tools/tests/perf_index/stress_file_write.c

   1 #include <fcntl.h>
   2 #include "perf_index.h"
   3 #include <errno.h>
   4
   5 #define MAXFILESIZE 8589934592L
   6
   7 static int *fds = NULL;
   8 static char writebuff[4096];
   9
  10 void stress_file_write_init(const char *fs_path, int num_threads, long long length) {
  11   int i;
  12   char filepath[MAXPATHLEN];
  13
  14   if(fds == NULL)
  15     fds = (int*)malloc(sizeof(int)*num_threads);
  16   for(i=0; i<num_threads; i++) {
  17     snprintf(filepath, sizeof(filepath), "%s/file_write-%d", fs_path, i);
  18     fds[i] = open(filepath, O_CREAT | O_EXCL | O_WRONLY, 0644);
  19     assert(fds[i] > 0);
  20   }
  21   bzero(writebuff, sizeof(writebuff));
  22 }
  23
  24 void stress_file_write(const char *fs_path, int thread_id, int num_threads, long long length, long long max_file_size) {
  25   long long left;
  26   size_t file_offset = 0;
  27   int writelen;
  28   char filepath[MAXPATHLEN];
  29   int fd = fds[thread_id];
  30
  31   if(max_file_size == 0)
  32     max_file_size = MAXFILESIZE;
  33
  34   for(left=length; left>0;) {
  35     writelen = sizeof(writebuff) < left ? sizeof(writebuff) : left;
  36     assert(write(fd, writebuff, writelen) == writelen);
  37     left -= writelen;
  38     file_offset += writelen;
  39     if(file_offset>max_file_size/num_threads) {
  40       lseek(fd, 0, SEEK_SET);
  41       file_offset = 0;
  42     }
  43   }
  44   snprintf(filepath, sizeof(filepath), "%s/file_write-%d", fs_path, thread_id);
  45   assert(unlink(filepath)>=0);
  46 }