/* This file is part of
* ======================================================
- *
- * LyX, The Document Processor
*
- * The function lyx::sum is taken from GNU textutill-1.22
- * and is there part of the program chsum. The chsum program
- * is written by Q. Frank Xia, qx@math.columbia.edu.
- *
- * Modified for use in LyX by Lars G. Bjønnes.
+ * LyX, The Document Processor
+ * Copyright 2001 The LyX Team.
*
* ======================================================
*/
#include <config.h>
-#ifdef MODERN_STL_STREAMS
-#include <fstream>
-using std::ifstream;
-#else
-#include <cstdio>
-#endif
#include "support/lyxlib.h"
+#include "debug.h"
+#include <algorithm>
+#include <boost/crc.hpp>
-/* Number of bytes to read at once. */
-#define BUFLEN (1 << 16)
+using std::endl;
-// DO _NOT_ CHANGE _ANYTHING_ IN THIS TABLE
-static unsigned long const crctab[256] =
-{
- 0x0,
- 0x04C11DB7, 0x09823B6E, 0x0D4326D9, 0x130476DC, 0x17C56B6B,
- 0x1A864DB2, 0x1E475005, 0x2608EDB8, 0x22C9F00F, 0x2F8AD6D6,
- 0x2B4BCB61, 0x350C9B64, 0x31CD86D3, 0x3C8EA00A, 0x384FBDBD,
- 0x4C11DB70, 0x48D0C6C7, 0x4593E01E, 0x4152FDA9, 0x5F15ADAC,
- 0x5BD4B01B, 0x569796C2, 0x52568B75, 0x6A1936C8, 0x6ED82B7F,
- 0x639B0DA6, 0x675A1011, 0x791D4014, 0x7DDC5DA3, 0x709F7B7A,
- 0x745E66CD, 0x9823B6E0, 0x9CE2AB57, 0x91A18D8E, 0x95609039,
- 0x8B27C03C, 0x8FE6DD8B, 0x82A5FB52, 0x8664E6E5, 0xBE2B5B58,
- 0xBAEA46EF, 0xB7A96036, 0xB3687D81, 0xAD2F2D84, 0xA9EE3033,
- 0xA4AD16EA, 0xA06C0B5D, 0xD4326D90, 0xD0F37027, 0xDDB056FE,
- 0xD9714B49, 0xC7361B4C, 0xC3F706FB, 0xCEB42022, 0xCA753D95,
- 0xF23A8028, 0xF6FB9D9F, 0xFBB8BB46, 0xFF79A6F1, 0xE13EF6F4,
- 0xE5FFEB43, 0xE8BCCD9A, 0xEC7DD02D, 0x34867077, 0x30476DC0,
- 0x3D044B19, 0x39C556AE, 0x278206AB, 0x23431B1C, 0x2E003DC5,
- 0x2AC12072, 0x128E9DCF, 0x164F8078, 0x1B0CA6A1, 0x1FCDBB16,
- 0x018AEB13, 0x054BF6A4, 0x0808D07D, 0x0CC9CDCA, 0x7897AB07,
- 0x7C56B6B0, 0x71159069, 0x75D48DDE, 0x6B93DDDB, 0x6F52C06C,
- 0x6211E6B5, 0x66D0FB02, 0x5E9F46BF, 0x5A5E5B08, 0x571D7DD1,
- 0x53DC6066, 0x4D9B3063, 0x495A2DD4, 0x44190B0D, 0x40D816BA,
- 0xACA5C697, 0xA864DB20, 0xA527FDF9, 0xA1E6E04E, 0xBFA1B04B,
- 0xBB60ADFC, 0xB6238B25, 0xB2E29692, 0x8AAD2B2F, 0x8E6C3698,
- 0x832F1041, 0x87EE0DF6, 0x99A95DF3, 0x9D684044, 0x902B669D,
- 0x94EA7B2A, 0xE0B41DE7, 0xE4750050, 0xE9362689, 0xEDF73B3E,
- 0xF3B06B3B, 0xF771768C, 0xFA325055, 0xFEF34DE2, 0xC6BCF05F,
- 0xC27DEDE8, 0xCF3ECB31, 0xCBFFD686, 0xD5B88683, 0xD1799B34,
- 0xDC3ABDED, 0xD8FBA05A, 0x690CE0EE, 0x6DCDFD59, 0x608EDB80,
- 0x644FC637, 0x7A089632, 0x7EC98B85, 0x738AAD5C, 0x774BB0EB,
- 0x4F040D56, 0x4BC510E1, 0x46863638, 0x42472B8F, 0x5C007B8A,
- 0x58C1663D, 0x558240E4, 0x51435D53, 0x251D3B9E, 0x21DC2629,
- 0x2C9F00F0, 0x285E1D47, 0x36194D42, 0x32D850F5, 0x3F9B762C,
- 0x3B5A6B9B, 0x0315D626, 0x07D4CB91, 0x0A97ED48, 0x0E56F0FF,
- 0x1011A0FA, 0x14D0BD4D, 0x19939B94, 0x1D528623, 0xF12F560E,
- 0xF5EE4BB9, 0xF8AD6D60, 0xFC6C70D7, 0xE22B20D2, 0xE6EA3D65,
- 0xEBA91BBC, 0xEF68060B, 0xD727BBB6, 0xD3E6A601, 0xDEA580D8,
- 0xDA649D6F, 0xC423CD6A, 0xC0E2D0DD, 0xCDA1F604, 0xC960EBB3,
- 0xBD3E8D7E, 0xB9FF90C9, 0xB4BCB610, 0xB07DABA7, 0xAE3AFBA2,
- 0xAAFBE615, 0xA7B8C0CC, 0xA379DD7B, 0x9B3660C6, 0x9FF77D71,
- 0x92B45BA8, 0x9675461F, 0x8832161A, 0x8CF30BAD, 0x81B02D74,
- 0x857130C3, 0x5D8A9099, 0x594B8D2E, 0x5408ABF7, 0x50C9B640,
- 0x4E8EE645, 0x4A4FFBF2, 0x470CDD2B, 0x43CDC09C, 0x7B827D21,
- 0x7F436096, 0x7200464F, 0x76C15BF8, 0x68860BFD, 0x6C47164A,
- 0x61043093, 0x65C52D24, 0x119B4BE9, 0x155A565E, 0x18197087,
- 0x1CD86D30, 0x029F3D35, 0x065E2082, 0x0B1D065B, 0x0FDC1BEC,
- 0x3793A651, 0x3352BBE6, 0x3E119D3F, 0x3AD08088, 0x2497D08D,
- 0x2056CD3A, 0x2D15EBE3, 0x29D4F654, 0xC5A92679, 0xC1683BCE,
- 0xCC2B1D17, 0xC8EA00A0, 0xD6AD50A5, 0xD26C4D12, 0xDF2F6BCB,
- 0xDBEE767C, 0xE3A1CBC1, 0xE760D676, 0xEA23F0AF, 0xEEE2ED18,
- 0xF0A5BD1D, 0xF464A0AA, 0xF9278673, 0xFDE69BC4, 0x89B8FD09,
- 0x8D79E0BE, 0x803AC667, 0x84FBDBD0, 0x9ABC8BD5, 0x9E7D9662,
- 0x933EB0BB, 0x97FFAD0C, 0xAFB010B1, 0xAB710D06, 0xA6322BDF,
- 0xA2F33668, 0xBCB4666D, 0xB8757BDA, 0xB5365D03, 0xB1F740B4
-};
-
-/* Calculate the checksum of file FILE.
- Return crc if successful, 0 if an error occurs. */
-
-unsigned long
-lyx::sum (char const * file)
+// Various implementations of lyx::sum(), depending on what methods
+// are available. Order is faster to slowest.
+#if defined(HAVE_MMAP) && defined(HAVE_MUNMAP)
+
+// Make sure we get modern version of mmap and friends with void*,
+// not `compatibility' version with caddr_t.
+#define _POSIX_C_SOURCE 199506L
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+
+unsigned long lyx::sum(string const & file)
{
- unsigned long crc = 0;
- long length = 0;
- long bytes_read;
-#ifdef MODERN_STL_STREAMS
- char buf[BUFLEN];
- ifstream ifs(file);
- if (!ifs) {
- return 0;
- }
-
- while ((bytes_read = ifs.readsome(buf, BUFLEN)) > 0) {
- unsigned char * cp = reinterpret_cast<unsigned char*>(buf);
- length += bytes_read;
- while (bytes_read--)
- crc = (crc << 8) ^ crctab[((crc >> 24) ^ *(cp++)) & 0xFF];
- }
-
- if (ifs.fail()) {
- ifs.close();
+ lyxerr[Debug::FILES] << "lyx::sum() using mmap (lightning fast)"
+ << endl;
+
+ int fd = open(file.c_str(), O_RDONLY);
+ if (!fd)
return 0;
- }
- ifs.close();
- if (ifs.fail()) {
+ struct stat info;
+ fstat(fd, &info);
+
+ void * mm = mmap(0, info.st_size, PROT_READ,
+ MAP_PRIVATE, fd, 0);
+ // Some platforms have the wrong type for MAP_FAILED (compaq cxx).
+ if (mm == reinterpret_cast<void*>(MAP_FAILED)) {
+ close(fd);
return 0;
}
+
+ char * beg = static_cast<char*>(mm);
+ char * end = beg + info.st_size;
+
+ boost::crc_32_type crc;
+ crc.process_block(beg, end);
+ unsigned long result = crc.checksum();
+
+ munmap(mm, info.st_size);
+ close(fd);
+
+ return result;
+}
+#else // No mmap
+
+#include <fstream>
+#include <iterator>
+
+using std::for_each;
+
+namespace {
+
+template<typename InputIterator>
+inline
+unsigned long do_crc(InputIterator first, InputIterator last)
+{
+ boost::crc_32_type crc;
+ crc = for_each(first, last, crc);
+ return crc.checksum();
+}
+
+} // namespace
+
+#if HAVE_DECL_ISTREAMBUF_ITERATOR
+using std::ifstream;
+using std::istreambuf_iterator;
+
+unsigned long lyx::sum(string const & file)
+{
+ lyxerr[Debug::FILES] << "lyx::sum() using istreambuf_iterator (fast)"
+ << endl;
+
+ ifstream ifs(file.c_str());
+ if (!ifs) return 0;
+
+ istreambuf_iterator<char> beg(ifs);
+ istreambuf_iterator<char> end;
+
+ return do_crc(beg,end);
+}
#else
- unsigned char buf[BUFLEN];
-
- register FILE * fp = fopen (file, "r");
- if (fp == 0) {
- return 0;
- }
-
- while ((bytes_read = fread (buf, 1, BUFLEN, fp)) > 0) {
- unsigned char *cp = buf;
-
- length += bytes_read;
- while (bytes_read--)
- crc = (crc << 8) ^ crctab[((crc >> 24) ^ *(cp++)) & 0xFF];
- }
-
- if (ferror (fp)) {
- fclose (fp);
- return 0;
- }
-
- if (fclose (fp) == EOF) {
- return 0;
- }
-#endif
- bytes_read = length;
- while (bytes_read > 0) {
- crc = (crc << 8) ^ crctab[((crc >> 24) ^ bytes_read) & 0xFF];
- bytes_read >>= 8;
- }
-
- crc = ~crc & 0xFFFFFFFF;
-
- return crc;
+
+using std::istream_iterator;
+using std::ios;
+
+unsigned long lyx::sum(string const & file)
+{
+ lyxerr[Debug::FILES]
+ << "lyx::sum() using istream_iterator (slow as a snail)"
+ << endl;
+
+ ifstream ifs(file.c_str());
+ if (!ifs) return 0;
+
+ ifs.unsetf(ios::skipws);
+ istream_iterator<char> beg(ifs);
+ istream_iterator<char> end;
+
+ return do_crc(beg,end);
}
-
+#endif
+#endif // mmap
projects / lyx.git / blobdiff