/*
* parser_errposition
* Report a parse-analysis-time cursor position, if possible.
*
* This is expected to be used within an ereport() call. The return value
* is a dummy (always 0, in fact).
*
* The locations stored in raw parsetrees are byte offsets into the source
* string. We have to convert them to 1-based character indexes for reporting
* to clients. (We do things this way to avoid unnecessary overhead in the
* normal non-error case: computing character indexes would be much more
* expensive than storing token offsets.)
*/
int
parser_errposition(ParseState *pstate, int location)
{
int pos;
/* No-op if location was not provided */
if (location < 0)
return 0;
/* Can't do anything if source text is not available */
if (pstate == NULL || pstate->p_sourcetext == NULL)
return 0;
/* Convert offset to character number */
pos = pg_mbstrlen_with_len(pstate->p_sourcetext, location) + 1;
/* And pass it to the ereport mechanism */
return errposition(pos);
}
static int
ora_instr_mb(text *txt, text *pattern, int start, int nth)
{
int c_len_txt, c_len_pat;
int b_len_pat;
int *pos_txt;
const char *str_txt, *str_pat;
int beg, end, i, dx;
str_txt = VARDATA_ANY(txt);
c_len_txt = ora_mb_strlen(txt, NULL, &pos_txt);
str_pat = VARDATA_ANY(pattern);
b_len_pat = VARSIZE_ANY_EXHDR(pattern);
c_len_pat = pg_mbstrlen_with_len(str_pat, b_len_pat);
if (start > 0)
{
dx = 1;
beg = start - 1;
end = c_len_txt - c_len_pat + 1;
if (beg >= end)
return 0; /* out of range */
}
else
{
dx = -1;
beg = Min(c_len_txt + start, c_len_txt - c_len_pat);
end = -1;
if (beg <= end)
return 0; /* out of range */
}
for (i = beg; i != end; i += dx)
{
if (memcmp(str_txt + pos_txt[i], str_pat, b_len_pat) == 0)
{
if (--nth == 0)
return i + 1;
}
}
return 0;
}
levenshtein_internal(text *s, text *t,
int ins_c, int del_c, int sub_c)
#endif
{
int m,
n,
s_bytes,
t_bytes;
int *prev;
int *curr;
int *s_char_len = NULL;
int i,
j;
const char *s_data;
const char *t_data;
const char *y;
/*
* For levenshtein_less_equal_internal, we have real variables called
* start_column and stop_column; otherwise it's just short-hand for 0 and
* m.
*/
#ifdef LEVENSHTEIN_LESS_EQUAL
int start_column,
stop_column;
#undef START_COLUMN
#undef STOP_COLUMN
#define START_COLUMN start_column
#define STOP_COLUMN stop_column
#else
#undef START_COLUMN
#undef STOP_COLUMN
#define START_COLUMN 0
#define STOP_COLUMN m
#endif
/* Extract a pointer to the actual character data. */
s_data = VARDATA_ANY(s);
t_data = VARDATA_ANY(t);
/* Determine length of each string in bytes and characters. */
s_bytes = VARSIZE_ANY_EXHDR(s);
t_bytes = VARSIZE_ANY_EXHDR(t);
m = pg_mbstrlen_with_len(s_data, s_bytes);
n = pg_mbstrlen_with_len(t_data, t_bytes);
/*
* We can transform an empty s into t with n insertions, or a non-empty t
* into an empty s with m deletions.
*/
if (!m)
return n * ins_c;
if (!n)
return m * del_c;
/*
* For security concerns, restrict excessive CPU+RAM usage. (This
* implementation uses O(m) memory and has O(mn) complexity.)
*/
if (m > MAX_LEVENSHTEIN_STRLEN ||
n > MAX_LEVENSHTEIN_STRLEN)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("argument exceeds the maximum length of %d bytes",
MAX_LEVENSHTEIN_STRLEN)));
#ifdef LEVENSHTEIN_LESS_EQUAL
/* Initialize start and stop columns. */
start_column = 0;
stop_column = m + 1;
/*
* If max_d >= 0, determine whether the bound is impossibly tight. If so,
* return max_d + 1 immediately. Otherwise, determine whether it's tight
* enough to limit the computation we must perform. If so, figure out
* initial stop column.
*/
if (max_d >= 0)
{
int min_theo_d; /* Theoretical minimum distance. */
int max_theo_d; /* Theoretical maximum distance. */
int net_inserts = n - m;
min_theo_d = net_inserts < 0 ?
-net_inserts * del_c : net_inserts * ins_c;
if (min_theo_d > max_d)
return max_d + 1;
if (ins_c + del_c < sub_c)
sub_c = ins_c + del_c;
max_theo_d = min_theo_d + sub_c * Min(m, n);
if (max_d >= max_theo_d)
max_d = -1;
else if (ins_c + del_c > 0)
{
/*
* Figure out how much of the first row of the notional matrix we
* need to fill in. If the string is growing, the theoretical
* minimum distance already incorporates the cost of deleting the
* number of characters necessary to make the two strings equal in
* length. Each additional deletion forces another insertion, so
* the best-case total cost increases by ins_c + del_c. If the
* string is shrinking, the minimum theoretical cost assumes no
* excess deletions; that is, we're starting no further right than
* column n - m. If we do start further right, the best-case
* total cost increases by ins_c + del_c for each move right.
*/
int slack_d = max_d - min_theo_d;
int best_column = net_inserts < 0 ? -net_inserts : 0;
stop_column = best_column + (slack_d / (ins_c + del_c)) + 1;
if (stop_column > m)
stop_column = m + 1;
}
}
#endif
/*
* In order to avoid calling pg_mblen() repeatedly on each character in s,
* we cache all the lengths before starting the main loop -- but if all
* the characters in both strings are single byte, then we skip this and
* use a fast-path in the main loop. If only one string contains
* multi-byte characters, we still build the array, so that the fast-path
* needn't deal with the case where the array hasn't been initialized.
*/
if (m != s_bytes || n != t_bytes)
{
int i;
const char *cp = s_data;
s_char_len = (int *) palloc((m + 1) * sizeof(int));
for (i = 0; i < m; ++i)
{
s_char_len[i] = pg_mblen(cp);
cp += s_char_len[i];
}
s_char_len[i] = 0;
}
/* One more cell for initialization column and row. */
++m;
++n;
/* Previous and current rows of notional array. */
prev = (int *) palloc(2 * m * sizeof(int));
curr = prev + m;
/*
* To transform the first i characters of s into the first 0 characters of
* t, we must perform i deletions.
*/
for (i = START_COLUMN; i < STOP_COLUMN; i++)
prev[i] = i * del_c;
/* Loop through rows of the notional array */
for (y = t_data, j = 1; j < n; j++)
{
int *temp;
const char *x = s_data;
int y_char_len = n != t_bytes + 1 ? pg_mblen(y) : 1;
#ifdef LEVENSHTEIN_LESS_EQUAL
/*
* In the best case, values percolate down the diagonal unchanged, so
* we must increment stop_column unless it's already on the right end
* of the array. The inner loop will read prev[stop_column], so we
* have to initialize it even though it shouldn't affect the result.
*/
if (stop_column < m)
{
prev[stop_column] = max_d + 1;
++stop_column;
}
/*
* The main loop fills in curr, but curr[0] needs a special case: to
* transform the first 0 characters of s into the first j characters
* of t, we must perform j insertions. However, if start_column > 0,
* this special case does not apply.
*/
if (start_column == 0)
{
curr[0] = j * ins_c;
i = 1;
}
else
i = start_column;
#else
curr[0] = j * ins_c;
i = 1;
#endif
/*
* This inner loop is critical to performance, so we include a
* fast-path to handle the (fairly common) case where no multibyte
* characters are in the mix. The fast-path is entitled to assume
* that if s_char_len is not initialized then BOTH strings contain
* only single-byte characters.
*/
if (s_char_len != NULL)
{
for (; i < STOP_COLUMN; i++)
{
int ins;
int del;
int sub;
int x_char_len = s_char_len[i - 1];
/*
* Calculate costs for insertion, deletion, and substitution.
*
* When calculating cost for substitution, we compare the last
* character of each possibly-multibyte character first,
* because that's enough to rule out most mis-matches. If we
* get past that test, then we compare the lengths and the
* remaining bytes.
*/
ins = prev[i] + ins_c;
del = curr[i - 1] + del_c;
if (x[x_char_len - 1] == y[y_char_len - 1]
&& x_char_len == y_char_len &&
(x_char_len == 1 || rest_of_char_same(x, y, x_char_len)))
sub = prev[i - 1];
else
sub = prev[i - 1] + sub_c;
/* Take the one with minimum cost. */
curr[i] = Min(ins, del);
curr[i] = Min(curr[i], sub);
/* Point to next character. */
x += x_char_len;
}
}
else
{
for (; i < STOP_COLUMN; i++)
{
int ins;
int del;
int sub;
/* Calculate costs for insertion, deletion, and substitution. */
ins = prev[i] + ins_c;
del = curr[i - 1] + del_c;
sub = prev[i - 1] + ((*x == *y) ? 0 : sub_c);
/* Take the one with minimum cost. */
curr[i] = Min(ins, del);
curr[i] = Min(curr[i], sub);
/* Point to next character. */
x++;
}
}
/* Swap current row with previous row. */
temp = curr;
curr = prev;
prev = temp;
/* Point to next character. */
y += y_char_len;
#ifdef LEVENSHTEIN_LESS_EQUAL
/*
* This chunk of code represents a significant performance hit if used
* in the case where there is no max_d bound. This is probably not
* because the max_d >= 0 test itself is expensive, but rather because
* the possibility of needing to execute this code prevents tight
* optimization of the loop as a whole.
*/
if (max_d >= 0)
{
/*
* The "zero point" is the column of the current row where the
* remaining portions of the strings are of equal length. There
* are (n - 1) characters in the target string, of which j have
* been transformed. There are (m - 1) characters in the source
* string, so we want to find the value for zp where (n - 1) - j =
* (m - 1) - zp.
*/
int zp = j - (n - m);
/* Check whether the stop column can slide left. */
while (stop_column > 0)
{
int ii = stop_column - 1;
int net_inserts = ii - zp;
if (prev[ii] + (net_inserts > 0 ? net_inserts * ins_c :
-net_inserts * del_c) <= max_d)
break;
stop_column--;
}
/* Check whether the start column can slide right. */
while (start_column < stop_column)
{
int net_inserts = start_column - zp;
if (prev[start_column] +
(net_inserts > 0 ? net_inserts * ins_c :
-net_inserts * del_c) <= max_d)
break;
/*
* We'll never again update these values, so we must make sure
* there's nothing here that could confuse any future
* iteration of the outer loop.
*/
prev[start_column] = max_d + 1;
curr[start_column] = max_d + 1;
if (start_column != 0)
s_data += (s_char_len != NULL) ? s_char_len[start_column - 1] : 1;
start_column++;
}
/* If they cross, we're going to exceed the bound. */
if (start_column >= stop_column)
return max_d + 1;
}
#endif
}
/*
* Because the final value was swapped from the previous row to the
* current row, that's where we'll find it.
*/
return prev[m - 1];
}
Datum
rpad(PG_FUNCTION_ARGS)
{
text *string1 = PG_GETARG_TEXT_PP(0);
int32 len = PG_GETARG_INT32(1);
text *string2 = PG_GETARG_TEXT_PP(2);
text *ret;
char *ptr1,
*ptr2,
*ptr2start,
*ptr2end,
*ptr_ret;
int m,
s1len,
s2len;
int bytelen;
/* Negative len is silently taken as zero */
if (len < 0)
len = 0;
s1len = VARSIZE_ANY_EXHDR(string1);
if (s1len < 0)
s1len = 0; /* shouldn't happen */
s2len = VARSIZE_ANY_EXHDR(string2);
if (s2len < 0)
s2len = 0; /* shouldn't happen */
s1len = pg_mbstrlen_with_len(VARDATA_ANY(string1), s1len);
if (s1len > len)
s1len = len; /* truncate string1 to len chars */
if (s2len <= 0)
len = s1len; /* nothing to pad with, so don't pad */
bytelen = pg_database_encoding_max_length() * len;
/* Check for integer overflow */
if (len != 0 && bytelen / pg_database_encoding_max_length() != len)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("requested length too large")));
ret = (text *) palloc(VARHDRSZ + bytelen);
m = len - s1len;
ptr1 = VARDATA_ANY(string1);
ptr_ret = VARDATA(ret);
while (s1len--)
{
int mlen = pg_mblen(ptr1);
memcpy(ptr_ret, ptr1, mlen);
ptr_ret += mlen;
ptr1 += mlen;
}
ptr2 = ptr2start = VARDATA_ANY(string2);
ptr2end = ptr2 + s2len;
while (m--)
{
int mlen = pg_mblen(ptr2);
memcpy(ptr_ret, ptr2, mlen);
ptr_ret += mlen;
ptr2 += mlen;
if (ptr2 == ptr2end) /* wrap around at end of s2 */
ptr2 = ptr2start;
}
SET_VARSIZE(ret, ptr_ret - (char *) ret);
PG_RETURN_TEXT_P(ret);
}
/*
* bpchar_input -- common guts of bpcharin and bpcharrecv
*
* s is the input text of length len (may not be null-terminated)
* atttypmod is the typmod value to apply
*
* Note that atttypmod is measured in characters, which
* is not necessarily the same as the number of bytes.
*
* If the input string is too long, raise an error, unless the extra
* characters are spaces, in which case they're truncated. (per SQL)
*/
static BpChar *
bpchar_input(const char *s, size_t len, int32 atttypmod)
{
BpChar *result;
char *r;
size_t maxlen;
/* verify encoding */
pg_verifymbstr(s, len, false);
/* If typmod is -1 (or invalid), use the actual string length */
if (atttypmod < (int32) VARHDRSZ)
maxlen = len;
else
{
size_t charlen; /* number of CHARACTERS in the input */
maxlen = atttypmod - VARHDRSZ;
charlen = pg_mbstrlen_with_len(s, len);
if (charlen > maxlen)
{
/* Verify that extra characters are spaces, and clip them off */
size_t mbmaxlen = pg_mbcharcliplen(s, len, maxlen);
size_t j;
/*
* at this point, len is the actual BYTE length of the input
* string, maxlen is the max number of CHARACTERS allowed for this
* bpchar type, mbmaxlen is the length in BYTES of those chars.
*/
for (j = mbmaxlen; j < len; j++)
{
if (s[j] != ' ')
ereport(ERROR,
(errcode(ERRCODE_STRING_DATA_RIGHT_TRUNCATION),
errmsg("value too long for type character(%d)",
(int) maxlen)));
}
/*
* Now we set maxlen to the necessary byte length, not the number
* of CHARACTERS!
*/
maxlen = len = mbmaxlen;
}
else
{
/*
* Now we set maxlen to the necessary byte length, not the number
* of CHARACTERS!
*/
maxlen = len + (maxlen - charlen);
}
}
result = (BpChar *) palloc(maxlen + VARHDRSZ);
VARATT_SIZEP(result) = maxlen + VARHDRSZ;
r = VARDATA(result);
memcpy(r, s, len);
/* blank pad the string if necessary */
if (maxlen > len)
memset(r + len, ' ', maxlen - len);
return result;
}
/*
* Converts a CHARACTER type to the specified size.
*
* maxlen is the typmod, ie, declared length plus VARHDRSZ bytes.
* isExplicit is true if this is for an explicit cast to char(N).
*
* Truncation rules: for an explicit cast, silently truncate to the given
* length; for an implicit cast, raise error unless extra characters are
* all spaces. (This is sort-of per SQL: the spec would actually have us
* raise a "completion condition" for the explicit cast case, but Postgres
* hasn't got such a concept.)
*/
Datum
bpchar(PG_FUNCTION_ARGS)
{
BpChar *source = PG_GETARG_BPCHAR_P(0);
int32 maxlen = PG_GETARG_INT32(1);
bool isExplicit = PG_GETARG_BOOL(2);
BpChar *result;
int32 len;
char *r;
char *s;
int i;
int charlen; /* number of characters in the input string +
* VARHDRSZ */
/* No work if typmod is invalid */
if (maxlen < (int32) VARHDRSZ)
PG_RETURN_BPCHAR_P(source);
len = VARSIZE(source);
charlen = pg_mbstrlen_with_len(VARDATA(source), len - VARHDRSZ) + VARHDRSZ;
/* No work if supplied data matches typmod already */
if (charlen == maxlen)
PG_RETURN_BPCHAR_P(source);
if (charlen > maxlen)
{
/* Verify that extra characters are spaces, and clip them off */
size_t maxmblen;
maxmblen = pg_mbcharcliplen(VARDATA(source), len - VARHDRSZ,
maxlen - VARHDRSZ) + VARHDRSZ;
if (!isExplicit)
{
for (i = maxmblen - VARHDRSZ; i < len - VARHDRSZ; i++)
if (*(VARDATA(source) + i) != ' ')
ereport(ERROR,
(errcode(ERRCODE_STRING_DATA_RIGHT_TRUNCATION),
errmsg("value too long for type character(%d)",
maxlen - VARHDRSZ)));
}
len = maxmblen;
/*
* XXX: at this point, maxlen is the necessary byte length+VARHDRSZ,
* not the number of CHARACTERS!
*/
maxlen = len;
}
else
{
/*
* XXX: at this point, maxlen is the necessary byte length+VARHDRSZ,
* not the number of CHARACTERS!
*/
maxlen = len + (maxlen - charlen);
}
s = VARDATA(source);
result = palloc(maxlen);
VARATT_SIZEP(result) = maxlen;
r = VARDATA(result);
memcpy(r, s, len - VARHDRSZ);
/* blank pad the string if necessary */
if (maxlen > len)
memset(r + len - VARHDRSZ, ' ', maxlen - len);
PG_RETURN_BPCHAR_P(result);
}
/*
* similar_escape()
* Convert a SQL:2008 regexp pattern to POSIX style, so it can be used by
* our regexp engine.
*/
Datum
similar_escape(PG_FUNCTION_ARGS)
{
text *pat_text;
text *esc_text;
text *result;
char *p,
*e,
*r;
int plen,
elen;
bool afterescape = false;
bool incharclass = false;
int nquotes = 0;
/* This function is not strict, so must test explicitly */
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
pat_text = PG_GETARG_TEXT_PP(0);
p = VARDATA_ANY(pat_text);
plen = VARSIZE_ANY_EXHDR(pat_text);
if (PG_ARGISNULL(1))
{
/* No ESCAPE clause provided; default to backslash as escape */
e = "\\";
elen = 1;
}
else
{
esc_text = PG_GETARG_TEXT_PP(1);
e = VARDATA_ANY(esc_text);
elen = VARSIZE_ANY_EXHDR(esc_text);
if (elen == 0)
e = NULL; /* no escape character */
else
{
int escape_mblen = pg_mbstrlen_with_len(e, elen);
if (escape_mblen > 1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_ESCAPE_SEQUENCE),
errmsg("invalid escape string"),
errhint("Escape string must be empty or one character.")));
}
}
/*----------
* We surround the transformed input string with
* ^(?: ... )$
* which requires some explanation. We need "^" and "$" to force
* the pattern to match the entire input string as per SQL99 spec.
* The "(?:" and ")" are a non-capturing set of parens; we have to have
* parens in case the string contains "|", else the "^" and "$" will
* be bound into the first and last alternatives which is not what we
* want, and the parens must be non capturing because we don't want them
* to count when selecting output for SUBSTRING.
*----------
*/
/*
* We need room for the prefix/postfix plus as many as 3 output bytes per
* input byte; since the input is at most 1GB this can't overflow
*/
result = (text *) palloc(VARHDRSZ + 6 + 3 * plen);
r = VARDATA(result);
*r++ = '^';
*r++ = '(';
*r++ = '?';
*r++ = ':';
while (plen > 0)
{
char pchar = *p;
/*
* If both the escape character and the current character from the
* pattern are multi-byte, we need to take the slow path.
*
* But if one of them is single-byte, we can process the pattern one
* byte at a time, ignoring multi-byte characters. (This works
* because all server-encodings have the property that a valid
* multi-byte character representation cannot contain the
* representation of a valid single-byte character.)
*/
if (elen > 1)
{
int mblen = pg_mblen(p);
if (mblen > 1)
{
/* slow, multi-byte path */
if (afterescape)
{
*r++ = '\\';
memcpy(r, p, mblen);
r += mblen;
afterescape = false;
}
else if (e && elen == mblen && memcmp(e, p, mblen) == 0)
{
/* SQL99 escape character; do not send to output */
afterescape = true;
}
else
{
/*
* We know it's a multi-byte character, so we don't need
* to do all the comparisons to single-byte characters
* that we do below.
*/
memcpy(r, p, mblen);
r += mblen;
}
p += mblen;
plen -= mblen;
continue;
}
}
/* fast path */
if (afterescape)
{
if (pchar == '"' && !incharclass) /* for SUBSTRING patterns */
*r++ = ((nquotes++ % 2) == 0) ? '(' : ')';
else
{
*r++ = '\\';
*r++ = pchar;
}
afterescape = false;
}
else if (e && pchar == *e)
{
/* SQL99 escape character; do not send to output */
afterescape = true;
}
else if (incharclass)
{
if (pchar == '\\')
*r++ = '\\';
*r++ = pchar;
if (pchar == ']')
incharclass = false;
}
else if (pchar == '[')
{
*r++ = pchar;
incharclass = true;
}
else if (pchar == '%')
{
*r++ = '.';
*r++ = '*';
}
else if (pchar == '_')
*r++ = '.';
else if (pchar == '(')
{
/* convert to non-capturing parenthesis */
*r++ = '(';
*r++ = '?';
*r++ = ':';
}
else if (pchar == '\\' || pchar == '.' ||
pchar == '^' || pchar == '$')
{
*r++ = '\\';
*r++ = pchar;
}
else
*r++ = pchar;
p++, plen--;
}
*r++ = ')';
*r++ = '$';
SET_VARSIZE(result, r - ((char *) result));
PG_RETURN_TEXT_P(result);
}
