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Update foreach macros to match PG13 style

update-foreach-macros
Jelte Fennema-Nio 2023-10-24 17:00:00 +02:00
parent 2d1444188c
commit 55eed1b9d8
1 changed files with 21 additions and 31 deletions
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52
src/include/distributed/listutils.h
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@ -38,21 +38,14 @@ typedef struct ListCellAndListWrapper
* a convenience macro which loops through a pointer list without needing a * a convenience macro which loops through a pointer list without needing a
* ListCell, just a declared pointer variable to store the pointer of the * ListCell, just a declared pointer variable to store the pointer of the
* cell in. * cell in.
*
* How it works:
* - A ListCell is declared with the name {var}CellDoNotUse and used
* throughout the for loop using ## to concat.
* - To assign to var it needs to be done in the condition of the for loop,
* because we cannot use the initializer since a ListCell* variable is
* declared there.
* - || true is used to always enter the loop when cell is not null even if
* var is NULL.
*/ */
#define foreach_ptr(var, l) \ #define foreach_ptr(var, lst) \
for (ListCell *(var ## CellDoNotUse) = list_head(l); \ for (ForEachState var ## __state = { (lst), 0 }; \
(var ## CellDoNotUse) != NULL && \ (var ## __state.l != NIL && \
(((var) = lfirst(var ## CellDoNotUse)) || true); \ var ## __state.i < var ## __state.l->length) ? \
var ## CellDoNotUse = lnext(l, var ## CellDoNotUse)) (var = lfirst(&var ## __state.l->elements [var ## __state.i]), true) : \
(var = NULL, false); \
var ## __state.i ++)
/* /*
@ -61,11 +54,13 @@ typedef struct ListCellAndListWrapper
* ListCell, just a declared int variable to store the int of the cell in. * ListCell, just a declared int variable to store the int of the cell in.
* For explanation of how it works see foreach_ptr. * For explanation of how it works see foreach_ptr.
*/ */
#define foreach_int(var, l) \ #define foreach_int(var, lst) \
for (ListCell *(var ## CellDoNotUse) = list_head(l); \ for (ForEachState var ## __state = { (lst), 0 }; \
(var ## CellDoNotUse) != NULL && \ (var ## __state.l != NIL && \
(((var) = lfirst_int(var ## CellDoNotUse)) || true); \ var ## __state.i < var ## __state.l->length) ? \
var ## CellDoNotUse = lnext(l, var ## CellDoNotUse)) (var = lfirst_int(&var ## __state.l->elements [var ## __state.i]), true) : \
(var = 0, false); \
var ## __state.i ++)
/* /*
@ -74,11 +69,13 @@ typedef struct ListCellAndListWrapper
* ListCell, just a declared Oid variable to store the oid of the cell in. * ListCell, just a declared Oid variable to store the oid of the cell in.
* For explanation of how it works see foreach_ptr. * For explanation of how it works see foreach_ptr.
*/ */
#define foreach_oid(var, l) \ #define foreach_oid(var, lst) \
for (ListCell *(var ## CellDoNotUse) = list_head(l); \ for (ForEachState var ## __state = { (lst), 0 }; \
(var ## CellDoNotUse) != NULL && \ (var ## __state.l != NIL && \
(((var) = lfirst_oid(var ## CellDoNotUse)) || true); \ var ## __state.i < var ## __state.l->length) ? \
var ## CellDoNotUse = lnext(l, var ## CellDoNotUse)) (var = lfirst_oid(&var ## __state.l->elements [var ## __state.i]), true) : \
(var = 0, false); \
var ## __state.i ++)
/* /*
* forboth_ptr - * forboth_ptr -
@ -139,13 +136,6 @@ typedef struct ListCellAndListWrapper
* elements without needing a ListCell or and index variable, just a declared * elements without needing a ListCell or and index variable, just a declared
* pointer variable to store the iterated values. * pointer variable to store the iterated values.
* *
* PostgreSQL 13 changed the representation of Lists to expansible arrays,
* not chains of cons-cells. This changes the costs for accessing and
* mutating List contents. Therefore different implementations are provided.
*
* For more information, see postgres commit with sha
* 1cff1b95ab6ddae32faa3efe0d95a820dbfdc164
*
* How it works: * How it works:
* - An index is declared with the name {var}PositionDoNotUse and used * - An index is declared with the name {var}PositionDoNotUse and used
* throughout the for loop using ## to concat. * throughout the for loop using ## to concat.