database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-07-27 20:41:58 +03:00
Code Activity

Further enhancements to the showdb utility: A page number followed by "b"

Browse Source 
causes a btree decoding to occur on the page.

FossilOrigin-Name: 2ff824e58ce8b8f605c809ac960dcbfc51c30e30
This commit is contained in:
drh
2010-04-26 16:47:12 +00:00
parent 562cedb185
commit 7ecc14761e
3 changed files with 103 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

98
tool/showdb.c
View File

@ -23,10 +23,10 @@ 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 char *z, i64 *pVal){
static int decodeVarint(const unsigned char *z, i64 *pVal){
i64 v = 0;
int i = 0;
while( i<8 ){
int i;
for(i=0; i<8; i++){
v = (v<<7) + (z[i]&0x7f);
if( (z[i]&0x80)==0 ){ *pVal = v; return i+1; }
}
@ -138,13 +138,13 @@ static print_decode_line(
i += strlen(&zBuf[i]);
}
sprintf(&zBuf[i], " %9d", val);
printf(" %s %s\n", zBuf, zMsg);
printf("%s %s\n", zBuf, zMsg);
}
/*
** Decode the database header.
*/
static print_db_header(void){
static void print_db_header(void){
unsigned char *aData;
aData = print_byte_range(0, 100, 0);
printf("Decoded:\n");
@ -173,6 +173,79 @@ static print_db_header(void){
print_decode_line(aData, 96, 4, "meta[14]");
}
/*
** 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, 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;
}
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];
@ -216,6 +289,21 @@ int main(int argc, char **argv){
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);
free(a);
continue;
}else{
iEnd = iStart;
}