mariadb/include/row0ext.h
marko c60a8c2f55 branches/zip: Add row_ext_t for caching prefixes of externally stored columns.
This will be needed for fixing Bug #22496.

REC_MAX_INDEX_COL_LEN: New constant, copied from DICT_MAX_INDEX_COL_LEN.

row_ext_create(), row_ext_lookup(), row_ext_lookup_low(): New functions.
2006-09-26 07:28:23 +00:00

55 lines
1.7 KiB
C

/******************************************************
Caching of externally stored column prefixes
(c) 2006 Innobase Oy
Created September 2006 Marko Makela
*******************************************************/
#ifndef row0ext_h
#define row0ext_h
#include "univ.i"
#include "row0types.h"
#include "mem0mem.h"
/************************************************************************
Creates a cache of column prefixes of externally stored columns. */
UNIV_INLINE
row_ext_t*
row_ext_create(
/*===========*/
/* out,own: column prefix cache */
ulint n_ext, /* in: number of externally stored columns */
const ulint* ext, /* in: col_no's of externally stored columns */
ulint zip_size,/* compressed page size, or 0 */
mem_heap_t* heap); /* in: heap where created */
/************************************************************************
Looks up a column prefix of an externally stored column. */
UNIV_INLINE
byte*
row_ext_lookup(
/*===========*/
/* out: column prefix */
row_ext_t* ext, /* in/out: column prefix cache */
ulint col, /* in: column number */
const byte* field, /* in: locally stored part of the column */
ulint f_len, /* in: length of field, in bytes */
ulint* len); /* out: length of prefix, in bytes,
at most REC_MAX_INDEX_COL_LEN */
/* Prefixes of externally stored columns */
struct row_ext_struct{
ulint n_ext; /* number of externally stored columns */
const ulint* ext; /* col_no's of externally stored columns */
ulint zip_size;/* compressed page size, or 0 */
char* buf; /* backing store of the column prefix cache */
ulint len[1]; /* prefix lengths; 0 if not cached */
};
#ifndef UNIV_NONINL
#include "row0ext.ic"
#endif
#endif