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"
14 #include "support/debug.h"
15 #include "support/FileName.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 struct 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 #ifdef HAVE_SYS_TYPES_H
38 # include <sys/types.h>
40 #ifdef HAVE_SYS_STAT_H
41 # include <sys/stat.h>
54 unsigned long sum(char const * file)
56 //LYXERR(Debug::FILES, "lyx::sum() using mmap (lightning fast)");
58 int fd = open(file, O_RDONLY);
65 void * mm = mmap(0, info.st_size, PROT_READ,
67 // Some platforms have the wrong type for MAP_FAILED (compaq cxx).
68 if (mm == reinterpret_cast<void*>(MAP_FAILED)) {
73 char * beg = static_cast<char*>(mm);
74 char * end = beg + info.st_size;
76 boost::crc_32_type crc;
77 crc.process_block(beg, end);
78 unsigned long result = crc.checksum();
80 munmap(mm, info.st_size);
86 } // namespace support
96 template<typename InputIterator>
98 unsigned long do_crc(InputIterator first, InputIterator last)
100 boost::crc_32_type crc;
101 crc = for_each(first, last, crc);
102 return crc.checksum();
112 unsigned long sum(char const * file)
114 ifstream ifs(file, ios_base::in | ios_base::binary);
118 #if HAVE_DECL_ISTREAMBUF_ITERATOR
119 //LYXERR(Debug::FILES, "lyx::sum() using istreambuf_iterator (fast)");
120 istreambuf_iterator<char> beg(ifs);
121 istreambuf_iterator<char> end;
123 //LYXERR(Debug::FILES, "lyx::sum() using istream_iterator (slow as a snail)");
124 ifs.unsetf(ios::skipws);
125 istream_iterator<char> beg(ifs);
126 istream_iterator<char> end;
129 return do_crc(beg,end);
132 } // namespace support