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| 1 /* |
| 2 ** A utility for printing an SQLite database journal. |
| 3 */ |
| 4 #include <stdio.h> |
| 5 #include <ctype.h> |
| 6 #include <stdlib.h> |
| 7 #include <string.h> |
| 8 |
| 9 /* |
| 10 ** state information |
| 11 */ |
| 12 static int pageSize = 1024; |
| 13 static int sectorSize = 512; |
| 14 static FILE *db = 0; |
| 15 static int showPageContent = 0; |
| 16 static int fileSize = 0; |
| 17 static unsigned cksumNonce = 0; |
| 18 |
| 19 /* Report a memory allocation error */ |
| 20 static void out_of_memory(void){ |
| 21 fprintf(stderr,"Out of memory...\n"); |
| 22 exit(1); |
| 23 } |
| 24 |
| 25 /* |
| 26 ** Read N bytes of memory starting at iOfst into space obtained |
| 27 ** from malloc(). |
| 28 */ |
| 29 static char *read_content(int N, int iOfst){ |
| 30 int got; |
| 31 char *pBuf = malloc(N); |
| 32 if( pBuf==0 ) out_of_memory(); |
| 33 fseek(db, iOfst, SEEK_SET); |
| 34 got = fread(pBuf, 1, N, db); |
| 35 if( got<0 ){ |
| 36 fprintf(stderr, "I/O error reading %d bytes from %d\n", N, iOfst); |
| 37 memset(pBuf, 0, N); |
| 38 }else if( got<N ){ |
| 39 fprintf(stderr, "Short read: got only %d of %d bytes from %d\n", |
| 40 got, N, iOfst); |
| 41 memset(&pBuf[got], 0, N-got); |
| 42 } |
| 43 return pBuf; |
| 44 } |
| 45 |
| 46 /* Print a line of decode output showing a 4-byte integer. |
| 47 */ |
| 48 static unsigned print_decode_line( |
| 49 unsigned char *aData, /* Content being decoded */ |
| 50 int ofst, int nByte, /* Start and size of decode */ |
| 51 const char *zMsg /* Message to append */ |
| 52 ){ |
| 53 int i, j; |
| 54 unsigned val = aData[ofst]; |
| 55 char zBuf[100]; |
| 56 sprintf(zBuf, " %03x: %02x", ofst, aData[ofst]); |
| 57 i = strlen(zBuf); |
| 58 for(j=1; j<4; j++){ |
| 59 if( j>=nByte ){ |
| 60 sprintf(&zBuf[i], " "); |
| 61 }else{ |
| 62 sprintf(&zBuf[i], " %02x", aData[ofst+j]); |
| 63 val = val*256 + aData[ofst+j]; |
| 64 } |
| 65 i += strlen(&zBuf[i]); |
| 66 } |
| 67 sprintf(&zBuf[i], " %10u", val); |
| 68 printf("%s %s\n", zBuf, zMsg); |
| 69 return val; |
| 70 } |
| 71 |
| 72 /* |
| 73 ** Read and print a journal header. Store key information (page size, etc) |
| 74 ** in global variables. |
| 75 */ |
| 76 static unsigned decode_journal_header(int iOfst){ |
| 77 char *pHdr = read_content(64, iOfst); |
| 78 unsigned nPage; |
| 79 printf("Header at offset %d:\n", iOfst); |
| 80 print_decode_line(pHdr, 0, 4, "Header part 1 (3654616569)"); |
| 81 print_decode_line(pHdr, 4, 4, "Header part 2 (547447767)"); |
| 82 nPage = |
| 83 print_decode_line(pHdr, 8, 4, "page count"); |
| 84 cksumNonce = |
| 85 print_decode_line(pHdr, 12, 4, "chksum nonce"); |
| 86 print_decode_line(pHdr, 16, 4, "initial database size in pages"); |
| 87 sectorSize = |
| 88 print_decode_line(pHdr, 20, 4, "sector size"); |
| 89 pageSize = |
| 90 print_decode_line(pHdr, 24, 4, "page size"); |
| 91 print_decode_line(pHdr, 28, 4, "zero"); |
| 92 print_decode_line(pHdr, 32, 4, "zero"); |
| 93 print_decode_line(pHdr, 36, 4, "zero"); |
| 94 print_decode_line(pHdr, 40, 4, "zero"); |
| 95 free(pHdr); |
| 96 return nPage; |
| 97 } |
| 98 |
| 99 static void print_page(int iOfst){ |
| 100 unsigned char *aData; |
| 101 char zTitle[50]; |
| 102 aData = read_content(pageSize+8, iOfst); |
| 103 sprintf(zTitle, "page number for page at offset %d", iOfst); |
| 104 print_decode_line(aData, 0, 4, zTitle); |
| 105 free(aData); |
| 106 } |
| 107 |
| 108 int main(int argc, char **argv){ |
| 109 int rc; |
| 110 int nPage, cnt; |
| 111 int iOfst; |
| 112 if( argc!=2 ){ |
| 113 fprintf(stderr,"Usage: %s FILENAME\n", argv[0]); |
| 114 exit(1); |
| 115 } |
| 116 db = fopen(argv[1], "rb"); |
| 117 if( db==0 ){ |
| 118 fprintf(stderr,"%s: can't open %s\n", argv[0], argv[1]); |
| 119 exit(1); |
| 120 } |
| 121 fseek(db, 0, SEEK_END); |
| 122 fileSize = ftell(db); |
| 123 printf("journal file size: %d bytes\n", fileSize); |
| 124 fseek(db, 0, SEEK_SET); |
| 125 iOfst = 0; |
| 126 while( iOfst<fileSize ){ |
| 127 cnt = nPage = (int)decode_journal_header(iOfst); |
| 128 if( cnt==0 ){ |
| 129 cnt = (fileSize - sectorSize)/(pageSize+8); |
| 130 } |
| 131 iOfst += sectorSize; |
| 132 while( cnt && iOfst<fileSize ){ |
| 133 print_page(iOfst); |
| 134 iOfst += pageSize+8; |
| 135 } |
| 136 iOfst = (iOfst/sectorSize + 1)*sectorSize; |
| 137 } |
| 138 fclose(db); |
| 139 } |
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