tools/tests/perf_index/stress_file_read.c

   1 #include <fcntl.h>
   2 #include "perf_index.h"
   3 #include <errno.h>
   4
   5 #define MAXFILESIZE 8589934592L
   6 #define MIN(a,b) ((a)<(b) ? (a) : (b))
   7
   8 static char readbuff[4096];
   9
  10 void stress_file_read_init(const char *fs_path, int num_threads, long long length, long long max_file_size) {
  11   int fd;
  12   char filepath[MAXPATHLEN];
  13   long long left;
  14   size_t writelen;
  15
  16   if(max_file_size == 0)
  17     max_file_size = MAXFILESIZE;
  18
  19   left = MIN(length, max_file_size/num_threads);
  20
  21   snprintf(filepath, sizeof(filepath), "%s/file_read", fs_path);
  22   fd = open(filepath, O_CREAT | O_EXCL | O_WRONLY, 0644);
  23   assert(fd > 0);
  24   bzero(readbuff, sizeof(readbuff));
  25
  26   while(left > 0) {
  27     writelen = sizeof(readbuff) < left ? sizeof(readbuff) : left;
  28     assert(write(fd, readbuff, writelen) == writelen);
  29     left -= writelen;
  30   }
  31 }
  32
  33 void stress_file_read(const char *fs_path, int thread_id, int num_threads, long long length, long long max_file_size) {
  34   long long left;
  35   size_t file_offset = 0;
  36   int readlen;
  37   int fd;
  38   char filepath[MAXPATHLEN];
  39   long long filesize;
  40
  41
  42   if(max_file_size == 0)
  43     max_file_size = MAXFILESIZE;
  44   filesize =  MIN(length, max_file_size/num_threads);
  45
  46   snprintf(filepath, sizeof(filepath), "%s/file_read", fs_path);
  47   fd = open(filepath, O_RDONLY);
  48   assert(fd > 0);
  49   for(left=length; left>0;) {
  50     readlen = sizeof(readbuff) < left ? sizeof(readbuff) : left;
  51     if(file_offset+readlen > filesize) {
  52       lseek(fd, 0, SEEK_SET);
  53       file_offset = 0;
  54       continue;
  55     }
  56     assert(read(fd, readbuff, readlen) == readlen);
  57     left -= readlen;
  58     file_offset += readlen;
  59   }
  60 }
  61
  62 void stress_file_read_cleanup(const char *fs_path, int num_threads, long long length) {
  63   char filepath[MAXPATHLEN];
  64   snprintf(filepath, sizeof(filepath), "%s/file_read", fs_path);
  65   assert(unlink(filepath)>=0);
  66 }