comparison audioDB.cpp @ 173:42585bd03636 no-big-mmap

Don't use mmap() in database creation

 void audioDB::create(const char* dbName){
   if ((dbfid = open (dbName, O_RDWR|O_CREAT|O_EXCL, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)) < 0)
     error("Can't create database file", dbName, "open");
   get_lock(dbfid, 1);
 
-  // go to the location corresponding to the last byte
-  if (lseek (dbfid, size - 1, SEEK_SET) == -1)
-    error("lseek error in db file", "", "lseek");
-
-  // write a dummy byte at the last location
-  if (write (dbfid, "", 1) != 1)
-    error("write error", "", "write");
-  
   // mmap the output file
   if(verbosity) {
     cerr << "header size:" << O2_HEADERSIZE << endl;
   }
-  if ((db = (char*) mmap(0, size, PROT_READ | PROT_WRITE,
-			 MAP_SHARED, dbfid, 0)) == (caddr_t) -1)
-    error("mmap error for creating database", "", "mmap");
   
   dbH = new dbTableHeaderT();
   assert(dbH);
 
   unsigned int maxfiles = (unsigned int) rint((double) O2_MAXFILES * (double) size / (double) O2_DEFAULTDBSIZE);

   dbH->dataOffset = ALIGN_UP(dbH->trackTableOffset + O2_TRACKTABLESIZE*maxfiles, 8);
   dbH->l2normTableOffset = ALIGN_DOWN(size - maxfiles*O2_MEANNUMVECTORS*sizeof(double), 8);
   dbH->timesTableOffset = ALIGN_DOWN(dbH->l2normTableOffset - maxfiles*O2_MEANNUMVECTORS*sizeof(double), 8);
   dbH->dbSize = size;
 
-  memcpy (db, dbH, O2_HEADERSIZE);
+  write(dbfid, dbH, O2_HEADERSIZE);
+
+  // go to the location corresponding to the last byte
+  if (lseek (dbfid, size - 1, SEEK_SET) == -1)
+    error("lseek error in db file", "", "lseek");
+
+  // write a dummy byte at the last location
+  if (write (dbfid, "", 1) != 1)
+    error("write error", "", "write");
+  
   if(verbosity) {
     cerr << COM_CREATE << " " << dbName << endl;
   }
 }