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Adjust bytea get_bit/set_bit to use int8 not int4 for bit numbering.

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Since the existing bit number argument can't exceed INT32_MAX, it's
not possible for these functions to manipulate bits beyond the first
256MB of a bytea value.  Lift that restriction by redeclaring the
bit number arguments as int8 (which requires a catversion bump,
hence is not back-patchable).

The similarly-named functions for bit/varbit don't really have a
problem because we restrict those types to at most VARBITMAXLEN bits;
hence leave them alone.

While here, extend the encode/decode functions in utils/adt/encode.c
to allow dealing with values wider than 1GB.  This is not a live bug
or restriction in current usage, because no input could be more than
1GB, and since none of the encoders can expand a string more than 4X,
the result size couldn't overflow uint32.  But it might be desirable
to support more in future, so make the input length values size_t
and the potential-output-length values uint64.

Also add some test cases to improve the miserable code coverage
of these functions.

Movead Li, editorialized some by me; also reviewed by Ashutosh Bapat

Discussion: https://postgr.es/m/20200312115135445367128@highgo.ca
This commit is contained in:
Tom Lane
2020-04-07 15:57:58 -04:00
parent 9c74ceb20b
commit 26a944cf29
8 changed files with 217 additions and 71 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
src/backend/utils/adt/varlena.c
View File

@@ -389,7 +389,7 @@ byteaout(PG_FUNCTION_ARGS)
{
/* Print traditional escaped format */
char *vp;
int len;
uint64 len;
int i;
len = 1; /* empty string has 1 char */
@@ -403,7 +403,18 @@ byteaout(PG_FUNCTION_ARGS)
else
len++;
}
/*
* In principle len can't overflow uint32 if the input fit in 1GB, but
* for safety let's check rather than relying on palloc's internal
* check.
*/
if (len > MaxAllocSize)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg_internal("result of bytea output conversion is too large")));
rp = result = (char *) palloc(len);
vp = VARDATA_ANY(vlena);
for (i = VARSIZE_ANY_EXHDR(vlena); i != 0; i--, vp++)
{
@@ -3456,7 +3467,7 @@ Datum
byteaGetBit(PG_FUNCTION_ARGS)
{
bytea *v = PG_GETARG_BYTEA_PP(0);
int32 n = PG_GETARG_INT32(1);
int64 n = PG_GETARG_INT64(1);
int byteNo,
bitNo;
int len;
@@ -3464,14 +3475,15 @@ byteaGetBit(PG_FUNCTION_ARGS)
len = VARSIZE_ANY_EXHDR(v);
if (n < 0 || n >= len * 8)
if (n < 0 || n >= (int64) len * 8)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("index %d out of valid range, 0..%d",
n, len * 8 - 1)));
errmsg("index %lld out of valid range, 0..%lld",
(long long) n, (long long) len * 8 - 1)));
byteNo = n / 8;
bitNo = n % 8;
/* n/8 is now known < len, so safe to cast to int */
byteNo = (int) (n / 8);
bitNo = (int) (n % 8);
byte = ((unsigned char *) VARDATA_ANY(v))[byteNo];
@@ -3525,7 +3537,7 @@ Datum
byteaSetBit(PG_FUNCTION_ARGS)
{
bytea *res = PG_GETARG_BYTEA_P_COPY(0);
int32 n = PG_GETARG_INT32(1);
int64 n = PG_GETARG_INT64(1);
int32 newBit = PG_GETARG_INT32(2);
int len;
int oldByte,
@@ -3535,14 +3547,15 @@ byteaSetBit(PG_FUNCTION_ARGS)
len = VARSIZE(res) - VARHDRSZ;
if (n < 0 || n >= len * 8)
if (n < 0 || n >= (int64) len * 8)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("index %d out of valid range, 0..%d",
n, len * 8 - 1)));
errmsg("index %lld out of valid range, 0..%lld",
(long long) n, (long long) len * 8 - 1)));
byteNo = n / 8;
bitNo = n % 8;
/* n/8 is now known < len, so safe to cast to int */
byteNo = (int) (n / 8);
bitNo = (int) (n % 8);
/*
* sanity check!