Implement defined read of very long cpon ints and decimals

libshvchainpack/c/ccpon.c

@@ -1,7 +1,7 @@
 #include <shv/chainpack/ccpon.h>
 
 #include <string.h>
-#include <math.h>
+#include <assert.h>
 
 static inline uint8_t hexify(uint8_t b)
 {
@@ -801,16 +801,68 @@ const char* ccpon_unpack_skip_insignificant(ccpcp_unpack_context* unpack_context
 	}
 }
 
-static int unpack_int(ccpcp_unpack_context* unpack_context, int64_t *p_val)
+#ifdef _MSC_VER
+static bool add_with_overflow_check(int64_t a, int b, int64_t *result)
+{
+	// Check for overflow
+	if (a > INT64_MAX - b) {
+		return true; // Overflow occurred
+	}
+	*result = a + b;
+	return false;
+}
+
+static bool multiply_with_overflow_check(int64_t a, int b, int64_t* result)
+{
+	// Check for zero multiplication
+	if (a == 0 || b == 0) {
+		*result = 0;
+		return false; // No overflow
+	}
+
+	assert(a > 0 && b > 0);
+
+	// Check for overflow
+	if (a > INT64_MAX / b) {
+		return true; // Overflow occurred
+	}
+
+	*result = a * b;
+	return false; // No overflow
+}
+#else
+static bool add_with_overflow_check(int64_t a, int b, int64_t* result)
 {
-	int64_t val = 0;
+	return __builtin_add_overflow(a, b, result);
+}
+
+static bool multiply_with_overflow_check(int64_t a, int b, int64_t* result)
+{
+	return __builtin_mul_overflow(a, b, result);
+}
+#endif
+
+typedef struct {
+	int64_t value;
+	int digit_cnt;
+	int signum;
+	bool is_overflow;
+} read_int_result;
+
+static int unpack_int_to_result(ccpcp_unpack_context* unpack_context, int64_t init_value, read_int_result *result)
+{
+	result->digit_cnt = 0;
+	result->is_overflow = false;
+	result->value = init_value;
 	int neg = 0;
 	int base = 10;
 	int n = 0;
+	bool starts_with_signum = false;
 	for (; ; n++) {
 		const char *p = ccpcp_unpack_take_byte(unpack_context);
 		if(!p)
 			goto eonumb;
+		int digit = -1;
 		uint8_t b = (uint8_t)(*p);
 		switch (b) {
 		case '+':
@@ -819,20 +871,22 @@ static int unpack_int(ccpcp_unpack_context* unpack_context, int64_t *p_val)
 				unpack_context->current--;
 				goto eonumb;
 			}
+			starts_with_signum = true;
 			if(b == '-')
 				neg = 1;
 			break;
-		case 'x':
-			if(n == 1 && val != 0) {
-				unpack_context->current--;
-				goto eonumb;
+		case 'x': {
+			int expected_x_pos = 1 + (starts_with_signum? 1: 0);
+			if(n == expected_x_pos && result->value == 0) {
+				base = 16;
+				result->digit_cnt = 0;
 			}
-			if(n != 1) {
+			else {
 				unpack_context->current--;
 				goto eonumb;
 			}
-			base = 16;
 			break;
+		}
 		case '0':
 		case '1':
 		case '2':
@@ -843,8 +897,7 @@ static int unpack_int(ccpcp_unpack_context* unpack_context, int64_t *p_val)
 		case '7':
 		case '8':
 		case '9':
-			val *= base;
-			val += b - '0';
+			digit = b - '0';
 			break;
 		case 'a':
 		case 'b':
@@ -856,8 +909,7 @@ static int unpack_int(ccpcp_unpack_context* unpack_context, int64_t *p_val)
 				unpack_context->current--;
 				goto eonumb;
 			}
-			val *= base;
-			val += b - 'a' + 10;
+			digit = b - 'a' + 10;
 			break;
 		case 'A':
 		case 'B':
@@ -869,22 +921,38 @@ static int unpack_int(ccpcp_unpack_context* unpack_context, int64_t *p_val)
 				unpack_context->current--;
 				goto eonumb;
 			}
-			val *= base;
-			val += b - 'A' + 10;
+			digit = b - 'A' + 10;
 			break;
 		default:
 			unpack_context->current--;
 			goto eonumb;
 		}
+		if (digit >= 0) {
+			int64_t value;
+			if (multiply_with_overflow_check(result->value, base, &value)) {
+				result->is_overflow = true;
+			}
+			else if (add_with_overflow_check(value, digit, &value)) {
+				result->is_overflow = true;
+			}
+			else {
+				result->value = value;
+				result->digit_cnt++;
+			}
+		}
 	}
 eonumb:
-	if(neg)
-		val = -val;
+	result->signum = neg? -1: 1;
+	return n;
+}
+static int unpack_int(ccpcp_unpack_context* unpack_context, int64_t *p_val)
+{
+	read_int_result res;
+	int n = unpack_int_to_result(unpack_context, 0, &res);
 	if(p_val)
-		*p_val = val;
+		*p_val = res.value * res.signum;
 	return n;
 }
-
 void ccpon_unpack_date_time(ccpcp_unpack_context *unpack_context, struct tm *tm, int *msec, int *utc_offset)
 {
 	tm->tm_year = 0;
@@ -902,7 +970,7 @@ void ccpon_unpack_date_time(ccpcp_unpack_context *unpack_context, struct tm *tm,
 
 	int64_t val;
 	int n = unpack_int(unpack_context, &val);
-	if(n < 0) {
+	if(n == 0) {
 		unpack_context->err_no = CCPCP_RC_MALFORMED_INPUT;
 		unpack_context->err_msg = "Malformed year in DateTime";
 		return;
@@ -917,7 +985,7 @@ void ccpon_unpack_date_time(ccpcp_unpack_context *unpack_context, struct tm *tm,
 	}
 
 	n = unpack_int(unpack_context, &val);
-	if(n <= 0) {
+	if(n == 0) {
 		unpack_context->err_no = CCPCP_RC_MALFORMED_INPUT;
 		unpack_context->err_msg = "Malformed month in DateTime";
 		return;
@@ -932,7 +1000,7 @@ void ccpon_unpack_date_time(ccpcp_unpack_context *unpack_context, struct tm *tm,
 	}
 
 	n = unpack_int(unpack_context, &val);
-	if(n <= 0) {
+	if(n == 0) {
 		unpack_context->err_no = CCPCP_RC_MALFORMED_INPUT;
 		unpack_context->err_msg = "Malformed day in DateTime";
 		return;
@@ -947,7 +1015,7 @@ void ccpon_unpack_date_time(ccpcp_unpack_context *unpack_context, struct tm *tm,
 	}
 
 	n = unpack_int(unpack_context, &val);
-	if(n <= 0) {
+	if(n == 0) {
 		unpack_context->err_no = CCPCP_RC_MALFORMED_INPUT;
 		unpack_context->err_msg = "Malformed hour in DateTime";
 		return;
@@ -957,7 +1025,7 @@ void ccpon_unpack_date_time(ccpcp_unpack_context *unpack_context, struct tm *tm,
 	UNPACK_TAKE_BYTE(p);
 
 	n = unpack_int(unpack_context, &val);
-	if(n <= 0) {
+	if(n == 0) {
 		unpack_context->err_no = CCPCP_RC_MALFORMED_INPUT;
 		unpack_context->err_msg = "Malformed minutes in DateTime";
 		return;
@@ -967,7 +1035,7 @@ void ccpon_unpack_date_time(ccpcp_unpack_context *unpack_context, struct tm *tm,
 	UNPACK_TAKE_BYTE(p);
 
 	n = unpack_int(unpack_context, &val);
-	if(n <= 0) {
+	if(n == 0) {
 		unpack_context->err_no = CCPCP_RC_MALFORMED_INPUT;
 		unpack_context->err_msg = "Malformed seconds in DateTime";
 		return;
@@ -978,7 +1046,7 @@ void ccpon_unpack_date_time(ccpcp_unpack_context *unpack_context, struct tm *tm,
 	if(p) {
 		if(*p == '.') {
 			n = unpack_int(unpack_context, &val);
-			if(n < 0)
+			if(n == 0)
 				return;
 			*msec = (int)val;
 			p = ccpcp_unpack_take_byte(unpack_context);
@@ -1322,25 +1390,29 @@ void ccpon_unpack_next (ccpcp_unpack_context* unpack_context)
 	case '+':
 	case '-': {
 		// number
-		int64_t mantisa = 0;
+		int64_t mantissa = 0;
 		int64_t exponent = 0;
-		int64_t decimals = 0;
 		int dec_cnt = 0;
 		struct {
 			uint8_t is_decimal: 1;
 			uint8_t is_uint: 1;
 			uint8_t is_neg: 1;
+			uint8_t is_overflow: 1;
 		} flags;
 		flags.is_decimal = 0;
 		flags.is_uint = 0;
 		flags.is_neg = 0;
 
-		flags.is_neg = *p == '-';
-		if(!flags.is_neg)
-			unpack_context->current--;
-		int n = unpack_int(unpack_context, &mantisa);
-		if(n < 0)
+		unpack_context->current--;
+
+		read_int_result result;
+		unpack_int_to_result(unpack_context, 0, &result);
+		if(result.digit_cnt == 0) {
 			UNPACK_ERROR(CCPCP_RC_MALFORMED_INPUT, "Malformed number.")
+		}
+		mantissa = result.value;
+		flags.is_overflow = result.is_overflow;
+		flags.is_neg = result.signum == -1;
 		p = ccpcp_unpack_take_byte(unpack_context);
 		while(p) {
 			if(*p == CCPON_C_UNSIGNED_END) {
@@ -1349,18 +1421,20 @@ void ccpon_unpack_next (ccpcp_unpack_context* unpack_context)
 			}
 			if(*p == '.') {
 				flags.is_decimal = 1;
-				n = unpack_int(unpack_context, &decimals);
-				if(n < 0)
-					UNPACK_ERROR(CCPCP_RC_MALFORMED_INPUT, "Malformed number decimal part.")
-				dec_cnt = n;
+				unpack_int_to_result(unpack_context, mantissa, &result);
+				mantissa = result.value;
+				flags.is_overflow |= result.is_overflow;
+				dec_cnt = result.digit_cnt;
 				p = ccpcp_unpack_take_byte(unpack_context);
 				if(!p)
 					break;
 			}
 			if(*p == 'e' || *p == 'E') {
 				flags.is_decimal = 1;
-				n = unpack_int(unpack_context, &exponent);
-				if(n < 0)
+				unpack_int_to_result(unpack_context, 0, &result);
+				flags.is_overflow |= result.is_overflow;
+				exponent = result.value * result.signum;
+				if(result.digit_cnt == 0)
 					UNPACK_ERROR(CCPCP_RC_MALFORMED_INPUT, "Malformed number exponetional part.")
 				break;
 			}
@@ -1371,22 +1445,28 @@ void ccpon_unpack_next (ccpcp_unpack_context* unpack_context)
 			break;
 		}
 		if(flags.is_decimal) {
-			int i;
-			for (i = 0; i < dec_cnt; ++i)
-				mantisa *= 10;
-			mantisa += decimals;
 			unpack_context->item.type = CCPCP_ITEM_DECIMAL;
-			unpack_context->item.as.Decimal.mantisa = flags.is_neg? -mantisa: mantisa;
-			unpack_context->item.as.Decimal.exponent = (int)(exponent - dec_cnt);
+			if (flags.is_overflow && dec_cnt == 0) {
+				unpack_context->item.as.Decimal.mantisa = flags.is_neg? INT64_MIN: INT64_MAX;
+				unpack_context->item.as.Decimal.exponent = 0;
+			}
+			else {
+				unpack_context->item.as.Decimal.mantisa = flags.is_neg? -mantissa: mantissa;
+				unpack_context->item.as.Decimal.exponent = (int)(exponent - dec_cnt);
+			}
 		}
 		else if(flags.is_uint) {
 			unpack_context->item.type = CCPCP_ITEM_UINT;
-			unpack_context->item.as.UInt = (uint64_t)mantisa;
-
+			unpack_context->item.as.UInt = (uint64_t)(flags.is_overflow? INT64_MAX: mantissa);
 		}
 		else {
 			unpack_context->item.type = CCPCP_ITEM_INT;
-			unpack_context->item.as.Int = flags.is_neg? -mantisa: mantisa;
+			if (flags.is_overflow) {
+				unpack_context->item.as.Int = flags.is_neg? INT64_MIN: INT64_MAX;
+			}
+			else {
+				unpack_context->item.as.Int = flags.is_neg? -mantissa: mantissa;
+			}
 		}
 		unpack_context->err_no = CCPCP_RC_OK;
 		break;

libshvchainpack/include/shv/chainpack/rpcvalue.h

@@ -142,7 +142,7 @@ class SHVCHAINPACK_DECL_EXPORT RpcDecimal
 {
 	static constexpr int Base = 10;
 	struct Num {
-		int64_t mantisa = 0;
+		int64_t mantissa = 0;
 		int exponent = 0;
 
 		Num();
@@ -152,10 +152,11 @@ class SHVCHAINPACK_DECL_EXPORT RpcDecimal
 	Num m_num;
 public:
 	RpcDecimal();
-	RpcDecimal(int64_t mantisa, int exponent);
+	RpcDecimal(int64_t mantissa, int exponent);
 	RpcDecimal(int dec_places);
 
-	int64_t mantisa() const;
+	[[deprecated]] int64_t mantisa() const { return mantissa(); }
+	int64_t mantissa() const;
 	int exponent() const;
 
 	static RpcDecimal fromDouble(double d, int round_to_dec_places);

libshvchainpack/src/chainpackwriter.cpp

@@ -172,7 +172,7 @@ ChainPackWriter &ChainPackWriter::write_p(double value)
 
 ChainPackWriter &ChainPackWriter::write_p(RpcValue::Decimal value)
 {
-	cchainpack_pack_decimal(&m_outCtx, value.mantisa(), value.exponent());
+	cchainpack_pack_decimal(&m_outCtx, value.mantissa(), value.exponent());
 	return *this;
 }
 

libshvchainpack/src/cponwriter.cpp

@@ -375,7 +375,7 @@ CponWriter &CponWriter::write_p(double value)
 
 CponWriter &CponWriter::write_p(RpcValue::Decimal value)
 {
-	ccpon_pack_decimal(&m_outCtx, value.mantisa(), value.exponent());
+	ccpon_pack_decimal(&m_outCtx, value.mantissa(), value.exponent());
 	return *this;
 }