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Overview
Comment:Make the max() and min() aggregate functions magnetic.
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: fe083ef8a6923041a161299181db7530cc3dfc40
User & Date: dan 2011-07-28 20:19:13
Context
2011-07-29
17:06
Add missing file error01.test. check-in: e634279337 user: dan tags: trunk
2011-07-28
20:19
Make the max() and min() aggregate functions magnetic. check-in: fe083ef8a6 user: dan tags: trunk
19:32
Avoid concatenating multiple "syntax error" messages together. check-in: 2dd4975e9c user: dan tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/func.c.

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** or aggregate.
*/
struct Function {
  int nMinArg;
  int nMaxArg;
  const char *zName;
  JsonNode *(*xFunc)(int nArg, JsonNode **apArg);
  int (*xStep)(int nArg, JsonNode **apArg, void **);
  JsonNode *(*xFinal)(void *);
};

/*************************************************************************
** Start of implementation of aggregate functions:
**
**   count()
................................................................................
**     visited, NULL is returned. Otherwise, the expression avg(X) is 
**     equivalent to (sum(X)/count()).
*/

/*
** Aggregate function count().
*/
static int xCountStep(int nArg, JsonNode **apArg, void **pp){
  int *pnCount = (int *)*pp;
  if( pnCount==0 ){
    pnCount = xjd1MallocZero(sizeof(int));
    *pp = (void *)pnCount;
  }
  if( nArg==0 || apArg[0]->eJType!=XJD1_NULL ){
    (*pnCount)++;
................................................................................
  }
  return pRet;
}

/*
** Aggregate functions min() and max().
*/
static int xMinStep(int nArg, JsonNode **apArg, void **pp){
  JsonNode *pArg;
  JsonNode *pBest = *pp;
  assert( nArg==1 );
  pArg = apArg[0];
  if( !pBest || xjd1JsonCompare(pArg, pBest)<0 ){
    xjd1JsonFree(pBest);
    *pp = (void *)xjd1JsonRef(pArg);

  }
  return XJD1_OK;
}
static int xMaxStep(int nArg, JsonNode **apArg, void **pp){
  JsonNode *pArg;
  JsonNode *pBest = *pp;
  assert( nArg==1 );
  pArg = apArg[0];
  if( !pBest || xjd1JsonCompare(pArg, pBest)>0 ){
    xjd1JsonFree(pBest);
    *pp = (void *)xjd1JsonRef(pArg);

  }
  return XJD1_OK;
}
static JsonNode *xMinMaxFinal(void *p){
  JsonNode *pRet;
  if( p ){
    pRet = (JsonNode *)p;
................................................................................
  }
  return pRet;
}

/*
** Aggregate function array().
*/
static int xArrayStep(int nArg, JsonNode **apArg, void **pp){
  JsonNode *pArray = (JsonNode *)*pp;
  JsonNode *pArg = apArg[0];
  int nNew;
  if( !pArray ){
    pArray = xjd1JsonNew(0);
    pArray->eJType = XJD1_ARRAY;
    *pp = (void *)pArray;
................................................................................
  }
  return pArray;
}

/*
** Aggregate function sum()
*/
static int xSumStep(int nArg, JsonNode **apArg, void **pp){
  JsonNode *pVal = (JsonNode *)*pp;
  double rVal = 0.0;
  if( !pVal ){
    pVal = xjd1JsonNew(0);
    pVal->eJType = XJD1_REAL;
    *pp = (void *)pVal;
  }
................................................................................
** Aggregate function avg()
*/
typedef struct AvgCtx AvgCtx;
struct AvgCtx {
  int nRow;
  double rSum;
};
static int xAvgStep(int nArg, JsonNode **apArg, void **pp){
  AvgCtx *pCtx = (AvgCtx *)*pp;
  double rVal = 0.0;
  if( !pCtx ){
    pCtx = xjd1MallocZero(sizeof(AvgCtx));
    *pp = (void *)pCtx;
  }
  pCtx->nRow++;
................................................................................
  if( !p->u.func.apArg ){
    return XJD1_NOMEM;
  }

  return XJD1_OK;
}

static int aggExprStep(AggExpr *pAggExpr){
  Expr *p = pAggExpr->pExpr;
  Function *pFunc = p->u.func.pFunction;
  int i;
  int nItem = p->u.func.args->nEItem;

  assert( p->eType==TK_FUNCTION && p->eClass==XJD1_EXPR_FUNC );
  assert( pFunc->xStep && pFunc->xFinal && pFunc->xFunc==0 );

  for(i=0; i<nItem; i++){
    p->u.func.apArg[i] = xjd1ExprEval(p->u.func.args->apEItem[i].pExpr);
  }

  pFunc->xStep(nItem, p->u.func.apArg, &pAggExpr->pAggCtx);
  for(i=0; i<nItem; i++){
    xjd1JsonFree(p->u.func.apArg[i]);
  }

  return XJD1_OK;
}

int xjd1AggregateStep(Aggregate *pAgg){



  int i;                /* Used to iterate through aggregate functions */
  for(i=0; i<pAgg->nExpr; i++){
    int rc = aggExprStep(&pAgg->aAggExpr[i]);
    if( rc!=XJD1_OK ) return rc;
  }
  return XJD1_OK;;
}

int xjd1AggregateFinalize(Aggregate *pAgg){
  int i;







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** or aggregate.
*/
struct Function {
  int nMinArg;
  int nMaxArg;
  const char *zName;
  JsonNode *(*xFunc)(int nArg, JsonNode **apArg);
  int (*xStep)(int nArg, JsonNode **apArg, void **, int *pbSave);
  JsonNode *(*xFinal)(void *);
};

/*************************************************************************
** Start of implementation of aggregate functions:
**
**   count()
................................................................................
**     visited, NULL is returned. Otherwise, the expression avg(X) is 
**     equivalent to (sum(X)/count()).
*/

/*
** Aggregate function count().
*/
static int xCountStep(int nArg, JsonNode **apArg, void **pp, int *pbSave){
  int *pnCount = (int *)*pp;
  if( pnCount==0 ){
    pnCount = xjd1MallocZero(sizeof(int));
    *pp = (void *)pnCount;
  }
  if( nArg==0 || apArg[0]->eJType!=XJD1_NULL ){
    (*pnCount)++;
................................................................................
  }
  return pRet;
}

/*
** Aggregate functions min() and max().
*/
static int xMinStep(int nArg, JsonNode **apArg, void **pp, int *pbSave){
  JsonNode *pArg;
  JsonNode *pBest = *pp;
  assert( nArg==1 );
  pArg = apArg[0];
  if( !pBest || xjd1JsonCompare(pArg, pBest)<0 ){
    xjd1JsonFree(pBest);
    *pp = (void *)xjd1JsonRef(pArg);
    *pbSave = 1;
  }
  return XJD1_OK;
}
static int xMaxStep(int nArg, JsonNode **apArg, void **pp, int *pbSave){
  JsonNode *pArg;
  JsonNode *pBest = *pp;
  assert( nArg==1 );
  pArg = apArg[0];
  if( !pBest || xjd1JsonCompare(pArg, pBest)>0 ){
    xjd1JsonFree(pBest);
    *pp = (void *)xjd1JsonRef(pArg);
    *pbSave = 1;
  }
  return XJD1_OK;
}
static JsonNode *xMinMaxFinal(void *p){
  JsonNode *pRet;
  if( p ){
    pRet = (JsonNode *)p;
................................................................................
  }
  return pRet;
}

/*
** Aggregate function array().
*/
static int xArrayStep(int nArg, JsonNode **apArg, void **pp, int *pbSave){
  JsonNode *pArray = (JsonNode *)*pp;
  JsonNode *pArg = apArg[0];
  int nNew;
  if( !pArray ){
    pArray = xjd1JsonNew(0);
    pArray->eJType = XJD1_ARRAY;
    *pp = (void *)pArray;
................................................................................
  }
  return pArray;
}

/*
** Aggregate function sum()
*/
static int xSumStep(int nArg, JsonNode **apArg, void **pp, int *pbSave){
  JsonNode *pVal = (JsonNode *)*pp;
  double rVal = 0.0;
  if( !pVal ){
    pVal = xjd1JsonNew(0);
    pVal->eJType = XJD1_REAL;
    *pp = (void *)pVal;
  }
................................................................................
** Aggregate function avg()
*/
typedef struct AvgCtx AvgCtx;
struct AvgCtx {
  int nRow;
  double rSum;
};
static int xAvgStep(int nArg, JsonNode **apArg, void **pp, int *pbSave){
  AvgCtx *pCtx = (AvgCtx *)*pp;
  double rVal = 0.0;
  if( !pCtx ){
    pCtx = xjd1MallocZero(sizeof(AvgCtx));
    *pp = (void *)pCtx;
  }
  pCtx->nRow++;
................................................................................
  if( !p->u.func.apArg ){
    return XJD1_NOMEM;
  }

  return XJD1_OK;
}

static int aggExprStep(AggExpr *pAggExpr, int *pbSave){
  Expr *p = pAggExpr->pExpr;
  Function *pFunc = p->u.func.pFunction;
  int i;
  int nItem = p->u.func.args->nEItem;

  assert( p->eType==TK_FUNCTION && p->eClass==XJD1_EXPR_FUNC );
  assert( pFunc->xStep && pFunc->xFinal && pFunc->xFunc==0 );

  for(i=0; i<nItem; i++){
    p->u.func.apArg[i] = xjd1ExprEval(p->u.func.args->apEItem[i].pExpr);
  }

  pFunc->xStep(nItem, p->u.func.apArg, &pAggExpr->pAggCtx, pbSave);
  for(i=0; i<nItem; i++){
    xjd1JsonFree(p->u.func.apArg[i]);
  }

  return XJD1_OK;
}

int xjd1AggregateStep(
  Aggregate *pAgg, 
  int *pbSave                     /* OUT: True if this row should be saved */
){
  int i;                /* Used to iterate through aggregate functions */
  for(i=0; i<pAgg->nExpr; i++){
    int rc = aggExprStep(&pAgg->aAggExpr[i], pbSave);
    if( rc!=XJD1_OK ) return rc;
  }
  return XJD1_OK;;
}

int xjd1AggregateFinalize(Aggregate *pAgg){
  int i;

Changes to src/query.c.

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    ResultItem *pNext = pHead->pNext;
    assert( pNext==0 || cmpResultItem(pHead, pNext, pEList)<=(uniq?-1:0) );
    pHead = pNext;
  }
#endif
}

static void popResultList(ResultList *pList){
  ResultItem *pItem;
  int i;







  pItem = pList->pItem;

  pList->pItem = pItem->pNext;
  for(i=0; i<pList->nKey; i++){
    xjd1JsonFree(pItem->apKey[i]);

  }
}





















static void clearResultList(ResultList *pList){
  while( pList->pItem ) popResultList(pList);
  xjd1PoolDelete(pList->pPool);
  memset(pList, 0, sizeof(ResultList));
}

................................................................................
      ** GROUP BY, so no need to worry about that either. 
      */
      assert( p->u.simple.pHaving==0 );

      if( p->u.simple.grouped.pPool==0 ){
        JsonNode **apSrc;
        int nSrc;

        Pool *pPool;

        pPool = p->u.simple.grouped.pPool = xjd1PoolNew();
        if( !pPool ) return XJD1_NOMEM;

        p->u.simple.grouped.nKey = nSrc = xjd1DataSrcCount(p->u.simple.pFrom);
        apSrc = (JsonNode **)xjd1PoolMallocZero(pPool, nSrc*sizeof(JsonNode *));
        if( !apSrc ) return XJD1_NOMEM;

        /* Call the xStep() of each aggregate in the query for each row 
        ** matched by the query WHERE clause. */
        while( rc==XJD1_OK && XJD1_ROW==(rc = selectStepWhered(p) ) ){

          rc = xjd1AggregateStep(pAgg);

          xjd1DataSrcCacheSave(p->u.simple.pFrom, apSrc);


        }
        assert( rc!=XJD1_OK );
        if( rc==XJD1_DONE ){
          rc = addToResultList(&p->u.simple.grouped, apSrc);
        }
        if( rc==XJD1_OK ){
          rc = xjd1AggregateFinalize(pAgg);
................................................................................
  
        p->eDocFrom = XJD1_FROM_GROUPED;
        pItem = p->u.simple.grouped.pItem;
        if( pItem==0 ){
          rc = XJD1_DONE;
        }else{
          while( 1 ){

            ResultItem *pNext = pItem->pNext;
            rc = xjd1AggregateStep(pAgg);

            if( rc || !pNext || cmpResultItem(pItem, pNext, pGroupBy) ){

              break;
            }
            popResultList(&p->u.simple.grouped);
            pItem = p->u.simple.grouped.pItem;
          }

          if( XJD1_OK==rc && XJD1_OK==(rc = xjd1AggregateFinalize(pAgg)) ){
            rc = XJD1_ROW;
          }
        }

      }while( rc==XJD1_ROW 
           && p->u.simple.pHaving && !xjd1ExprTrue(p->u.simple.pHaving)







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    ResultItem *pNext = pHead->pNext;
    assert( pNext==0 || cmpResultItem(pHead, pNext, pEList)<=(uniq?-1:0) );
    pHead = pNext;
  }
#endif
}


static void freeResultListItem(ResultList *pList, ResultItem *pItem){
  int i;
  for(i=0; i<pList->nKey; i++){
    xjd1JsonFree(pItem->apKey[i]);
  }
}

static void popResultList(ResultList *pList){
  ResultItem *pItem;
  pItem = pList->pItem;
  if( pItem ){
    pList->pItem = pItem->pNext;


    freeResultListItem(pList, pItem);
  }
}

/*
** These two are used GROUP BY processing.
*/
static void saveResultList(ResultList *pList){
  if( pList->pSaved ){
    freeResultListItem(pList, pList->pSaved);
  }
  pList->pSaved = pList->pItem;
  pList->pItem = pList->pItem->pNext;
}
static void restoreResultList(ResultList *pList){
  if( pList->pSaved ){
    popResultList(pList);
    pList->pSaved->pNext = pList->pItem;
    pList->pItem = pList->pSaved;
    pList->pSaved = 0;
  }
}


static void clearResultList(ResultList *pList){
  while( pList->pItem ) popResultList(pList);
  xjd1PoolDelete(pList->pPool);
  memset(pList, 0, sizeof(ResultList));
}

................................................................................
      ** GROUP BY, so no need to worry about that either. 
      */
      assert( p->u.simple.pHaving==0 );

      if( p->u.simple.grouped.pPool==0 ){
        JsonNode **apSrc;
        int nSrc;
        int saved = 0;;
        Pool *pPool;

        pPool = p->u.simple.grouped.pPool = xjd1PoolNew();
        if( !pPool ) return XJD1_NOMEM;

        p->u.simple.grouped.nKey = nSrc = xjd1DataSrcCount(p->u.simple.pFrom);
        apSrc = (JsonNode **)xjd1PoolMallocZero(pPool, nSrc*sizeof(JsonNode *));
        if( !apSrc ) return XJD1_NOMEM;

        /* Call the xStep() of each aggregate in the query for each row 
        ** matched by the query WHERE clause. */
        while( rc==XJD1_OK && XJD1_ROW==(rc = selectStepWhered(p) ) ){
          int saveThisRow = 0;
          rc = xjd1AggregateStep(pAgg, &saveThisRow);
          if( saved==0 || saveThisRow ){
            xjd1DataSrcCacheSave(p->u.simple.pFrom, apSrc);
            saved = 1;
          }
        }
        assert( rc!=XJD1_OK );
        if( rc==XJD1_DONE ){
          rc = addToResultList(&p->u.simple.grouped, apSrc);
        }
        if( rc==XJD1_OK ){
          rc = xjd1AggregateFinalize(pAgg);
................................................................................
  
        p->eDocFrom = XJD1_FROM_GROUPED;
        pItem = p->u.simple.grouped.pItem;
        if( pItem==0 ){
          rc = XJD1_DONE;
        }else{
          while( 1 ){
            int saveThisRow = 0;
            ResultItem *pNext = pItem->pNext;
            rc = xjd1AggregateStep(pAgg, &saveThisRow);
            if( saveThisRow ) saveResultList(&p->u.simple.grouped);
            if( rc || !pNext || cmpResultItem(pItem, pNext, pGroupBy) ){
              restoreResultList(&p->u.simple.grouped);
              break;
            }
            if( !saveThisRow ) popResultList(&p->u.simple.grouped);
            pItem = p->u.simple.grouped.pItem;
          }

          if( XJD1_OK==rc && XJD1_OK==(rc = xjd1AggregateFinalize(pAgg)) ){
            rc = XJD1_ROW;
          }
        }

      }while( rc==XJD1_ROW 
           && p->u.simple.pHaving && !xjd1ExprTrue(p->u.simple.pHaving)

Changes to src/xjd1Int.h.

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  String errMsg;                  /* Error message string */
};

/* A list of sorted results. */
struct ResultList {
  Pool *pPool;
  int nKey;

  ResultItem *pItem;
};

struct Aggregate {
  int nExpr;                      /* Number of aggregate functions */
  struct AggExpr {
    Expr *pExpr;                  /* Array of aggregate functions */
................................................................................

/******************************** func.c *************************************/
int xjd1FunctionInit(Expr *p, xjd1_stmt *pStmt, Query *pQuery, int bAggOk);
JsonNode *xjd1FunctionEval(Expr *p);
void xjd1FunctionClose(Expr *p);

int xjd1AggregateInit(xjd1_stmt *, Query *, Expr *);
int xjd1AggregateStep(Aggregate *);
int xjd1AggregateFinalize(Aggregate *);
void xjd1AggregateClear(Query *);

#endif /* _XJD1INT_H */







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  String errMsg;                  /* Error message string */
};

/* A list of sorted results. */
struct ResultList {
  Pool *pPool;
  int nKey;
  ResultItem *pSaved;
  ResultItem *pItem;
};

struct Aggregate {
  int nExpr;                      /* Number of aggregate functions */
  struct AggExpr {
    Expr *pExpr;                  /* Array of aggregate functions */
................................................................................

/******************************** func.c *************************************/
int xjd1FunctionInit(Expr *p, xjd1_stmt *pStmt, Query *pQuery, int bAggOk);
JsonNode *xjd1FunctionEval(Expr *p);
void xjd1FunctionClose(Expr *p);

int xjd1AggregateInit(xjd1_stmt *, Query *, Expr *);
int xjd1AggregateStep(Aggregate *, int *);
int xjd1AggregateFinalize(Aggregate *);
void xjd1AggregateClear(Query *);

#endif /* _XJD1INT_H */

Changes to test/base05.test.

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.testcase 12
SELECT count(c1) FROM c1;
SELECT count(c1) FROM c1 WHERE c1.i < 10;
.result 17 9

.testcase 13
SELECT {a: count(c1), b : c1} FROM c1;
.result {"a":17,"b":{"i":11,"z":"Fig"}}

.testcase 14
SELECT count(c1) FROM c1, c1 AS b;
SELECT count(c1) FROM c1, c1 AS b WHERE c1.i<3 && b.i<3;
SELECT count(c1) FROM c1, c1 AS b WHERE c1.i==1;
.result 289 4 17

................................................................................
.testcase 19
SELECT DISTINCT c2.a FROM c2;
.result "a" "b" "c"

.testcase 20
SELECT DISTINCT c2.a FROM c2 ORDER BY c2.a DESC;
.result "c" "b" "a"








































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.testcase 12
SELECT count(c1) FROM c1;
SELECT count(c1) FROM c1 WHERE c1.i < 10;
.result 17 9

.testcase 13
SELECT {a: count(c1), b : c1} FROM c1;
.result {"a":17,"b":{"i":13,"z":"Grape"}}

.testcase 14
SELECT count(c1) FROM c1, c1 AS b;
SELECT count(c1) FROM c1, c1 AS b WHERE c1.i<3 && b.i<3;
SELECT count(c1) FROM c1, c1 AS b WHERE c1.i==1;
.result 289 4 17

................................................................................
.testcase 19
SELECT DISTINCT c2.a FROM c2;
.result "a" "b" "c"

.testcase 20
SELECT DISTINCT c2.a FROM c2 ORDER BY c2.a DESC;
.result "c" "b" "a"



-- Test the magneticness of max() and min().
--
CREATE COLLECTION c3;
INSERT INTO c3 VALUE { a:2, z:"two" };
INSERT INTO c3 VALUE { a:3, z:"three"};
INSERT INTO c3 VALUE { a:7, z:"seven"};
INSERT INTO c3 VALUE { a:5, z:"five"};
INSERT INTO c3 VALUE { a:1, z:"one"};
INSERT INTO c3 VALUE { a:4, z:"four"};
INSERT INTO c3 VALUE { a:6, z:"six"};

.testcase 21
SELECT { max: max(c3.a), z: c3.z } FROM c3;
.json {max:7, z:"seven"}

.testcase 22
SELECT { min: min(c3.a), z: c3.z } FROM c3;
.json {min:1, z:"one"}

.testcase 23
SELECT { min: min(c3.a), z: c3.z } FROM c3 GROUP BY c3.a%2;
.json {min:2, z:"two"} {min:1, z:"one"} 

.testcase 24
SELECT { max: max(c3.a), z: c3.z } FROM c3 GROUP BY c3.a%2;
.json {max:6, z:"six"} {max:7, z:"seven"}