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 "support/FileName.h"
19 #include <boost/crc.hpp>
27 // OK, this is ugly, but it is the only workaround I found to compile
28 // with gcc (any version) on a system which uses a non-GNU toolchain.
29 // The problem is that gcc uses a weak symbol for a particular
30 // instantiation and that the system linker usually does not
31 // understand those weak symbols (seen on HP-UX, tru64, AIX and
32 // others). Thus we force an explicit instanciation of this particular
34 template struct boost::detail::crc_table_t<32, 0x04C11DB7, true>;
36 // Various implementations of lyx::sum(), depending on what methods
37 // are available. Order is faster to slowest.
38 #if defined(HAVE_MMAP) && defined(HAVE_MUNMAP)
40 // Make sure we get modern version of mmap and friends with void*,
41 // not `compatibility' version with caddr_t.
42 #define _POSIX_C_SOURCE 199506L
44 #ifdef HAVE_SYS_TYPES_H
45 # include <sys/types.h>
47 #ifdef HAVE_SYS_STAT_H
48 # include <sys/stat.h>
61 unsigned long sum(FileName const & file)
63 LYXERR(Debug::FILES) << "lyx::sum() using mmap (lightning fast)"
66 int fd = open(file.toFilesystemEncoding().c_str(), O_RDONLY);
73 void * mm = mmap(0, info.st_size, PROT_READ,
75 // Some platforms have the wrong type for MAP_FAILED (compaq cxx).
76 if (mm == reinterpret_cast<void*>(MAP_FAILED)) {
81 char * beg = static_cast<char*>(mm);
82 char * end = beg + info.st_size;
84 boost::crc_32_type crc;
85 crc.process_block(beg, end);
86 unsigned long result = crc.checksum();
88 munmap(mm, info.st_size);
94 } // namespace support
105 template<typename InputIterator>
107 unsigned long do_crc(InputIterator first, InputIterator last)
109 boost::crc_32_type crc;
110 crc = std::for_each(first, last, crc);
111 return crc.checksum();
121 #if HAVE_DECL_ISTREAMBUF_ITERATOR
122 using std::istreambuf_iterator;
124 unsigned long sum(FileName const & file)
126 LYXERR(Debug::FILES) << "lyx::sum() using istreambuf_iterator (fast)"
129 ifstream ifs(file.toFilesystemEncoding().c_str());
132 istreambuf_iterator<char> beg(ifs);
133 istreambuf_iterator<char> end;
135 return do_crc(beg,end);
139 using std::istream_iterator;
142 unsigned long sum(FileName const & file)
145 << "lyx::sum() using istream_iterator (slow as a snail)"
148 ifstream ifs(file.toFilesystemEncoding().c_str());
151 ifs.unsetf(ios::skipws);
152 istream_iterator<char> beg(ifs);
153 istream_iterator<char> end;
155 return do_crc(beg,end);
159 } // namespace support