On 12/30/15, Domingo Alvarez Duarte <sqlite-mail at dev.dadbiz.es> wrote: > Hello Richard ! > > I just saw this commit https://www.sqlite.org/src/info/6a4cfc7ab62046eb and > noticed you've been using magic numbers would it be better to use a macro > instead ? > > I think for other people (and maybe yourself) would be easier to see > something like "INFO_SIZE_ADJUST" (or any meaningful name) instead of "4".
OVFL_PTR_SZ might be a better name. 4 is the size (in bytes) used by the pointer to the first overflow page that occurs at the end of the on-page record. I spent some time editing the code - substituting OVFL_PTR_SZ for 4 in appropriate places. But after looking at that for a while, I felt like OVFL_PTR_SZ obscured more than it clarified. So I typed "fossil revert" to go back to the code as it stands. I'll continue look for an alternative way to make the intent of the code clearer. > > > This also happen on other places, although I understand that is hard to > maintain consistency (there is several places where sqlite3 do use macros > instead of magic numbers). > > Cheers ! > in src/btree.c > > 1054 pInfo->nSize = (u16)(&pInfo->pPayload[pInfo->nLocal] - pCell) + 4; > 1079 assert( pPage->childPtrSize==4 ); > 1083 pInfo->nSize = 4 + getVarint(&pCell[4], (u64*)&pInfo->nKey); > 1153 if( pInfo->nSize<4 ) pInfo->nSize = 4; > 1191 if( pInfo->nSize<4 ) pInfo->nSize = 4; > 1309 Pgno ovfl = get4byte(&pCell[info.nSize-4]); > 3349 && iFrom==get4byte(pCell+info.nSize-4) > 5999 ovflPgno = get4byte(pCell + info.nSize - 4); > 6000 assert( pBt->usableSize > 4 ); > 6001 ovflPageSize = pBt->usableSize - 4; > 6858 Pgno ovfl = get4byte(&z[info.nSize-4]); > 9164 assert( pc + info.nSize - 4 <= usableSize ); > 9166 pgnoOvfl = get4byte(&pCell[info.nSize - 4]); > > _______________________________________________ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > -- D. Richard Hipp drh at sqlite.org
