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/lyxlib.h"
17 #include <boost/crc.hpp>
24 // OK, this is ugly, but it is the only workaround I found to compile
25 // with gcc (any version) on a system which uses a non-GNU toolchain.
26 // The problem is that gcc uses a weak symbol for a particular
27 // instantiation and that the system linker usually does not
28 // understand those weak symbols (seen on HP-UX, tru64, AIX and
29 // others). Thus we force an explicit instanciation of this particular
31 template class boost::detail::crc_table_t<32, 0x04C11DB7, true>;
33 // Various implementations of lyx::sum(), depending on what methods
34 // are available. Order is faster to slowest.
35 #if defined(HAVE_MMAP) && defined(HAVE_MUNMAP)
37 // Make sure we get modern version of mmap and friends with void*,
38 // not `compatibility' version with caddr_t.
39 #define _POSIX_C_SOURCE 199506L
41 #include <sys/types.h>
48 unsigned long lyx::support::sum(string const & file)
50 lyxerr[Debug::FILES] << "lyx::sum() using mmap (lightning fast)"
53 int fd = open(file.c_str(), O_RDONLY);
60 void * mm = mmap(0, info.st_size, PROT_READ,
62 // Some platforms have the wrong type for MAP_FAILED (compaq cxx).
63 if (mm == reinterpret_cast<void*>(MAP_FAILED)) {
68 char * beg = static_cast<char*>(mm);
69 char * end = beg + info.st_size;
71 boost::crc_32_type crc;
72 crc.process_block(beg, end);
73 unsigned long result = crc.checksum();
75 munmap(mm, info.st_size);
88 template<typename InputIterator>
90 unsigned long do_crc(InputIterator first, InputIterator last)
92 boost::crc_32_type crc;
93 crc = std::for_each(first, last, crc);
94 return crc.checksum();
99 #if HAVE_DECL_ISTREAMBUF_ITERATOR
101 using std::istreambuf_iterator;
103 unsigned long lyx::support::sum(string const & file)
105 lyxerr[Debug::FILES] << "lyx::sum() using istreambuf_iterator (fast)"
108 ifstream ifs(file.c_str());
111 istreambuf_iterator<char> beg(ifs);
112 istreambuf_iterator<char> end;
114 return do_crc(beg,end);
118 using std::istream_iterator;
121 unsigned long lyx::support::sum(string const & file)
124 << "lyx::sum() using istream_iterator (slow as a snail)"
127 ifstream ifs(file.c_str());
130 ifs.unsetf(ios::skipws);
131 istream_iterator<char> beg(ifs);
132 istream_iterator<char> end;
134 return do_crc(beg,end);