/*
** 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 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;
int cellToDecode = -2;
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;
case 'd': {
if( !ISDIGIT(zArgs[1]) ){
cellToDecode = -1;
}else{
cellToDecode = 0;
while( ISDIGIT(zArgs[1]) ){
zArgs++;
cellToDecode = cellToDecode*10 + zArgs[0] - '0';
}
}
break;
}
}
zArgs++;
}
nCell = a[3]*256 + a[4];
iCellPtr = (a[0]==2 || a[0]==5) ? 12 : 8;
if( cellToDecode>=nCell ){
printf("Page %d has only %d cells\n", pgno, nCell);
return;
}
printf("Header on 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");
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");
}
if( cellToDecode==(-2) && nCell>0 ){
printf(" key: lx=left-child n=payload-size r=rowid\n");
}
if( showMap ){
zMap = sqlite3_malloc(g.pagesize);
memset(zMap, '.', g.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;
i64 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], '*', (size_t)n);
zMap[cofst] = '[';
zMap[cofst+n-1] = ']';
sprintf(zBuf, "%d", i);
j = (int)strlen(zBuf);
if( j<=n-2 ) memcpy(&zMap[cofst+1], zBuf, j);
}
if( cellToDecode==(-2) ){
printf(" %03x: cell[%d] %s\n", cofst, i, zDesc);
}else if( cellToDecode==(-1) || cellToDecode==i ){
decodeCell(a, pgno, i, hdrSize, cofst-hdrSize);
}
}
if( showMap ){
printf("Page map: (H=header P=cell-index 1=page-1-header .=free-space)\n");
for(i=0; i<g.pagesize; i+=64){
printf(" %03x: %.64s\n", i, &zMap[i]);
}
sqlite3_free(zMap);
}
}
