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-rw-r--r--src/backend/utils/adt/quote.c131
1 files changed, 131 insertions, 0 deletions
diff --git a/src/backend/utils/adt/quote.c b/src/backend/utils/adt/quote.c
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+++ b/src/backend/utils/adt/quote.c
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+/*-------------------------------------------------------------------------
+ *
+ * quote.c
+ * Functions for quoting identifiers and literals
+ *
+ * Portions Copyright (c) 2000-2021, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/utils/adt/quote.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "utils/builtins.h"
+
+
+/*
+ * quote_ident -
+ * returns a properly quoted identifier
+ */
+Datum
+quote_ident(PG_FUNCTION_ARGS)
+{
+ text *t = PG_GETARG_TEXT_PP(0);
+ const char *qstr;
+ char *str;
+
+ str = text_to_cstring(t);
+ qstr = quote_identifier(str);
+ PG_RETURN_TEXT_P(cstring_to_text(qstr));
+}
+
+/*
+ * quote_literal_internal -
+ * helper function for quote_literal and quote_literal_cstr
+ *
+ * NOTE: think not to make this function's behavior change with
+ * standard_conforming_strings. We don't know where the result
+ * literal will be used, and so we must generate a result that
+ * will work with either setting. Take a look at what dblink
+ * uses this for before thinking you know better.
+ */
+static size_t
+quote_literal_internal(char *dst, const char *src, size_t len)
+{
+ const char *s;
+ char *savedst = dst;
+
+ for (s = src; s < src + len; s++)
+ {
+ if (*s == '\\')
+ {
+ *dst++ = ESCAPE_STRING_SYNTAX;
+ break;
+ }
+ }
+
+ *dst++ = '\'';
+ while (len-- > 0)
+ {
+ if (SQL_STR_DOUBLE(*src, true))
+ *dst++ = *src;
+ *dst++ = *src++;
+ }
+ *dst++ = '\'';
+
+ return dst - savedst;
+}
+
+/*
+ * quote_literal -
+ * returns a properly quoted literal
+ */
+Datum
+quote_literal(PG_FUNCTION_ARGS)
+{
+ text *t = PG_GETARG_TEXT_PP(0);
+ text *result;
+ char *cp1;
+ char *cp2;
+ int len;
+
+ len = VARSIZE_ANY_EXHDR(t);
+ /* We make a worst-case result area; wasting a little space is OK */
+ result = (text *) palloc(len * 2 + 3 + VARHDRSZ);
+
+ cp1 = VARDATA_ANY(t);
+ cp2 = VARDATA(result);
+
+ SET_VARSIZE(result, VARHDRSZ + quote_literal_internal(cp2, cp1, len));
+
+ PG_RETURN_TEXT_P(result);
+}
+
+/*
+ * quote_literal_cstr -
+ * returns a properly quoted literal
+ */
+char *
+quote_literal_cstr(const char *rawstr)
+{
+ char *result;
+ int len;
+ int newlen;
+
+ len = strlen(rawstr);
+ /* We make a worst-case result area; wasting a little space is OK */
+ result = palloc(len * 2 + 3 + 1);
+
+ newlen = quote_literal_internal(result, rawstr, len);
+ result[newlen] = '\0';
+
+ return result;
+}
+
+/*
+ * quote_nullable -
+ * Returns a properly quoted literal, with null values returned
+ * as the text string 'NULL'.
+ */
+Datum
+quote_nullable(PG_FUNCTION_ARGS)
+{
+ if (PG_ARGISNULL(0))
+ PG_RETURN_TEXT_P(cstring_to_text("NULL"));
+ else
+ PG_RETURN_DATUM(DirectFunctionCall1(quote_literal,
+ PG_GETARG_DATUM(0)));
+}