#include "funcapi.h"
#include "libpq/pqformat.h"
#include "utils/int8.h"
+#include "utils/builtins.h"
#define MAXINT8LEN 25
int8out(PG_FUNCTION_ARGS)
{
int64 val = PG_GETARG_INT64(0);
- char *result;
- int len;
char buf[MAXINT8LEN + 1];
+ char *result;
- if ((len = snprintf(buf, MAXINT8LEN, INT64_FORMAT, val)) < 0)
- elog(ERROR, "could not format int8");
-
+ pg_lltoa(val, buf);
result = pstrdup(buf);
PG_RETURN_CSTRING(result);
}
* numutils.c
* utility functions for I/O of built-in numeric types.
*
- * integer: pg_atoi, pg_itoa, pg_ltoa
- *
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
}
/*
- * pg_itoa - converts a short int to its string represention
+ * pg_itoa: converts a signed 16-bit integer to its string representation
+ *
+ * Caller must ensure that 'a' points to enough memory to hold the result
+ * (at least 7 bytes, counting a leading sign and trailing NUL).
*
- * Note:
- * previously based on ~ingres/source/gutil/atoi.c
- * now uses vendor's sprintf conversion
+ * It doesn't seem worth implementing this separately.
*/
void
pg_itoa(int16 i, char *a)
{
- sprintf(a, "%hd", (short) i);
+ pg_ltoa((int32)i, a);
+}
+
+/*
+ * pg_ltoa: converts a signed 32-bit integer to its string representation
+ *
+ * Caller must ensure that 'a' points to enough memory to hold the result
+ * (at least 12 bytes, counting a leading sign and trailing NUL).
+ */
+void
+pg_ltoa(int32 value, char *a)
+{
+ char *start = a;
+ bool neg = false;
+
+ /*
+ * Avoid problems with the most negative integer not being representable
+ * as a positive integer.
+ */
+ if (value == INT32_MIN)
+ {
+ memcpy(a, "-2147483648", 12);
+ return;
+ }
+ else if (value < 0)
+ {
+ value = -value;
+ neg = true;
+ }
+
+ /* Compute the result backwards. */
+ do
+ {
+ int32 remainder;
+ int32 oldval = value;
+ value /= 10;
+ remainder = oldval - value * 10;
+ *a++ = '0' + remainder;
+ } while (value != 0);
+ if (neg)
+ *a++ = '-';
+
+ /* Add trailing NUL byte. */
+ *a-- = '\0';
+
+ /* reverse string */
+ while (start < a)
+ {
+ char swap = *start;
+ *start++ = *a;
+ *a-- = swap;
+ }
}
/*
- * pg_ltoa - converts a long int to its string represention
+ * pg_lltoa: convert a signed 64bit integer to its string representation
*
- * Note:
- * previously based on ~ingres/source/gutil/atoi.c
- * now uses vendor's sprintf conversion
+ * Caller must ensure that 'a' points to enough memory to hold the result
+ * (at least MAXINT8LEN+1 bytes, counting a leading sign and trailing NUL).
*/
void
-pg_ltoa(int32 l, char *a)
+pg_lltoa(int64 value, char *a)
{
- sprintf(a, "%d", l);
+ char *start = a;
+ bool neg = false;
+
+ /*
+ * Avoid problems with the most negative integer not being representable
+ * as a positive integer.
+ */
+ if (value == INT64_MIN)
+ {
+ memcpy(a, "-9223372036854775808", 21);
+ return;
+ }
+ else if (value < 0)
+ {
+ value = -value;
+ neg = true;
+ }
+
+ /* Build the string by computing the wanted string backwards. */
+ do
+ {
+ int64 remainder;
+ int64 oldval = value;
+ value /= 10;
+ remainder = oldval - value * 10;
+ *a++ = '0' + remainder;
+ } while (value != 0);
+
+ if (neg)
+ *a++ = '-';
+
+ /* Add trailing NUL byte. */
+ *a-- = '\0';
+
+ /* Reverse string. */
+ while (start < a)
+ {
+ char swap = *start;
+ *start++ = *a;
+ *a-- = swap;
+ }
}
projects / postgresql / commitdiff