Annotation of embedaddon/sqlite3/tool/showjournal.c, revision 1.1.1.1
1.1 misho 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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