Add mbverifystr() functions specific to each encoding.

This makes pg_verify_mbstr() function faster, by allowing more efficient
encoding-specific implementations. All the implementations included in
this commit are pretty naive, they just call the same encoding-specific
verifychar functions that were used previously, but that already gives a
performance boost because the tight character-at-a-time loop is simpler.

Reviewed-by: John Naylor
Discussion: https://www.postgresql.org/message-id/e7861509-3960-538a-9025-b75a61188e01@iki.fi

src/backend/commands/extension.c

@@ -682,7 +682,7 @@ read_extension_script_file(const ExtensionControlFile *control,
 		src_encoding = control->encoding;
 
 	/* make sure that source string is valid in the expected encoding */
-	pg_verify_mbstr_len(src_encoding, src_str, len, false);
+	(void) pg_verify_mbstr(src_encoding, src_str, len, false);
 
 	/*
 	 * Convert the encoding to the database encoding. read_whole_file

src/backend/utils/mb/conv.c

@@ -653,7 +653,7 @@ LocalToUtf(const unsigned char *iso, int len,
 			continue;
 		}
 
-		l = pg_encoding_verifymb(encoding, (const char *) iso, len);
+		l = pg_encoding_verifymbchar(encoding, (const char *) iso, len);
 		if (l < 0)
 			break;
 

src/backend/utils/mb/conversion_procs/euc2004_sjis2004/euc2004_sjis2004.c

@@ -87,7 +87,7 @@ euc_jis_20042shift_jis_2004(const unsigned char *euc, unsigned char *p, int len)
 			continue;
 		}
 
-		l = pg_encoding_verifymb(PG_EUC_JIS_2004, (const char *) euc, len);
+		l = pg_encoding_verifymbchar(PG_EUC_JIS_2004, (const char *) euc, len);
 
 		if (l < 0)
 			report_invalid_encoding(PG_EUC_JIS_2004,
@@ -238,7 +238,7 @@ shift_jis_20042euc_jis_2004(const unsigned char *sjis, unsigned char *p, int len
 			continue;
 		}
 
-		l = pg_encoding_verifymb(PG_SHIFT_JIS_2004, (const char *) sjis, len);
+		l = pg_encoding_verifymbchar(PG_SHIFT_JIS_2004, (const char *) sjis, len);
 
 		if (l < 0 || l > len)
 			report_invalid_encoding(PG_SHIFT_JIS_2004,

src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c

@@ -291,7 +291,7 @@ mic2sjis(const unsigned char *mic, unsigned char *p, int len)
 			len--;
 			continue;
 		}
-		l = pg_encoding_verifymb(PG_MULE_INTERNAL, (const char *) mic, len);
+		l = pg_encoding_verifymbchar(PG_MULE_INTERNAL, (const char *) mic, len);
 		if (l < 0)
 			report_invalid_encoding(PG_MULE_INTERNAL,
 									(const char *) mic, len);
@@ -381,7 +381,7 @@ euc_jp2mic(const unsigned char *euc, unsigned char *p, int len)
 			len--;
 			continue;
 		}
-		l = pg_encoding_verifymb(PG_EUC_JP, (const char *) euc, len);
+		l = pg_encoding_verifymbchar(PG_EUC_JP, (const char *) euc, len);
 		if (l < 0)
 			report_invalid_encoding(PG_EUC_JP,
 									(const char *) euc, len);
@@ -431,7 +431,7 @@ mic2euc_jp(const unsigned char *mic, unsigned char *p, int len)
 			len--;
 			continue;
 		}
-		l = pg_encoding_verifymb(PG_MULE_INTERNAL, (const char *) mic, len);
+		l = pg_encoding_verifymbchar(PG_MULE_INTERNAL, (const char *) mic, len);
 		if (l < 0)
 			report_invalid_encoding(PG_MULE_INTERNAL,
 									(const char *) mic, len);
@@ -485,7 +485,7 @@ euc_jp2sjis(const unsigned char *euc, unsigned char *p, int len)
 			len--;
 			continue;
 		}
-		l = pg_encoding_verifymb(PG_EUC_JP, (const char *) euc, len);
+		l = pg_encoding_verifymbchar(PG_EUC_JP, (const char *) euc, len);
 		if (l < 0)
 			report_invalid_encoding(PG_EUC_JP,
 									(const char *) euc, len);
@@ -580,7 +580,7 @@ sjis2euc_jp(const unsigned char *sjis, unsigned char *p, int len)
 			len--;
 			continue;
 		}
-		l = pg_encoding_verifymb(PG_SJIS, (const char *) sjis, len);
+		l = pg_encoding_verifymbchar(PG_SJIS, (const char *) sjis, len);
 		if (l < 0)
 			report_invalid_encoding(PG_SJIS,
 									(const char *) sjis, len);

src/backend/utils/mb/conversion_procs/euc_kr_and_mic/euc_kr_and_mic.c

@@ -76,7 +76,7 @@ euc_kr2mic(const unsigned char *euc, unsigned char *p, int len)
 		c1 = *euc;
 		if (IS_HIGHBIT_SET(c1))
 		{
-			l = pg_encoding_verifymb(PG_EUC_KR, (const char *) euc, len);
+			l = pg_encoding_verifymbchar(PG_EUC_KR, (const char *) euc, len);
 			if (l != 2)
 				report_invalid_encoding(PG_EUC_KR,
 										(const char *) euc, len);
@@ -122,7 +122,7 @@ mic2euc_kr(const unsigned char *mic, unsigned char *p, int len)
 			len--;
 			continue;
 		}
-		l = pg_encoding_verifymb(PG_MULE_INTERNAL, (const char *) mic, len);
+		l = pg_encoding_verifymbchar(PG_MULE_INTERNAL, (const char *) mic, len);
 		if (l < 0)
 			report_invalid_encoding(PG_MULE_INTERNAL,
 									(const char *) mic, len);

src/backend/utils/mb/conversion_procs/euc_tw_and_big5/euc_tw_and_big5.c

@@ -148,7 +148,7 @@ euc_tw2mic(const unsigned char *euc, unsigned char *p, int len)
 		c1 = *euc;
 		if (IS_HIGHBIT_SET(c1))
 		{
-			l = pg_encoding_verifymb(PG_EUC_TW, (const char *) euc, len);
+			l = pg_encoding_verifymbchar(PG_EUC_TW, (const char *) euc, len);
 			if (l < 0)
 				report_invalid_encoding(PG_EUC_TW,
 										(const char *) euc, len);
@@ -213,7 +213,7 @@ mic2euc_tw(const unsigned char *mic, unsigned char *p, int len)
 			len--;
 			continue;
 		}
-		l = pg_encoding_verifymb(PG_MULE_INTERNAL, (const char *) mic, len);
+		l = pg_encoding_verifymbchar(PG_MULE_INTERNAL, (const char *) mic, len);
 		if (l < 0)
 			report_invalid_encoding(PG_MULE_INTERNAL,
 									(const char *) mic, len);
@@ -272,7 +272,7 @@ big52mic(const unsigned char *big5, unsigned char *p, int len)
 			len--;
 			continue;
 		}
-		l = pg_encoding_verifymb(PG_BIG5, (const char *) big5, len);
+		l = pg_encoding_verifymbchar(PG_BIG5, (const char *) big5, len);
 		if (l < 0)
 			report_invalid_encoding(PG_BIG5,
 									(const char *) big5, len);
@@ -321,7 +321,7 @@ mic2big5(const unsigned char *mic, unsigned char *p, int len)
 			len--;
 			continue;
 		}
-		l = pg_encoding_verifymb(PG_MULE_INTERNAL, (const char *) mic, len);
+		l = pg_encoding_verifymbchar(PG_MULE_INTERNAL, (const char *) mic, len);
 		if (l < 0)
 			report_invalid_encoding(PG_MULE_INTERNAL,
 									(const char *) mic, len);

src/backend/utils/mb/mbutils.c

@@ -519,7 +519,7 @@ pg_convert(PG_FUNCTION_ARGS)
 	/* make sure that source string is valid */
 	len = VARSIZE_ANY_EXHDR(string);
 	src_str = VARDATA_ANY(string);
-	pg_verify_mbstr_len(src_encoding, src_str, len, false);
+	(void) pg_verify_mbstr(src_encoding, src_str, len, false);
 
 	/* perform conversion */
 	dest_str = (char *) pg_do_encoding_conversion((unsigned char *) unconstify(char *, src_str),
@@ -1215,10 +1215,10 @@ static bool
 pg_generic_charinc(unsigned char *charptr, int len)
 {
 	unsigned char *lastbyte = charptr + len - 1;
-	mbverifier	mbverify;
+	mbchar_verifier mbverify;
 
 	/* We can just invoke the character verifier directly. */
-	mbverify = pg_wchar_table[GetDatabaseEncoding()].mbverify;
+	mbverify = pg_wchar_table[GetDatabaseEncoding()].mbverifychar;
 
 	while (*lastbyte < (unsigned char) 255)
 	{
@@ -1445,8 +1445,7 @@ pg_database_encoding_max_length(void)
 bool
 pg_verifymbstr(const char *mbstr, int len, bool noError)
 {
-	return
-		pg_verify_mbstr_len(GetDatabaseEncoding(), mbstr, len, noError) >= 0;
+	return pg_verify_mbstr(GetDatabaseEncoding(), mbstr, len, noError);
 }
 
 /*
@@ -1456,7 +1455,18 @@ pg_verifymbstr(const char *mbstr, int len, bool noError)
 bool
 pg_verify_mbstr(int encoding, const char *mbstr, int len, bool noError)
 {
-	return pg_verify_mbstr_len(encoding, mbstr, len, noError) >= 0;
+	int			oklen;
+
+	Assert(PG_VALID_ENCODING(encoding));
+
+	oklen = pg_wchar_table[encoding].mbverifystr((const unsigned char *) mbstr, len);
+	if (oklen != len)
+	{
+		if (noError)
+			return false;
+		report_invalid_encoding(encoding, mbstr + oklen, len - oklen);
+	}
+	return true;
 }
 
 /*
@@ -1469,11 +1479,14 @@ pg_verify_mbstr(int encoding, const char *mbstr, int len, bool noError)
  * If OK, return length of string in the encoding.
  * If a problem is found, return -1 when noError is
  * true; when noError is false, ereport() a descriptive message.
+ *
+ * Note: We cannot use the faster encoding-specific mbverifystr() function
+ * here, because we need to count the number of characters in the string.
  */
 int
 pg_verify_mbstr_len(int encoding, const char *mbstr, int len, bool noError)
 {
-	mbverifier	mbverify;
+	mbchar_verifier mbverifychar;
 	int			mb_len;
 
 	Assert(PG_VALID_ENCODING(encoding));
@@ -1493,7 +1506,7 @@ pg_verify_mbstr_len(int encoding, const char *mbstr, int len, bool noError)
 	}
 
 	/* fetch function pointer just once */
-	mbverify = pg_wchar_table[encoding].mbverify;
+	mbverifychar = pg_wchar_table[encoding].mbverifychar;
 
 	mb_len = 0;
 
@@ -1516,7 +1529,7 @@ pg_verify_mbstr_len(int encoding, const char *mbstr, int len, bool noError)
 			report_invalid_encoding(encoding, mbstr, len);
 		}
 
-		l = (*mbverify) ((const unsigned char *) mbstr, len);
+		l = (*mbverifychar) ((const unsigned char *) mbstr, len);
 
 		if (l < 0)
 		{

src/include/mb/pg_wchar.h

@@ -371,7 +371,9 @@ typedef int (*mbdisplaylen_converter) (const unsigned char *mbstr);
 
 typedef bool (*mbcharacter_incrementer) (unsigned char *mbstr, int len);
 
-typedef int (*mbverifier) (const unsigned char *mbstr, int len);
+typedef int (*mbchar_verifier) (const unsigned char *mbstr, int len);
+
+typedef int (*mbstr_verifier) (const unsigned char *mbstr, int len);
 
 typedef struct
 {
@@ -381,7 +383,8 @@ typedef struct
 													 * to a multibyte */
 	mblen_converter mblen;		/* get byte length of a char */
 	mbdisplaylen_converter dsplen;	/* get display width of a char */
-	mbverifier	mbverify;		/* verify multibyte sequence */
+	mbchar_verifier mbverifychar;	/* verify multibyte character */
+	mbstr_verifier mbverifystr; /* verify multibyte string */
 	int			maxmblen;		/* max bytes for a char in this encoding */
 } pg_wchar_tbl;
 
@@ -554,7 +557,8 @@ extern int	pg_valid_server_encoding_id(int encoding);
  */
 extern int	pg_encoding_mblen(int encoding, const char *mbstr);
 extern int	pg_encoding_dsplen(int encoding, const char *mbstr);
-extern int	pg_encoding_verifymb(int encoding, const char *mbstr, int len);
+extern int	pg_encoding_verifymbchar(int encoding, const char *mbstr, int len);
+extern int	pg_encoding_verifymbstr(int encoding, const char *mbstr, int len);
 extern int	pg_encoding_max_length(int encoding);
 extern int	pg_valid_client_encoding(const char *name);
 extern int	pg_valid_server_encoding(const char *name);