Added another single byte oriented decompressor, useful for

comparision functions.

Added all lztext comparision functions, operators and a default
operator class for nbtree on lztext.

Jan

src/backend/utils/adt/lztext.c

 /* ----------
  * lztext.c -
  *
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/lztext.c,v 1.3 1999/11/24 03:45:12 ishii Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/lztext.c,v 1.4 1999/11/25 01:28:04 wieck Exp $
  *
  *	Text type with internal LZ compressed representation. Uses the
  *	standard PostgreSQL compression method.
@@ -290,3 +290,146 @@ lztext_text(lztext *lz)
 }
 
 
+/* ----------
+ * lztext_cmp -
+ *
+ *		Comparision function for two lztext datum's.
+ *
+ *		Returns -1, 0 or 1.
+ * ----------
+ */
+int32
+lztext_cmp(lztext *lz1, lztext *lz2)
+{
+#ifdef USE_LOCALE
+
+	char   *cp1;
+	char   *cp2;
+	int		result;
+
+	if (lz1 == NULL || lz2 == NULL)
+		return (int32)0;
+
+	cp1 = lztextout(lz1);
+	cp2 = lztextout(lz2);
+
+	result = strcoll(cp1, cp2);
+
+	pfree(cp1);
+	pfree(cp2);
+
+	return result;
+
+#else /* !USE_LOCALE */
+
+	PGLZ_DecompState	ds1;
+	PGLZ_DecompState	ds2;
+	int					c1;
+	int					c2;
+	int32				result = (int32)0;
+
+	if (lz1 == NULL || lz2 == NULL)
+		return (int32)0;
+
+	pglz_decomp_init(&ds1, lz1);
+	pglz_decomp_init(&ds2, lz2);
+
+	for(;;)
+	{
+		c1 = pglz_decomp_getchar(&ds1);
+		c2 = pglz_decomp_getchar(&ds2);
+
+		if (c1 == EOF)
+		{
+			if (c2 != EOF)
+				result = (int32)-1;
+			break;
+		} else {
+			if (c2 == EOF)
+			{
+				result = (int32)1;
+			}
+		}
+		if (c1 != c2)
+		{
+			result = (int32)(c1 - c2);
+			break;
+		}
+	}
+
+	pglz_decomp_end(&ds1);
+	pglz_decomp_end(&ds2);
+
+	return result;
+
+#endif /* USE_LOCALE */
+}
+
+
+/* ----------
+ * lztext_eq ... -
+ *
+ *		=, !=, >, >=, < and <= operator functions for two
+ *		lztext datums.
+ * ----------
+ */
+bool
+lztext_eq(lztext *lz1, lztext *lz2)
+{
+	if (lz1 == NULL || lz2 == NULL)
+		return false;
+
+	return (bool)(lztext_cmp(lz1, lz2) == 0);
+}
+
+
+bool
+lztext_ne(lztext *lz1, lztext *lz2)
+{
+	if (lz1 == NULL || lz2 == NULL)
+		return false;
+
+	return (bool)(lztext_cmp(lz1, lz2) != 0);
+}
+
+
+bool
+lztext_gt(lztext *lz1, lztext *lz2)
+{
+	if (lz1 == NULL || lz2 == NULL)
+		return false;
+
+	return (bool)(lztext_cmp(lz1, lz2) > 0);
+}
+
+
+bool
+lztext_ge(lztext *lz1, lztext *lz2)
+{
+	if (lz1 == NULL || lz2 == NULL)
+		return false;
+
+	return (bool)(lztext_cmp(lz1, lz2) >= 0);
+}
+
+
+bool
+lztext_lt(lztext *lz1, lztext *lz2)
+{
+	if (lz1 == NULL || lz2 == NULL)
+		return false;
+
+	return (bool)(lztext_cmp(lz1, lz2) < 0);
+}
+
+
+bool
+lztext_le(lztext *lz1, lztext *lz2)
+{
+	if (lz1 == NULL || lz2 == NULL)
+		return false;
+
+	return (bool)(lztext_cmp(lz1, lz2) <= 0);
+}
+
+

src/backend/utils/adt/pg_lzcompress.c

 /* ----------
  * pg_lzcompress.c -
  *
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/pg_lzcompress.c,v 1.2 1999/11/17 22:18:45 wieck Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/pg_lzcompress.c,v 1.3 1999/11/25 01:28:04 wieck Exp $
  *
  *		This is an implementation of LZ compression for PostgreSQL.
  *		It uses a simple history table and generates 2-3 byte tags
@@ -671,3 +671,167 @@ pglz_decompress (PGLZ_Header *source, char *dest)
 }
 
 
+/* ----------
+ * pglz_get_next_decomp_char_from_lzdata -
+ *
+ *		Reads the next character from a decompression state if the
+ *		input data to pglz_decomp_init() was in compressed format.
+ * ----------
+ */
+int
+pglz_get_next_decomp_char_from_lzdata(PGLZ_DecompState *dstate)
+{
+	unsigned char		retval;
+
+	if (dstate->tocopy > 0)
+	{
+		/* ----------
+		 * Copy one byte from output to output until we did it
+		 * for the length specified by the last tag. Return that
+		 * byte.
+		 * ----------
+		 */
+		dstate->tocopy--;
+		return (*(dstate->cp_out++) = *(dstate->cp_copy++));
+	}
+
+	if (dstate->ctrl_count == 0)
+	{
+		/* ----------
+		 * Get the next control byte if we need to, but check
+		 * for EOF before.
+		 * ----------
+		 */
+		if (dstate->cp_in == dstate->cp_end)
+		{
+			return EOF;
+		}
+
+		/* ----------
+		 * This decompression method saves time only, if we stop near
+		 * the beginning of the data (maybe because we're called by a
+		 * comparision function and a difference occurs early). Otherwise,
+		 * all the checks, needed here, cause too much overhead.
+		 *
+		 * Thus we decompress the entire rest at once into the temporary
+		 * buffer and change the decomp state to return the prepared
+		 * data from the buffer by the more simple calls to
+		 * pglz_get_next_decomp_char_from_plain().
+		 * ----------
+		 */
+		if (dstate->cp_out - dstate->temp_buf >= 256)
+		{
+			unsigned char	   *cp_in		= dstate->cp_in;
+			unsigned char	   *cp_out		= dstate->cp_out;
+			unsigned char	   *cp_end		= dstate->cp_end;
+			unsigned char	   *cp_copy;
+			unsigned char		ctrl;
+			int					off;
+			int					len;
+			int					i;
+
+			while (cp_in < cp_end)
+			{
+				ctrl = *cp_in++;
+
+				for (i = 0; i < 8; i++)
+				{
+					if (cp_in == cp_end)
+						break;
+
+					if (ctrl & 0x01)
+					{
+						len = (cp_in[0] & 0x0f) + 3;
+						off = ((cp_in[0] & 0xf0) << 4) | cp_in[1];
+						cp_in += 2;
+						if (len == 18)
+							len += *cp_in++;
+
+						cp_copy = cp_out - off;
+						while(len--)
+							*cp_out++ = *cp_copy++;
+					} else {
+						*cp_out++ = *cp_in++;
+					}
+					ctrl >>= 1;
+				}
+			}
+
+			dstate->cp_in		= dstate->cp_out;
+			dstate->cp_end		= cp_out;
+			dstate->next_char	= pglz_get_next_decomp_char_from_plain;
+
+			return (int)(*(dstate->cp_in++));
+		}
+
+		/* ----------
+		 * Not yet, get next control byte into decomp state.
+		 * ----------
+		 */
+		dstate->ctrl = (unsigned char)(*(dstate->cp_in++));
+		dstate->ctrl_count = 8;
+	}
+
+	/* ----------
+	 * Check for EOF in tag/literal byte data.
+	 * ----------
+	 */
+	if (dstate->cp_in == dstate->cp_end)
+	{
+		return EOF;
+	}
+
+	/* ----------
+	 * Handle next control bit.
+	 * ----------
+	 */
+	dstate->ctrl_count--;
+	if (dstate->ctrl & 0x01)
+	{
+		/* ----------
+		 * Bit is set, so tag is following. Setup copy information
+		 * and do the copy for the first byte as above.
+		 * ----------
+		 */
+		int		off;
+
+		dstate->tocopy	= (dstate->cp_in[0] & 0x0f) + 3;
+		off				= ((dstate->cp_in[0] & 0xf0) << 4) | dstate->cp_in[1];
+		dstate->cp_in	+= 2;
+		if (dstate->tocopy == 18)
+			dstate->tocopy += *(dstate->cp_in++);
+		dstate->cp_copy = dstate->cp_out - off;
+
+		dstate->tocopy--;
+		retval = (*(dstate->cp_out++) = *(dstate->cp_copy++));
+	} else {
+		/* ----------
+		 * Bit is unset, so literal byte follows.
+		 * ----------
+		 */
+		retval = (int)(*(dstate->cp_out++) = *(dstate->cp_in++));
+	}
+	dstate->ctrl >>= 1;
+
+	return (int)retval;
+}
+
+
+/* ----------
+ * pglz_get_next_decomp_char_from_plain -
+ *
+ *		The input data to pglz_decomp_init() was stored in uncompressed
+ *		format. So we don't have a temporary output buffer and simply
+ *		return bytes from the input until EOF.
+ * ----------
+ */
+int
+pglz_get_next_decomp_char_from_plain(PGLZ_DecompState *dstate)
+{
+	if (dstate->cp_in >= dstate->cp_end)
+		return EOF;
+
+	return (int)(*(dstate->cp_in++));
+}
+
+

src/include/catalog/pg_amop.h

@@ -7,7 +7,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_amop.h,v 1.24 1999/09/29 21:13:30 wieck Exp $
+ * $Id: pg_amop.h,v 1.25 1999/11/25 01:28:05 wieck Exp $
  *
  * NOTES
  *	 the genbki.sh script reads this file and generates .bki
@@ -348,6 +348,16 @@ DATA(insert OID = 0 (  403 1768 1752 3 btreesel btreenpage ));
 DATA(insert OID = 0 (  403 1768 1757 4 btreesel btreenpage ));
 DATA(insert OID = 0 (  403 1768 1756 5 btreesel btreenpage ));
 
+/*
+ *	nbtree lztext
+ */
+
+DATA(insert OID = 0 (  403 1663 1659 1 btreesel btreenpage ));
+DATA(insert OID = 0 (  403 1663 1660 2 btreesel btreenpage ));
+DATA(insert OID = 0 (  403 1663 1657 3 btreesel btreenpage ));
+DATA(insert OID = 0 (  403 1663 1662 4 btreesel btreenpage ));
+DATA(insert OID = 0 (  403 1663 1661 5 btreesel btreenpage ));
+
 /*
  *	hash table _ops
  */

src/include/catalog/pg_amproc.h

@@ -9,7 +9,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_amproc.h,v 1.15 1999/09/29 21:13:30 wieck Exp $
+ * $Id: pg_amproc.h,v 1.16 1999/11/25 01:28:05 wieck Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -97,6 +97,7 @@ DATA(insert OID = 0 (403 1313 1315 1));
 DATA(insert OID = 0 (403 810 836 1));
 DATA(insert OID = 0 (403 935 926 1));
 DATA(insert OID = 0 (403 1768 1769 1));
+DATA(insert OID = 0 (403 1663 1636 1));
 
 
 /* hash */

src/include/catalog/pg_opclass.h

@@ -7,7 +7,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_opclass.h,v 1.22 1999/11/23 04:47:39 momjian Exp $
+ * $Id: pg_opclass.h,v 1.23 1999/11/25 01:28:05 wieck Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -117,5 +117,7 @@ DATA(insert OID = 652  (	cidr_ops        650	  ));
 DESCR("");
 DATA(insert OID = 1768 (	numeric_ops    1700	  ));
 DESCR("");
+DATA(insert OID = 1663 (	lztext_ops    1625	));
+DESCR("");
 
 #endif	 /* PG_OPCLASS_H */

src/include/catalog/pg_operator.h

@@ -7,7 +7,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_operator.h,v 1.61 1999/11/22 17:56:37 momjian Exp $
+ * $Id: pg_operator.h,v 1.62 1999/11/25 01:28:05 wieck Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -687,6 +687,14 @@ DATA(insert OID = 1761 (  "/"	   PGUID 0 b t f 1700 1700 1700    0	0 0 0 numeric
 DATA(insert OID = 1762 (  "%"	   PGUID 0 b t f 1700 1700 1700    0	0 0 0 numeric_mod - - ));
 DATA(insert OID = 1763 (  "@"	   PGUID 0 l t f	0 1700 1700    0	0 0 0 numeric_abs - - ));
 
+/* LZTEXT type */
+DATA(insert OID = 1657 (  "="	   PGUID 0 b t f 1625 1625	 16 1657 1658 1659 1659 lztext_eq eqsel eqjoinsel ));
+DATA(insert OID = 1658 (  "<>"	   PGUID 0 b t f 1625 1625	 16 1658 1657 0 0 lztext_ne neqsel neqjoinsel ));
+DATA(insert OID = 1659 (  "<"	   PGUID 0 b t f 1625 1625	 16 1661 1662 0 0 lztext_lt intltsel intltjoinsel ));
+DATA(insert OID = 1660 (  "<="	   PGUID 0 b t f 1625 1625	 16 1662 1661 0 0 lztext_le intltsel intltjoinsel ));
+DATA(insert OID = 1661 (  ">"	   PGUID 0 b t f 1625 1625	 16 1659 1660 0 0 lztext_gt intgtsel intgtjoinsel ));
+DATA(insert OID = 1662 (  ">="	   PGUID 0 b t f 1625 1625	 16 1660 1659 0 0 lztext_ge intgtsel intgtjoinsel ));
+
 
 
 /*

src/include/catalog/pg_proc.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_proc.h,v 1.106 1999/11/17 21:21:50 wieck Exp $
+ * $Id: pg_proc.h,v 1.107 1999/11/25 01:28:05 wieck Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -2359,6 +2359,20 @@ DATA(insert OID = 1634 ( lztextoctetlen	   		PGUID 11 f t t 1 f 23 "1625" 100 0
 DESCR("octet length");
 DATA(insert OID = 1635 ( octet_length	   		PGUID 11 f t t 1 f 23 "1625" 100 0 1 0  lztextoctetlen - ));
 DESCR("octet length");
+DATA(insert OID = 1636 ( lztext_cmp	   			PGUID 11 f t t 2 f 23 "1625 1625" 100 0 1 0  lztext_cmp - ));
+DESCR("compare lztext vs. lztext");
+DATA(insert OID = 1637 ( lztext_eq	   			PGUID 11 f t t 2 f 16 "1625 1625" 100 0 1 0  lztext_eq - ));
+DESCR("equal");
+DATA(insert OID = 1638 ( lztext_ne	   			PGUID 11 f t t 2 f 16 "1625 1625" 100 0 1 0  lztext_ne - ));
+DESCR("not equal");
+DATA(insert OID = 1639 ( lztext_gt	   			PGUID 11 f t t 2 f 16 "1625 1625" 100 0 1 0  lztext_gt - ));
+DESCR("greater-than");
+DATA(insert OID = 1654 ( lztext_ge	   			PGUID 11 f t t 2 f 16 "1625 1625" 100 0 1 0  lztext_ge - ));
+DESCR("greater-than-or-equal");
+DATA(insert OID = 1655 ( lztext_lt	   			PGUID 11 f t t 2 f 16 "1625 1625" 100 0 1 0  lztext_lt - ));
+DESCR("lower-than");
+DATA(insert OID = 1656 ( lztext_le	   			PGUID 11 f t t 2 f 16 "1625 1625" 100 0 1 0  lztext_le - ));
+DESCR("lower-than-or-equal");
 
 
 /*

src/include/utils/builtins.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: builtins.h,v 1.90 1999/11/17 21:21:51 wieck Exp $
+ * $Id: builtins.h,v 1.91 1999/11/25 01:28:07 wieck Exp $
  *
  * NOTES
  *	  This should normally only be included by fmgr.h.
@@ -635,5 +635,12 @@ text	   *lztext_text(lztext *lz);
 lztext	   *text_lztext(text *txt);
 int32		lztextlen(lztext *lz);
 int32		lztextoctetlen(lztext *lz);
+int32		lztext_cmp(lztext *lz1, lztext *lz2);
+bool		lztext_eq(lztext *lz1, lztext *lz2);
+bool		lztext_ne(lztext *lz1, lztext *lz2);
+bool		lztext_gt(lztext *lz1, lztext *lz2);
+bool		lztext_ge(lztext *lz1, lztext *lz2);
+bool		lztext_lt(lztext *lz1, lztext *lz2);
+bool		lztext_le(lztext *lz1, lztext *lz2);
 
 #endif	 /* BUILTINS_H */

src/include/utils/pg_lzcompress.h

 /* ----------
  * pg_lzcompress.h -
  *
- * $Header: /cvsroot/pgsql/src/include/utils/pg_lzcompress.h,v 1.2 1999/11/17 22:18:46 wieck Exp $
+ * $Header: /cvsroot/pgsql/src/include/utils/pg_lzcompress.h,v 1.3 1999/11/25 01:28:07 wieck Exp $
  *
  *	Definitions for the builtin LZ compressor
  * ----------
@@ -110,6 +110,26 @@ typedef struct PGLZ_Strategy {
 } PGLZ_Strategy;
 
 
+/* ----------
+ * PGLZ_DecompState -
+ *
+ *		Decompression state variable for byte-per-byte decompression
+ *		using pglz_decomp_getchar() macro.
+ * ----------
+ */
+typedef struct PGLZ_DecompState {
+	unsigned char	   *temp_buf;
+	unsigned char	   *cp_in;
+	unsigned char	   *cp_end;
+	unsigned char	   *cp_out;
+	unsigned char	   *cp_copy;
+	int					(*next_char)(struct PGLZ_DecompState *dstate);
+	int					tocopy;
+	int					ctrl_count;
+	unsigned char		ctrl;
+} PGLZ_DecompState;
+
+
 /* ----------
  * The standard strategies
  *
@@ -139,6 +159,55 @@ extern PGLZ_Strategy	*PGLZ_strategy_allways;
 extern PGLZ_Strategy	*PGLZ_strategy_never;
 
 
+/* ----------
+ * pglz_decomp_getchar -
+ *
+ *		Get next character (or EOF) from decompressor.
+ *		The status variable must be initialized before and deinitialized
+ *		after compression with the next two macros below.
+ * ----------
+ */
+#define pglz_decomp_getchar(_ds)											\
+	((*((_ds)->next_char))((_ds)))
+
+
+/* ----------
+ * pglz_decomp_init -
+ *
+ *		Initialize a decomp state from a compressed input.
+ * ----------
+ */
+#define pglz_decomp_init(_ds,_lz) {											\
+		(_ds)->cp_in		= ((unsigned char *)(_lz)) 						\
+											+ sizeof(PGLZ_Header);			\
+		(_ds)->cp_end		= (_ds)->cp_in + (_lz)->varsize 				\
+											- sizeof(PGLZ_Header);			\
+		if (PGLZ_IS_COMPRESSED((_lz))) {									\
+			(_ds)->temp_buf		= (unsigned char *)							\
+										palloc(PGLZ_RAW_SIZE((_lz)));		\
+			(_ds)->cp_out		= (_ds)->temp_buf;							\
+			(_ds)->next_char	= pglz_get_next_decomp_char_from_lzdata;	\
+			(_ds)->tocopy		= 0;										\
+			(_ds)->ctrl_count	= 0;										\
+		} else {															\
+			(_ds)->temp_buf		= NULL;										\
+			(_ds)->next_char	= pglz_get_next_decomp_char_from_plain;		\
+		}																	\
+	}
+
+
+/* ----------
+ * pglz_decomp_end -
+ *
+ *		Deallocate resources after decompression.
+ * ----------
+ */
+#define pglz_decomp_end(_ds) {												\
+		if ((_ds)->temp_buf != NULL)										\
+			pfree((void *)((_ds)->temp_buf));								\
+	}
+
+
 /* ----------
  * Global function declarations
  * ----------
@@ -148,5 +217,13 @@ int	pglz_compress (char *source, int32 slen, PGLZ_Header *dest,
 int pglz_decompress (PGLZ_Header *source, char *dest);
 
 
+/* ----------
+ * Functions used by pglz_decomp_getchar().
+ * Internal use only.
+ * ----------
+ */
+extern int pglz_get_next_decomp_char_from_lzdata(PGLZ_DecompState *dstate);
+extern int pglz_get_next_decomp_char_from_plain(PGLZ_DecompState *dstate);
+
 #endif /* _PG_LZCOMPRESS_H_ */