl(const zlib_params& p)
368 : eof_(false)
369 { init(p, false, static_cast<zlib_allocator<Alloc>&>(*this)); }
370
371 template<typename Alloc>
372 zlib_decompressor_impl<Alloc>::~zlib_decompressor_impl()
373 { reset(false, false); }
374
375 template<typename Alloc>
376 zlib_decompressor_impl<Alloc>::zlib_decompressor_impl(int window_bits)
377 {
378 zlib_params p;
379 p.window_bits = window_bits;
380 init(p, false, static_cast<zlib_allocator<Alloc>&>(*this));
381 }
382
383 template<typename Alloc>
384 bool zlib_decompressor_impl<Alloc>::filter
385 ( const char*& src_begin, const char* src_end,
386 char*& dest_begin, char* dest_end, bool /* flush */ )
387 {
388 before(src_begin, src_end, dest_begin, dest_end);
389 int result = xinflate(zlib::sync_flush);
390 after(src_begin, dest_begin, false);
391 zlib_error::check BOOST_PREVENT_MACRO_SUBSTITUTION(result);
392 return !(eof_ = result == zlib::stream_end);
393 }
394
395 template<typename Alloc>
396 void zlib_decompressor_impl<Alloc>::close() {
397 eof_ = false;
398 reset(false, true);
399 }
400
401 } // End namespace detail.
402
403 //------------------Implementation of zlib_decompressor-----------------------//
404
405 template<typename Alloc>
406 basic_zlib_compressor<Alloc>::basic_zlib_compressor
407 (const zlib_params& p, std::streamsize buffer_size)
408 : base_type(buffer_size, p) { }
409
410 //------------------Implementation of zlib_decompressor-----------------------//
411
412 template<typename Alloc>
413 basic_zlib_decompressor<Alloc>::basic_zlib_decompressor
414 (int window_bits, std::streamsize buffer_size)
415 : base_type(buffer_size, window_bits) { }
416
417 template<typename Alloc>
418 basic_zlib_decompressor<Alloc>::basic_zlib_decompressor
419 (const zlib_params& p, std::streamsize buffer_size)
420 : base_type(buffer_size, p) { }
421
422 //----------------------------------------------------------------------------//
423
424 } } // End namespaces iostreams, boost.
425
426 #include <boost/config/abi_suffix.hpp> // Pops abi_suffix.hpp pragmas.
427 #ifdef BOOST_MSVC
428 # pragma warning(pop)
429 #endif
430
431 #endif // #ifndef BOOST_IOSTREAMS_ZLIB_HPP_INCLUDED
432