SQLite

Check-in [5748e64376]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Rearrange some code in the RowSet logic for clarity of presentation, while adding an /*OPTIMIZATION-IF-TRUE*/ comment. It should operate identically.
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 5748e64376c1c2be5154a632d1527cfebbb9ec74
User & Date: drh 2016-04-28 18:53:08.454
Context
2016-04-28
19:23
Fix typo in comment. No changes to code. (check-in: 9f6f17b5c9 user: mistachkin tags: trunk)
18:53
Rearrange some code in the RowSet logic for clarity of presentation, while adding an /*OPTIMIZATION-IF-TRUE*/ comment. It should operate identically. (check-in: 5748e64376 user: drh tags: trunk)
14:15
Use comments to mark several branches as optimizations. No changes to code. (check-in: 33e6274727 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/rowset.c.
︙︙
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354





355
356
357
358
359
360
361

  int iDepth
){
  struct RowSetEntry *p;         /* Root of the new tree */
  struct RowSetEntry *pLeft;     /* Left subtree */
  if( *ppList==0 ){
    return 0;
  }
  if( iDepth==1 ){
    p = *ppList;
    *ppList = p->pRight;
    p->pLeft = p->pRight = 0;
    return p;
  }
  pLeft = rowSetNDeepTree(ppList, iDepth-1);
  p = *ppList;
  if( p==0 ){
    return pLeft;
  }
  p->pLeft = pLeft;
  *ppList = p->pRight;
  p->pRight = rowSetNDeepTree(ppList, iDepth-1);





  return p;
}

/*
** Convert a sorted list of elements into a binary tree. Make the tree
** as deep as it needs to be in order to contain the entire list.
*/








|
|
|
|
<
<
|
|
|
|
|
|
|
|
>
>
>
>
>








334
335
336
337
338
339
340
341
342
343
344


345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364

  int iDepth
){
  struct RowSetEntry *p;         /* Root of the new tree */
  struct RowSetEntry *pLeft;     /* Left subtree */
  if( *ppList==0 ){
    return 0;
  }
  if( iDepth>1 ){   /*OPTIMIZATION-IF-TRUE*/
    /* This branch cases a *balanced* tree to be generated.  A valid tree
    ** is still generated without this branch, but it is wildly unbalanced
    ** and inefficient. */


    pLeft = rowSetNDeepTree(ppList, iDepth-1);
    p = *ppList;
    if( p==0 ){
      return pLeft;
    }
    p->pLeft = pLeft;
    *ppList = p->pRight;
    p->pRight = rowSetNDeepTree(ppList, iDepth-1);
  }else{
    p = *ppList;
    *ppList = p->pRight;
    p->pLeft = p->pRight = 0;
  }
  return p;
}

/*
** Convert a sorted list of elements into a binary tree. Make the tree
** as deep as it needs to be in order to contain the entire list.
*/
︙︙