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Commit79c3b71

Browse files
Jan WieckJan Wieck
Jan Wieck
authored and
Jan Wieck
committed
The new LZ compression and an lztext data type based on it.
Jan
1 parentddc3352 commit79c3b71

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8 files changed

+1123
-5
lines changed

8 files changed

+1123
-5
lines changed

‎src/backend/utils/adt/Makefile

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -4,7 +4,7 @@
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# Makefile for utils/adt
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#
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# IDENTIFICATION
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# $Header: /cvsroot/pgsql/src/backend/utils/adt/Makefile,v 1.26 1999/09/30 14:54:22 wieck Exp $
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# $Header: /cvsroot/pgsql/src/backend/utils/adt/Makefile,v 1.27 1999/11/17 21:21:50 wieck Exp $
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#
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#-------------------------------------------------------------------------
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@@ -35,7 +35,7 @@ OBJS = acl.o arrayfuncs.o arrayutils.o bool.o cash.o char.o chunk.o \
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regexp.o regproc.o ruleutils.o selfuncs.o sets.o\
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tid.o timestamp.o varchar.o varlena.o version.o\
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network.o mac.o inet_net_ntop.o inet_net_pton.o\
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ri_triggers.o
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ri_triggers.o pg_lzcompress.o lztext.o
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all: SUBSYS.o
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‎src/backend/utils/adt/lztext.c

Lines changed: 266 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,266 @@
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/* ----------
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* lztext.c -
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*
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* $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/lztext.c,v 1.1 1999/11/17 21:21:50 wieck Exp $
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*
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*Text type with internal LZ compressed representation. Uses the
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*standard PostgreSQL compression method.
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* ----------
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*/
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#include<stdio.h>
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#include<stdlib.h>
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#include<string.h>
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#include<math.h>
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#include<errno.h>
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#include"postgres.h"
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#include"utils/builtins.h"
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#include"utils/palloc.h"
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#include"utils/pg_lzcompress.h"
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/* ----------
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* lztextin -
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*
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*Input function for datatype lztext
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* ----------
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*/
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lztext*
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lztextin(char*str)
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{
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lztext*result;
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int32rawsize;
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lztext*tmp;
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inttmp_size;
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/* ----------
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* Handle NULL
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* ----------
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*/
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if (str==NULL)
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returnNULL;
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/* ----------
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* Determine input size and eventually tuple size
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* ----------
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*/
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rawsize=strlen(str);
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tmp_size=PGLZ_MAX_OUTPUT(rawsize);
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/* ----------
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* Allocate a temporary result and compress into it
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* ----------
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*/
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tmp= (lztext*)palloc(tmp_size);
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pglz_compress(str,rawsize,tmp,NULL);
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/* ----------
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* If we miss less than x% bytes at the end of the temp value,
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* so be it. Therefore we save a memcpy().
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* ----------
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*/
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if (tmp_size-tmp->varsize<256||
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tmp_size-tmp->varsize<tmp_size /4)
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{
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result=tmp;
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}else {
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result= (lztext*)palloc(tmp->varsize);
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memcpy(result,tmp,tmp->varsize);
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pfree(tmp);
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}
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returnresult;
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}
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/* ----------
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* lztextout -
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*
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*Output function for data type lztext
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* ----------
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*/
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char*
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lztextout(lztext*lz)
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{
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char*result;
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/* ----------
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* Handle NULL
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* ----------
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*/
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if (lz==NULL)
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{
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result= (char*)palloc(2);
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result[0]='-';
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result[1]='\0';
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returnresult;
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}
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/* ----------
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* Allocate the result string - the required size is remembered
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* in the lztext header so we don't need a temporary buffer or
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* have to diddle with realloc's.
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* ----------
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*/
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result= (char*)palloc(PGLZ_RAW_SIZE(lz)+1);
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/* ----------
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* Decompress and add terminating ZERO
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* ----------
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*/
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pglz_decompress(lz,result);
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result[lz->rawsize]='\0';
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/* ----------
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* Return the result
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* ----------
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*/
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returnresult;
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}
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/* ----------
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* lztextlen -
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*
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*Logical length of lztext field (it's the uncompressed size
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*of the original data).
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* ----------
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*/
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int32
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lztextlen(lztext*lz)
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{
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/* ----------
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* Handle NULL
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* ----------
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*/
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if (lz==NULL)
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return0;
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/* ----------
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* without multibyte support, it's the remembered rawsize
142+
* ----------
143+
*/
144+
returnlz->rawsize;
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}
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/* ----------
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* lztextoctetlen -
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*
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*Physical length of lztext field (it's the compressed size
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*plus the rawsize field).
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* ----------
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*/
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int32
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lztextoctetlen(lztext*lz)
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{
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/* ----------
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* Handle NULL
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* ----------
161+
*/
162+
if (lz==NULL)
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return0;
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/* ----------
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* Return the varsize minus the VARSIZE field itself.
167+
* ----------
168+
*/
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returnlz->varsize-sizeof(int32);
170+
}
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/* ----------
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* text_lztext -
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*
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*Convert text to lztext
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* ----------
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*/
179+
lztext*
180+
text_lztext(text*txt)
181+
{
182+
lztext*result;
183+
int32rawsize;
184+
lztext*tmp;
185+
inttmp_size;
186+
char*str;
187+
188+
/* ----------
189+
* Handle NULL
190+
* ----------
191+
*/
192+
if (txt==NULL)
193+
returnNULL;
194+
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/* ----------
196+
* Determine input size and eventually tuple size
197+
* ----------
198+
*/
199+
rawsize=VARSIZE(txt)-VARHDRSZ;
200+
str=VARDATA(txt);
201+
tmp_size=PGLZ_MAX_OUTPUT(rawsize);
202+
203+
/* ----------
204+
* Allocate a temporary result and compress into it
205+
* ----------
206+
*/
207+
tmp= (lztext*)palloc(tmp_size);
208+
pglz_compress(str,rawsize,tmp,NULL);
209+
210+
/* ----------
211+
* If we miss less than x% bytes at the end of the temp value,
212+
* so be it. Therefore we save a memcpy().
213+
* ----------
214+
*/
215+
if (tmp_size-tmp->varsize<256||
216+
tmp_size-tmp->varsize<tmp_size /4)
217+
{
218+
result=tmp;
219+
}else {
220+
result= (lztext*)palloc(tmp->varsize);
221+
memcpy(result,tmp,tmp->varsize);
222+
pfree(tmp);
223+
}
224+
225+
returnresult;
226+
227+
228+
}
229+
230+
231+
/* ----------
232+
* lztext_text -
233+
*
234+
*Convert lztext to text
235+
* ----------
236+
*/
237+
text*
238+
lztext_text(lztext*lz)
239+
{
240+
text*result;
241+
242+
/* ----------
243+
* Handle NULL
244+
* ----------
245+
*/
246+
if (lz==NULL)
247+
returnNULL;
248+
249+
/* ----------
250+
* Allocate and initialize the text result
251+
* ----------
252+
*/
253+
result= (text*)palloc(lz->rawsize+VARHDRSZ+1);
254+
VARSIZE(result)=lz->rawsize+VARHDRSZ;
255+
256+
/* ----------
257+
* Decompress directly into the text data area.
258+
* ----------
259+
*/
260+
pglz_decompress(lz,VARDATA(result));
261+
VARDATA(result)[lz->rawsize]=0;
262+
263+
returnresult;
264+
}
265+
266+

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