diff options
Diffstat (limited to 'src/backend/utils/adt/varlena.c')
| -rw-r--r-- | src/backend/utils/adt/varlena.c | 132 |
1 files changed, 78 insertions, 54 deletions
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c index 5fc3128360c..3f67403ba44 100644 --- a/src/backend/utils/adt/varlena.c +++ b/src/backend/utils/adt/varlena.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.137 2005/10/17 16:24:19 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.138 2005/10/18 20:38:58 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -24,11 +24,11 @@ #include "mb/pg_wchar.h" #include "miscadmin.h" #include "parser/scansup.h" +#include "regex/regex.h" #include "utils/array.h" #include "utils/builtins.h" #include "utils/lsyscache.h" #include "utils/pg_locale.h" -#include "regex/regex.h" typedef struct varlena unknown; @@ -2066,7 +2066,8 @@ replace_text(PG_FUNCTION_ARGS) /* * check_replace_text_has_escape_char - * check whether replace_text has escape char. + * + * check whether replace_text contains escape char. */ static bool check_replace_text_has_escape_char(const text *replace_text) @@ -2077,14 +2078,18 @@ check_replace_text_has_escape_char(const text *replace_text) if (pg_database_encoding_max_length() == 1) { for (; p < p_end; p++) + { if (*p == '\\') return true; + } } else { for (; p < p_end; p += pg_mblen(p)) + { if (*p == '\\') return true; + } } return false; @@ -2092,7 +2097,9 @@ check_replace_text_has_escape_char(const text *replace_text) /* * appendStringInfoRegexpSubstr - * append string by using back references of regexp. + * + * Append replace_text to str, substituting regexp back references for + * \n escapes. */ static void appendStringInfoRegexpSubstr(StringInfo str, text *replace_text, @@ -2100,50 +2107,41 @@ appendStringInfoRegexpSubstr(StringInfo str, text *replace_text, { const char *p = VARDATA(replace_text); const char *p_end = p + (VARSIZE(replace_text) - VARHDRSZ); - int eml = pg_database_encoding_max_length(); - int substr_start = 1; - int ch_cnt; - - int so; - int eo; - - while (1) + for (;;) { - /* Find escape char. */ - ch_cnt = 0; + const char *chunk_start = p; + int so; + int eo; + + /* Find next escape char. */ if (eml == 1) { for (; p < p_end && *p != '\\'; p++) - ch_cnt++; + /* nothing */ ; } else { for (; p < p_end && *p != '\\'; p += pg_mblen(p)) - ch_cnt++; + /* nothing */ ; } - /* - * Copy the text when there is a text in the left of escape char or - * escape char is not found. - */ - if (ch_cnt) - { - text *append_text = text_substring(PointerGetDatum(replace_text), - substr_start, ch_cnt, false); - - appendStringInfoText(str, append_text); - pfree(append_text); - } - substr_start += ch_cnt + 1; + /* Copy the text we just scanned over, if any. */ + if (p > chunk_start) + appendBinaryStringInfo(str, chunk_start, p - chunk_start); - if (p >= p_end) /* When escape char is not found. */ + /* Done if at end of string, else advance over escape char. */ + if (p >= p_end) break; - - /* See the next character of escape char. */ p++; - so = eo = -1; + + if (p >= p_end) + { + /* Escape at very end of input. Treat same as unexpected char */ + appendStringInfoChar(str, '\\'); + break; + } if (*p >= '1' && *p <= '9') { @@ -2153,7 +2151,6 @@ appendStringInfoRegexpSubstr(StringInfo str, text *replace_text, so = pmatch[idx].rm_so; eo = pmatch[idx].rm_eo; p++; - substr_start++; } else if (*p == '&') { @@ -2161,15 +2158,36 @@ appendStringInfoRegexpSubstr(StringInfo str, text *replace_text, so = pmatch[0].rm_so; eo = pmatch[0].rm_eo; p++; - substr_start++; + } + else if (*p == '\\') + { + /* \\ means transfer one \ to output. */ + appendStringInfoChar(str, '\\'); + p++; + continue; + } + else + { + /* + * If escape char is not followed by any expected char, + * just treat it as ordinary data to copy. (XXX would it be + * better to throw an error?) + */ + appendStringInfoChar(str, '\\'); + continue; } if (so != -1 && eo != -1) { - /* Copy the text that is back reference of regexp. */ - text *append_text = text_substring(PointerGetDatum(src_text), - so + 1, (eo - so), false); + /* + * Copy the text that is back reference of regexp. Because so and + * eo are counted in characters not bytes, it's easiest to use + * text_substring to pull out the correct chunk of text. + */ + text *append_text; + append_text = text_substring(PointerGetDatum(src_text), + so + 1, (eo - so), false); appendStringInfoText(str, append_text); pfree(append_text); } @@ -2180,17 +2198,19 @@ appendStringInfoRegexpSubstr(StringInfo str, text *replace_text, /* * replace_text_regexp + * * replace text that matches to regexp in src_text to replace_text. + * + * Note: to avoid having to include regex.h in builtins.h, we declare + * the regexp argument as void *, but really it's regex_t *. */ -Datum -replace_text_regexp(PG_FUNCTION_ARGS) +text * +replace_text_regexp(text *src_text, void *regexp, + text *replace_text, bool glob) { text *ret_text; - text *src_text = PG_GETARG_TEXT_P(0); + regex_t *re = (regex_t *) regexp; int src_text_len = VARSIZE(src_text) - VARHDRSZ; - regex_t *re = (regex_t *) PG_GETARG_POINTER(1); - text *replace_text = PG_GETARG_TEXT_P(2); - bool global = PG_GETARG_BOOL(3); StringInfo str = makeStringInfo(); int regexec_result; regmatch_t pmatch[REGEXP_REPLACE_BACKREF_CNT]; @@ -2233,14 +2253,18 @@ replace_text_regexp(PG_FUNCTION_ARGS) break; /* - * Copy the text when there is a text in the left of matched position. + * Copy the text to the left of the match position. Because we + * are working with character not byte indexes, it's easiest to + * use text_substring to pull out the needed data. */ if (pmatch[0].rm_so - data_pos > 0) { - text *left_text = text_substring(PointerGetDatum(src_text), - data_pos + 1, - pmatch[0].rm_so - data_pos, false); + text *left_text; + left_text = text_substring(PointerGetDatum(src_text), + data_pos + 1, + pmatch[0].rm_so - data_pos, + false); appendStringInfoText(str, left_text); pfree(left_text); } @@ -2259,7 +2283,7 @@ replace_text_regexp(PG_FUNCTION_ARGS) /* * When global option is off, replace the first instance only. */ - if (!global) + if (!glob) break; /* @@ -2270,14 +2294,14 @@ replace_text_regexp(PG_FUNCTION_ARGS) } /* - * Copy the text when there is a text at the right of last matched or - * regexp is not matched. + * Copy the text to the right of the last match. */ if (data_pos < data_len) { - text *right_text = text_substring(PointerGetDatum(src_text), - data_pos + 1, -1, true); + text *right_text; + right_text = text_substring(PointerGetDatum(src_text), + data_pos + 1, -1, true); appendStringInfoText(str, right_text); pfree(right_text); } @@ -2287,7 +2311,7 @@ replace_text_regexp(PG_FUNCTION_ARGS) pfree(str); pfree(data); - PG_RETURN_TEXT_P(ret_text); + return ret_text; } /* |