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>
21 // OK, this is ugly, but it is the only workaround I found to compile
22 // with gcc (any version) on a system which uses a non-GNU toolchain.
23 // The problem is that gcc uses a weak symbol for a particular
24 // instantiation and that the system linker usually does not
25 // understand those weak symbols (seen on HP-UX, tru64, AIX and
26 // others). Thus we force an explicit instanciation of this particular
28 template class boost::detail::crc_table_t<32, 0x04C11DB7, true>;
30 // Various implementations of lyx::sum(), depending on what methods
31 // are available. Order is faster to slowest.
32 #if defined(HAVE_MMAP) && defined(HAVE_MUNMAP)
34 // Make sure we get modern version of mmap and friends with void*,
35 // not `compatibility' version with caddr_t.
36 #define _POSIX_C_SOURCE 199506L
38 #include <sys/types.h>
45 unsigned long lyx::support::sum(string const & file)
47 lyxerr[Debug::FILES] << "lyx::sum() using mmap (lightning fast)"
50 int fd = open(file.c_str(), O_RDONLY);
57 void * mm = mmap(0, info.st_size, PROT_READ,
59 // Some platforms have the wrong type for MAP_FAILED (compaq cxx).
60 if (mm == reinterpret_cast<void*>(MAP_FAILED)) {
65 char * beg = static_cast<char*>(mm);
66 char * end = beg + info.st_size;
68 boost::crc_32_type crc;
69 crc.process_block(beg, end);
70 unsigned long result = crc.checksum();
72 munmap(mm, info.st_size);
85 template<typename InputIterator>
87 unsigned long do_crc(InputIterator first, InputIterator last)
89 boost::crc_32_type crc;
90 crc = std::for_each(first, last, crc);
91 return crc.checksum();
96 #if HAVE_DECL_ISTREAMBUF_ITERATOR
98 using std::istreambuf_iterator;
100 unsigned long lyx::support::sum(string const & file)
102 lyxerr[Debug::FILES] << "lyx::sum() using istreambuf_iterator (fast)"
105 ifstream ifs(file.c_str());
108 istreambuf_iterator<char> beg(ifs);
109 istreambuf_iterator<char> end;
111 return do_crc(beg,end);
115 using std::istream_iterator;
118 unsigned long lyx::support::sum(string const & file)
121 << "lyx::sum() using istream_iterator (slow as a snail)"
124 ifstream ifs(file.c_str());
127 ifs.unsetf(ios::skipws);
128 istream_iterator<char> beg(ifs);
129 istream_iterator<char> end;
131 return do_crc(beg,end);