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/* ----------
* lztext.c -
*
* $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/lztext.c,v 1.3 1999/11/24 03:45:12 ishii Exp $
*
* Text type with internal LZ compressed representation. Uses the
* standard PostgreSQL compression method.
*
* This code requires that the LZ compressor found in pg_lzcompress
* codes a usable VARSIZE word at the beginning of the output buffer.
* ----------
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <errno.h>
#include "postgres.h"
#include "utils/builtins.h"
#include "utils/palloc.h"
#include "utils/pg_lzcompress.h"
#ifdef MULTIBYTE
#include "mb/pg_wchar.h"
#endif
/* ----------
* lztextin -
*
* Input function for datatype lztext
* ----------
*/
lztext *
lztextin(char *str)
{
lztext *result;
int32 rawsize;
lztext *tmp;
int tmp_size;
/* ----------
* Handle NULL
* ----------
*/
if (str == NULL)
return NULL;
/* ----------
* Determine input size and maximum output Datum size
* ----------
*/
rawsize = strlen(str);
tmp_size = PGLZ_MAX_OUTPUT(rawsize);
/* ----------
* Allocate a temporary result and compress into it
* ----------
*/
tmp = (lztext *) palloc(tmp_size);
pglz_compress(str, rawsize, tmp, NULL);
/* ----------
* If we miss less than 25% bytes at the end of the temp value,
* so be it. Therefore we save a palloc()/memcpy()/pfree()
* sequence.
* ----------
*/
if (tmp_size - tmp->varsize < 256 ||
tmp_size - tmp->varsize < tmp_size / 4)
{
result = tmp;
} else {
result = (lztext *) palloc(tmp->varsize);
memcpy(result, tmp, tmp->varsize);
pfree(tmp);
}
return result;
}
/* ----------
* lztextout -
*
* Output function for data type lztext
* ----------
*/
char *
lztextout(lztext *lz)
{
char *result;
/* ----------
* Handle NULL
* ----------
*/
if (lz == NULL)
{
result = (char *) palloc(2);
result[0] = '-';
result[1] = '\0';
return result;
}
/* ----------
* Allocate the result string - the required size is remembered
* in the lztext header so we don't need a temporary buffer or
* have to diddle with realloc's.
* ----------
*/
result = (char *) palloc(PGLZ_RAW_SIZE(lz) + 1);
/* ----------
* Decompress and add terminating ZERO
* ----------
*/
pglz_decompress(lz, result);
result[lz->rawsize] = '\0';
/* ----------
* Return the result
* ----------
*/
return result;
}
/* ----------
* lztextlen -
*
* Logical length of lztext field (it's the uncompressed size
* of the original data).
* ----------
*/
int32
lztextlen(lztext *lz)
{
#ifdef MULTIBYTE
unsigned char *s1,*s2;
int len;
int l;
int wl;
#endif
/* ----------
* Handle NULL
* ----------
*/
if (lz == NULL)
return 0;
#ifdef MULTIBYTE
len = 0;
s1 = s2 = (unsigned char *)lztextout(lz);
l = PGLZ_RAW_SIZE(lz);
while (l > 0)
{
wl = pg_mblen(s1);
l -= wl;
s1 += wl;
len++;
}
pfree((char *)s2);
return (len);
#else
/* ----------
* without multibyte support, it's the remembered rawsize
* ----------
*/
return PGLZ_RAW_SIZE(lz);
#endif
}
/* ----------
* lztextoctetlen -
*
* Physical length of lztext field (it's the compressed size
* plus the rawsize field).
* ----------
*/
int32
lztextoctetlen(lztext *lz)
{
/* ----------
* Handle NULL
* ----------
*/
if (lz == NULL)
return 0;
/* ----------
* Return the varsize minus the VARSIZE field itself.
* ----------
*/
return VARSIZE(lz) - VARHDRSZ;
}
/* ----------
* text_lztext -
*
* Convert text to lztext
* ----------
*/
lztext *
text_lztext(text *txt)
{
lztext *result;
int32 rawsize;
lztext *tmp;
int tmp_size;
char *str;
/* ----------
* Handle NULL
* ----------
*/
if (txt == NULL)
return NULL;
/* ----------
* Determine input size and eventually tuple size
* ----------
*/
rawsize = VARSIZE(txt) - VARHDRSZ;
str = VARDATA(txt);
tmp_size = PGLZ_MAX_OUTPUT(rawsize);
/* ----------
* Allocate a temporary result and compress into it
* ----------
*/
tmp = (lztext *) palloc(tmp_size);
pglz_compress(str, rawsize, tmp, NULL);
/* ----------
* If we miss less than 25% bytes at the end of the temp value,
* so be it. Therefore we save a palloc()/memcpy()/pfree()
* sequence.
* ----------
*/
if (tmp_size - tmp->varsize < 256 ||
tmp_size - tmp->varsize < tmp_size / 4)
{
result = tmp;
} else {
result = (lztext *) palloc(tmp->varsize);
memcpy(result, tmp, tmp->varsize);
pfree(tmp);
}
return result;
}
/* ----------
* lztext_text -
*
* Convert lztext to text
* ----------
*/
text *
lztext_text(lztext *lz)
{
text *result;
/* ----------
* Handle NULL
* ----------
*/
if (lz == NULL)
return NULL;
/* ----------
* Allocate and initialize the text result
* ----------
*/
result = (text *) palloc(PGLZ_RAW_SIZE(lz) + VARHDRSZ + 1);
VARSIZE(result) = lz->rawsize + VARHDRSZ;
/* ----------
* Decompress directly into the text data area.
* ----------
*/
VARDATA(result)[lz->rawsize] = 0;
pglz_decompress(lz, VARDATA(result));
return result;
}
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