]> git.ipfire.org Git - thirdparty/postgresql.git/commitdiff
Further cleanup of array behavior. Slice assignments to arrays with
authorTom Lane <tgl@sss.pgh.pa.us>
Sun, 23 Jul 2000 01:36:05 +0000 (01:36 +0000)
committerTom Lane <tgl@sss.pgh.pa.us>
Sun, 23 Jul 2000 01:36:05 +0000 (01:36 +0000)
varlena elements work now.  Allow assignment to previously-nonexistent
subscript position to extend array, but only for 1-D arrays and only
if adjacent to existing positions (could do more if we had a way to
represent nulls in arrays, but I don't want to tackle that now).
Arrange for assignment of NULL to an array element in UPDATE to be a
no-op, rather than setting the entire array to NULL as it used to.
(Throwing an error would be a reasonable alternative, but it's never
done that...)  Update regress test accordingly.

src/backend/executor/execQual.c
src/backend/utils/adt/arrayfuncs.c
src/test/regress/expected/arrays.out
src/test/regress/sql/arrays.sql

index 1aeb07a7a9ffda1f4620cf408e11dbce69526f6c..a445a57d9cf6e6ecbb70e2940b046ad076314ce1 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/executor/execQual.c,v 1.75 2000/07/22 03:34:27 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/executor/execQual.c,v 1.76 2000/07/23 01:35:58 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -64,18 +64,30 @@ static Datum ExecEvalVar(Var *variable, ExprContext *econtext, bool *isNull);
 static Datum ExecMakeFunctionResult(Node *node, List *arguments,
                                           ExprContext *econtext, bool *isNull, bool *isDone);
 
-/*
+/*----------
  *       ExecEvalArrayRef
  *
  *        This function takes an ArrayRef and returns the extracted Datum
  *        if it's a simple reference, or the modified array value if it's
- *        an array assignment (read array element insertion).
+ *        an array assignment (i.e., array element or slice insertion).
+ *
+ * NOTE: if we get a NULL result from a subexpression, we return NULL when
+ * it's an array reference, or the unmodified source array when it's an
+ * array assignment.  This may seem peculiar, but if we return NULL (as was
+ * done in versions up through 7.0) then an assignment like
+ *                     UPDATE table SET arrayfield[4] = NULL
+ * will result in setting the whole array to NULL, which is certainly not
+ * very desirable.  By returning the source array we make the assignment
+ * into a no-op, instead.  (Eventually we need to redesign arrays so that
+ * individual elements can be NULL, but for now, let's try to protect users
+ * from shooting themselves in the foot.)
  *
  * NOTE: we deliberately refrain from applying DatumGetArrayTypeP() here,
  * even though that might seem natural, because this code needs to support
  * both varlena arrays and fixed-length array types.  DatumGetArrayTypeP()
  * only works for the varlena kind.  The routines we call in arrayfuncs.c
  * have to know the difference (that's what they need refattrlength for).
+ *----------
  */
 static Datum
 ExecEvalArrayRef(ArrayRef *arrayRef,
@@ -85,6 +97,7 @@ ExecEvalArrayRef(ArrayRef *arrayRef,
 {
        ArrayType  *array_source;
        ArrayType  *resultArray;
+       bool            isAssignment = (arrayRef->refassgnexpr != NULL);
        List       *elt;
        int                     i = 0,
                                j = 0;
@@ -102,7 +115,11 @@ ExecEvalArrayRef(ArrayRef *arrayRef,
                                                                                 econtext,
                                                                                 isNull,
                                                                                 isDone));
-               /* If refexpr yields NULL, result is always NULL, for now anyway */
+               /*
+                * If refexpr yields NULL, result is always NULL, for now anyway.
+                * (This means you cannot assign to an element or slice of an array
+                * that's NULL; it'll just stay NULL.)
+                */
                if (*isNull)
                        return (Datum) NULL;
        }
@@ -110,7 +127,7 @@ ExecEvalArrayRef(ArrayRef *arrayRef,
        {
 
                /*
-                * Null refexpr indicates we are doing an INSERT into an array
+                * Empty refexpr indicates we are doing an INSERT into an array
                 * column. For now, we just take the refassgnexpr (which the
                 * parser will have ensured is an array value) and return it
                 * as-is, ignoring any subscripts that may have been supplied in
@@ -130,9 +147,14 @@ ExecEvalArrayRef(ArrayRef *arrayRef,
                                                                                                         econtext,
                                                                                                         isNull,
                                                                                                         &dummy));
-               /* If any index expr yields NULL, result is NULL */
+               /* If any index expr yields NULL, result is NULL or source array */
                if (*isNull)
-                       return (Datum) NULL;
+               {
+                       if (! isAssignment || array_source == NULL)
+                               return (Datum) NULL;
+                       *isNull = false;
+                       return PointerGetDatum(array_source);
+               }
        }
 
        if (arrayRef->reflowerindexpr != NIL)
@@ -147,9 +169,14 @@ ExecEvalArrayRef(ArrayRef *arrayRef,
                                                                                                                 econtext,
                                                                                                                 isNull,
                                                                                                                 &dummy));
-                       /* If any index expr yields NULL, result is NULL */
+                       /* If any index expr yields NULL, result is NULL or source array */
                        if (*isNull)
-                               return (Datum) NULL;
+                       {
+                               if (! isAssignment || array_source == NULL)
+                                       return (Datum) NULL;
+                               *isNull = false;
+                               return PointerGetDatum(array_source);
+                       }
                }
                if (i != j)
                        elog(ERROR,
@@ -159,18 +186,26 @@ ExecEvalArrayRef(ArrayRef *arrayRef,
        else
                lIndex = NULL;
 
-       if (arrayRef->refassgnexpr != NULL)
+       if (isAssignment)
        {
                Datum           sourceData = ExecEvalExpr(arrayRef->refassgnexpr,
                                                                                          econtext,
                                                                                          isNull,
                                                                                          &dummy);
-               /* For now, can't cope with inserting NULL into an array */
+               /*
+                * For now, can't cope with inserting NULL into an array,
+                * so make it a no-op per discussion above...
+                */
                if (*isNull)
-                       return (Datum) NULL;
+               {
+                       if (array_source == NULL)
+                               return (Datum) NULL;
+                       *isNull = false;
+                       return PointerGetDatum(array_source);
+               }
 
                if (array_source == NULL)
-                       return sourceData;      /* XXX do something else? */
+                       return sourceData;              /* XXX do something else? */
 
                if (lIndex == NULL)
                        resultArray = array_set(array_source, i,
index b4bc71f349adc7883c39025ebd8556ddbf912bd3..d9a210592c51dbe4cfa17a19cb2854af5175c3a0 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.62 2000/07/22 03:34:43 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.63 2000/07/23 01:35:58 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "utils/memutils.h"
 #include "utils/syscache.h"
 
-#define ASSGN   "="
-
-#define RETURN_NULL(type)  do { *isNull = true; return (type) 0; } while (0)
-
 
 /*
  * An array has the following internal structure:
  * The actual data starts on a MAXALIGN boundary.
  */
 
+
+/* ----------
+ * Local definitions
+ * ----------
+ */
+#ifndef MIN
+#define MIN(a,b) (((a)<(b)) ? (a) : (b))
+#endif
+#ifndef MAX
+#define MAX(a,b) (((a)>(b)) ? (a) : (b))
+#endif
+
+#define ASSGN   "="
+
+#define RETURN_NULL(type)  do { *isNull = true; return (type) 0; } while (0)
+
+
 static int     ArrayCount(char *str, int *dim, int typdelim);
 static Datum *ReadArrayStr(char *arrayStr, int nitems, int ndim, int *dim,
                          FmgrInfo *inputproc, Oid typelem, int32 typmod,
@@ -48,16 +61,22 @@ static void CopyArrayEls(char *p, Datum *values, int nitems,
                                                 bool typbyval, int typlen, char typalign,
                                                 bool freedata);
 static void system_cache_lookup(Oid element_type, bool input, int *typlen,
-                                bool *typbyval, char *typdelim, Oid *typelem, Oid *proc,
-                                       char *typalign);
+                                                               bool *typbyval, char *typdelim, Oid *typelem,
+                                                               Oid *proc, char *typalign);
 static Datum ArrayCast(char *value, bool byval, int len);
-static void ArrayClipCopy(int *st, int *endp, int bsize, char *destPtr,
-                                                 ArrayType *array, bool from);
-static int     ArrayClipCount(int *st, int *endp, ArrayType *array);
 static int     ArrayCastAndSet(Datum src, bool typbyval, int typlen, char *dest);
-static bool SanityCheckInput(int ndim, int n, int *dim, int *lb, int *indx);
-static int     array_read(char *destptr, int eltsize, int nitems, char *srcptr);
+static int     array_nelems_size(char *ptr, int eltsize, int nitems);
 static char *array_seek(char *ptr, int eltsize, int nitems);
+static int     array_copy(char *destptr, int eltsize, int nitems, char *srcptr);
+static int     array_slice_size(int ndim, int *dim, int *lb, char *arraydataptr,
+                                                        int eltsize, int *st, int *endp);
+static void array_extract_slice(int ndim, int *dim, int *lb,
+                                                               char *arraydataptr, int eltsize,
+                                                               int *st, int *endp, char *destPtr);
+static void array_insert_slice(int ndim, int *dim, int *lb,
+                                                          char *origPtr, int origdatasize,
+                                                          char *destPtr, int eltsize,
+                                                          int *st, int *endp, char *srcPtr);
 
 
 /*---------------------------------------------------------------------
@@ -153,7 +172,7 @@ array_in(PG_FUNCTION_ARGS)
        {
                while (isspace((int) *p))
                        p++;
-               if (strncmp(p, ASSGN, strlen(ASSGN)))
+               if (strncmp(p, ASSGN, strlen(ASSGN)) != 0)
                        elog(ERROR, "array_in: missing assignment operator");
                p += strlen(ASSGN);
                while (isspace((int) *p))
@@ -172,6 +191,7 @@ array_in(PG_FUNCTION_ARGS)
        nitems = ArrayGetNItems(ndim, dim);
        if (nitems == 0)
        {
+               /* Return empty array */
                retval = (ArrayType *) palloc(sizeof(ArrayType));
                MemSet(retval, 0, sizeof(ArrayType));
                retval->size = sizeof(ArrayType);
@@ -677,6 +697,10 @@ array_dims(PG_FUNCTION_ARGS)
        int                *dimv,
                           *lb;
 
+       /* Sanity check: does it look like an array at all? */
+       if (ARR_NDIM(v) <= 0 || ARR_NDIM(v) > MAXDIM)
+               PG_RETURN_NULL();
+
        nbytes = ARR_NDIM(v) * 33 + 1;
        /*
         * 33 since we assume 15 digits per number + ':' +'[]'
@@ -716,11 +740,15 @@ array_ref(ArrayType *array,
                  int arraylen,
                  bool *isNull)
 {
-       int                     ndim,
+       int                     i,
+                               ndim,
                           *dim,
                           *lb,
-                               offset;
-       char       *retptr;
+                               offset,
+                               fixedDim[1],
+                               fixedLb[1];
+       char       *arraydataptr,
+                          *retptr;
 
        if (array == (ArrayType *) NULL)
                RETURN_NULL(Datum);
@@ -730,27 +758,39 @@ array_ref(ArrayType *array,
                /*
                 * fixed-length arrays -- these are assumed to be 1-d, 0-based
                 */
-               if (nSubscripts != 1)
-                       RETURN_NULL(Datum);
-               if (indx[0] < 0 || indx[0] * elmlen >= arraylen)
-                       RETURN_NULL(Datum);
-               retptr = (char *) array + indx[0] * elmlen;
-               return ArrayCast(retptr, elmbyval, elmlen);
+               ndim = 1;
+               fixedDim[0] = arraylen / elmlen;
+               fixedLb[0] = 0;
+               dim = fixedDim;
+               lb = fixedLb;
+               arraydataptr = (char *) array;
        }
+       else
+       {
+               /* detoast input if necessary */
+               array = DatumGetArrayTypeP(PointerGetDatum(array));
 
-       /* detoast input if necessary */
-       array = DatumGetArrayTypeP(PointerGetDatum(array));
-
-       ndim = ARR_NDIM(array);
-       dim = ARR_DIMS(array);
-       lb = ARR_LBOUND(array);
+               ndim = ARR_NDIM(array);
+               dim = ARR_DIMS(array);
+               lb = ARR_LBOUND(array);
+               arraydataptr = ARR_DATA_PTR(array);
+       }
 
-       if (!SanityCheckInput(ndim, nSubscripts, dim, lb, indx))
+       /*
+        * Return NULL for invalid subscript
+        */
+       if (ndim != nSubscripts || ndim <= 0 || ndim > MAXDIM)
                RETURN_NULL(Datum);
+       for (i = 0; i < ndim; i++)
+               if (indx[i] < lb[i] || indx[i] >= (dim[i] + lb[i]))
+                       RETURN_NULL(Datum);
 
+       /*
+        * OK, get the element
+        */
        offset = ArrayGetOffset(nSubscripts, dim, lb, indx);
 
-       retptr = array_seek(ARR_DATA_PTR(array), elmlen, offset);
+       retptr = array_seek(arraydataptr, elmlen, offset);
 
        return ArrayCast(retptr, elmbyval, elmlen);
 }
@@ -760,6 +800,9 @@ array_ref(ArrayType *array,
  *                This routine takes an array and a range of indices (upperIndex and
  *                lowerIndx), creates a new array structure for the referred elements
  *                and returns a pointer to it.
+ *
+ * NOTE: we assume it is OK to scribble on the provided index arrays
+ * lowerIndx[] and upperIndx[].  These are generally just temporaries.
  *-----------------------------------------------------------------------------
  */
 ArrayType *
@@ -776,7 +819,10 @@ array_get_slice(ArrayType *array,
                                ndim,
                           *dim,
                           *lb;
-       ArrayType  *newArr;
+       int                     fixedDim[1],
+                               fixedLb[1];
+       char       *arraydataptr;
+       ArrayType  *newarray;
        int                     bytes,
                                span[MAXDIM];
 
@@ -786,44 +832,68 @@ array_get_slice(ArrayType *array,
        if (arraylen > 0)
        {
                /*
-                * fixed-length arrays -- no can do slice...
+                * fixed-length arrays -- currently, cannot slice these because
+                * parser labels output as being of the fixed-length array type!
+                * Code below shows how we could support it if the parser were
+                * changed to label output as a suitable varlena array type.
                 */
                elog(ERROR, "Slices of fixed-length arrays not implemented");
-       }
 
-       /* detoast input if necessary */
-       array = DatumGetArrayTypeP(PointerGetDatum(array));
+               /*
+                * fixed-length arrays -- these are assumed to be 1-d, 0-based
+                */
+               ndim = 1;
+               fixedDim[0] = arraylen / elmlen;
+               fixedLb[0] = 0;
+               dim = fixedDim;
+               lb = fixedLb;
+               arraydataptr = (char *) array;
+       }
+       else
+       {
+               /* detoast input if necessary */
+               array = DatumGetArrayTypeP(PointerGetDatum(array));
 
-       ndim = ARR_NDIM(array);
-       dim = ARR_DIMS(array);
-       lb = ARR_LBOUND(array);
+               ndim = ARR_NDIM(array);
+               dim = ARR_DIMS(array);
+               lb = ARR_LBOUND(array);
+               arraydataptr = ARR_DATA_PTR(array);
+       }
 
-       if (!SanityCheckInput(ndim, nSubscripts, dim, lb, upperIndx) ||
-               !SanityCheckInput(ndim, nSubscripts, dim, lb, lowerIndx))
+       /*
+        * Check provided subscripts.  A slice exceeding the current array
+        * limits is silently truncated to the array limits.  If we end up with
+        * an empty slice, return NULL (should it be an empty array instead?)
+        */
+       if (ndim != nSubscripts || ndim <= 0 || ndim > MAXDIM)
                RETURN_NULL(ArrayType *);
 
-       for (i = 0; i < nSubscripts; i++)
+       for (i = 0; i < ndim; i++)
+       {
+               if (lowerIndx[i] < lb[i])
+                       lowerIndx[i] = lb[i];
+               if (upperIndx[i] >= (dim[i] + lb[i]))
+                       upperIndx[i] = dim[i] + lb[i] - 1;
                if (lowerIndx[i] > upperIndx[i])
                        RETURN_NULL(ArrayType *);
+       }
 
        mda_get_range(nSubscripts, span, lowerIndx, upperIndx);
 
-       if (elmlen > 0)
-               bytes = ArrayGetNItems(nSubscripts, span) * elmlen;
-       else
-               bytes = ArrayClipCount(lowerIndx, upperIndx, array);
-       bytes += ARR_OVERHEAD(nSubscripts);
-
-       newArr = (ArrayType *) palloc(bytes);
-       newArr->size = bytes;
-       newArr->ndim = array->ndim;
-       newArr->flags = array->flags;
-       memcpy(ARR_DIMS(newArr), span, nSubscripts * sizeof(int));
-       memcpy(ARR_LBOUND(newArr), lowerIndx, nSubscripts * sizeof(int));
-       ArrayClipCopy(lowerIndx, upperIndx, elmlen, ARR_DATA_PTR(newArr),
-                                 array, true);
-
-       return newArr;
+       bytes = array_slice_size(ndim, dim, lb, arraydataptr,
+                                                        elmlen, lowerIndx, upperIndx);
+       bytes += ARR_OVERHEAD(ndim);
+
+       newarray = (ArrayType *) palloc(bytes);
+       newarray->size = bytes;
+       newarray->ndim = ndim;
+       newarray->flags = 0;
+       memcpy(ARR_DIMS(newarray), span, ndim * sizeof(int));
+       memcpy(ARR_LBOUND(newarray), lowerIndx, ndim * sizeof(int));
+       array_extract_slice(ndim, dim, lb, arraydataptr, elmlen,
+                                               lowerIndx, upperIndx, ARR_DATA_PTR(newarray));
+
+       return newarray;
 }
 
 /*-----------------------------------------------------------------------------
@@ -834,7 +904,11 @@ array_get_slice(ArrayType *array,
  *               A new array is returned, just like the old except for the one
  *               modified entry.
  *
- * NOTE: For assignments, we throw an error for silly subscripts etc,
+ * For one-dimensional arrays only, we allow the array to be extended
+ * by assigning to the position one above or one below the existing range.
+ * (We could be more flexible if we had a way to represent NULL elements.)
+ *
+ * NOTE: For assignments, we throw an error for invalid subscripts etc,
  * rather than returning a NULL as the fetch operations do.  The reasoning
  * is that returning a NULL would cause the user's whole array to be replaced
  * with NULL, which will probably not make him happy.
@@ -850,19 +924,22 @@ array_set(ArrayType *array,
                  int arraylen,
                  bool *isNull)
 {
-       int                     ndim,
-                          *dim,
-                          *lb,
+       int                     i,
+                               ndim,
+                               dim[MAXDIM],
+                               lb[MAXDIM],
                                offset;
        ArrayType  *newarray;
        char       *elt_ptr;
-       int                     oldsize,
+       bool            extendbefore = false;
+       bool            extendafter = false;
+       int                     olddatasize,
                                newsize,
-                               oldlen,
-                               newlen,
-                               lth0,
-                               lth1,
-                               lth2;
+                               olditemlen,
+                               newitemlen,
+                               overheadlen,
+                               lenbefore,
+                               lenafter;
 
        if (array == (ArrayType *) NULL)
                RETURN_NULL(ArrayType *);
@@ -870,7 +947,8 @@ array_set(ArrayType *array,
        if (arraylen > 0)
        {
                /*
-                * fixed-length arrays -- these are assumed to be 1-d, 0-based
+                * fixed-length arrays -- these are assumed to be 1-d, 0-based.
+                * We cannot extend them, either.
                 */
                if (nSubscripts != 1)
                        elog(ERROR, "Invalid array subscripts");
@@ -887,40 +965,99 @@ array_set(ArrayType *array,
        array = DatumGetArrayTypeP(PointerGetDatum(array));
 
        ndim = ARR_NDIM(array);
-       dim = ARR_DIMS(array);
-       lb = ARR_LBOUND(array);
-
-       if (!SanityCheckInput(ndim, nSubscripts, dim, lb, indx))
+       if (ndim != nSubscripts || ndim <= 0 || ndim > MAXDIM)
                elog(ERROR, "Invalid array subscripts");
 
-       offset = ArrayGetOffset(nSubscripts, dim, lb, indx);
+       /* copy dim/lb since we may modify them */
+       memcpy(dim, ARR_DIMS(array), ndim * sizeof(int));
+       memcpy(lb, ARR_LBOUND(array), ndim * sizeof(int));
 
-       elt_ptr = array_seek(ARR_DATA_PTR(array), elmlen, offset);
+       /*
+        * Check subscripts
+        */
+       for (i = 0; i < ndim; i++)
+       {
+               if (indx[i] < lb[i])
+               {
+                       if (ndim == 1 && indx[i] == lb[i] - 1)
+                       {
+                               dim[i]++;
+                               lb[i]--;
+                               extendbefore = true;
+                       }
+                       else
+                       {
+                               elog(ERROR, "Invalid array subscripts");
+                       }
+               }
+               if (indx[i] >= (dim[i] + lb[i]))
+               {
+                       if (ndim == 1 && indx[i] == (dim[i] + lb[i]))
+                       {
+                               dim[i]++;
+                               extendafter = true;
+                       }
+                       else
+                       {
+                               elog(ERROR, "Invalid array subscripts");
+                       }
+               }
+       }
 
-       if (elmlen > 0)
+       /*
+        * Compute sizes of items and areas to copy
+        */
+       overheadlen = ARR_OVERHEAD(ndim);
+       olddatasize = ARR_SIZE(array) - overheadlen;
+       if (extendbefore)
+       {
+               lenbefore = 0;
+               olditemlen = 0;
+               lenafter = olddatasize;
+       }
+       else if (extendafter)
        {
-               oldlen = newlen = elmlen;
+               lenbefore = olddatasize;
+               olditemlen = 0;
+               lenafter = 0;
        }
        else
        {
-               /* varlena type */
-               oldlen = INTALIGN(*(int32 *) elt_ptr);
-               newlen = INTALIGN(*(int32 *) DatumGetPointer(dataValue));
+               offset = ArrayGetOffset(nSubscripts, dim, lb, indx);
+               elt_ptr = array_seek(ARR_DATA_PTR(array), elmlen, offset);
+               lenbefore = (int) (elt_ptr - ARR_DATA_PTR(array));
+               if (elmlen > 0)
+                       olditemlen = elmlen;
+               else
+                       olditemlen = INTALIGN(*(int32 *) elt_ptr);
+               lenafter = (int) (olddatasize - lenbefore - olditemlen);
        }
 
-       oldsize = ARR_SIZE(array);
-       lth0 = ARR_OVERHEAD(ndim);
-       lth1 = (int) (elt_ptr - ARR_DATA_PTR(array));
-       lth2 = (int) (oldsize - lth0 - lth1 - oldlen);
-       newsize = lth0 + lth1 + newlen + lth2;
+       if (elmlen > 0)
+               newitemlen = elmlen;
+       else
+               newitemlen = INTALIGN(*(int32 *) DatumGetPointer(dataValue));
+
+       newsize = overheadlen + lenbefore + newitemlen + lenafter;
 
+       /*
+        * OK, do the assignment
+        */
        newarray = (ArrayType *) palloc(newsize);
-       memcpy((char *) newarray, (char *) array, lth0 + lth1);
-       memcpy((char *) newarray + lth0 + lth1 + newlen,
-                  (char *) array + lth0 + lth1 + oldlen, lth2);
        newarray->size = newsize;
-       newlen = ArrayCastAndSet(dataValue, elmbyval, elmlen,
-                                                        (char *) newarray + lth0 + lth1);
+       newarray->ndim = ndim;
+       newarray->flags = 0;
+       memcpy(ARR_DIMS(newarray), dim, ndim * sizeof(int));
+       memcpy(ARR_LBOUND(newarray), lb, ndim * sizeof(int));
+       memcpy((char *) newarray + overheadlen,
+                  (char *) array + overheadlen,
+                  lenbefore);
+       memcpy((char *) newarray + overheadlen + lenbefore + newitemlen,
+                  (char *) array + overheadlen + lenbefore + olditemlen,
+                  lenafter);
+
+       ArrayCastAndSet(dataValue, elmbyval, elmlen,
+                                       (char *) newarray + overheadlen + lenbefore);
 
        return newarray;
 }
@@ -953,55 +1090,162 @@ array_set_slice(ArrayType *array,
 {
        int                     i,
                                ndim,
-                          *dim,
-                          *lb;
-       int                     span[MAXDIM];
+                               dim[MAXDIM],
+                               lb[MAXDIM],
+                               span[MAXDIM];
+       ArrayType  *newarray;
+       int                     nsrcitems,
+                               olddatasize,
+                               newsize,
+                               olditemsize,
+                               newitemsize,
+                               overheadlen,
+                               lenbefore,
+                               lenafter;
 
        if (array == (ArrayType *) NULL)
                RETURN_NULL(ArrayType *);
        if (srcArray == (ArrayType *) NULL)
-               RETURN_NULL(ArrayType *);
+               return array;
 
        if (arraylen > 0)
        {
                /*
-                * fixed-length arrays -- no can do slice...
+                * fixed-length arrays -- not got round to doing this...
                 */
                elog(ERROR, "Updates on slices of fixed-length arrays not implemented");
        }
 
-       /* detoast array, making sure we get an overwritable copy */
-       array = DatumGetArrayTypePCopy(PointerGetDatum(array));
-
-       /* detoast source array if necessary */
+       /* detoast arrays if necessary */
+       array = DatumGetArrayTypeP(PointerGetDatum(array));
        srcArray = DatumGetArrayTypeP(PointerGetDatum(srcArray));
 
-       if (elmlen < 0)
-               elog(ERROR, "Updates on slices of arrays of variable length elements not implemented");
-
        ndim = ARR_NDIM(array);
-       dim = ARR_DIMS(array);
-       lb = ARR_LBOUND(array);
-
-       if (!SanityCheckInput(ndim, nSubscripts, dim, lb, upperIndx) ||
-               !SanityCheckInput(ndim, nSubscripts, dim, lb, lowerIndx))
+       if (ndim != nSubscripts || ndim <= 0 || ndim > MAXDIM)
                elog(ERROR, "Invalid array subscripts");
 
-       for (i = 0; i < nSubscripts; i++)
+       /* copy dim/lb since we may modify them */
+       memcpy(dim, ARR_DIMS(array), ndim * sizeof(int));
+       memcpy(lb, ARR_LBOUND(array), ndim * sizeof(int));
+
+       /*
+        * Check provided subscripts.  A slice exceeding the current array
+        * limits throws an error, *except* in the 1-D case where we will
+        * extend the array as long as no hole is created.
+        * An empty slice is an error, too.
+        */
+       for (i = 0; i < ndim; i++)
+       {
                if (lowerIndx[i] > upperIndx[i])
-               elog(ERROR, "Invalid array subscripts");
+                       elog(ERROR, "Invalid array subscripts");
+               if (lowerIndx[i] < lb[i])
+               {
+                       if (ndim == 1 && upperIndx[i] >= lb[i] - 1)
+                       {
+                               dim[i] += lb[i] - lowerIndx[i];
+                               lb[i] = lowerIndx[i];
+                       }
+                       else
+                       {
+                               elog(ERROR, "Invalid array subscripts");
+                       }
+               }
+               if (upperIndx[i] >= (dim[i] + lb[i]))
+               {
+                       if (ndim == 1 && lowerIndx[i] <= (dim[i] + lb[i]))
+                       {
+                               dim[i] = upperIndx[i] - lb[i] + 1;
+                       }
+                       else
+                       {
+                               elog(ERROR, "Invalid array subscripts");
+                       }
+               }
+       }
 
-       /* make sure source array has enough entries */
+       /*
+        * Make sure source array has enough entries.  Note we ignore the shape
+        * of the source array and just read entries serially.
+        */
        mda_get_range(ndim, span, lowerIndx, upperIndx);
-
-       if (ArrayGetNItems(ndim, span) >
-               ArrayGetNItems(ARR_NDIM(srcArray), ARR_DIMS(srcArray)))
+       nsrcitems = ArrayGetNItems(ndim, span);
+       if (nsrcitems > ArrayGetNItems(ARR_NDIM(srcArray), ARR_DIMS(srcArray)))
                elog(ERROR, "Source array too small");
 
-       ArrayClipCopy(lowerIndx, upperIndx, elmlen, ARR_DATA_PTR(srcArray),
-                                 array, false);
+       /*
+        * Compute space occupied by new entries, space occupied by replaced
+        * entries, and required space for new array.
+        */
+       newitemsize = array_nelems_size(ARR_DATA_PTR(srcArray), elmlen,
+                                                                       nsrcitems);
+       overheadlen = ARR_OVERHEAD(ndim);
+       olddatasize = ARR_SIZE(array) - overheadlen;
+       if (ndim > 1)
+       {
+               /*
+                * here we do not need to cope with extension of the array;
+                * it would be a lot more complicated if we had to do so...
+                */
+               olditemsize = array_slice_size(ndim, dim, lb, ARR_DATA_PTR(array),
+                                                                          elmlen, lowerIndx, upperIndx);
+               lenbefore = lenafter = 0; /* keep compiler quiet */
+       }
+       else
+       {
+               /*
+                * here we must allow for possibility of slice larger than orig array
+                */
+               int             oldlb = ARR_LBOUND(array)[0];
+               int             oldub = oldlb + ARR_DIMS(array)[0] - 1;
+               int             slicelb = MAX(oldlb, lowerIndx[0]);
+               int             sliceub = MIN(oldub, upperIndx[0]);
+               char   *oldarraydata = ARR_DATA_PTR(array);
+
+               lenbefore = array_nelems_size(oldarraydata,
+                                                                         elmlen,
+                                                                         slicelb - oldlb);
+               if (slicelb > sliceub)
+                       olditemsize = 0;
+               else
+                       olditemsize = array_nelems_size(oldarraydata + lenbefore,
+                                                                                       elmlen,
+                                                                                       sliceub - slicelb + 1);
+               lenafter = olddatasize - lenbefore - olditemsize;
+       }
+
+       newsize = overheadlen + olddatasize - olditemsize + newitemsize;
+
+       newarray = (ArrayType *) palloc(newsize);
+       newarray->size = newsize;
+       newarray->ndim = ndim;
+       newarray->flags = 0;
+       memcpy(ARR_DIMS(newarray), dim, ndim * sizeof(int));
+       memcpy(ARR_LBOUND(newarray), lb, ndim * sizeof(int));
+
+       if (ndim > 1)
+       {
+               /*
+                * here we do not need to cope with extension of the array;
+                * it would be a lot more complicated if we had to do so...
+                */
+               array_insert_slice(ndim, dim, lb, ARR_DATA_PTR(array), olddatasize,
+                                                  ARR_DATA_PTR(newarray), elmlen,
+                                                  lowerIndx, upperIndx, ARR_DATA_PTR(srcArray));
+       }
+       else
+       {
+               memcpy((char *) newarray + overheadlen,
+                          (char *) array + overheadlen,
+                          lenbefore);
+               memcpy((char *) newarray + overheadlen + lenbefore,
+                          ARR_DATA_PTR(srcArray),
+                          newitemsize);
+               memcpy((char *) newarray + overheadlen + lenbefore + newitemsize,
+                          (char *) array + overheadlen + lenbefore + olditemsize,
+                          lenafter);
+       }
 
-       return array;
+       return newarray;
 }
 
 /*
@@ -1326,7 +1570,9 @@ system_cache_lookup(Oid element_type,
                *proc = typeStruct->typoutput;
 }
 
-/* Fetch array value at pointer, converted correctly to a Datum */
+/*
+ * Fetch array element at pointer, converted correctly to a Datum
+ */
 static Datum
 ArrayCast(char *value, bool byval, int len)
 {
@@ -1402,138 +1648,196 @@ ArrayCastAndSet(Datum src,
        return inc;
 }
 
-/* Do Sanity check on input subscripting info */
-static bool
-SanityCheckInput(int ndim, int n, int *dim, int *lb, int *indx)
+/*
+ * Compute total size of the nitems array elements starting at *ptr
+ *
+ * XXX should consider alignment spec for fixed-length types
+ */
+static int
+array_nelems_size(char *ptr, int eltsize, int nitems)
 {
+       char       *origptr;
        int                     i;
 
-       if (n != ndim || ndim <= 0 || ndim > MAXDIM)
-               return false;
-       for (i = 0; i < ndim; i++)
-               if ((lb[i] > indx[i]) || (indx[i] >= (dim[i] + lb[i])))
-                       return false;
-       return true;
+       /* fixed-size elements? */
+       if (eltsize > 0)
+               return eltsize * nitems;
+       /* else assume they are varlena items */
+       origptr = ptr;
+       for (i = 0; i < nitems; i++)
+               ptr += INTALIGN(*(int32 *) ptr);
+       return ptr - origptr;
 }
 
-/* Copy an array slice into or out of an array */
-static void
-ArrayClipCopy(int *st,
-                         int *endp,
-                         int bsize,
-                         char *destPtr,
-                         ArrayType *array,
-                         bool from)
+/*
+ * Advance ptr over nitems array elements
+ */
+static char *
+array_seek(char *ptr, int eltsize, int nitems)
 {
-       int                     n,
-                          *dim,
-                          *lb,
-                               st_pos,
-                               prod[MAXDIM];
-       int                     span[MAXDIM],
-                               dist[MAXDIM],
-                               indx[MAXDIM];
-       int                     i,
-                               j,
-                               inc;
-       char       *srcPtr;
+       return ptr + array_nelems_size(ptr, eltsize, nitems);
+}
 
-       n = ARR_NDIM(array);
-       dim = ARR_DIMS(array);
-       lb = ARR_LBOUND(array);
-       st_pos = ArrayGetOffset(n, dim, lb, st);
-       srcPtr = array_seek(ARR_DATA_PTR(array), bsize, st_pos);
-       mda_get_prod(n, dim, prod);
-       mda_get_range(n, span, st, endp);
-       mda_get_offset_values(n, dist, prod, span);
-       for (i = 0; i < n; i++)
-               indx[i] = 0;
-       j = n - 1;
-       do
-       {
-               srcPtr = array_seek(srcPtr, bsize, dist[j]);
-               if (from)
-                       inc = array_read(destPtr, bsize, 1, srcPtr);
-               else
-                       inc = array_read(srcPtr, bsize, 1, destPtr);
-               destPtr += inc;
-               srcPtr += inc;
-       } while ((j = mda_next_tuple(n, indx, span)) != -1);
+/*
+ * Copy nitems array elements from srcptr to destptr
+ *
+ * Returns number of bytes copied
+ */
+static int
+array_copy(char *destptr, int eltsize, int nitems, char *srcptr)
+{
+       int                     numbytes = array_nelems_size(srcptr, eltsize, nitems);
+
+       memmove(destptr, srcptr, numbytes);
+       return numbytes;
 }
 
-/* Compute space needed for an array slice of varlena items */
+/*
+ * Compute space needed for a slice of an array
+ *
+ * We assume the caller has verified that the slice coordinates are valid.
+ */
 static int
-ArrayClipCount(int *st, int *endp, ArrayType *array)
+array_slice_size(int ndim, int *dim, int *lb, char *arraydataptr,
+                                int eltsize, int *st, int *endp)
 {
-       int                     n,
-                          *dim,
-                          *lb,
-                               st_pos,
-                               prod[MAXDIM];
-       int                     span[MAXDIM],
+       int                     st_pos,
+                               span[MAXDIM],
+                               prod[MAXDIM],
                                dist[MAXDIM],
                                indx[MAXDIM];
+       char       *ptr;
        int                     i,
                                j,
                                inc;
        int                     count = 0;
-       char       *ptr;
 
-       n = ARR_NDIM(array);
-       dim = ARR_DIMS(array);
-       lb = ARR_LBOUND(array);
-       st_pos = ArrayGetOffset(n, dim, lb, st);
-       ptr = array_seek(ARR_DATA_PTR(array), -1, st_pos);
-       mda_get_prod(n, dim, prod);
-       mda_get_range(n, span, st, endp);
-       mda_get_offset_values(n, dist, prod, span);
-       for (i = 0; i < n; i++)
+       mda_get_range(ndim, span, st, endp);
+
+       /* Pretty easy for fixed element length ... */
+       if (eltsize > 0)
+               return ArrayGetNItems(ndim, span) * eltsize;
+
+       /* Else gotta do it the hard way */
+       st_pos = ArrayGetOffset(ndim, dim, lb, st);
+       ptr = array_seek(arraydataptr, eltsize, st_pos);
+       mda_get_prod(ndim, dim, prod);
+       mda_get_offset_values(ndim, dist, prod, span);
+       for (i = 0; i < ndim; i++)
                indx[i] = 0;
-       j = n - 1;
+       j = ndim - 1;
        do
        {
-               ptr = array_seek(ptr, -1, dist[j]);
+               ptr = array_seek(ptr, eltsize, dist[j]);
                inc = INTALIGN(*(int32 *) ptr);
                ptr += inc;
                count += inc;
-       } while ((j = mda_next_tuple(n, indx, span)) != -1);
+       } while ((j = mda_next_tuple(ndim, indx, span)) != -1);
        return count;
 }
 
-/* Advance over nitems array elements */
-static char *
-array_seek(char *ptr, int eltsize, int nitems)
+/*
+ * Extract a slice of an array into consecutive elements at *destPtr.
+ *
+ * We assume the caller has verified that the slice coordinates are valid
+ * and allocated enough storage at *destPtr.
+ */
+static void
+array_extract_slice(int ndim,
+                                       int *dim,
+                                       int *lb,
+                                       char *arraydataptr,
+                                       int eltsize,
+                                       int *st,
+                                       int *endp,
+                                       char *destPtr)
 {
-       int                     i;
+       int                     st_pos,
+                               prod[MAXDIM],
+                               span[MAXDIM],
+                               dist[MAXDIM],
+                               indx[MAXDIM];
+       char       *srcPtr;
+       int                     i,
+                               j,
+                               inc;
 
-       if (eltsize > 0)
-               return ptr + eltsize * nitems;
-       for (i = 0; i < nitems; i++)
-               ptr += INTALIGN(*(int32 *) ptr);
-       return ptr;
+       st_pos = ArrayGetOffset(ndim, dim, lb, st);
+       srcPtr = array_seek(arraydataptr, eltsize, st_pos);
+       mda_get_prod(ndim, dim, prod);
+       mda_get_range(ndim, span, st, endp);
+       mda_get_offset_values(ndim, dist, prod, span);
+       for (i = 0; i < ndim; i++)
+               indx[i] = 0;
+       j = ndim - 1;
+       do
+       {
+               srcPtr = array_seek(srcPtr, eltsize, dist[j]);
+               inc = array_copy(destPtr, eltsize, 1, srcPtr);
+               destPtr += inc;
+               srcPtr += inc;
+       } while ((j = mda_next_tuple(ndim, indx, span)) != -1);
 }
 
-/* Copy nitems array elements from srcptr to destptr */
-static int
-array_read(char *destptr, int eltsize, int nitems, char *srcptr)
+/*
+ * Insert a slice into an array.
+ *
+ * ndim/dim/lb are dimensions of the dest array, which has data area
+ * starting at origPtr.  A new array with those same dimensions is to
+ * be constructed; its data area starts at destPtr.
+ *
+ * Elements within the slice volume are taken from consecutive locations
+ * at srcPtr; elements outside it are copied from origPtr.
+ *
+ * We assume the caller has verified that the slice coordinates are valid
+ * and allocated enough storage at *destPtr.
+ */
+static void
+array_insert_slice(int ndim,
+                                  int *dim,
+                                  int *lb,
+                                  char *origPtr,
+                                  int origdatasize,
+                                  char *destPtr,
+                                  int eltsize,
+                                  int *st,
+                                  int *endp,
+                                  char *srcPtr)
 {
+       int                     st_pos,
+                               prod[MAXDIM],
+                               span[MAXDIM],
+                               dist[MAXDIM],
+                               indx[MAXDIM];
+       char       *origEndpoint = origPtr + origdatasize;
        int                     i,
-                               inc,
-                               tmp;
+                               j,
+                               inc;
 
-       if (eltsize > 0)
-       {
-               memmove(destptr, srcptr, eltsize * nitems);
-               return eltsize * nitems;
-       }
-       inc = 0;
-       for (i = 0; i < nitems; i++)
+       st_pos = ArrayGetOffset(ndim, dim, lb, st);
+       inc = array_copy(destPtr, eltsize, st_pos, origPtr);
+       destPtr += inc;
+       origPtr += inc;
+       mda_get_prod(ndim, dim, prod);
+       mda_get_range(ndim, span, st, endp);
+       mda_get_offset_values(ndim, dist, prod, span);
+       for (i = 0; i < ndim; i++)
+               indx[i] = 0;
+       j = ndim - 1;
+       do
        {
-               tmp = (INTALIGN(*(int32 *) srcptr));
-               memmove(destptr, srcptr, tmp);
-               srcptr += tmp;
-               destptr += tmp;
-               inc += tmp;
-       }
-       return inc;
+               /* Copy/advance over elements between here and next part of slice */
+               inc = array_copy(destPtr, eltsize, dist[j], origPtr);
+               destPtr += inc;
+               origPtr += inc;
+               /* Copy new element at this slice position */
+               inc = array_copy(destPtr, eltsize, 1, srcPtr);
+               destPtr += inc;
+               srcPtr += inc;
+               /* Advance over old element at this slice position */
+               origPtr = array_seek(origPtr, eltsize, 1);
+       } while ((j = mda_next_tuple(ndim, indx, span)) != -1);
+
+       /* don't miss any data at the end */
+       memcpy(destPtr, origPtr, origEndpoint - origPtr);
 }
index c100ea6ce4baccd6fbd2ede089229b0ee5eb6625..b68783806402aed6a04cc6de7b54b63056d77fe7 100644 (file)
@@ -39,17 +39,17 @@ SELECT a[1:3],
      a      |        b        |       c       |         d         
 ------------+-----------------+---------------+-------------------
  {1,2,3}    | {{{0,0},{1,2}}} |               | 
- {11,12,23} |                 |               | {{"elt1","elt2"}}
+ {11,12,23} |                 | {"foobar"}    | {{"elt1","elt2"}}
             |                 | {"foo","bar"} | 
 (3 rows)
 
--- returns three different results--
-SELECT array_dims(arrtest.b) AS x;
-        x        
------------------
- [1:1][1:2][1:2]
- [1:2][1:2]
- [1:2]
+SELECT array_dims(a) AS a,array_dims(b) AS b,array_dims(c) AS c
+   FROM arrtest;
+   a   |        b        |   c   
+-------+-----------------+-------
+ [1:5] | [1:1][1:2][1:2] | 
+ [1:3] | [1:2][1:2]      | [1:1]
      | [1:2]           | [1:2]
 (3 rows)
 
 -- returns nothing 
@@ -62,18 +62,32 @@ SELECT *
 (0 rows)
 
 UPDATE arrtest
-  SET a[1:2] = '{16,25}',
-      b[1:1][1:1][1:2] = '{113, 117}', 
-      c[1:1] = '{"new_word"}';
+  SET a[1:2] = '{16,25}'
+  WHERE NOT a = '{}'::_int2;
+UPDATE arrtest
+  SET b[1:1][1:1][1:2] = '{113, 117}',
+      b[1:1][1:2][2:2] = '{142, 147}'
+  WHERE array_dims(b) = '[1:1][1:2][1:2]';
+UPDATE arrtest
+  SET c[2:2] = '{"new_word"}'
+  WHERE array_dims(c) is not null;
+SELECT a,b,c FROM arrtest;
+       a       |           b           |           c           
+---------------+-----------------------+-----------------------
+ {16,25,3,4,5} | {{{113,142},{1,147}}} | {}
+ {16,25,23}    | {{3,4},{4,5}}         | {"foobar","new_word"}
+ {}            | {3,4}                 | {"foo","new_word"}
+(3 rows)
+
 SELECT a[1:3],
           b[1:1][1:2][1:2],
           c[1:2], 
           d[1:1][2:2]
    FROM arrtest;
-     a      |          b          |         c          |     d      
-------------+---------------------+--------------------+------------
- {16,25,3}  | {{{113,117},{1,2}}} |                    | 
- {16,25,23} |                     |                    | {{"elt2"}}
-            |                     | {"new_word","bar"} | 
+     a      |           b           |           c           |     d      
+------------+-----------------------+-----------------------+------------
+ {16,25,3}  | {{{113,142},{1,147}}} |                       | 
+ {16,25,23} |                       | {"foobar","new_word"} | {{"elt2"}}
+            |                       | {"foo","new_word"}    | 
 (3 rows)
 
index 58615a66b97724928a8e54eb1bf2c309e1491c2a..3b02acf6427252a14e57a2aca414fbc28e9a8ad7 100644 (file)
@@ -20,8 +20,8 @@ SELECT a[1:3],
           d[1:1][1:2]
    FROM arrtest;
 
--- returns three different results--
-SELECT array_dims(arrtest.b) AS x;
+SELECT array_dims(a) AS a,array_dims(b) AS b,array_dims(c) AS c
+   FROM arrtest;
 
 -- returns nothing 
 SELECT *
@@ -30,9 +30,19 @@ SELECT *
          c = '{"foobar"}'::_name;
 
 UPDATE arrtest
-  SET a[1:2] = '{16,25}',
-      b[1:1][1:1][1:2] = '{113, 117}', 
-      c[1:1] = '{"new_word"}';
+  SET a[1:2] = '{16,25}'
+  WHERE NOT a = '{}'::_int2;
+
+UPDATE arrtest
+  SET b[1:1][1:1][1:2] = '{113, 117}',
+      b[1:1][1:2][2:2] = '{142, 147}'
+  WHERE array_dims(b) = '[1:1][1:2][1:2]';
+
+UPDATE arrtest
+  SET c[2:2] = '{"new_word"}'
+  WHERE array_dims(c) is not null;
+
+SELECT a,b,c FROM arrtest;
 
 SELECT a[1:3],
           b[1:1][1:2][1:2],