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Extend format() to handle field width and left/right alignment.

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This change adds some more standard sprintf() functionality to format().

Pavel Stehule, reviewed by Dean Rasheed and Kyotaro Horiguchi
This commit is contained in:
Tom Lane
2013-03-14 22:56:56 -04:00
parent 1a1832eb08
commit 73e7025bd8
4 changed files with 657 additions and 98 deletions
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397
src/backend/utils/adt/varlena.c
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@ -56,32 +56,41 @@ typedef struct
#define PG_GETARG_UNKNOWN_P_COPY(n) DatumGetUnknownPCopy(PG_GETARG_DATUM(n))
#define PG_RETURN_UNKNOWN_P(x) PG_RETURN_POINTER(x)
static int text_cmp(text *arg1, text *arg2, Oid collid);
static int32 text_length(Datum str);
static int text_position(text *t1, text *t2);
static void text_position_setup(text *t1, text *t2, TextPositionState *state);
static int text_position_next(int start_pos, TextPositionState *state);
static void text_position_cleanup(TextPositionState *state);
static text *text_catenate(text *t1, text *t2);
static text *text_substring(Datum str,
int32 start,
int32 length,
bool length_not_specified);
static text *text_overlay(text *t1, text *t2, int sp, int sl);
static void appendStringInfoText(StringInfo str, const text *t);
static int text_position(text *t1, text *t2);
static void text_position_setup(text *t1, text *t2, TextPositionState *state);
static int text_position_next(int start_pos, TextPositionState *state);
static void text_position_cleanup(TextPositionState *state);
static int text_cmp(text *arg1, text *arg2, Oid collid);
static bytea *bytea_catenate(bytea *t1, bytea *t2);
static bytea *bytea_substring(Datum str,
int S,
int L,
bool length_not_specified);
static bytea *bytea_overlay(bytea *t1, bytea *t2, int sp, int sl);
static StringInfo makeStringAggState(FunctionCallInfo fcinfo);
static void text_format_string_conversion(StringInfo buf, char conversion,
FmgrInfo *typOutputInfo,
Datum value, bool isNull);
static void appendStringInfoText(StringInfo str, const text *t);
static Datum text_to_array_internal(PG_FUNCTION_ARGS);
static text *array_to_text_internal(FunctionCallInfo fcinfo, ArrayType *v,
const char *fldsep, const char *null_string);
static StringInfo makeStringAggState(FunctionCallInfo fcinfo);
static bool text_format_parse_digits(const char **ptr, const char *end_ptr,
int *value);
static const char *text_format_parse_format(const char *start_ptr,
const char *end_ptr,
int *argpos, int *widthpos,
int *flags, int *width);
static void text_format_string_conversion(StringInfo buf, char conversion,
FmgrInfo *typOutputInfo,
Datum value, bool isNull,
int flags, int width);
static void text_format_append_string(StringInfo buf, const char *str,
int flags, int width);
/*****************************************************************************
@ -3996,8 +4005,22 @@ text_reverse(PG_FUNCTION_ARGS)
PG_RETURN_TEXT_P(result);
}
/*
* Returns a formated string
* Support macros for text_format()
*/
#define TEXT_FORMAT_FLAG_MINUS 0x0001 /* is minus flag present? */
#define ADVANCE_PARSE_POINTER(ptr,end_ptr) \
do { \
if (++(ptr) >= (end_ptr)) \
ereport(ERROR, \
(errcode(ERRCODE_INVALID_PARAMETER_VALUE), \
errmsg("unterminated format specifier"))); \
} while (0)
/*
* Returns a formatted string
*/
Datum
text_format(PG_FUNCTION_ARGS)
@ -4008,16 +4031,18 @@ text_format(PG_FUNCTION_ARGS)
const char *start_ptr;
const char *end_ptr;
text *result;
int arg = 0;
int arg;
bool funcvariadic;
int nargs;
Datum *elements = NULL;
bool *nulls = NULL;
Oid element_type = InvalidOid;
Oid prev_type = InvalidOid;
Oid prev_width_type = InvalidOid;
FmgrInfo typoutputfinfo;
FmgrInfo typoutputinfo_width;
/* When format string is null, returns null */
/* When format string is null, immediately return null */
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
@ -4081,10 +4106,15 @@ text_format(PG_FUNCTION_ARGS)
start_ptr = VARDATA_ANY(fmt);
end_ptr = start_ptr + VARSIZE_ANY_EXHDR(fmt);
initStringInfo(&str);
arg = 1; /* next argument position to print */
/* Scan format string, looking for conversion specifiers. */
for (cp = start_ptr; cp < end_ptr; cp++)
{
int argpos;
int widthpos;
int flags;
int width;
Datum value;
bool isNull;
Oid typid;
@ -4099,11 +4129,7 @@ text_format(PG_FUNCTION_ARGS)
continue;
}
/* Did we run off the end of the string? */
if (++cp >= end_ptr)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unterminated conversion specifier")));
ADVANCE_PARSE_POINTER(cp, end_ptr);
/* Easy case: %% outputs a single % */
if (*cp == '%')
@ -4112,69 +4138,89 @@ text_format(PG_FUNCTION_ARGS)
continue;
}
/* Parse the optional portions of the format specifier */
cp = text_format_parse_format(cp, end_ptr,
&argpos, &widthpos,
&flags, &width);
/*
* If the user hasn't specified an argument position, we just advance
* to the next one. If they have, we must parse it.
* Next we should see the main conversion specifier. Whether or not
* an argument position was present, it's known that at least one
* character remains in the string at this point. Experience suggests
* that it's worth checking that that character is one of the expected
* ones before we try to fetch arguments, so as to produce the least
* confusing response to a mis-formatted specifier.
*/
if (*cp < '0' || *cp > '9')
if (strchr("sIL", *cp) == NULL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized conversion type specifier \"%c\"",
*cp)));
/* If indirect width was specified, get its value */
if (widthpos >= 0)
{
++arg;
if (arg <= 0) /* overflow? */
{
/*
* Should not happen, as you can't pass billions of arguments
* to a function, but better safe than sorry.
*/
/* Collect the specified or next argument position */
if (widthpos > 0)
arg = widthpos;
if (arg >= nargs)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("argument number is out of range")));
}
}
else
{
bool unterminated = false;
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("too few arguments for format")));
/* Parse digit string. */
arg = 0;
do
/* Get the value and type of the selected argument */
if (!funcvariadic)
{
int newarg = arg * 10 + (*cp - '0');
if (newarg / 10 != arg) /* overflow? */
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("argument number is out of range")));
arg = newarg;
++cp;
} while (cp < end_ptr && *cp >= '0' && *cp <= '9');
/*
* If we ran off the end, or if there's not a $ next, or if the $
* is the last character, the conversion specifier is improperly
* terminated.
*/
if (cp == end_ptr || *cp != '$')
unterminated = true;
value = PG_GETARG_DATUM(arg);
isNull = PG_ARGISNULL(arg);
typid = get_fn_expr_argtype(fcinfo->flinfo, arg);
}
else
{
++cp;
if (cp == end_ptr)
unterminated = true;
value = elements[arg - 1];
isNull = nulls[arg - 1];
typid = element_type;
}
if (unterminated)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unterminated conversion specifier")));
if (!OidIsValid(typid))
elog(ERROR, "could not determine data type of format() input");
/* There's no argument 0. */
if (arg == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("conversion specifies argument 0, but arguments are numbered from 1")));
arg++;
/* We can treat NULL width the same as zero */
if (isNull)
width = 0;
else if (typid == INT4OID)
width = DatumGetInt32(value);
else if (typid == INT2OID)
width = DatumGetInt16(value);
else
{
/* For less-usual datatypes, convert to text then to int */
char *str;
if (typid != prev_width_type)
{
Oid typoutputfunc;
bool typIsVarlena;
getTypeOutputInfo(typid, &typoutputfunc, &typIsVarlena);
fmgr_info(typoutputfunc, &typoutputinfo_width);
prev_width_type = typid;
}
str = OutputFunctionCall(&typoutputinfo_width, value);
/* pg_atoi will complain about bad data or overflow */
width = pg_atoi(str, sizeof(int), '\0');
pfree(str);
}
}
/* Not enough arguments? Deduct 1 to avoid counting format string. */
if (arg > nargs - 1)
/* Collect the specified or next argument position */
if (argpos > 0)
arg = argpos;
if (arg >= nargs)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("too few arguments for format")));
@ -4195,6 +4241,8 @@ text_format(PG_FUNCTION_ARGS)
if (!OidIsValid(typid))
elog(ERROR, "could not determine data type of format() input");
arg++;
/*
* Get the appropriate typOutput function, reusing previous one if
* same type as previous argument. That's particularly useful in the
@ -4211,9 +4259,7 @@ text_format(PG_FUNCTION_ARGS)
}
/*
* At this point, we should see the main conversion specifier. Whether
* or not an argument position was present, it's known that at least
* one character remains in the string at this point.
* And now we can format the value.
*/
switch (*cp)
{
@ -4221,13 +4267,16 @@ text_format(PG_FUNCTION_ARGS)
case 'I':
case 'L':
text_format_string_conversion(&str, *cp, &typoutputfinfo,
value, isNull);
value, isNull,
flags, width);
break;
default:
/* should not get here, because of previous check */
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized conversion specifier \"%c\"",
errmsg("unrecognized conversion type specifier \"%c\"",
*cp)));
break;
}
}
@ -4244,19 +4293,157 @@ text_format(PG_FUNCTION_ARGS)
PG_RETURN_TEXT_P(result);
}
/* Format a %s, %I, or %L conversion. */
/*
* Parse contiguous digits as a decimal number.
*
* Returns true if some digits could be parsed.
* The value is returned into *value, and *ptr is advanced to the next
* character to be parsed.
*
* Note parsing invariant: at least one character is known available before
* string end (end_ptr) at entry, and this is still true at exit.
*/
static bool
text_format_parse_digits(const char **ptr, const char *end_ptr, int *value)
{
bool found = false;
const char *cp = *ptr;
int val = 0;
while (*cp >= '0' && *cp <= '9')
{
int newval = val * 10 + (*cp - '0');
if (newval / 10 != val) /* overflow? */
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("number is out of range")));
val = newval;
ADVANCE_PARSE_POINTER(cp, end_ptr);
found = true;
}
*ptr = cp;
*value = val;
return found;
}
/*
* Parse a format specifier (generally following the SUS printf spec).
*
* We have already advanced over the initial '%', and we are looking for
* [argpos][flags][width]type (but the type character is not consumed here).
*
* Inputs are start_ptr (the position after '%') and end_ptr (string end + 1).
* Output parameters:
* argpos: argument position for value to be printed. -1 means unspecified.
* widthpos: argument position for width. Zero means the argument position
* was unspecified (ie, take the next arg) and -1 means no width
* argument (width was omitted or specified as a constant).
* flags: bitmask of flags.
* width: directly-specified width value. Zero means the width was omitted
* (note it's not necessary to distinguish this case from an explicit
* zero width value).
*
* The function result is the next character position to be parsed, ie, the
* location where the type character is/should be.
*
* Note parsing invariant: at least one character is known available before
* string end (end_ptr) at entry, and this is still true at exit.
*/
static const char *
text_format_parse_format(const char *start_ptr, const char *end_ptr,
int *argpos, int *widthpos,
int *flags, int *width)
{
const char *cp = start_ptr;
int n;
/* set defaults for output parameters */
*argpos = -1;
*widthpos = -1;
*flags = 0;
*width = 0;
/* try to identify first number */
if (text_format_parse_digits(&cp, end_ptr, &n))
{
if (*cp != '$')
{
/* Must be just a width and a type, so we're done */
*width = n;
return cp;
}
/* The number was argument position */
*argpos = n;
/* Explicit 0 for argument index is immediately refused */
if (n == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("format specifies argument 0, but arguments are numbered from 1")));
ADVANCE_PARSE_POINTER(cp, end_ptr);
}
/* Handle flags (only minus is supported now) */
while (*cp == '-')
{
*flags |= TEXT_FORMAT_FLAG_MINUS;
ADVANCE_PARSE_POINTER(cp, end_ptr);
}
if (*cp == '*')
{
/* Handle indirect width */
ADVANCE_PARSE_POINTER(cp, end_ptr);
if (text_format_parse_digits(&cp, end_ptr, &n))
{
/* number in this position must be closed by $ */
if (*cp != '$')
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("width argument position must be ended by \"$\"")));
/* The number was width argument position */
*widthpos = n;
/* Explicit 0 for argument index is immediately refused */
if (n == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("format specifies argument 0, but arguments are numbered from 1")));
ADVANCE_PARSE_POINTER(cp, end_ptr);
}
else
*widthpos = 0; /* width's argument position is unspecified */
}
else
{
/* Check for direct width specification */
if (text_format_parse_digits(&cp, end_ptr, &n))
*width = n;
}
/* cp should now be pointing at type character */
return cp;
}
/*
* Format a %s, %I, or %L conversion
*/
static void
text_format_string_conversion(StringInfo buf, char conversion,
FmgrInfo *typOutputInfo,
Datum value, bool isNull)
Datum value, bool isNull,
int flags, int width)
{
char *str;
/* Handle NULL arguments before trying to stringify the value. */
if (isNull)
{
if (conversion == 'L')
appendStringInfoString(buf, "NULL");
if (conversion == 's')
text_format_append_string(buf, "", flags, width);
else if (conversion == 'L')
text_format_append_string(buf, "NULL", flags, width);
else if (conversion == 'I')
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
@ -4271,23 +4458,71 @@ text_format_string_conversion(StringInfo buf, char conversion,
if (conversion == 'I')
{
/* quote_identifier may or may not allocate a new string. */
appendStringInfoString(buf, quote_identifier(str));
text_format_append_string(buf, quote_identifier(str), flags, width);
}
else if (conversion == 'L')
{
char *qstr = quote_literal_cstr(str);
appendStringInfoString(buf, qstr);
text_format_append_string(buf, qstr, flags, width);
/* quote_literal_cstr() always allocates a new string */
pfree(qstr);
}
else
appendStringInfoString(buf, str);
text_format_append_string(buf, str, flags, width);
/* Cleanup. */
pfree(str);
}
/*
* Append str to buf, padding as directed by flags/width
*/
static void
text_format_append_string(StringInfo buf, const char *str,
int flags, int width)
{
bool align_to_left = false;
int len;
/* fast path for typical easy case */
if (width == 0)
{
appendStringInfoString(buf, str);
return;
}
if (width < 0)
{
/* Negative width: implicit '-' flag, then take absolute value */
align_to_left = true;
/* -INT_MIN is undefined */
if (width <= INT_MIN)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("number is out of range")));
width = -width;
}
else if (flags & TEXT_FORMAT_FLAG_MINUS)
align_to_left = true;
len = pg_mbstrlen(str);
if (align_to_left)
{
/* left justify */
appendStringInfoString(buf, str);
if (len < width)
appendStringInfoSpaces(buf, width - len);
}
else
{
/* right justify */
if (len < width)
appendStringInfoSpaces(buf, width - len);
appendStringInfoString(buf, str);
}
}
/*
* text_format_nv - nonvariadic wrapper for text_format function.
*