356 lines
9.2 KiB
C
356 lines
9.2 KiB
C
/*
|
|
** A utility for printing content from a write-ahead log file.
|
|
*/
|
|
#include <stdio.h>
|
|
#include <ctype.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <fcntl.h>
|
|
#include <unistd.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
|
|
static int pagesize = 1024; /* Size of a database page */
|
|
static int fd = -1; /* File descriptor for reading the WAL file */
|
|
static int mxFrame = 0; /* Last frame */
|
|
static int perLine = 16; /* HEX elements to print per line */
|
|
|
|
typedef long long int i64; /* Datatype for 64-bit integers */
|
|
|
|
|
|
/*
|
|
** Convert the var-int format into i64. Return the number of bytes
|
|
** in the var-int. Write the var-int value into *pVal.
|
|
*/
|
|
static int decodeVarint(const unsigned char *z, i64 *pVal){
|
|
i64 v = 0;
|
|
int i;
|
|
for(i=0; i<8; i++){
|
|
v = (v<<7) + (z[i]&0x7f);
|
|
if( (z[i]&0x80)==0 ){ *pVal = v; return i+1; }
|
|
}
|
|
v = (v<<8) + (z[i]&0xff);
|
|
*pVal = v;
|
|
return 9;
|
|
}
|
|
|
|
/* Report an out-of-memory error and die.
|
|
*/
|
|
static void out_of_memory(void){
|
|
fprintf(stderr,"Out of memory...\n");
|
|
exit(1);
|
|
}
|
|
|
|
/*
|
|
** Read content from the file.
|
|
**
|
|
** Space to hold the content is obtained from malloc() and needs to be
|
|
** freed by the caller.
|
|
*/
|
|
static unsigned char *getContent(int ofst, int nByte){
|
|
unsigned char *aData;
|
|
aData = malloc(nByte);
|
|
if( aData==0 ) out_of_memory();
|
|
lseek(fd, ofst, SEEK_SET);
|
|
read(fd, aData, nByte);
|
|
return aData;
|
|
}
|
|
|
|
/*
|
|
** Print a range of bytes as hex and as ascii.
|
|
*/
|
|
static void print_byte_range(
|
|
int ofst, /* First byte in the range of bytes to print */
|
|
int nByte, /* Number of bytes to print */
|
|
unsigned char *aData, /* Content to print */
|
|
int printOfst /* Add this amount to the index on the left column */
|
|
){
|
|
int i, j;
|
|
const char *zOfstFmt;
|
|
|
|
if( ((printOfst+nByte)&~0xfff)==0 ){
|
|
zOfstFmt = " %03x: ";
|
|
}else if( ((printOfst+nByte)&~0xffff)==0 ){
|
|
zOfstFmt = " %04x: ";
|
|
}else if( ((printOfst+nByte)&~0xfffff)==0 ){
|
|
zOfstFmt = " %05x: ";
|
|
}else if( ((printOfst+nByte)&~0xffffff)==0 ){
|
|
zOfstFmt = " %06x: ";
|
|
}else{
|
|
zOfstFmt = " %08x: ";
|
|
}
|
|
|
|
for(i=0; i<nByte; i += perLine){
|
|
fprintf(stdout, zOfstFmt, i+printOfst);
|
|
for(j=0; j<perLine; j++){
|
|
if( i+j>nByte ){
|
|
fprintf(stdout, " ");
|
|
}else{
|
|
fprintf(stdout,"%02x ", aData[i+j]);
|
|
}
|
|
}
|
|
for(j=0; j<perLine; j++){
|
|
if( i+j>nByte ){
|
|
fprintf(stdout, " ");
|
|
}else{
|
|
fprintf(stdout,"%c", isprint(aData[i+j]) ? aData[i+j] : '.');
|
|
}
|
|
}
|
|
fprintf(stdout,"\n");
|
|
}
|
|
}
|
|
|
|
/* Print a line of decode output showing a 4-byte integer.
|
|
*/
|
|
static void print_decode_line(
|
|
unsigned char *aData, /* Content being decoded */
|
|
int ofst, int nByte, /* Start and size of decode */
|
|
int asHex, /* If true, output value as hex */
|
|
const char *zMsg /* Message to append */
|
|
){
|
|
int i, j;
|
|
int val = aData[ofst];
|
|
char zBuf[100];
|
|
sprintf(zBuf, " %03x: %02x", ofst, aData[ofst]);
|
|
i = strlen(zBuf);
|
|
for(j=1; j<4; j++){
|
|
if( j>=nByte ){
|
|
sprintf(&zBuf[i], " ");
|
|
}else{
|
|
sprintf(&zBuf[i], " %02x", aData[ofst+j]);
|
|
val = val*256 + aData[ofst+j];
|
|
}
|
|
i += strlen(&zBuf[i]);
|
|
}
|
|
if( asHex ){
|
|
sprintf(&zBuf[i], " 0x%08x", val);
|
|
}else{
|
|
sprintf(&zBuf[i], " %9d", val);
|
|
}
|
|
printf("%s %s\n", zBuf, zMsg);
|
|
}
|
|
|
|
/*
|
|
** Print an entire page of content as hex
|
|
*/
|
|
static void print_frame(int iFrame){
|
|
int iStart;
|
|
unsigned char *aData;
|
|
iStart = 32 + (iFrame-1)*(pagesize+24);
|
|
fprintf(stdout, "Frame %d: (offsets 0x%x..0x%x)\n",
|
|
iFrame, iStart, iStart+pagesize+24);
|
|
aData = getContent(iStart, pagesize+24);
|
|
print_decode_line(aData, 0, 4, 0, "Page number");
|
|
print_decode_line(aData, 4, 4, 0, "DB size, or 0 for non-commit");
|
|
print_decode_line(aData, 8, 4, 1, "Salt-1");
|
|
print_decode_line(aData,12, 4, 1, "Salt-2");
|
|
print_decode_line(aData,16, 4, 1, "Checksum-1");
|
|
print_decode_line(aData,20, 4, 1, "Checksum-2");
|
|
print_byte_range(iStart+24, pagesize, aData+24, 0);
|
|
free(aData);
|
|
}
|
|
|
|
/*
|
|
** extract a 32-bit big-endian integer
|
|
*/
|
|
static unsigned int getInt32(const unsigned char *a){
|
|
unsigned int x = (a[0]<<24) + (a[1]<<16) + (a[2]<<8) + a[3];
|
|
return x;
|
|
}
|
|
|
|
/*
|
|
** Print an entire page of content as hex
|
|
*/
|
|
static void print_oneline_frame(int iFrame){
|
|
int iStart;
|
|
unsigned char *aData;
|
|
iStart = 32 + (iFrame-1)*(pagesize+24);
|
|
aData = getContent(iStart, 24);
|
|
fprintf(stdout, "Frame %4d: %6d %6d 0x%08x 0x%08x 0x%08x 0x%08x\n",
|
|
iFrame,
|
|
getInt32(aData),
|
|
getInt32(aData+4),
|
|
getInt32(aData+8),
|
|
getInt32(aData+12),
|
|
getInt32(aData+16),
|
|
getInt32(aData+20)
|
|
);
|
|
free(aData);
|
|
}
|
|
|
|
/*
|
|
** Decode the WAL header.
|
|
*/
|
|
static void print_wal_header(void){
|
|
unsigned char *aData;
|
|
aData = getContent(0, 32);
|
|
printf("WAL Header:\n");
|
|
print_decode_line(aData, 0, 4,1,"Magic. 0x377f0682 (le) or 0x377f0683 (be)");
|
|
print_decode_line(aData, 4, 4, 0, "File format");
|
|
print_decode_line(aData, 8, 4, 0, "Database page size");
|
|
print_decode_line(aData, 12,4, 0, "Checkpoint sequence number");
|
|
print_decode_line(aData, 16,4, 1, "Salt-1");
|
|
print_decode_line(aData, 20,4, 1, "Salt-2");
|
|
print_decode_line(aData, 24,4, 1, "Checksum-1");
|
|
print_decode_line(aData, 28,4, 1, "Checksum-2");
|
|
free(aData);
|
|
}
|
|
|
|
/*
|
|
** Create a description for a single cell.
|
|
*/
|
|
static int describeCell(unsigned char cType, unsigned char *a, char **pzDesc){
|
|
int i;
|
|
int nDesc = 0;
|
|
int n = 0;
|
|
int leftChild;
|
|
i64 nPayload;
|
|
i64 rowid;
|
|
static char zDesc[100];
|
|
i = 0;
|
|
if( cType<=5 ){
|
|
leftChild = ((a[0]*256 + a[1])*256 + a[2])*256 + a[3];
|
|
a += 4;
|
|
n += 4;
|
|
sprintf(zDesc, "left-child: %d ", leftChild);
|
|
nDesc = strlen(zDesc);
|
|
}
|
|
if( cType!=5 ){
|
|
i = decodeVarint(a, &nPayload);
|
|
a += i;
|
|
n += i;
|
|
sprintf(&zDesc[nDesc], "sz: %lld ", nPayload);
|
|
nDesc += strlen(&zDesc[nDesc]);
|
|
}
|
|
if( cType==5 || cType==13 ){
|
|
i = decodeVarint(a, &rowid);
|
|
a += i;
|
|
n += i;
|
|
sprintf(&zDesc[nDesc], "rowid: %lld ", rowid);
|
|
nDesc += strlen(&zDesc[nDesc]);
|
|
}
|
|
*pzDesc = zDesc;
|
|
return n;
|
|
}
|
|
|
|
/*
|
|
** Decode a btree page
|
|
*/
|
|
static void decode_btree_page(unsigned char *a, int pgno, int hdrSize){
|
|
const char *zType = "unknown";
|
|
int nCell;
|
|
int i;
|
|
int iCellPtr;
|
|
switch( a[0] ){
|
|
case 2: zType = "index interior node"; break;
|
|
case 5: zType = "table interior node"; break;
|
|
case 10: zType = "index leaf"; break;
|
|
case 13: zType = "table leaf"; break;
|
|
}
|
|
printf("Decode of btree page %d:\n", pgno);
|
|
print_decode_line(a, 0, 1, 0, zType);
|
|
print_decode_line(a, 1, 2, 0, "Offset to first freeblock");
|
|
print_decode_line(a, 3, 2, 0, "Number of cells on this page");
|
|
nCell = a[3]*256 + a[4];
|
|
print_decode_line(a, 5, 2, 0, "Offset to cell content area");
|
|
print_decode_line(a, 7, 1, 0, "Fragmented byte count");
|
|
if( a[0]==2 || a[0]==5 ){
|
|
print_decode_line(a, 8, 4, 0, "Right child");
|
|
iCellPtr = 12;
|
|
}else{
|
|
iCellPtr = 8;
|
|
}
|
|
for(i=0; i<nCell; i++){
|
|
int cofst = iCellPtr + i*2;
|
|
char *zDesc;
|
|
cofst = a[cofst]*256 + a[cofst+1];
|
|
describeCell(a[0], &a[cofst-hdrSize], &zDesc);
|
|
printf(" %03x: cell[%d] %s\n", cofst, i, zDesc);
|
|
}
|
|
}
|
|
|
|
int main(int argc, char **argv){
|
|
struct stat sbuf;
|
|
unsigned char zPgSz[2];
|
|
if( argc<2 ){
|
|
fprintf(stderr,"Usage: %s FILENAME ?PAGE? ...\n", argv[0]);
|
|
exit(1);
|
|
}
|
|
fd = open(argv[1], O_RDONLY);
|
|
if( fd<0 ){
|
|
fprintf(stderr,"%s: can't open %s\n", argv[0], argv[1]);
|
|
exit(1);
|
|
}
|
|
zPgSz[0] = 0;
|
|
zPgSz[1] = 0;
|
|
lseek(fd, 10, SEEK_SET);
|
|
read(fd, zPgSz, 2);
|
|
pagesize = zPgSz[0]*256 + zPgSz[1];
|
|
if( pagesize==0 ) pagesize = 1024;
|
|
printf("Pagesize: %d\n", pagesize);
|
|
fstat(fd, &sbuf);
|
|
if( sbuf.st_size<32 ){
|
|
printf("file too small to be a WAL\n");
|
|
return 0;
|
|
}
|
|
mxFrame = (sbuf.st_size - 32)/(pagesize + 24);
|
|
printf("Available pages: 1..%d\n", mxFrame);
|
|
if( argc==2 ){
|
|
int i;
|
|
print_wal_header();
|
|
for(i=1; i<=mxFrame; i++) print_oneline_frame(i);
|
|
}else{
|
|
int i;
|
|
for(i=2; i<argc; i++){
|
|
int iStart, iEnd;
|
|
char *zLeft;
|
|
if( strcmp(argv[i], "header")==0 ){
|
|
print_wal_header();
|
|
continue;
|
|
}
|
|
if( !isdigit(argv[i][0]) ){
|
|
fprintf(stderr, "%s: unknown option: [%s]\n", argv[0], argv[i]);
|
|
continue;
|
|
}
|
|
iStart = strtol(argv[i], &zLeft, 0);
|
|
if( zLeft && strcmp(zLeft,"..end")==0 ){
|
|
iEnd = mxFrame;
|
|
}else if( zLeft && zLeft[0]=='.' && zLeft[1]=='.' ){
|
|
iEnd = strtol(&zLeft[2], 0, 0);
|
|
#if 0
|
|
}else if( zLeft && zLeft[0]=='b' ){
|
|
int ofst, nByte, hdrSize;
|
|
unsigned char *a;
|
|
if( iStart==1 ){
|
|
ofst = hdrSize = 100;
|
|
nByte = pagesize-100;
|
|
}else{
|
|
hdrSize = 0;
|
|
ofst = (iStart-1)*pagesize;
|
|
nByte = pagesize;
|
|
}
|
|
a = getContent(ofst, nByte);
|
|
decode_btree_page(a, iStart, hdrSize);
|
|
free(a);
|
|
continue;
|
|
#endif
|
|
}else{
|
|
iEnd = iStart;
|
|
}
|
|
if( iStart<1 || iEnd<iStart || iEnd>mxFrame ){
|
|
fprintf(stderr,
|
|
"Page argument should be LOWER?..UPPER?. Range 1 to %d\n",
|
|
mxFrame);
|
|
exit(1);
|
|
}
|
|
while( iStart<=iEnd ){
|
|
print_frame(iStart);
|
|
iStart++;
|
|
}
|
|
}
|
|
}
|
|
close(fd);
|
|
return 0;
|
|
}
|