move hex_decode() to /common so it can be called from frontend

This allows removal of a copy of hex_decode() from ecpg, and will be
used by the soon-to-be added pg_alterckey command.

Backpatch-through: master

src/backend/utils/adt/encode.c

@@ -15,6 +15,7 @@
 
 #include <ctype.h>
 
+#include "common/hex_decode.h"
 #include "mb/pg_wchar.h"
 #include "utils/builtins.h"
 #include "utils/memutils.h"
@@ -146,17 +147,6 @@ binary_decode(PG_FUNCTION_ARGS)
 
 static const char hextbl[] = "0123456789abcdef";
 
-static const int8 hexlookup[128] = {
-	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
-	-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-	-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-};
-
 uint64
 hex_encode(const char *src, size_t len, char *dst)
 {
@@ -171,58 +161,6 @@ hex_encode(const char *src, size_t len, char *dst)
 	return (uint64) len * 2;
 }
 
-static inline char
-get_hex(const char *cp)
-{
-	unsigned char c = (unsigned char) *cp;
-	int			res = -1;
-
-	if (c < 127)
-		res = hexlookup[c];
-
-	if (res < 0)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("invalid hexadecimal digit: \"%.*s\"",
-						pg_mblen(cp), cp)));
-
-	return (char) res;
-}
-
-uint64
-hex_decode(const char *src, size_t len, char *dst)
-{
-	const char *s,
-			   *srcend;
-	char		v1,
-				v2,
-			   *p;
-
-	srcend = src + len;
-	s = src;
-	p = dst;
-	while (s < srcend)
-	{
-		if (*s == ' ' || *s == '\n' || *s == '\t' || *s == '\r')
-		{
-			s++;
-			continue;
-		}
-		v1 = get_hex(s) << 4;
-		s++;
-		if (s >= srcend)
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("invalid hexadecimal data: odd number of digits")));
-
-		v2 = get_hex(s);
-		s++;
-		*p++ = v1 | v2;
-	}
-
-	return p - dst;
-}
-
 static uint64
 hex_enc_len(const char *src, size_t srclen)
 {

src/backend/utils/adt/varlena.c

@@ -22,6 +22,7 @@
 #include "catalog/pg_type.h"
 #include "common/hashfn.h"
 #include "common/int.h"
+#include "common/hex_decode.h"
 #include "common/unicode_norm.h"
 #include "lib/hyperloglog.h"
 #include "libpq/pqformat.h"

src/common/Makefile

@@ -58,6 +58,7 @@ OBJS_COMMON = \
 	file_perm.o \
 	file_utils.o \
 	hashfn.o \
+	hex_decode.o \
 	ip.o \
 	jsonapi.o \
 	keywords.o \

src/common/hex_decode.c

@@ -0,0 +1,106 @@
+/*-------------------------------------------------------------------------
+ *
+ * hex_decode.c
+ *		hex decoding
+ *
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/hex_decode.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#ifdef FRONTEND
+#include "common/logging.h"
+#else
+#include "mb/pg_wchar.h"
+#endif
+#include "common/hex_decode.h"
+
+
+static const int8 hexlookup[128] = {
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
+	-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+};
+
+static inline char
+get_hex(const char *cp)
+{
+	unsigned char c = (unsigned char) *cp;
+	int			res = -1;
+
+	if (c < 127)
+		res = hexlookup[c];
+
+	if (res < 0)
+	{
+#ifdef FRONTEND
+		pg_log_fatal("invalid hexadecimal digit");
+		exit(EXIT_FAILURE);
+#else
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid hexadecimal digit: \"%.*s\"",
+						pg_mblen(cp), cp)));
+#endif
+	}
+
+	return (char) res;
+}
+
+uint64
+hex_decode(const char *src, size_t len, char *dst)
+{
+	const char *s,
+			   *srcend;
+	char		v1,
+				v2,
+			   *p;
+
+	srcend = src + len;
+	s = src;
+	p = dst;
+	while (s < srcend)
+	{
+		if (*s == ' ' || *s == '\n' || *s == '\t' || *s == '\r')
+		{
+			s++;
+			continue;
+		}
+		v1 = get_hex(s) << 4;
+		s++;
+		if (s >= srcend)
+		{
+#ifdef FRONTEND
+			pg_log_fatal("invalid hexadecimal data: odd number of digits");
+			exit(EXIT_FAILURE);
+#else
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("invalid hexadecimal data: odd number of digits")));
+#endif
+		}
+		v2 = get_hex(s);
+		s++;
+		*p++ = v1 | v2;
+	}
+
+	return p - dst;
+}

src/include/common/hex_decode.h

@@ -0,0 +1,16 @@
+/*
+ *	hex_decode.h
+ *		hex decoding
+ *
+ *	Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ *	Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *	src/include/common/hex_decode.h
+ */
+#ifndef COMMON_HEX_DECODE_H
+#define COMMON_HEX_DECODE_H
+
+extern uint64 hex_decode(const char *src, size_t len, char *dst);
+
+
+#endif							/* COMMON_HEX_DECODE_H */

src/include/utils/builtins.h

@@ -33,7 +33,6 @@ extern int	errdomainconstraint(Oid datatypeOid, const char *conname);
 
 /* encode.c */
 extern uint64 hex_encode(const char *src, size_t len, char *dst);
-extern uint64 hex_decode(const char *src, size_t len, char *dst);
 
 /* int.c */
 extern int2vector *buildint2vector(const int16 *int2s, int n);

src/interfaces/ecpg/ecpglib/data.c

@@ -5,6 +5,7 @@
 
 #include <math.h>
 
+#include "common/hex_decode.h"
 #include "ecpgerrno.h"
 #include "ecpglib.h"
 #include "ecpglib_extern.h"
@@ -136,57 +137,6 @@ ecpg_hex_dec_len(unsigned srclen)
 	return srclen >> 1;
 }
 
-static inline char
-get_hex(char c)
-{
-	static const int8 hexlookup[128] = {
-		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
-		-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-		-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-		-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-	};
-	int			res = -1;
-
-	if (c > 0 && c < 127)
-		res = hexlookup[(unsigned char) c];
-
-	return (char) res;
-}
-
-static unsigned
-hex_decode(const char *src, unsigned len, char *dst)
-{
-	const char *s,
-			   *srcend;
-	char		v1,
-				v2,
-			   *p;
-
-	srcend = src + len;
-	s = src;
-	p = dst;
-	while (s < srcend)
-	{
-		if (*s == ' ' || *s == '\n' || *s == '\t' || *s == '\r')
-		{
-			s++;
-			continue;
-		}
-		v1 = get_hex(*s++) << 4;
-		if (s >= srcend)
-			return -1;
-
-		v2 = get_hex(*s++);
-		*p++ = v1 | v2;
-	}
-
-	return p - dst;
-}
-
 unsigned
 ecpg_hex_encode(const char *src, unsigned len, char *dst)
 {

src/tools/msvc/Mkvcbuild.pm

@@ -121,7 +121,7 @@ sub mkvcbuild
 	our @pgcommonallfiles = qw(
 	  archive.c base64.c checksum_helper.c
 	  config_info.c controldata_utils.c d2s.c encnames.c exec.c
-	  f2s.c file_perm.c file_utils.c hashfn.c ip.c jsonapi.c
+	  f2s.c file_perm.c file_utils.c hashfn.c hex_decode.c ip.c jsonapi.c
 	  keywords.c kwlookup.c link-canary.c md5_common.c
 	  pg_get_line.c pg_lzcompress.c pgfnames.c psprintf.c relpath.c rmtree.c
 	  saslprep.c scram-common.c string.c stringinfo.c unicode_norm.c username.c