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Postgres FD Implementation
Commit cb50ee28 authored by Joe Conway's avatar Joe Conway
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Tighened up syntax checking of array input processing considerably. Junk that 

was previously allowed in odd places with odd results now causes an ERROR.
Also changed behavior with respect to whitespace -- trailing whitespace is
now ignored as well as leading whitespace (which has always been ignored).

Documentation updated to reflect change in whitespace handling. Also some
refactoring to what I believe is a more sensible order of several paragraphs.
parent 988d84f4
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Showing with 187 additions and 51 deletions
doc/src/sgml/array.sgml
View file @ cb50ee28
<!-- $PostgreSQL: pgsql/doc/src/sgml/array.sgml,v 1.36 2004/08/05 03:29:11 joe Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/array.sgml,v 1.37 2004/08/08 05:01:51 joe Exp $ -->
<sect1 id="arrays">
<title>Arrays</title>
......@@ -95,10 +95,12 @@ CREATE TABLE tictactoe (
</synopsis>
where <replaceable>delim</replaceable> is the delimiter character
for the type, as recorded in its <literal>pg_type</literal> entry.
(For all built-in types, this is the comma character
<quote><literal>,</literal></>.) Each
<replaceable>val</replaceable> is either a constant of the array
element type, or a subarray. An example of an array constant is
Among the standard data types provided in the
<productname>PostgreSQL</productname> distribution, type
<literal>box</> uses a semicolon (<literal>;</>) but all the others
use comma (<literal>,</>). Each <replaceable>val</replaceable> is
either a constant of the array element type, or a subarray. An example
of an array constant is
<programlisting>
'{{1,2,3},{4,5,6},{7,8,9}}'
</programlisting>
......@@ -161,7 +163,7 @@ SELECT * FROM sal_emp;
</para>
<para>
The <literal>ARRAY</literal> expression syntax may also be used:
The <literal>ARRAY</> constructor syntax may also be used:
<programlisting>
INSERT INTO sal_emp
VALUES ('Bill',
......@@ -176,8 +178,8 @@ INSERT INTO sal_emp
Notice that the array elements are ordinary SQL constants or
expressions; for instance, string literals are single quoted, instead of
double quoted as they would be in an array literal. The <literal>ARRAY</>
expression syntax is discussed in more detail in <xref
linkend="sql-syntax-array-constructors">.
constructor syntax is discussed in more detail in
<xref linkend="sql-syntax-array-constructors">.
</para>
</sect2>
......@@ -524,10 +526,17 @@ SELECT * FROM sal_emp WHERE 10000 = ALL (pay_by_quarter);
use comma.) In a multidimensional array, each dimension (row, plane,
cube, etc.) gets its own level of curly braces, and delimiters
must be written between adjacent curly-braced entities of the same level.
You may write whitespace before a left brace, after a right
brace, or before any individual item string. Whitespace after an item
is not ignored, however: after skipping leading whitespace, everything
up to the next right brace or delimiter is taken as the item value.
</para>
<para>
The array output routine will put double quotes around element values
if they are empty strings or contain curly braces, delimiter characters,
double quotes, backslashes, or white space. Double quotes and backslashes
embedded in element values will be backslash-escaped. For numeric
data types it is safe to assume that double quotes will never appear, but
for textual data types one should be prepared to cope with either presence
or absence of quotes. (This is a change in behavior from pre-7.2
<productname>PostgreSQL</productname> releases.)
</para>
<para>
......@@ -573,26 +582,22 @@ SELECT f1[1][-2][3] AS e1, f1[1][-1][5] AS e2
<para>
As shown previously, when writing an array value you may write double
quotes around any individual array
element. You <emphasis>must</> do so if the element value would otherwise
confuse the array-value parser. For example, elements containing curly
braces, commas (or whatever the delimiter character is), double quotes,
backslashes, or leading white space must be double-quoted. To put a double
quote or backslash in a quoted array element value, precede it with a
backslash.
Alternatively, you can use backslash-escaping to protect all data characters
that would otherwise be taken as array syntax or ignorable white space.
quotes around any individual array element. You <emphasis>must</> do so
if the element value would otherwise confuse the array-value parser.
For example, elements containing curly braces, commas (or whatever the
delimiter character is), double quotes, backslashes, or leading white
space must be double-quoted. To put a double quote or backslash in a
quoted array element value, precede it with a backslash. Alternatively,
you can use backslash-escaping to protect all data characters that would
otherwise be taken as array syntax.
</para>
<para>
The array output routine will put double quotes around element values
if they are empty strings or contain curly braces, delimiter characters,
double quotes, backslashes, or white space. Double quotes and backslashes
embedded in element values will be backslash-escaped. For numeric
data types it is safe to assume that double quotes will never appear, but
for textual data types one should be prepared to cope with either presence
or absence of quotes. (This is a change in behavior from pre-7.2
<productname>PostgreSQL</productname> releases.)
You may write whitespace before a left brace or after a right
brace. You may also write whitespace before or after any individual item
string. In all of these cases the whitespace will be ignored. However,
whitespace within double quoted elements, or surrounded on both sides by
non-whitespace characters of an element, are not ignored.
</para>
<note>
......@@ -616,10 +621,11 @@ INSERT ... VALUES ('{"\\\\","\\""}');
<tip>
<para>
The <literal>ARRAY</> constructor syntax is often easier to work with
than the array-literal syntax when writing array values in SQL commands.
In <literal>ARRAY</>, individual element values are written the same way
they would be written when not members of an array.
The <literal>ARRAY</> constructor syntax (see
<xref linkend="sql-syntax-array-constructors">) is often easier to work
with than the array-literal syntax when writing array values in SQL
commands. In <literal>ARRAY</>, individual element values are written the
same way they would be written when not members of an array.
</para>
</tip>
</sect2>
......
src/backend/utils/adt/arrayfuncs.c
View file @ cb50ee28
......@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.106 2004/08/05 03:29:37 joe Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.107 2004/08/08 05:01:55 joe Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -351,18 +351,32 @@ array_in(PG_FUNCTION_ARGS)
* The syntax for array input is C-like nested curly braces
*-----------------------------------------------------------------------------
*/
typedef enum
{
ARRAY_NO_LEVEL,
ARRAY_LEVEL_STARTED,
ARRAY_ELEM_STARTED,
ARRAY_ELEM_COMPLETED,
ARRAY_QUOTED_ELEM_STARTED,
ARRAY_QUOTED_ELEM_COMPLETED,
ARRAY_ELEM_DELIMITED,
ARRAY_LEVEL_COMPLETED,
ARRAY_LEVEL_DELIMITED
} ArrayParseState;
static int
ArrayCount(char *str, int *dim, char typdelim)
{
int nest_level = 0,
i;
int ndim = 1,
temp[MAXDIM],
nelems[MAXDIM],
nelems_last[MAXDIM];
bool scanning_string = false;
bool eoArray = false;
char *ptr;
int nest_level = 0,
i;
int ndim = 1,
temp[MAXDIM],
nelems[MAXDIM],
nelems_last[MAXDIM];
bool scanning_string = false;
bool eoArray = false;
char *ptr;
ArrayParseState parse_state = ARRAY_NO_LEVEL;
for (i = 0; i < MAXDIM; ++i)
{
......@@ -370,6 +384,7 @@ ArrayCount(char *str, int *dim, char typdelim)
nelems_last[i] = nelems[i] = 1;
}
/* special case for an empty array */
if (strncmp(str, "{}", 2) == 0)
return 0;
......@@ -389,6 +404,20 @@ ArrayCount(char *str, int *dim, char typdelim)
errmsg("malformed array literal: \"%s\"", str)));
break;
case '\\':
/*
* An escape must be after a level start, after an
* element start, or after an element delimiter. In any
* case we now must be past an element start.
*/
if (parse_state != ARRAY_LEVEL_STARTED &&
parse_state != ARRAY_ELEM_STARTED &&
parse_state != ARRAY_QUOTED_ELEM_STARTED &&
parse_state != ARRAY_ELEM_DELIMITED)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("malformed array literal: \"%s\"", str)));
if (parse_state != ARRAY_QUOTED_ELEM_STARTED)
parse_state = ARRAY_ELEM_STARTED;
/* skip the escaped character */
if (*(ptr + 1))
ptr++;
......@@ -398,11 +427,38 @@ ArrayCount(char *str, int *dim, char typdelim)
errmsg("malformed array literal: \"%s\"", str)));
break;
case '\"':
/*
* A quote must be after a level start, after a quoted
* element start, or after an element delimiter. In any
* case we now must be past an element start.
*/
if (parse_state != ARRAY_LEVEL_STARTED &&
parse_state != ARRAY_QUOTED_ELEM_STARTED &&
parse_state != ARRAY_ELEM_DELIMITED)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("malformed array literal: \"%s\"", str)));
scanning_string = !scanning_string;
if (scanning_string)
parse_state = ARRAY_QUOTED_ELEM_STARTED;
else
parse_state = ARRAY_QUOTED_ELEM_COMPLETED;
break;
case '{':
if (!scanning_string)
{
/*
* A left brace can occur if no nesting has
* occurred yet, after a level start, or
* after a level delimiter.
*/
if (parse_state != ARRAY_NO_LEVEL &&
parse_state != ARRAY_LEVEL_STARTED &&
parse_state != ARRAY_LEVEL_DELIMITED)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("malformed array literal: \"%s\"", str)));
parse_state = ARRAY_LEVEL_STARTED;
if (nest_level >= MAXDIM)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
......@@ -417,6 +473,19 @@ ArrayCount(char *str, int *dim, char typdelim)
case '}':
if (!scanning_string)
{
/*
* A right brace can occur after an element start,
* an element completion, a quoted element completion,
* or a level completion.
*/
if (parse_state != ARRAY_ELEM_STARTED &&
parse_state != ARRAY_ELEM_COMPLETED &&
parse_state != ARRAY_QUOTED_ELEM_COMPLETED &&
parse_state != ARRAY_LEVEL_COMPLETED)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("malformed array literal: \"%s\"", str)));
parse_state = ARRAY_LEVEL_COMPLETED;
if (nest_level == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
......@@ -445,10 +514,45 @@ ArrayCount(char *str, int *dim, char typdelim)
}
break;
default:
if (*ptr == typdelim && !scanning_string)
if (!scanning_string)
{
itemdone = true;
nelems[nest_level - 1]++;
if (*ptr == typdelim)
{
/*
* Delimiters can occur after an element start,
* an element completion, a quoted element
* completion, or a level completion.
*/
if (parse_state != ARRAY_ELEM_STARTED &&
parse_state != ARRAY_ELEM_COMPLETED &&
parse_state != ARRAY_QUOTED_ELEM_COMPLETED &&
parse_state != ARRAY_LEVEL_COMPLETED)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("malformed array literal: \"%s\"", str)));
if (parse_state == ARRAY_LEVEL_COMPLETED)
parse_state = ARRAY_LEVEL_DELIMITED;
else
parse_state = ARRAY_ELEM_DELIMITED;
itemdone = true;
nelems[nest_level - 1]++;
}
else if (!isspace(*ptr))
{
/*
* Other non-space characters must be after a level
* start, after an element start, or after an element
* delimiter. In any case we now must be past an
* element start.
*/
if (parse_state != ARRAY_LEVEL_STARTED &&
parse_state != ARRAY_ELEM_STARTED &&
parse_state != ARRAY_ELEM_DELIMITED)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("malformed array literal: \"%s\"", str)));
parse_state = ARRAY_ELEM_STARTED;
}
}
break;
}
......@@ -511,12 +615,15 @@ ReadArrayStr(char *arrayStr,
while (!eoArray)
{
bool itemdone = false;
bool itemquoted = false;
int i = -1;
char *itemstart;
char *eptr;
/* skip leading whitespace */
while (isspace((unsigned char) *ptr))
ptr++;
itemstart = ptr;
while (!itemdone)
......@@ -547,11 +654,15 @@ ReadArrayStr(char *arrayStr,
char *cptr;
scanning_string = !scanning_string;
/* Crunch the string on top of the quote. */
for (cptr = ptr; *cptr != '\0'; cptr++)
*cptr = *(cptr + 1);
/* Back up to not miss following character. */
ptr--;
if (scanning_string)
{
itemquoted = true;
/* Crunch the string on top of the first quote. */
for (cptr = ptr; *cptr != '\0'; cptr++)
*cptr = *(cptr + 1);
/* Back up to not miss following character. */
ptr--;
}
break;
}
case '{':
......@@ -615,6 +726,25 @@ ReadArrayStr(char *arrayStr,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("malformed array literal: \"%s\"", arrayStr)));
/*
* skip trailing whitespace
*/
eptr = ptr - 1;
if (!itemquoted)
{
/* skip to last non-NULL, non-space, character */
while ((*eptr == '\0') || (isspace((unsigned char) *eptr)))
eptr--;
*(++eptr) = '\0';
}
else
{
/* skip to last quote character */
while (*eptr != '"')
eptr--;
*eptr = '\0';
}
values[i] = FunctionCall3(inputproc,
CStringGetDatum(itemstart),
ObjectIdGetDatum(typioparam),
......
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