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sqlite/tool/showdb.c
drh 47fb000854 Fix a usage comment typo in the showdb utility. 
FossilOrigin-Name: 8744ced4ec495852b7aa2de573001cb4993e6328
2011-04-13 16:52:41 +00:00

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/*
** A utility for printing all or part of an SQLite database 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 db = -1; /* File descriptor for reading the DB */
static int mxPage = 0; /* Last page number */
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;
}
/*
** Extract a big-endian 32-bit integer
*/
static unsigned int decodeInt32(const unsigned char *z){
return (z[0]<<24) + (z[1]<<16) + (z[2]<<8) + z[3];
}
/* 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+32);
if( aData==0 ) out_of_memory();
memset(aData, 0, nByte+32);
lseek(db, ofst, SEEK_SET);
read(db, aData, nByte);
return aData;
}
/*
** Print a range of bytes as hex and as ascii.
*/
static unsigned char *print_byte_range(
int ofst, /* First byte in the range of bytes to print */
int nByte, /* Number of bytes to print */
int printOfst /* Add this amount to the index on the left column */
){
unsigned char *aData;
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: ";
}
aData = getContent(ofst, nByte);
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");
}
return aData;
}
/*
** Print an entire page of content as hex
*/
static print_page(int iPg){
int iStart;
unsigned char *aData;
iStart = (iPg-1)*pagesize;
fprintf(stdout, "Page %d: (offsets 0x%x..0x%x)\n",
iPg, iStart, iStart+pagesize-1);
aData = print_byte_range(iStart, pagesize, 0);
free(aData);
}
/* Print a line of decode output showing a 4-byte integer.
*/
static print_decode_line(
unsigned char *aData, /* Content being decoded */
int ofst, int nByte, /* Start and size of decode */
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]);
}
sprintf(&zBuf[i], " %9d", val);
printf("%s %s\n", zBuf, zMsg);
}
/*
** Decode the database header.
*/
static void print_db_header(void){
unsigned char *aData;
aData = print_byte_range(0, 100, 0);
printf("Decoded:\n");
print_decode_line(aData, 16, 2, "Database page size");
print_decode_line(aData, 18, 1, "File format write version");
print_decode_line(aData, 19, 1, "File format read version");
print_decode_line(aData, 20, 1, "Reserved space at end of page");
print_decode_line(aData, 24, 4, "File change counter");
print_decode_line(aData, 28, 4, "Size of database in pages");
print_decode_line(aData, 32, 4, "Page number of first freelist page");
print_decode_line(aData, 36, 4, "Number of freelist pages");
print_decode_line(aData, 40, 4, "Schema cookie");
print_decode_line(aData, 44, 4, "Schema format version");
print_decode_line(aData, 48, 4, "Default page cache size");
print_decode_line(aData, 52, 4, "Largest auto-vac root page");
print_decode_line(aData, 56, 4, "Text encoding");
print_decode_line(aData, 60, 4, "User version");
print_decode_line(aData, 64, 4, "Incremental-vacuum mode");
print_decode_line(aData, 68, 4, "meta[7]");
print_decode_line(aData, 72, 4, "meta[8]");
print_decode_line(aData, 76, 4, "meta[9]");
print_decode_line(aData, 80, 4, "meta[10]");
print_decode_line(aData, 84, 4, "meta[11]");
print_decode_line(aData, 88, 4, "meta[12]");
print_decode_line(aData, 92, 4, "Change counter for version number");
print_decode_line(aData, 96, 4, "SQLite version number");
}
/*
** Describe cell content.
*/
static int describeContent(
unsigned char *a, /* Cell content */
int nLocal, /* Bytes in a[] */
char *zDesc /* Write description here */
){
int nDesc = 0;
int n, i, j;
i64 x, v;
const unsigned char *pData;
const unsigned char *pLimit;
char sep = ' ';
pLimit = &a[nLocal];
n = decodeVarint(a, &x);
pData = &a[x];
a += n;
i = x - n;
while( i>0 && pData<=pLimit ){
n = decodeVarint(a, &x);
a += n;
i -= n;
nLocal -= n;
zDesc[0] = sep;
sep = ',';
nDesc++;
zDesc++;
if( x==0 ){
sprintf(zDesc, "*"); /* NULL is a "*" */
}else if( x>=1 && x<=6 ){
v = (signed char)pData[0];
pData++;
switch( x ){
case 6: v = (v<<16) + (pData[0]<<8) + pData[1]; pData += 2;
case 5: v = (v<<16) + (pData[0]<<8) + pData[1]; pData += 2;
case 4: v = (v<<8) + pData[0]; pData++;
case 3: v = (v<<8) + pData[0]; pData++;
case 2: v = (v<<8) + pData[0]; pData++;
}
sprintf(zDesc, "%lld", v);
}else if( x==7 ){
sprintf(zDesc, "real");
pData += 8;
}else if( x==8 ){
sprintf(zDesc, "0");
}else if( x==9 ){
sprintf(zDesc, "1");
}else if( x>=12 ){
int size = (x-12)/2;
if( (x&1)==0 ){
sprintf(zDesc, "blob(%d)", size);
}else{
sprintf(zDesc, "txt(%d)", size);
}
pData += size;
}
j = strlen(zDesc);
zDesc += j;
nDesc += j;
}
return nDesc;
}
/*
** Compute the local payload size given the total payload size and
** the page size.
*/
static int localPayload(i64 nPayload, char cType){
int maxLocal;
int minLocal;
int surplus;
int nLocal;
if( cType==13 ){
/* Table leaf */
maxLocal = pagesize-35;
minLocal = (pagesize-12)*32/255-23;
}else{
maxLocal = (pagesize-12)*64/255-23;
minLocal = (pagesize-12)*32/255-23;
}
if( nPayload>maxLocal ){
surplus = minLocal + (nPayload-minLocal)%(pagesize-4);
if( surplus<=maxLocal ){
nLocal = surplus;
}else{
nLocal = minLocal;
}
}else{
nLocal = nPayload;
}
return nLocal;
}
/*
** Create a description for a single cell.
**
** The return value is the local cell size.
*/
static int describeCell(
unsigned char cType, /* Page type */
unsigned char *a, /* Cell content */
int showCellContent, /* Show cell content if true */
char **pzDesc /* Store description here */
){
int i;
int nDesc = 0;
int n = 0;
int leftChild;
i64 nPayload;
i64 rowid;
int nLocal;
static char zDesc[1000];
i = 0;
if( cType<=5 ){
leftChild = ((a[0]*256 + a[1])*256 + a[2])*256 + a[3];
a += 4;
n += 4;
sprintf(zDesc, "lx: %d ", leftChild);
nDesc = strlen(zDesc);
}
if( cType!=5 ){
i = decodeVarint(a, &nPayload);
a += i;
n += i;
sprintf(&zDesc[nDesc], "n: %lld ", nPayload);
nDesc += strlen(&zDesc[nDesc]);
nLocal = localPayload(nPayload, cType);
}else{
nPayload = nLocal = 0;
}
if( cType==5 || cType==13 ){
i = decodeVarint(a, &rowid);
a += i;
n += i;
sprintf(&zDesc[nDesc], "r: %lld ", rowid);
nDesc += strlen(&zDesc[nDesc]);
}
if( nLocal<nPayload ){
int ovfl;
unsigned char *b = &a[nLocal];
ovfl = ((b[0]*256 + b[1])*256 + b[2])*256 + b[3];
sprintf(&zDesc[nDesc], "ov: %d ", ovfl);
nDesc += strlen(&zDesc[nDesc]);
n += 4;
}
if( showCellContent && cType!=5 ){
nDesc += describeContent(a, nLocal, &zDesc[nDesc-1]);
}
*pzDesc = zDesc;
return nLocal+n;
}
/*
** Decode a btree page
*/
static void decode_btree_page(
unsigned char *a, /* Page content */
int pgno, /* Page number */
int hdrSize, /* Size of the page header. 0 or 100 */
char *zArgs /* Flags to control formatting */
){
const char *zType = "unknown";
int nCell;
int i, j;
int iCellPtr;
int showCellContent = 0;
int showMap = 0;
char *zMap = 0;
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;
}
while( zArgs[0] ){
switch( zArgs[0] ){
case 'c': showCellContent = 1; break;
case 'm': showMap = 1; break;
}
zArgs++;
}
printf("Decode of btree page %d:\n", pgno);
print_decode_line(a, 0, 1, zType);
print_decode_line(a, 1, 2, "Offset to first freeblock");
print_decode_line(a, 3, 2, "Number of cells on this page");
nCell = a[3]*256 + a[4];
print_decode_line(a, 5, 2, "Offset to cell content area");
print_decode_line(a, 7, 1, "Fragmented byte count");
if( a[0]==2 || a[0]==5 ){
print_decode_line(a, 8, 4, "Right child");
iCellPtr = 12;
}else{
iCellPtr = 8;
}
if( nCell>0 ){
printf(" key: lx=left-child n=payload-size r=rowid\n");
}
if( showMap ){
zMap = malloc(pagesize);
memset(zMap, '.', pagesize);
memset(zMap, '1', hdrSize);
memset(&zMap[hdrSize], 'H', iCellPtr);
memset(&zMap[hdrSize+iCellPtr], 'P', 2*nCell);
}
for(i=0; i<nCell; i++){
int cofst = iCellPtr + i*2;
char *zDesc;
int n;
cofst = a[cofst]*256 + a[cofst+1];
n = describeCell(a[0], &a[cofst-hdrSize], showCellContent, &zDesc);
if( showMap ){
char zBuf[30];
memset(&zMap[cofst], '*', n);
zMap[cofst] = '[';
zMap[cofst+n-1] = ']';
sprintf(zBuf, "%d", i);
j = strlen(zBuf);
if( j<=n-2 ) memcpy(&zMap[cofst+1], zBuf, j);
}
printf(" %03x: cell[%d] %s\n", cofst, i, zDesc);
}
if( showMap ){
for(i=0; i<pagesize; i+=64){
printf(" %03x: %.64s\n", i, &zMap[i]);
}
free(zMap);
}
}
/*
** Decode a freelist trunk page.
*/
static void decode_trunk_page(
int pgno, /* The page number */
int pagesize, /* Size of each page */
int detail, /* Show leaf pages if true */
int recursive /* Follow the trunk change if true */
){
int n, i, k;
unsigned char *a;
while( pgno>0 ){
a = getContent((pgno-1)*pagesize, pagesize);
printf("Decode of freelist trunk page %d:\n", pgno);
print_decode_line(a, 0, 4, "Next freelist trunk page");
print_decode_line(a, 4, 4, "Number of entries on this page");
if( detail ){
n = (int)decodeInt32(&a[4]);
for(i=0; i<n; i++){
unsigned int x = decodeInt32(&a[8+4*i]);
char zIdx[10];
sprintf(zIdx, "[%d]", i);
printf(" %5s %7u", zIdx, x);
if( i%5==4 ) printf("\n");
}
if( i%5!=0 ) printf("\n");
}
if( !recursive ){
pgno = 0;
}else{
pgno = (int)decodeInt32(&a[0]);
}
free(a);
}
}
/*
** Print a usage comment
*/
static void usage(const char *argv0){
fprintf(stderr, "Usage %s FILENAME ?args...?\n\n", argv0);
fprintf(stderr,
"args:\n"
" dbheader Show database header\n"
" NNN..MMM Show hex of pages NNN through MMM\n"
" NNN..end Show hex of pages NNN through end of file\n"
" NNNb Decode btree page NNN\n"
" NNNbc Decode btree page NNN and show content\n"
" NNNbm Decode btree page NNN and show a layout map\n"
" NNNt Decode freelist trunk page NNN\n"
" NNNtd Show leaf freelist pages on the decode\n"
" NNNtr Recurisvely decode freelist starting at NNN\n"
);
}
int main(int argc, char **argv){
struct stat sbuf;
unsigned char zPgSz[2];
if( argc<2 ){
usage(argv[0]);
exit(1);
}
db = open(argv[1], O_RDONLY);
if( db<0 ){
fprintf(stderr,"%s: can't open %s\n", argv[0], argv[1]);
exit(1);
}
zPgSz[0] = 0;
zPgSz[1] = 0;
lseek(db, 16, SEEK_SET);
read(db, zPgSz, 2);
pagesize = zPgSz[0]*256 + zPgSz[1]*65536;
if( pagesize==0 ) pagesize = 1024;
printf("Pagesize: %d\n", pagesize);
fstat(db, &sbuf);
mxPage = sbuf.st_size/pagesize;
printf("Available pages: 1..%d\n", mxPage);
if( argc==2 ){
int i;
for(i=1; i<=mxPage; i++) print_page(i);
}else{
int i;
for(i=2; i<argc; i++){
int iStart, iEnd;
char *zLeft;
if( strcmp(argv[i], "dbheader")==0 ){
print_db_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 = mxPage;
}else if( zLeft && zLeft[0]=='.' && zLeft[1]=='.' ){
iEnd = strtol(&zLeft[2], 0, 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, &zLeft[1]);
free(a);
continue;
}else if( zLeft && zLeft[0]=='t' ){
unsigned char *a;
int detail = 0;
int recursive = 0;
int i;
for(i=1; zLeft[i]; i++){
if( zLeft[i]=='r' ) recursive = 1;
if( zLeft[i]=='d' ) detail = 1;
}
decode_trunk_page(iStart, pagesize, detail, recursive);
continue;
}else{
iEnd = iStart;
}
if( iStart<1 || iEnd<iStart || iEnd>mxPage ){
fprintf(stderr,
"Page argument should be LOWER?..UPPER?. Range 1 to %d\n",
mxPage);
exit(1);
}
while( iStart<=iEnd ){
print_page(iStart);
iStart++;
}
}
}
close(db);
}
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