From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Serge Petrenko Subject: [PATCH v2 2/8] decimal: fix encoding numbers with positive exponent. Date: Thu, 8 Aug 2019 14:55:53 +0300 Message-Id: <53d58fa5cad01273d3e60fe034c8e74f023d3c0e.1565263272.git.sergepetrenko@tarantool.org> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: vdavydov.dev@gmail.com Cc: tarantool-patches@freelists.org, kostja@tarantool.org, Serge Petrenko List-ID: When a number having a positive exponent is encoded, the internal decPackedFromNumber function returns a negative scale, which differs from the scale, returned by decimal_scale(). This leads to errors in decoding. Account for negative scale in decimal_pack() and decimal_unpack(). Follow-up #692 --- src/lib/core/decimal.c | 10 +++++++--- test/unit/decimal.c | 15 +++++++++++++-- test/unit/decimal.result | 11 ++++++++--- 3 files changed, 28 insertions(+), 8 deletions(-) diff --git a/src/lib/core/decimal.c b/src/lib/core/decimal.c index 6ef351f81..840aa5dfe 100644 --- a/src/lib/core/decimal.c +++ b/src/lib/core/decimal.c @@ -33,6 +33,7 @@ #include "third_party/decNumber/decContext.h" #include "third_party/decNumber/decPacked.h" #include "lib/core/tt_static.h" +#include "lib/msgpuck/msgpuck.h" #include #include #include /* DBL_DIG */ @@ -340,12 +341,15 @@ char * decimal_pack(char *data, const decimal_t *dec) { uint32_t len = decimal_len(dec); - *data++ = decimal_scale(dec); + /* reserve space for resulting scale */ + char *svp = data++; len--; int32_t scale; char *tmp = (char *)decPackedFromNumber((uint8_t *)data, len, &scale, dec); assert(tmp == data); - assert(scale == (int32_t)decimal_scale(dec)); + /* scale may be negative, when exponent is > 0 */ + assert(scale == (int32_t)decimal_scale(dec) || scale < 0); + mp_store_u8(svp, (int8_t)scale); (void)tmp; data += len; return data; @@ -354,7 +358,7 @@ decimal_pack(char *data, const decimal_t *dec) decimal_t * decimal_unpack(const char **data, uint32_t len, decimal_t *dec) { - int32_t scale = *((*data)++); + int32_t scale = (int8_t)mp_load_u8(data); len--; decimal_t *res = decPackedToNumber((uint8_t *)*data, len, &scale, dec); if (res) diff --git a/test/unit/decimal.c b/test/unit/decimal.c index b587e1f14..b55333ed7 100644 --- a/test/unit/decimal.c +++ b/test/unit/decimal.c @@ -91,7 +91,7 @@ char buf[32]; static int test_pack_unpack(void) { - plan(146); + plan(151); test_decpack("0"); test_decpack("-0"); @@ -112,13 +112,24 @@ test_pack_unpack(void) test_decpack("99999999999999999999999999999999999999"); test_decpack("-99999999999999999999999999999999999999"); + /* Check correct encoding of positive exponent numbers. */ + decimal_t dec, d1; + decimal_from_string(&dec, "1e10"); + uint32_t l1 = decimal_len(&dec); + ok(l1 == 2, "decimal_len() is small for positive exponent decimal"); + char *b1 = decimal_pack(buf, &dec); + is(b1, buf + l1, "positive exponent decimal length"); + const char *b2 = buf; + is(decimal_unpack(&b2, l1, &d1), &d1, "decimal_unpack() of a positive exponent decimal"); + is(b1, b2, "decimal_unpack uses every byte packed by decimal_pack"); + is(decimal_compare(&dec, &d1), 0, "positive exponent number is packed/unpacked correctly"); + /* Pack an invalid decimal. */ char *b = buf; *b++ = 1; *b++ = '\xab'; *b++ = '\xcd'; const char *bb = buf; - decimal_t dec; is(decimal_unpack(&bb, 3, &dec), NULL, "unpack malformed decimal fails"); is(bb, buf, "decode malformed decimal preserves buffer position"); diff --git a/test/unit/decimal.result b/test/unit/decimal.result index 1c72cdfab..2dd91af49 100644 --- a/test/unit/decimal.result +++ b/test/unit/decimal.result @@ -277,7 +277,7 @@ ok 275 - decimal_from_string(-1) ok 276 - decimal_log10(-1) - error on wrong operands. ok 277 - decimal_from_string(-10) ok 278 - decimal_sqrt(-10) - error on wrong operands. - 1..146 + 1..151 ok 1 - decimal_len(0) ok 2 - decimal_len(0) == len(decimal_pack(0) ok 3 - decimal_unpack(decimal_pack(0)) @@ -422,6 +422,11 @@ ok 278 - decimal_sqrt(-10) - error on wrong operands. ok 142 - decimal_unpack(decimal_pack(-99999999999999999999999999999999999999)) scale ok 143 - decimal_unpack(decimal_pack(-99999999999999999999999999999999999999)) precision ok 144 - str(decimal_unpack(decimal_pack(-99999999999999999999999999999999999999)) == -99999999999999999999999999999999999999 - ok 145 - unpack malformed decimal fails - ok 146 - decode malformed decimal preserves buffer position + ok 145 - decimal_len() is small for positive exponent decimal + ok 146 - positive exponent decimal length + ok 147 - decimal_unpack() of a positive exponent decimal + ok 148 - decimal_unpack uses every byte packed by decimal_pack + ok 149 - positive exponent number is packed/unpacked correctly + ok 150 - unpack malformed decimal fails + ok 151 - decode malformed decimal preserves buffer position ok 279 - subtests -- 2.20.1 (Apple Git-117)