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%16llx: %s", (long long)epos, __buf); \
  13 }
  14
  15 static char error[1024];
  16 static off_t 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 = ftello(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 = ftello(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 off_t process(FILE *fp) {
  76     long argc;
  77     off_t pos = 0;
  78     int i, multi = 0;
  79     char *str;
  80
  81     while(1) {
  82         if (!multi) pos = ftello(fp);
  83         if (!readArgc(fp, &argc)) break;
  84
  85         for (i = 0; i < argc; i++) {
  86             if (!readString(fp,&str)) break;
  87             if (i == 0) {
  88                 if (strcasecmp(str, "multi") == 0) {
  89                     if (multi++) {
  90                         ERROR("Unexpected MULTI");
  91                         break;
  92                     }
  93                 } else if (strcasecmp(str, "exec") == 0) {
  94                     if (--multi) {
  95                         ERROR("Unexpected EXEC");
  96                         break;
  97                     }
  98                 }
  99             }
 100             free(str);
 101         }
 102
 103         /* Stop if the loop did not finish */
 104         if (i < argc) {
 105             if (str) free(str);
 106             break;
 107         }
 108     }
 109
 110     if (feof(fp) && multi && strlen(error) == 0) {
 111         ERROR("Reached EOF before reading EXEC for MULTI");
 112     }
 113     if (strlen(error) > 0) {
 114         printf("%s\n", error);
 115     }
 116     return pos;
 117 }
 118
 119 int main(int argc, char **argv) {
 120     char *filename;
 121     int fix = 0;
 122
 123     if (argc < 2) {
 124         printf("Usage: %s [--fix] <file.aof>\n", argv[0]);
 125         exit(1);
 126     } else if (argc == 2) {
 127         filename = argv[1];
 128     } else if (argc == 3) {
 129         if (strcmp(argv[1],"--fix") != 0) {
 130             printf("Invalid argument: %s\n", argv[1]);
 131             exit(1);
 132         }
 133         filename = argv[2];
 134         fix = 1;
 135     } else {
 136         printf("Invalid arguments\n");
 137         exit(1);
 138     }
 139
 140     FILE *fp = fopen(filename,"r+");
 141     if (fp == NULL) {
 142         printf("Cannot open file: %s\n", filename);
 143         exit(1);
 144     }
 145
 146     struct redis_stat sb;
 147     if (redis_fstat(fileno(fp),&sb) == -1) {
 148         printf("Cannot stat file: %s\n", filename);
 149         exit(1);
 150     }
 151
 152     off_t size = sb.st_size;
 153     if (size == 0) {
 154         printf("Empty file: %s\n", filename);
 155         exit(1);
 156     }
 157
 158     off_t pos = process(fp);
 159     off_t diff = size-pos;
 160     printf("AOF analyzed: size=%lld, ok_up_to=%lld, diff=%lld\n",
 161         (long long) size, (long long) pos, (long long) diff);
 162     if (diff > 0) {
 163         if (fix) {
 164             char buf[2];
 165             printf("This will shrink the AOF from %lld bytes, with %lld bytes, to %lld bytes\n",(long long)size,(long long)diff,(long long)pos);
 166             printf("Continue? [y/N]: ");
 167             if (fgets(buf,sizeof(buf),stdin) == NULL ||
 168                 strncasecmp(buf,"y",1) != 0) {
 169                     printf("Aborting...\n");
 170                     exit(1);
 171             }
 172             if (ftruncate(fileno(fp), pos) == -1) {
 173                 printf("Failed to truncate AOF\n");
 174                 exit(1);
 175             } else {
 176                 printf("Successfully truncated AOF\n");
 177             }
 178         } else {
 179             printf("AOF is not valid\n");
 180             exit(1);
 181         }
 182     } else {
 183         printf("AOF is valid\n");
 184     }
 185
 186     fclose(fp);
 187     return 0;
 188 }