3 * This file is part of LyX, the document processor.
4 * Licence details can be found in the file COPYING.
6 * \author Lars Gullik Bjønnes
8 * Full author contact details are available in file CREDITS.
13 #include "support/debug.h"
15 #include <boost/crc.hpp>
22 // OK, this is ugly, but it is the only workaround I found to compile
23 // with gcc (any version) on a system which uses a non-GNU toolchain.
24 // The problem is that gcc uses a weak symbol for a particular
25 // instantiation and that the system linker usually does not
26 // understand those weak symbols (seen on HP-UX, tru64, AIX and
27 // others). Thus we force an explicit instanciation of this particular
29 template struct boost::detail::crc_table_t<32, 0x04C11DB7, true>;
31 // Various implementations of lyx::sum(), depending on what methods
32 // are available. Order is faster to slowest.
33 #if defined(HAVE_MMAP) && defined(HAVE_MUNMAP)
35 #ifdef HAVE_SYS_TYPES_H
36 # include <sys/types.h>
38 #ifdef HAVE_SYS_STAT_H
39 # include <sys/stat.h>
52 unsigned long sum(char const * file)
54 //LYXERR(Debug::FILES, "lyx::sum() using mmap (lightning fast)");
56 int fd = open(file, O_RDONLY);
63 void * mm = mmap(0, info.st_size, PROT_READ,
65 // Some platforms have the wrong type for MAP_FAILED (compaq cxx).
66 if (mm == reinterpret_cast<void*>(MAP_FAILED)) {
71 char * beg = static_cast<char*>(mm);
72 char * end = beg + info.st_size;
74 boost::crc_32_type crc;
75 crc.process_block(beg, end);
76 unsigned long result = crc.checksum();
78 munmap(mm, info.st_size);
84 } // namespace support
94 template<typename InputIterator>
96 unsigned long do_crc(InputIterator first, InputIterator last)
98 boost::crc_32_type crc;
99 crc = for_each(first, last, crc);
100 return crc.checksum();
110 unsigned long sum(char const * file)
112 ifstream ifs(file, ios_base::in | ios_base::binary);
116 #if HAVE_DECL_ISTREAMBUF_ITERATOR
117 //LYXERR(Debug::FILES, "lyx::sum() using istreambuf_iterator (fast)");
118 istreambuf_iterator<char> beg(ifs);
119 istreambuf_iterator<char> end;
121 //LYXERR(Debug::FILES, "lyx::sum() using istream_iterator (slow as a snail)");
122 ifs.unsetf(ios::skipws);
123 istream_iterator<char> beg(ifs);
124 istream_iterator<char> end;
127 return do_crc(beg,end);
130 } // namespace support