src/redis-check-aof.c

   1 #include "fmacros.h"
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include <string.h>
   5 #include <unistd.h>
   6 #include <sys/stat.h>
   7 #include "config.h"
   8
   9 #define ERROR(...) { \
  10     char __buf[1024]; \
  11     sprintf(__buf, __VA_ARGS__); \
  12     sprintf(error, "0x%08lx: %s", epos, __buf); \
  13 }
  14
  15 static char error[1024];
  16 static long epos;
  17
  18 int consumeNewline(char *buf) {
  19     if (strncmp(buf,"\r\n",2) != 0) {
  20         ERROR("Expected \\r\\n, got: %02x%02x",buf[0],buf[1]);
  21         return 0;
  22     }
  23     return 1;
  24 }
  25
  26 int readLong(FILE *fp, char prefix, long *target) {
  27     char buf[128], *eptr;
  28     epos = ftell(fp);
  29     if (fgets(buf,sizeof(buf),fp) == NULL) {
  30         return 0;
  31     }
  32     if (buf[0] != prefix) {
  33         ERROR("Expected prefix '%c', got: '%c'",buf[0],prefix);
  34         return 0;
  35     }
  36     *target = strtol(buf+1,&eptr,10);
  37     return consumeNewline(eptr);
  38 }
  39
  40 int readBytes(FILE *fp, char *target, long length) {
  41     long real;
  42     epos = ftell(fp);
  43     real = fread(target,1,length,fp);
  44     if (real != length) {
  45         ERROR("Expected to read %ld bytes, got %ld bytes",length,real);
  46         return 0;
  47     }
  48     return 1;
  49 }
  50
  51 int readString(FILE *fp, char** target) {
  52     long len;
  53     *target = NULL;
  54     if (!readLong(fp,'$',&len)) {
  55         return 0;
  56     }
  57
  58     /* Increase length to also consume \r\n */
  59     len += 2;
  60     *target = (char*)malloc(len);
  61     if (!readBytes(fp,*target,len)) {
  62         return 0;
  63     }
  64     if (!consumeNewline(*target+len-2)) {
  65         return 0;
  66     }
  67     (*target)[len-2] = '\0';
  68     return 1;
  69 }
  70
  71 int readArgc(FILE *fp, long *target) {
  72     return readLong(fp,'*',target);
  73 }
  74
  75 long process(FILE *fp) {
  76     long argc, pos = 0;
  77     int i, multi = 0;
  78     char *str;
  79
  80     while(1) {
  81         if (!multi) pos = ftell(fp);
  82         if (!readArgc(fp, &argc)) break;
  83
  84         for (i = 0; i < argc; i++) {
  85             if (!readString(fp,&str)) break;
  86             if (i == 0) {
  87                 if (strcasecmp(str, "multi") == 0) {
  88                     if (multi++) {
  89                         ERROR("Unexpected MULTI");
  90                         break;
  91                     }
  92                 } else if (strcasecmp(str, "exec") == 0) {
  93                     if (--multi) {
  94                         ERROR("Unexpected EXEC");
  95                         break;
  96                     }
  97                 }
  98             }
  99             free(str);
 100         }
 101
 102         /* Stop if the loop did not finish */
 103         if (i < argc) {
 104             if (str) free(str);
 105             break;
 106         }
 107     }
 108
 109     if (feof(fp) && multi && strlen(error) == 0) {
 110         ERROR("Reached EOF before reading EXEC for MULTI");
 111     }
 112     if (strlen(error) > 0) {
 113         printf("%s\n", error);
 114     }
 115     return pos;
 116 }
 117
 118 int main(int argc, char **argv) {
 119     char *filename;
 120     int fix = 0;
 121
 122     if (argc < 2) {
 123         printf("Usage: %s [--fix] <file.aof>\n", argv[0]);
 124         exit(1);
 125     } else if (argc == 2) {
 126         filename = argv[1];
 127     } else if (argc == 3) {
 128         if (strcmp(argv[1],"--fix") != 0) {
 129             printf("Invalid argument: %s\n", argv[1]);
 130             exit(1);
 131         }
 132         filename = argv[2];
 133         fix = 1;
 134     } else {
 135         printf("Invalid arguments\n");
 136         exit(1);
 137     }
 138
 139     FILE *fp = fopen(filename,"r+");
 140     if (fp == NULL) {
 141         printf("Cannot open file: %s\n", filename);
 142         exit(1);
 143     }
 144
 145     struct redis_stat sb;
 146     if (redis_fstat(fileno(fp),&sb) == -1) {
 147         printf("Cannot stat file: %s\n", filename);
 148         exit(1);
 149     }
 150
 151     long size = sb.st_size;
 152     if (size == 0) {
 153         printf("Empty file: %s\n", filename);
 154         exit(1);
 155     }
 156
 157     long pos = process(fp);
 158     long diff = size-pos;
 159     if (diff > 0) {
 160         if (fix) {
 161             char buf[2];
 162             printf("This will shrink the AOF from %ld bytes, with %ld bytes, to %ld bytes\n",size,diff,pos);
 163             printf("Continue? [y/N]: ");
 164             if (fgets(buf,sizeof(buf),stdin) == NULL ||
 165                 strncasecmp(buf,"y",1) != 0) {
 166                     printf("Aborting...\n");
 167                     exit(1);
 168             }
 169             if (ftruncate(fileno(fp), pos) == -1) {
 170                 printf("Failed to truncate AOF\n");
 171                 exit(1);
 172             } else {
 173                 printf("Successfully truncated AOF\n");
 174             }
 175         } else {
 176             printf("AOF is not valid\n");
 177             exit(1);
 178         }
 179     } else {
 180         printf("AOF is valid\n");
 181     }
 182
 183     fclose(fp);
 184     return 0;
 185 }