paulhorn/sqlite
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Further simplifications to btree.c, especially the sqlite3BtreeKey() and

Browse Source 
sqlite3BtreeData() functions.  New assert() statements added to verify
that these routines are called correctly. (CVS 6917)

FossilOrigin-Name: 96cfd079528501f6f1e658ce8a5a4e3bdea729be
This commit is contained in:
drh
2009-07-22 00:35:23 +00:00
parent 89bc4bc645
commit ea8ffdfec7
6 changed files with 73 additions and 52 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/btree.c
+47 -36
View File
@@ -9,7 +9,7 @@
** May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btree.c,v 1.697 2009/07/21 19:25:24 danielk1977 Exp $
** $Id: btree.c,v 1.698 2009/07/22 00:35:24 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
@@ -539,6 +539,9 @@ static void btreeClearHasContent(BtShared *pBt){
/*
** Save the current cursor position in the variables BtCursor.nKey
** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
**
** The caller must ensure that the cursor is valid (has eState==CURSOR_VALID)
** prior to calling this routine.
*/
static int saveCursorPosition(BtCursor *pCur){
int rc;
@@ -548,7 +551,7 @@ static int saveCursorPosition(BtCursor *pCur){
assert( cursorHoldsMutex(pCur) );
rc = sqlite3BtreeKeySize(pCur, &pCur->nKey);
assert( rc==SQLITE_OK ); /* Cannot fail since pCur->eState==VALID */
assert( rc==SQLITE_OK ); /* KeySize() cannot fail */
/* If this is an intKey table, then the above call to BtreeKeySize()
** stores the integer key in pCur->nKey. In this case this value is
@@ -2707,11 +2710,14 @@ static int allocateBtreePage(BtShared *, MemPage **, Pgno *, Pgno, u8);
** database so that the last page of the file currently in use
** is no longer in use.
**
** If the nFin parameter is non-zero, the implementation assumes
** If the nFin parameter is non-zero, this function assumes
** that the caller will keep calling incrVacuumStep() until
** it returns SQLITE_DONE or an error, and that nFin is the
** number of pages the database file will contain after this
** process is complete.
** process is complete. If nFin is zero, it is assumed that
** incrVacuumStep() will be called a finite amount of times
** which may or may not empty the freelist. A full autovacuum
** has nFin>0. A "PRAGMA incremental_vacuum" has nFin==0.
*/
static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg){
Pgno nFreeList; /* Number of pages still on the free-list */
@@ -2855,8 +2861,8 @@ static int autoVacuumCommit(BtShared *pBt){
invalidateAllOverflowCache(pBt);
assert(pBt->autoVacuum);
if( !pBt->incrVacuum ){
Pgno nFin; /* Number of pages to be freed */
Pgno nFree; /* Number of pages no the freelist */
Pgno nFin; /* Number of pages in database after autovacuuming */
Pgno nFree; /* Number of pages on the freelist initially */
Pgno nPtrmap; /* Number of PtrMap pages to be freed */
Pgno iFree; /* The next page to be freed */
int nEntry; /* Number of entries on one ptrmap page */
@@ -3441,6 +3447,17 @@ int sqlite3BtreeCloseCursor(BtCursor *pCur){
}
#endif /* _MSC_VER */
#ifndef NDEBUG /* The next routine used only within assert() statements */
/*
** Return true if the given BtCursor is valid. A valid cursor is one
** that is currently pointing to a row in a (non-empty) table.
** This is a verification routine is used only within assert() statements.
*/
int sqlite3BtreeCursorIsValid(BtCursor *pCur){
return pCur && pCur->eState==CURSOR_VALID;
}
#endif /* NDEBUG */
/*
** Set *pSize to the size of the buffer needed to hold the value of
** the key for the current entry. If the cursor is not pointing
@@ -3448,47 +3465,41 @@ int sqlite3BtreeCloseCursor(BtCursor *pCur){
**
** For a table with the INTKEY flag set, this routine returns the key
** itself, not the number of bytes in the key.
**
** The caller must position the cursor prior to invoking this routine.
**
** This routine cannot fail. It always returns SQLITE_OK.
*/
int sqlite3BtreeKeySize(BtCursor *pCur, i64 *pSize){
int rc;
assert( cursorHoldsMutex(pCur) );
rc = restoreCursorPosition(pCur);
if( rc==SQLITE_OK ){
assert( pCur->eState==CURSOR_INVALID || pCur->eState==CURSOR_VALID );
if( pCur->eState==CURSOR_INVALID ){
*pSize = 0;
}else{
getCellInfo(pCur);
*pSize = pCur->info.nKey;
}
assert( pCur->eState==CURSOR_INVALID || pCur->eState==CURSOR_VALID );
if( pCur->eState!=CURSOR_VALID ){
*pSize = 0;
}else{
getCellInfo(pCur);
*pSize = pCur->info.nKey;
}
return rc;
return SQLITE_OK;
}
/*
** Set *pSize to the number of bytes of data in the entry the
** cursor currently points to. Always return SQLITE_OK.
** Failure is not possible. If the cursor is not currently
** pointing to an entry (which can happen, for example, if
** the database is empty) then *pSize is set to 0.
** cursor currently points to.
**
** The caller must guarantee that the cursor is pointing to a non-NULL
** valid entry. In other words, the calling procedure must guarantee
** that the cursor has Cursor.eState==CURSOR_VALID.
**
** Failure is not possible. This function always returns SQLITE_OK.
** It might just as well be a procedure (returning void) but we continue
** to return an integer result code for historical reasons.
*/
int sqlite3BtreeDataSize(BtCursor *pCur, u32 *pSize){
int rc;
assert( cursorHoldsMutex(pCur) );
rc = restoreCursorPosition(pCur);
if( rc==SQLITE_OK ){
assert( pCur->eState==CURSOR_INVALID || pCur->eState==CURSOR_VALID );
if( pCur->eState==CURSOR_INVALID ){
/* Not pointing at a valid entry - set *pSize to 0. */
*pSize = 0;
}else{
getCellInfo(pCur);
*pSize = pCur->info.nData;
}
}
return rc;
assert( pCur->eState==CURSOR_VALID );
getCellInfo(pCur);
*pSize = pCur->info.nData;
return SQLITE_OK;
}
/*
src/btree.h
+5 -1
View File
@@ -13,7 +13,7 @@
** subsystem. See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.119 2009/07/09 05:07:38 danielk1977 Exp $
** @(#) $Id: btree.h,v 1.120 2009/07/22 00:35:24 drh Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_
@@ -185,6 +185,10 @@ int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
void sqlite3BtreeCacheOverflow(BtCursor *);
void sqlite3BtreeClearCursor(BtCursor *);
#ifndef NDEBUG
int sqlite3BtreeCursorIsValid(BtCursor*);
#endif
#ifndef SQLITE_OMIT_BTREECOUNT
int sqlite3BtreeCount(BtCursor *, i64 *);
#endif
src/vdbe.c
+7 -3
View File
@@ -43,7 +43,7 @@
** in this file for details. If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.872 2009/07/14 18:35:45 drh Exp $
** $Id: vdbe.c,v 1.873 2009/07/22 00:35:24 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"
@@ -2055,6 +2055,7 @@ case OP_Column: {
payloadSize = pC->payloadSize;
zRec = (char*)pC->aRow;
}else if( pC->isIndex ){
assert( sqlite3BtreeCursorIsValid(pCrsr) );
rc = sqlite3BtreeKeySize(pCrsr, &payloadSize64);
assert( rc==SQLITE_OK ); /* True because of CursorMoveto() call above */
/* sqlite3BtreeParseCellPtr() uses getVarint32() to extract the
@@ -2063,8 +2064,9 @@ case OP_Column: {
assert( (payloadSize64 & SQLITE_MAX_U32)==(u64)payloadSize64 );
payloadSize = (u32)payloadSize64;
}else{
assert( sqlite3BtreeCursorIsValid(pCrsr) );
rc = sqlite3BtreeDataSize(pCrsr, &payloadSize);
assert( rc==SQLITE_OK ); /* True because of CursorMoveto() call above */
assert( rc==SQLITE_OK ); /* DataSize() cannot fail */
}
}else if( pC->pseudoTable ){
/* The record is the sole entry of a pseudo-table */
@@ -3593,6 +3595,7 @@ case OP_NewRowid: { /* out2-prerelease */
if( res ){
v = 1;
}else{
assert( sqlite3BtreeCursorIsValid(pC->pCursor) );
rc = sqlite3BtreeKeySize(pC->pCursor, &v);
assert( rc==SQLITE_OK ); /* Cannot fail following BtreeLast() */
if( v==MAX_ROWID ){
@@ -3879,6 +3882,7 @@ case OP_RowData: {
assert( pC->pseudoTable==0 );
assert( pC->pCursor!=0 );
pCrsr = pC->pCursor;
assert( sqlite3BtreeCursorIsValid(pCrsr) );
/* The OP_RowKey and OP_RowData opcodes always follow OP_NotExists or
** OP_Rewind/Op_Next with no intervening instructions that might invalidate
@@ -3899,7 +3903,7 @@ case OP_RowData: {
n = (u32)n64;
}else{
rc = sqlite3BtreeDataSize(pCrsr, &n);
assert( rc==SQLITE_OK ); /* True because of CursorMoveto() call above */
assert( rc==SQLITE_OK ); /* DataSize() cannot fail */
if( n>(u32)db->aLimit[SQLITE_LIMIT_LENGTH] ){
goto too_big;
}
src/vdbeaux.c
+3 -1
View File
@@ -14,7 +14,7 @@
** to version 2.8.7, all this code was combined into the vdbe.c source file.
** But that file was getting too big so this subroutines were split out.
**
** $Id: vdbeaux.c,v 1.476 2009/07/17 17:25:43 danielk1977 Exp $
** $Id: vdbeaux.c,v 1.477 2009/07/22 00:35:24 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"
@@ -2599,6 +2599,7 @@ int sqlite3VdbeIdxRowid(sqlite3 *db, BtCursor *pCur, i64 *rowid){
** Any corruption is detected in sqlite3BtreeParseCellPtr(), though, so
** this code can safely assume that nCellKey is 32-bits
*/
assert( sqlite3BtreeCursorIsValid(pCur) );
rc = sqlite3BtreeKeySize(pCur, &nCellKey);
assert( rc==SQLITE_OK ); /* pCur is always valid so KeySize cannot fail */
assert( (nCellKey & SQLITE_MAX_U32)==(u64)nCellKey );
@@ -2675,6 +2676,7 @@ int sqlite3VdbeIdxKeyCompare(
BtCursor *pCur = pC->pCursor;
Mem m;
assert( sqlite3BtreeCursorIsValid(pCur) );
rc = sqlite3BtreeKeySize(pCur, &nCellKey);
assert( rc==SQLITE_OK ); /* pCur is always valid so KeySize cannot fail */
/* nCellKey will always be between 0 and 0xffffffff because of the say