database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-19 13:42:17 +03:00
Code Activity

Add backend-only appendStringInfoStringQuoted

Browse Source 
This provides a mechanism to emit literal values in informative
messages, such as query parameters.  The new code is more complex than
what it replaces, primarily because it wants to be more efficient.
It also has the (currently unused) additional optional capability of
specifying a maximum size to print.

The new function lives out of common/stringinfo.c so that frontend users
of that file need not pull in unnecessary multibyte-encoding support
code.

Author: Álvaro Herrera and Alexey Bashtanov, after a suggestion from Andres Freund
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/20190920203905.xkv5udsd5dxfs6tr@alap3.anarazel.de
This commit is contained in:
Alvaro Herrera
2019-12-10 17:09:32 -03:00
parent 0da33c762b
commit 6cafde1bd4
8 changed files with 152 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

86
src/backend/utils/mb/stringinfo_mb.c Normal file
View File

@@ -0,0 +1,86 @@
/*-------------------------------------------------------------------------
*
* stringinfo_mb.c
* Multibyte encoding-aware additional StringInfo facilites
*
* This is separate from common/stringinfo.c so that frontend users
* of that file need not pull in unnecessary multibyte-encoding support
* code.
*
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/utils/mb/stringinfo_mb.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "mb/stringinfo_mb.h"
#include "mb/pg_wchar.h"
/*
* appendStringInfoStringQuoted
*
* Append up to maxlen characters from s to str, or the whole input string if
* maxlen <= 0, adding single quotes around it and doubling all single quotes.
* Add an ellipsis if the copy is incomplete.
*/
void
appendStringInfoStringQuoted(StringInfo str, const char *s, int maxlen)
{
char *copy = NULL;
const char *chunk_search_start,
*chunk_copy_start,
*chunk_end;
int slen;
bool ellipsis;
Assert(str != NULL);
slen = strlen(s);
if (maxlen > 0 && maxlen < slen)
{
int finallen = pg_mbcliplen(s, slen, maxlen);
copy = pnstrdup(s, finallen);
chunk_search_start = copy;
chunk_copy_start = copy;
ellipsis = true;
}
else
{
chunk_search_start = s;
chunk_copy_start = s;
ellipsis = false;
}
appendStringInfoCharMacro(str, '\'');
while ((chunk_end = strchr(chunk_search_start, '\'')) != NULL)
{
/* copy including the found delimiting ' */
appendBinaryStringInfoNT(str,
chunk_copy_start,
chunk_end - chunk_copy_start + 1);
/* in order to double it, include this ' into the next chunk as well */
chunk_copy_start = chunk_end;
chunk_search_start = chunk_end + 1;
}
/* copy the last chunk and terminate */
if (ellipsis)
appendStringInfo(str, "%s...'", chunk_copy_start);
else
appendStringInfo(str, "%s'", chunk_copy_start);
if (copy)
pfree(copy);
}