Allow direct conversion between EUC_JP and SJIS to improve

performance. patches submitted by Atsushi Ogawa.

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

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c,v 1.10 2005/06/10 16:43:56 ishii Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/mb/conversion_procs/euc_jp_and_sjis/euc_jp_and_sjis.c,v 1.11 2005/06/24 13:56:39 ishii Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -58,6 +58,8 @@ static void sjis2mic(unsigned char *sjis, unsigned char *p, int len);
 static void mic2sjis(unsigned char *mic, unsigned char *p, int len);
 static void euc_jp2mic(unsigned char *euc, unsigned char *p, int len);
 static void mic2euc_jp(unsigned char *mic, unsigned char *p, int len);
+static void euc_jp2sjis(unsigned char *mic, unsigned char *p, int len);
+static void sjis2euc_jp(unsigned char *mic, unsigned char *p, int len);
 
 Datum
 euc_jp_to_sjis(PG_FUNCTION_ARGS)
@@ -65,16 +67,12 @@ euc_jp_to_sjis(PG_FUNCTION_ARGS)
 	unsigned char *src = PG_GETARG_CSTRING(2);
 	unsigned char *dest = PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
-	unsigned char *buf;
 
 	Assert(PG_GETARG_INT32(0) == PG_EUC_JP);
 	Assert(PG_GETARG_INT32(1) == PG_SJIS);
 	Assert(len >= 0);
 
-	buf = palloc(len * ENCODING_GROWTH_RATE);
+	euc_jp2sjis(src, dest, len);
-	euc_jp2mic(src, buf, len);
-	mic2sjis(buf, dest, strlen(buf));
-	pfree(buf);
 
 	PG_RETURN_VOID();
 }
@@ -85,16 +83,12 @@ sjis_to_euc_jp(PG_FUNCTION_ARGS)
 	unsigned char *src = PG_GETARG_CSTRING(2);
 	unsigned char *dest = PG_GETARG_CSTRING(3);
 	int			len = PG_GETARG_INT32(4);
-	unsigned char *buf;
 
 	Assert(PG_GETARG_INT32(0) == PG_SJIS);
 	Assert(PG_GETARG_INT32(1) == PG_EUC_JP);
 	Assert(len >= 0);
 
-	buf = palloc(len * ENCODING_GROWTH_RATE);
+	sjis2euc_jp(src, dest, len);
-	sjis2mic(src, buf, len);
-	mic2euc_jp(buf, dest, strlen(buf));
-	pfree(buf);
 
 	PG_RETURN_VOID();
 }
@@ -454,3 +448,199 @@ mic2euc_jp(unsigned char *mic, unsigned char *p, int len)
 	}
 	*p = '\0';
 }
+
+/*
+ * EUC_JP -> SJIS
+ */
+static void
+euc_jp2sjis(unsigned char *euc, unsigned char *p, int len)
+{
+	int			c1,
+				c2,
+				k;
+	unsigned char *euc_end = euc + len;
+
+	while (euc_end >= euc && (c1 = *euc++))
+	{
+		if(c1 < 0x80)
+		{
+			/* should be ASCII */
+			*p++ = c1;
+		}
+		else if (c1 == SS2)
+		{
+			/* hankaku kana? */
+			*p++ = *euc++;
+		}
+		else if (c1 == SS3)
+		{
+			/* JIS X0212 kanji? */
+			c1 = *euc++;
+			c2 = *euc++;
+			k = c1 << 8 | c2;
+			if (k >= 0xf5a1)
+			{
+				/* UDC2 */
+				c1 -= 0x54;
+				*p++ = ((c1 - 0xa1) >> 1) + ((c1 < 0xdf) ? 0x81 : 0xc1) + 0x74;
+				*p++ = c2 - ((c1 & 1) ? ((c2 < 0xe0) ? 0x61 : 0x60) : 2);
+			}
+			else
+			{
+				int			i, k2;
+
+				/* IBM kanji */
+				for (i = 0;; i++)
+				{
+					k2 = ibmkanji[i].euc & 0xffff;
+					if (k2 == 0xffff)
+					{
+						*p++ = PGSJISALTCODE >> 8;
+						*p++ = PGSJISALTCODE & 0xff;
+						break;
+					}
+					if (k2 == k)
+					{
+						k = ibmkanji[i].sjis;
+						*p++ = k >> 8;
+						*p++ = k & 0xff;
+						break;
+					}
+				}
+			}
+		} 
+		else
+		{	
+			/* JIS X0208 kanji? */
+			c2 = *euc++;
+			k = (c1 << 8) | (c2 & 0xff);
+			if (k >= 0xf5a1)
+			{
+				/* UDC1 */
+				c1 -= 0x54;
+				*p++ = ((c1 - 0xa1) >> 1) + ((c1 < 0xdf) ? 0x81 : 0xc1) + 0x6f;
+			}
+			else
+				*p++ = ((c1 - 0xa1) >> 1) + ((c1 < 0xdf) ? 0x81 : 0xc1);
+			*p++ = c2 - ((c1 & 1) ? ((c2 < 0xe0) ? 0x61 : 0x60) : 2);
+		}
+	}
+	*p = '\0';
+}
+
+/*
+ * SJIS ---> EUC_JP
+ */
+static void
+sjis2euc_jp(unsigned char *sjis, unsigned char *p, int len)
+{
+	int			c1,
+				c2,
+				i,
+				k,
+				k2;
+	unsigned char *sjis_end = sjis + len;
+
+	while (sjis_end >= sjis && (c1 = *sjis++))
+	{
+		if(c1 < 0x80)
+		{
+			/* should be ASCII */
+			*p++ = c1;
+		}
+		else if (c1 >= 0xa1 && c1 <= 0xdf)
+		{
+			/* JIS X0201 (1 byte kana) */
+			*p++ = SS2;
+			*p++ = c1;
+		}
+		else
+		{
+			/*
+			 * JIS X0208, X0212, user defined extended characters
+			 */
+			c2 = *sjis++;
+			k = (c1 << 8) + c2;
+			if (k >= 0xed40 && k < 0xf040)
+			{
+				/* NEC selection IBM kanji */
+				for (i = 0;; i++)
+				{
+					k2 = ibmkanji[i].nec;
+					if (k2 == 0xffff)
+						break;
+					if (k2 == k)
+					{
+						k = ibmkanji[i].sjis;
+						c1 = (k >> 8) & 0xff;
+						c2 = k & 0xff;
+					}
+				}
+			}
+
+			if (k < 0xeb3f)
+			{
+				/* JIS X0208 */
+				*p++ = ((c1 & 0x3f) << 1) + 0x9f + (c2 > 0x9e);
+				*p++ = c2 + ((c2 > 0x9e) ? 2 : 0x60) + (c2 < 0x80);
+			}
+			else if ((k >= 0xeb40 && k < 0xf040) || (k >= 0xfc4c && k <= 0xfcfc))
+			{
+				/* NEC selection IBM kanji - Other undecided justice */
+				*p++ = PGEUCALTCODE >> 8;
+				*p++ = PGEUCALTCODE & 0xff;
+			}
+			else if (k >= 0xf040 && k < 0xf540)
+			{
+				/*
+				 * UDC1 mapping to X0208 85 ku - 94 ku JIS code 0x7521 -
+				 * 0x7e7e EUC 0xf5a1 - 0xfefe
+				 */
+				c1 -= 0x6f;
+				*p++ = ((c1 & 0x3f) << 1) + 0xf3 + (c2 > 0x9e);
+				*p++ = c2 + ((c2 > 0x9e) ? 2 : 0x60) + (c2 < 0x80);
+			}
+			else if (k >= 0xf540 && k < 0xfa40)
+			{
+				/*
+				 * UDC2 mapping to X0212 85 ku - 94 ku JIS code 0x7521 -
+				 * 0x7e7e EUC 0x8ff5a1 - 0x8ffefe
+				 */
+				*p++ = SS3;
+				c1 -= 0x74;
+				*p++ = ((c1 & 0x3f) << 1) + 0xf3 + (c2 > 0x9e);
+				*p++ = c2 + ((c2 > 0x9e) ? 2 : 0x60) + (c2 < 0x80);
+			}
+			else if (k >= 0xfa40)
+			{
+				/*
+				 * mapping IBM kanji to X0208 and X0212
+				 *
+				 */
+				for (i = 0;; i++)
+				{
+					k2 = ibmkanji[i].sjis;
+					if (k2 == 0xffff)
+						break;
+					if (k2 == k)
+					{
+						k = ibmkanji[i].euc;
+						if (k >= 0x8f0000)
+						{
+							*p++ = SS3;
+							*p++ = 0x80 | ((k & 0xff00) >> 8);
+							*p++ = 0x80 | (k & 0xff);
+						}
+						else
+						{
+							*p++ = 0x80 | (k >> 8);
+							*p++ = 0x80 | (k & 0xff);
+						}
+					}
+				}
+			}
+		}
+	}
+	*p = '\0';
+}
+