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Teach PQescapeByteaConn() to use hex format when the target connection is

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to a server >= 8.5.  Per my proposal in discussion of hex-format patch.
This commit is contained in:
Tom Lane 2009-08-04 18:05:42 +00:00
parent a2a8c7a662
commit 5b8ee5c128
1 changed files with 136 additions and 108 deletions
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244
src/interfaces/libpq/fe-exec.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/interfaces/libpq/fe-exec.c,v 1.204 2009/08/04 16:08:36 tgl Exp $
* $PostgreSQL: pgsql/src/interfaces/libpq/fe-exec.c,v 1.205 2009/08/04 18:05:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -3058,114 +3058,9 @@ PQescapeString(char *to, const char *from, size_t length)
static_std_strings);
}
/*
* PQescapeBytea - converts from binary string to the
* minimal encoding necessary to include the string in an SQL
* INSERT statement with a bytea type column as the target.
*
* The following transformations are applied
* '\0' == ASCII 0 == \000
* '\'' == ASCII 39 == ''
* '\\' == ASCII 92 == \\
* anything < 0x20, or > 0x7e ---> \ooo
* (where ooo is an octal expression)
* If not std_strings, all backslashes sent to the output are doubled.
*/
static unsigned char *
PQescapeByteaInternal(PGconn *conn,
const unsigned char *from, size_t from_length,
size_t *to_length, bool std_strings)
{
const unsigned char *vp;
unsigned char *rp;
unsigned char *result;
size_t i;
size_t len;
size_t bslash_len = (std_strings ? 1 : 2);
/*
* empty string has 1 char ('\0')
*/
len = 1;
vp = from;
for (i = from_length; i > 0; i--, vp++)
{
if (*vp < 0x20 || *vp > 0x7e)
len += bslash_len + 3;
else if (*vp == '\'')
len += 2;
else if (*vp == '\\')
len += bslash_len + bslash_len;
else
len++;
}
*to_length = len;
rp = result = (unsigned char *) malloc(len);
if (rp == NULL)
{
if (conn)
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("out of memory\n"));
return NULL;
}
vp = from;
for (i = from_length; i > 0; i--, vp++)
{
if (*vp < 0x20 || *vp > 0x7e)
{
int val = *vp;
if (!std_strings)
*rp++ = '\\';
*rp++ = '\\';
*rp++ = (val >> 6) + '0';
*rp++ = ((val >> 3) & 07) + '0';
*rp++ = (val & 07) + '0';
}
else if (*vp == '\'')
{
*rp++ = '\'';
*rp++ = '\'';
}
else if (*vp == '\\')
{
if (!std_strings)
{
*rp++ = '\\';
*rp++ = '\\';
}
*rp++ = '\\';
*rp++ = '\\';
}
else
*rp++ = *vp;
}
*rp = '\0';
return result;
}
unsigned char *
PQescapeByteaConn(PGconn *conn,
const unsigned char *from, size_t from_length,
size_t *to_length)
{
if (!conn)
return NULL;
return PQescapeByteaInternal(conn, from, from_length, to_length,
conn->std_strings);
}
unsigned char *
PQescapeBytea(const unsigned char *from, size_t from_length, size_t *to_length)
{
return PQescapeByteaInternal(NULL, from, from_length, to_length,
static_std_strings);
}
/* HEX encoding support for bytea */
static const char hextbl[] = "0123456789abcdef";
static const int8 hexlookup[128] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
@ -3190,6 +3085,139 @@ get_hex(char c)
}
/*
* PQescapeBytea - converts from binary string to the
* minimal encoding necessary to include the string in an SQL
* INSERT statement with a bytea type column as the target.
*
* We can use either hex or escape (traditional) encoding.
* In escape mode, the following transformations are applied:
* '\0' == ASCII 0 == \000
* '\'' == ASCII 39 == ''
* '\\' == ASCII 92 == \\
* anything < 0x20, or > 0x7e ---> \ooo
* (where ooo is an octal expression)
*
* If not std_strings, all backslashes sent to the output are doubled.
*/
static unsigned char *
PQescapeByteaInternal(PGconn *conn,
const unsigned char *from, size_t from_length,
size_t *to_length, bool std_strings, bool use_hex)
{
const unsigned char *vp;
unsigned char *rp;
unsigned char *result;
size_t i;
size_t len;
size_t bslash_len = (std_strings ? 1 : 2);
/*
* empty string has 1 char ('\0')
*/
len = 1;
if (use_hex)
{
len += bslash_len + 1 + 2 * from_length;
}
else
{
vp = from;
for (i = from_length; i > 0; i--, vp++)
{
if (*vp < 0x20 || *vp > 0x7e)
len += bslash_len + 3;
else if (*vp == '\'')
len += 2;
else if (*vp == '\\')
len += bslash_len + bslash_len;
else
len++;
}
}
*to_length = len;
rp = result = (unsigned char *) malloc(len);
if (rp == NULL)
{
if (conn)
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("out of memory\n"));
return NULL;
}
if (use_hex)
{
if (!std_strings)
*rp++ = '\\';
*rp++ = '\\';
*rp++ = 'x';
}
vp = from;
for (i = from_length; i > 0; i--, vp++)
{
unsigned char c = *vp;
if (use_hex)
{
*rp++ = hextbl[(c >> 4) & 0xF];
*rp++ = hextbl[c & 0xF];
}
else if (c < 0x20 || c > 0x7e)
{
if (!std_strings)
*rp++ = '\\';
*rp++ = '\\';
*rp++ = (c >> 6) + '0';
*rp++ = ((c >> 3) & 07) + '0';
*rp++ = (c & 07) + '0';
}
else if (c == '\'')
{
*rp++ = '\'';
*rp++ = '\'';
}
else if (c == '\\')
{
if (!std_strings)
{
*rp++ = '\\';
*rp++ = '\\';
}
*rp++ = '\\';
*rp++ = '\\';
}
else
*rp++ = c;
}
*rp = '\0';
return result;
}
unsigned char *
PQescapeByteaConn(PGconn *conn,
const unsigned char *from, size_t from_length,
size_t *to_length)
{
if (!conn)
return NULL;
return PQescapeByteaInternal(conn, from, from_length, to_length,
conn->std_strings,
(conn->sversion >= 80500));
}
unsigned char *
PQescapeBytea(const unsigned char *from, size_t from_length, size_t *to_length)
{
return PQescapeByteaInternal(NULL, from, from_length, to_length,
static_std_strings,
false /* can't use hex */ );
}
#define ISFIRSTOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '3')
#define ISOCTDIGIT(CH) ((CH) >= '0' && (CH) <= '7')
#define OCTVAL(CH) ((CH) - '0')