From 26a7b48e10bea67be719f5bb88cbaa8d4ec1c9b3 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 7 Oct 2010 20:32:21 -0400
Subject: [PATCH] Eliminate some repetitive coding in tuplesort.c.
Use a macro LogicalTapeReadExact() to encapsulate the error check when
we want to read an exact number of bytes from a "tape". Per a suggestion
of Takahiro Itagaki.
---
src/backend/utils/sort/tuplesort.c | 69 ++++++++++++++----------------
1 file changed, 32 insertions(+), 37 deletions(-)
diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 00137032505..dae73f15afa 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -120,9 +120,9 @@
/* sort-type codes for sort__start probes */
-#define HEAP_SORT 0
-#define INDEX_SORT 1
-#define DATUM_SORT 2
+#define HEAP_SORT 0
+#define INDEX_SORT 1
+#define DATUM_SORT 2
#define CLUSTER_SORT 3
/* GUC variables */
@@ -435,6 +435,13 @@ struct Tuplesortstate
* a lot better than what we were doing before 7.3.
*/
+/* When using this macro, beware of double evaluation of len */
+#define LogicalTapeReadExact(tapeset, tapenum, ptr, len) \
+ do { \
+ if (LogicalTapeRead(tapeset, tapenum, ptr, len) != (size_t) (len)) \
+ elog(ERROR, "unexpected end of data"); \
+ } while(0)
+
static Tuplesortstate *tuplesort_begin_common(int workMem, bool randomAccess);
static void puttuple_common(Tuplesortstate *state, SortTuple *tuple);
@@ -2576,8 +2583,8 @@ getlen(Tuplesortstate *state, int tapenum, bool eofOK)
{
unsigned int len;
- if (LogicalTapeRead(state->tapeset, tapenum, (void *) &len,
- sizeof(len)) != sizeof(len))
+ if (LogicalTapeRead(state->tapeset, tapenum,
+ &len, sizeof(len)) != sizeof(len))
elog(ERROR, "unexpected end of tape");
if (len == 0 && !eofOK)
elog(ERROR, "unexpected end of data");
@@ -2810,14 +2817,11 @@ readtup_heap(Tuplesortstate *state, SortTuple *stup,
USEMEM(state, GetMemoryChunkSpace(tuple));
/* read in the tuple proper */
tuple->t_len = tuplen;
- if (LogicalTapeRead(state->tapeset, tapenum,
- (void *) tupbody,
- tupbodylen) != (size_t) tupbodylen)
- elog(ERROR, "unexpected end of data");
+ LogicalTapeReadExact(state->tapeset, tapenum,
+ tupbody, tupbodylen);
if (state->randomAccess) /* need trailing length word? */
- if (LogicalTapeRead(state->tapeset, tapenum, (void *) &tuplen,
- sizeof(tuplen)) != sizeof(tuplen))
- elog(ERROR, "unexpected end of data");
+ LogicalTapeReadExact(state->tapeset, tapenum,
+ &tuplen, sizeof(tuplen));
stup->tuple = (void *) tuple;
/* set up first-column key value */
htup.t_len = tuple->t_len + MINIMAL_TUPLE_OFFSET;
@@ -2998,20 +3002,16 @@ readtup_cluster(Tuplesortstate *state, SortTuple *stup,
/* Reconstruct the HeapTupleData header */
tuple->t_data = (HeapTupleHeader) ((char *) tuple + HEAPTUPLESIZE);
tuple->t_len = t_len;
- if (LogicalTapeRead(state->tapeset, tapenum,
- &tuple->t_self,
- sizeof(ItemPointerData)) != sizeof(ItemPointerData))
- elog(ERROR, "unexpected end of data");
+ LogicalTapeReadExact(state->tapeset, tapenum,
+ &tuple->t_self, sizeof(ItemPointerData));
/* We don't currently bother to reconstruct t_tableOid */
tuple->t_tableOid = InvalidOid;
/* Read in the tuple body */
- if (LogicalTapeRead(state->tapeset, tapenum,
- tuple->t_data, tuple->t_len) != tuple->t_len)
- elog(ERROR, "unexpected end of data");
+ LogicalTapeReadExact(state->tapeset, tapenum,
+ tuple->t_data, tuple->t_len);
if (state->randomAccess) /* need trailing length word? */
- if (LogicalTapeRead(state->tapeset, tapenum, &tuplen,
- sizeof(tuplen)) != sizeof(tuplen))
- elog(ERROR, "unexpected end of data");
+ LogicalTapeReadExact(state->tapeset, tapenum,
+ &tuplen, sizeof(tuplen));
stup->tuple = (void *) tuple;
/* set up first-column key value, if it's a simple column */
if (state->indexInfo->ii_KeyAttrNumbers[0] != 0)
@@ -3243,13 +3243,11 @@ readtup_index(Tuplesortstate *state, SortTuple *stup,
IndexTuple tuple = (IndexTuple) palloc(tuplen);
USEMEM(state, GetMemoryChunkSpace(tuple));
- if (LogicalTapeRead(state->tapeset, tapenum, (void *) tuple,
- tuplen) != tuplen)
- elog(ERROR, "unexpected end of data");
+ LogicalTapeReadExact(state->tapeset, tapenum,
+ tuple, tuplen);
if (state->randomAccess) /* need trailing length word? */
- if (LogicalTapeRead(state->tapeset, tapenum, (void *) &tuplen,
- sizeof(tuplen)) != sizeof(tuplen))
- elog(ERROR, "unexpected end of data");
+ LogicalTapeReadExact(state->tapeset, tapenum,
+ &tuplen, sizeof(tuplen));
stup->tuple = (void *) tuple;
/* set up first-column key value */
stup->datum1 = index_getattr(tuple,
@@ -3357,9 +3355,8 @@ readtup_datum(Tuplesortstate *state, SortTuple *stup,
else if (state->datumTypeByVal)
{
Assert(tuplen == sizeof(Datum));
- if (LogicalTapeRead(state->tapeset, tapenum, (void *) &stup->datum1,
- tuplen) != tuplen)
- elog(ERROR, "unexpected end of data");
+ LogicalTapeReadExact(state->tapeset, tapenum,
+ &stup->datum1, tuplen);
stup->isnull1 = false;
stup->tuple = NULL;
}
@@ -3367,9 +3364,8 @@ readtup_datum(Tuplesortstate *state, SortTuple *stup,
{
void *raddr = palloc(tuplen);
- if (LogicalTapeRead(state->tapeset, tapenum, raddr,
- tuplen) != tuplen)
- elog(ERROR, "unexpected end of data");
+ LogicalTapeReadExact(state->tapeset, tapenum,
+ raddr, tuplen);
stup->datum1 = PointerGetDatum(raddr);
stup->isnull1 = false;
stup->tuple = raddr;
@@ -3377,9 +3373,8 @@ readtup_datum(Tuplesortstate *state, SortTuple *stup,
}
if (state->randomAccess) /* need trailing length word? */
- if (LogicalTapeRead(state->tapeset, tapenum, (void *) &tuplen,
- sizeof(tuplen)) != sizeof(tuplen))
- elog(ERROR, "unexpected end of data");
+ LogicalTapeReadExact(state->tapeset, tapenum,
+ &tuplen, sizeof(tuplen));
}
static void
--
GitLab