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>
25 // OK, this is ugly, but it is the only workaround I found to compile
26 // with gcc (any version) on a system which uses a non-GNU toolchain.
27 // The problem is that gcc uses a weak symbol for a particular
28 // instantiation and that the system linker usually does not
29 // understand those weak symbols (seen on HP-UX, tru64, AIX and
30 // others). Thus we force an explicit instanciation of this particular
32 template struct boost::detail::crc_table_t<32, 0x04C11DB7, true>;
34 // Various implementations of lyx::sum(), depending on what methods
35 // are available. Order is faster to slowest.
36 #if defined(HAVE_MMAP) && defined(HAVE_MUNMAP)
38 // Make sure we get modern version of mmap and friends with void*,
39 // not `compatibility' version with caddr_t.
40 #define _POSIX_C_SOURCE 199506L
42 #include <sys/types.h>
51 unsigned long lyx::support::sum(string const & file)
53 lyxerr[Debug::FILES] << "lyx::sum() using mmap (lightning fast)"
56 int fd = open(file.c_str(), 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);
91 template<typename InputIterator>
93 unsigned long do_crc(InputIterator first, InputIterator last)
95 boost::crc_32_type crc;
96 crc = std::for_each(first, last, crc);
97 return crc.checksum();
102 #if HAVE_DECL_ISTREAMBUF_ITERATOR
104 using std::istreambuf_iterator;
106 unsigned long lyx::support::sum(string const & file)
108 lyxerr[Debug::FILES] << "lyx::sum() using istreambuf_iterator (fast)"
111 ifstream ifs(file.c_str());
114 istreambuf_iterator<char> beg(ifs);
115 istreambuf_iterator<char> end;
117 return do_crc(beg,end);
121 using std::istream_iterator;
124 unsigned long lyx::support::sum(string const & file)
127 << "lyx::sum() using istream_iterator (slow as a snail)"
130 ifstream ifs(file.c_str());
133 ifs.unsetf(ios::skipws);
134 istream_iterator<char> beg(ifs);
135 istream_iterator<char> end;
137 return do_crc(beg,end);