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Overview
| Comment: | Enhancements to the previous check-in to make it a little smaller and faster. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
291d9e0c328a7bd0f255b0b7e819ca2c |
| User & Date: | drh 2015-06-27 20:55:00.648 |
Context
|
2015-06-27
| ||
| 22:49 | Add the BtCursor.curIntKey field and use it for a small size reduction and performance boost. (check-in: 4a17df139a user: drh tags: trunk) | |
| 20:55 | Enhancements to the previous check-in to make it a little smaller and faster. (check-in: 291d9e0c32 user: drh tags: trunk) | |
| 19:45 | Performance improvements in moveToChild() by shifting some work over to getAndInitPage(). Net improvement is about 800K cycles at cost of 30 bytes. (check-in: 1956a4ce8e user: drh tags: trunk) | |
Changes
Changes to src/btree.c.
| ︙ | ︙ | |||
1907 1908 1909 1910 1911 1912 1913 | assert( ((p->pBt->nPage)&0x8000000)==0 ); return btreePagecount(p->pBt); } /* ** Get a page from the pager and initialize it. ** | | > | > | | | | 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 |
assert( ((p->pBt->nPage)&0x8000000)==0 );
return btreePagecount(p->pBt);
}
/*
** Get a page from the pager and initialize it.
**
** If pCur!=0 then the page is being fetched as part of a moveToChild()
** call. Do additional sanity checking on the page in this case.
** And if the fetch fails, this routine must decrement pCur->iPage.
**
** The page is fetched as read-write unless pCur is not NULL and is
** a read-only cursor.
**
** If an error occurs, then *ppPage is undefined. It
** may remain unchanged, or it may be set to an invalid value.
*/
static int getAndInitPage(
BtShared *pBt, /* The database file */
Pgno pgno, /* Number of the page to get */
MemPage **ppPage, /* Write the page pointer here */
BtCursor *pCur, /* Cursor to receive the page, or NULL */
int bReadOnly /* True for a read-only page */
){
int rc;
DbPage *pDbPage;
assert( sqlite3_mutex_held(pBt->mutex) );
assert( pCur==0 || ppPage==&pCur->apPage[pCur->iPage] );
assert( pCur==0 || bReadOnly==pCur->curPagerFlags );
assert( pCur==0 || pCur->iPage>0 );
if( pgno>btreePagecount(pBt) ){
rc = SQLITE_CORRUPT_BKPT;
goto getAndInitPage_error;
}
rc = sqlite3PagerAcquire(pBt->pPager, pgno, (DbPage**)&pDbPage, bReadOnly);
if( rc ){
goto getAndInitPage_error;
}
*ppPage = btreePageFromDbPage(pDbPage, pgno, pBt);
if( (*ppPage)->isInit==0 ){
rc = btreeInitPage(*ppPage);
if( rc!=SQLITE_OK ){
releasePage(*ppPage);
goto getAndInitPage_error;
}
}
/* If obtaining a child page for a cursor, we must verify that the page is
** compatible with the root page. */
if( pCur
&& ((*ppPage)->nCell<1 || (*ppPage)->intKey!=pCur->apPage[0]->intKey)
){
rc = SQLITE_CORRUPT_BKPT;
releasePage(*ppPage);
goto getAndInitPage_error;
}
|
| ︙ | ︙ | |||
4771 4772 4773 4774 4775 4776 4777 |
releasePageNotNull(pCur->apPage[pCur->iPage--]);
}
}else if( pCur->pgnoRoot==0 ){
pCur->eState = CURSOR_INVALID;
return SQLITE_OK;
}else{
assert( pCur->iPage==(-1) );
| < | | 4773 4774 4775 4776 4777 4778 4779 4780 4781 4782 4783 4784 4785 4786 4787 4788 |
releasePageNotNull(pCur->apPage[pCur->iPage--]);
}
}else if( pCur->pgnoRoot==0 ){
pCur->eState = CURSOR_INVALID;
return SQLITE_OK;
}else{
assert( pCur->iPage==(-1) );
rc = getAndInitPage(pCur->pBtree->pBt, pCur->pgnoRoot, &pCur->apPage[0],
0, pCur->curPagerFlags);
if( rc!=SQLITE_OK ){
pCur->eState = CURSOR_INVALID;
return rc;
}
pCur->iPage = 0;
}
pRoot = pCur->apPage[0];
|
| ︙ | ︙ |