src/backend/utils/mb/stringinfo_mb.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * stringinfo_mb.c
   4  *              Multibyte encoding-aware additional StringInfo facilities
   5  *
   6  * This is separate from common/stringinfo.c so that frontend users
   7  * of that file need not pull in unnecessary multibyte-encoding support
   8  * code.
   9  *
  10  *
  11  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
  12  * Portions Copyright (c) 1994, Regents of the University of California
  13  *
  14  *
  15  * IDENTIFICATION
  16  *        src/backend/utils/mb/stringinfo_mb.c
  17  *
  18  *-------------------------------------------------------------------------
  19  */
  20 #include "postgres.h"
  21
  22 #include "mb/stringinfo_mb.h"
  23 #include "mb/pg_wchar.h"
  24
  25
  26 /*
  27  * appendStringInfoStringQuoted
  28  *
  29  * Append up to maxlen bytes from s to str, or the whole input string if
  30  * maxlen < 0, adding single quotes around it and doubling all single quotes.
  31  * Add an ellipsis if the copy is incomplete.
  32  */
  33 void
  34 appendStringInfoStringQuoted(StringInfo str, const char *s, int maxlen)
  35 {
  36         char       *copy = NULL;
  37         const char *chunk_search_start,
  38                            *chunk_copy_start,
  39                            *chunk_end;
  40         int                     slen;
  41         bool            ellipsis;
  42
  43         Assert(str != NULL);
  44
  45         slen = strlen(s);
  46         if (maxlen >= 0 && maxlen < slen)
  47         {
  48                 int                     finallen = pg_mbcliplen(s, slen, maxlen);
  49
  50                 copy = pnstrdup(s, finallen);
  51                 chunk_search_start = copy;
  52                 chunk_copy_start = copy;
  53
  54                 ellipsis = true;
  55         }
  56         else
  57         {
  58                 chunk_search_start = s;
  59                 chunk_copy_start = s;
  60
  61                 ellipsis = false;
  62         }
  63
  64         appendStringInfoCharMacro(str, '\'');
  65
  66         while ((chunk_end = strchr(chunk_search_start, '\'')) != NULL)
  67         {
  68                 /* copy including the found delimiting ' */
  69                 appendBinaryStringInfoNT(str,
  70                                                                  chunk_copy_start,
  71                                                                  chunk_end - chunk_copy_start + 1);
  72
  73                 /* in order to double it, include this ' into the next chunk as well */
  74                 chunk_copy_start = chunk_end;
  75                 chunk_search_start = chunk_end + 1;
  76         }
  77
  78         /* copy the last chunk and terminate */
  79         if (ellipsis)
  80                 appendStringInfo(str, "%s...'", chunk_copy_start);
  81         else
  82                 appendStringInfo(str, "%s'", chunk_copy_start);
  83
  84         if (copy)
  85                 pfree(copy);
  86 }