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Add support for zero-blobs to the OP_MakeRecord opcode.

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First test cases of zeroblob functionality. (CVS 3897)

FossilOrigin-Name: e6d560ddeeb48fb0cbd9f5a10612280b055baef7
This commit is contained in:
drh
2007-05-02 13:30:27 +00:00
parent d04417963f
commit fdf972a9ba
7 changed files with 150 additions and 49 deletions
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41
src/vdbeaux.c
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@@ -1722,6 +1722,7 @@ int sqlite3VdbeCursorMoveto(Cursor *p){
*/
u32 sqlite3VdbeSerialType(Mem *pMem, int file_format){
int flags = pMem->flags;
int n;
if( flags&MEM_Null ){
return 0;
@@ -1745,13 +1746,13 @@ u32 sqlite3VdbeSerialType(Mem *pMem, int file_format){
if( flags&MEM_Real ){
return 7;
}
if( flags&MEM_Str ){
int n = pMem->n;
assert( n>=0 );
return ((n*2) + 13);
assert( flags&(MEM_Str|MEM_Blob) );
n = pMem->n;
if( flags & MEM_Zero ){
n += pMem->u.i;
}
assert( (flags & MEM_Blob)!=0 );
return (pMem->n*2 + 12);
assert( n>=0 );
return ((n*2) + 12 + ((flags&MEM_Str)!=0));
}
/*
@@ -1770,8 +1771,21 @@ int sqlite3VdbeSerialTypeLen(u32 serial_type){
** Write the serialized data blob for the value stored in pMem into
** buf. It is assumed that the caller has allocated sufficient space.
** Return the number of bytes written.
**
** nBuf is the amount of space left in buf[]. nBuf must always be
** large enough to hold the entire field. Except, if the field is
** a blob with a zero-filled tail, then buf[] might be just the right
** size to hold everything except for the zero-filled tail. If buf[]
** is only big enough to hold the non-zero prefix, then only write that
** prefix into buf[]. But if buf[] is large enough to hold both the
** prefix and the tail then write the prefix and set the tail to all
** zeros.
**
** Return the number of bytes actually written into buf[]. The number
** of bytes in the zero-filled tail is included in the return value only
** if those bytes were zeroed in buf[].
*/
int sqlite3VdbeSerialPut(unsigned char *buf, Mem *pMem, int file_format){
int sqlite3VdbeSerialPut(u8 *buf, int nBuf, Mem *pMem, int file_format){
u32 serial_type = sqlite3VdbeSerialType(pMem, file_format);
int len;
@@ -1786,6 +1800,7 @@ int sqlite3VdbeSerialPut(unsigned char *buf, Mem *pMem, int file_format){
v = pMem->u.i;
}
len = i = sqlite3VdbeSerialTypeLen(serial_type);
assert( len<=nBuf );
while( i-- ){
buf[i] = (v&0xFF);
v >>= 8;
@@ -1795,8 +1810,18 @@ int sqlite3VdbeSerialPut(unsigned char *buf, Mem *pMem, int file_format){
/* String or blob */
if( serial_type>=12 ){
len = sqlite3VdbeSerialTypeLen(serial_type);
assert( pMem->n + ((pMem->flags & MEM_Zero)?pMem->u.i:0)
== sqlite3VdbeSerialTypeLen(serial_type) );
assert( pMem->n<=nBuf );
len = pMem->n;
memcpy(buf, pMem->z, len);
if( pMem->flags & MEM_Zero ){
len += pMem->u.i;
if( len>nBuf ){
len = nBuf;
}
memset(&buf[pMem->n], 0, len-pMem->n);
}
return len;
}