redis-check-aof.c

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