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3a0d473192
This makes almost all core code follow the policy introduced in the previous commit. Specific decisions: - Text search support functions with char* and length arguments, such as prsstart and lexize, may receive unaligned strings. I doubt maintainers of non-core text search code will notice. - Use plain VARDATA() on values detoasted or synthesized earlier in the same function. Use VARDATA_ANY() on varlenas sourced outside the function, even if they happen to always have four-byte headers. As an exception, retain the universal practice of using VARDATA() on return values of SendFunctionCall(). - Retain PG_GETARG_BYTEA_P() in pageinspect. (Page images are too large for a one-byte header, so this misses no optimization.) Sites that do not call get_page_from_raw() typically need the four-byte alignment. - For now, do not change btree_gist. Its use of four-byte headers in memory is partly entangled with storage of 4-byte headers inside GBT_VARKEY, on disk. - For now, do not change gtrgm_consistent() or gtrgm_distance(). They incorporate the varlena header into a cache, and there are multiple credible implementation strategies to consider.
132 lines
2.6 KiB
C
132 lines
2.6 KiB
C
/*-------------------------------------------------------------------------
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*
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* quote.c
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* Functions for quoting identifiers and literals
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*
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* Portions Copyright (c) 2000-2017, PostgreSQL Global Development Group
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*
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*
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* IDENTIFICATION
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* src/backend/utils/adt/quote.c
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "utils/builtins.h"
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/*
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* quote_ident -
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* returns a properly quoted identifier
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*/
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Datum
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quote_ident(PG_FUNCTION_ARGS)
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{
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text *t = PG_GETARG_TEXT_PP(0);
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const char *qstr;
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char *str;
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str = text_to_cstring(t);
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qstr = quote_identifier(str);
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PG_RETURN_TEXT_P(cstring_to_text(qstr));
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}
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/*
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* quote_literal_internal -
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* helper function for quote_literal and quote_literal_cstr
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*
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* NOTE: think not to make this function's behavior change with
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* standard_conforming_strings. We don't know where the result
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* literal will be used, and so we must generate a result that
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* will work with either setting. Take a look at what dblink
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* uses this for before thinking you know better.
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*/
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static size_t
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quote_literal_internal(char *dst, const char *src, size_t len)
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{
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const char *s;
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char *savedst = dst;
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for (s = src; s < src + len; s++)
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{
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if (*s == '\\')
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{
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*dst++ = ESCAPE_STRING_SYNTAX;
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break;
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}
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}
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*dst++ = '\'';
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while (len-- > 0)
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{
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if (SQL_STR_DOUBLE(*src, true))
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*dst++ = *src;
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*dst++ = *src++;
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}
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*dst++ = '\'';
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return dst - savedst;
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}
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/*
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* quote_literal -
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* returns a properly quoted literal
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*/
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Datum
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quote_literal(PG_FUNCTION_ARGS)
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{
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text *t = PG_GETARG_TEXT_PP(0);
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text *result;
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char *cp1;
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char *cp2;
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int len;
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len = VARSIZE_ANY_EXHDR(t);
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/* We make a worst-case result area; wasting a little space is OK */
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result = (text *) palloc(len * 2 + 3 + VARHDRSZ);
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cp1 = VARDATA_ANY(t);
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cp2 = VARDATA(result);
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SET_VARSIZE(result, VARHDRSZ + quote_literal_internal(cp2, cp1, len));
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PG_RETURN_TEXT_P(result);
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}
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/*
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* quote_literal_cstr -
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* returns a properly quoted literal
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*/
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char *
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quote_literal_cstr(const char *rawstr)
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{
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char *result;
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int len;
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int newlen;
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len = strlen(rawstr);
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/* We make a worst-case result area; wasting a little space is OK */
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result = palloc(len * 2 + 3 + 1);
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newlen = quote_literal_internal(result, rawstr, len);
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result[newlen] = '\0';
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return result;
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}
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/*
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* quote_nullable -
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* Returns a properly quoted literal, with null values returned
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* as the text string 'NULL'.
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*/
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Datum
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quote_nullable(PG_FUNCTION_ARGS)
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{
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if (PG_ARGISNULL(0))
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PG_RETURN_TEXT_P(cstring_to_text("NULL"));
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else
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PG_RETURN_DATUM(DirectFunctionCall1(quote_literal,
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PG_GETARG_DATUM(0)));
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}
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