forcerecovery.cpp

FastDb是高效的内存数据库系统

#include <stdio.h>
#include <string.h>
#include "fastdb.h"


int main(int argc, char* argv[])
{
  if (argc < 2)
  {
    fprintf(stderr, "Usage: forcerecovery [-shadow] [-norecovery] DATABASE-FILE-NAME\n");
    return 1;
  }

  bool swapCurr = false;
  int  dirty = 1;
  FILE* f = NULL;

  for (int i = 1; i < argc; i++)
  {
    if (strcmp(argv[i], "-shadow") == 0)
    {
      swapCurr = true;
    }
    else if (strcmp(argv[i], "-norecovery") == 0)
    {
      dirty = 0;
    }
    else if (*argv[i] == '-')
    {
      fprintf(stderr, "No such option '%s'\n", argv[i]);
      return 1;
    }
    else if (f != NULL)
    {
      fprintf(stderr, "File was already specified\n");
      return 1;
    }
    else
    {
      f = fopen(argv[i], "r+b");

      if (f == NULL)
      {
        fprintf(stderr, "Failed to open database file '%s'\n", argv[1]);
        return 1;
      }
    }
  }

  if (f == NULL)
  {
    fprintf(stderr, "File was not specified\n");
    return 1;
  }

  dbHeader rec;

  if (fread(&rec, sizeof(dbRecord), 1, f) != 1)
  {
    fprintf(stderr, "Failed to read database header\n");
    return 1;
  }

  if (swapCurr)
  {
    rec.curr = 1 - rec.curr;
  }

  rec.dirty = dirty;
  fseek(f, 0, 0);

  if (fwrite(&rec, sizeof(dbRecord), 1, f) != 1)
  {
    fprintf(stderr, "Failed to write database header\n");
    return 1;
  }

  fclose(f);
  return 0;
}