1: /* mmapを抽象化する
    2:  *
    3:  * *Unix系のシステムコールをソース中に散らさないため
    4:  * *将来的には一つのファイルを複数の目的にmapすることも考慮
    5:  *
    6:  * Copyright (C) 2005 TABATA Yusuke
    7:  *
    8:  */
    9: /*
   10:   This library is free software; you can redistribute it and/or
   11:   modify it under the terms of the GNU Lesser General Public
   12:   License as published by the Free Software Foundation; either
   13:   version 2 of the License, or (at your option) any later version.
   14: 
   15:   This library is distributed in the hope that it will be useful,
   16:   but WITHOUT ANY WARRANTY; without even the implied warranty of
   17:   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   18:   Lesser General Public License for more details.
   19: 
   20:   You should have received a copy of the GNU Lesser General Public
   21:   License along with this library; if not, write to the Free Software
   22:   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
   23:  */
   24: #include <sys/types.h>
   25: #include <sys/mman.h>
   26: #include <sys/stat.h>
   27: #include <unistd.h>
   28: #include <fcntl.h>
   29: #include <stdlib.h>
   30: 
   31: #include <anthy/filemap.h>
   32: #include <anthy/logger.h>
   33: 
   34: struct filemapping {
   35:   /* 書き込みモード */
   36:   int wr;
   37:   /* mmapしたアドレス */
   38:   void *ptr;
   39:   /* mmapした領域の長さ */
   40:   size_t size;
   41: };
   42: 
   43: struct filemapping *
   44: anthy_mmap(const char *fn, int wr)
   45: {
   46:   int fd;
   47:   void *ptr;
   48:   int r;
   49:   struct filemapping *m;
   50:   struct stat st;
   51:   int prot;
   52:   int flags;
   53:   mode_t mode;
   54: 
   55:   if (wr) {
   56:     prot = PROT_READ | PROT_WRITE;
   57:     flags = O_RDWR;
   58:     mode = S_IRUSR | S_IWUSR;
   59:   } else {
   60:     prot = PROT_READ;
   61:     flags = O_RDONLY;
   62:     mode = S_IRUSR;
   63:   }
   64: 
   65:   fd = open(fn, flags, mode);
   66: 
   67:   if (fd == -1) {
   68:     anthy_log(0, "Failed to open (%s).\n", fn);
   69:     return NULL;
   70:   }
   71: 
   72:   r = fstat(fd, &st);
   73:   if (r == -1) {
   74:     anthy_log(0, "Failed to stat() (%s).\n", fn);
   75:     close(fd);
   76:     return NULL;
   77:   }
   78:   if (st.st_size == 0) {
   79:     anthy_log(0, "Failed to mmap 0size file (%s).\n", fn);
   80:     close(fd);
   81:     return NULL;
   82:   }
   83: 
   84:   ptr = mmap(NULL, st.st_size, prot, MAP_SHARED, fd, 0);
   85:   close(fd);
   86:   if (ptr == MAP_FAILED) {
   87:     anthy_log(0, "Failed to mmap() (%s).\n", fn);
   88:     return NULL;
   89:   }
   90: 
   91:   /* mmapに成功したので情報を返す */
   92:   m = malloc(sizeof(struct filemapping));
   93:   m->size = st.st_size;
   94:   m->ptr = ptr;
   95:   m->wr = wr;
   96: 
   97:   return m;
   98: }
   99: 
  100: void *
  101: anthy_mmap_address(struct filemapping *m)
  102: {
  103:   if (!m) {
  104:     return NULL;
  105:   }
  106:   return m->ptr;
  107: }
  108: 
  109: int
  110: anthy_mmap_size(struct filemapping *m)
  111: {
  112:   if (!m) {
  113:     return 0;
  114:   }
  115:   return m->size;
  116: }
  117: 
  118: int
  119: anthy_mmap_is_writable(struct filemapping *m)
  120: {
  121:   if (!m) {
  122:     return 0;
  123:   }
  124:   return m->wr;
  125: }
  126: 
  127: void
  128: anthy_munmap(struct filemapping *m)
  129: {
  130:   if (!m) {
  131:     return ;
  132:   }
  133:   munmap(m->ptr, m->size);
  134:   free(m);
  135: }