_packrec.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:32k
- /* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
- /* Functions to compressed records */
- #include "isamdef.h"
- #define IS_CHAR ((uint) 32768) /* Bit if char (not offset) in tree */
- #if INT_MAX > 65536L
- #define BITS_SAVED 32
- #define MAX_QUICK_TABLE_BITS 9 /* Because we may shift in 24 bits */
- #else
- #define BITS_SAVED 16
- #define MAX_QUICK_TABLE_BITS 6
- #endif
- #define get_bit(BU) ((BU)->bits ?
- (BU)->current_byte & ((bit_type) 1 << --(BU)->bits) :
- (fill_buffer(BU), (BU)->bits= BITS_SAVED-1,
- (BU)->current_byte & ((bit_type) 1 << (BITS_SAVED-1))))
- #define skipp_to_next_byte(BU) ((BU)->bits&=~7)
- #define get_bits(BU,count) (((BU)->bits >= count) ? (((BU)->current_byte >> ((BU)->bits-=count)) & mask[count]) : fill_and_get_bits(BU,count))
- #define decode_bytes_test_bit(bit)
- if (low_byte & (1 << (7-bit)))
- pos++;
- if (*pos & IS_CHAR)
- { bits-=(bit+1); break; }
- pos+= *pos
- static void read_huff_table(BIT_BUFF *bit_buff,DECODE_TREE *decode_tree,
- uint16 **decode_table,byte **intervall_buff,
- uint16 *tmp_buff);
- static void make_quick_table(uint16 *to_table,uint16 *decode_table,
- uint *next_free,uint value,uint bits,
- uint max_bits);
- static void fill_quick_table(uint16 *table,uint bits, uint max_bits,
- uint value);
- static uint copy_decode_table(uint16 *to_pos,uint offset,
- uint16 *decode_table);
- static uint find_longest_bitstream(uint16 *table);
- static void (*get_unpack_function(N_RECINFO *rec))(N_RECINFO *field,
- BIT_BUFF *buff,
- uchar *to,
- uchar *end);
- static void uf_zerofill_skipp_zero(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void uf_skipp_zero(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void uf_space_normal(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void uf_space_endspace_selected(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to, uchar *end);
- static void uf_endspace_selected(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void uf_space_endspace(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void uf_endspace(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void uf_space_prespace_selected(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to, uchar *end);
- static void uf_prespace_selected(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void uf_space_prespace(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void uf_prespace(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void uf_zerofill_normal(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void uf_constant(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void uf_intervall(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void uf_zero(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static void decode_bytes(N_RECINFO *rec,BIT_BUFF *bit_buff,
- uchar *to,uchar *end);
- static uint decode_pos(BIT_BUFF *bit_buff,DECODE_TREE *decode_tree);
- static void init_bit_buffer(BIT_BUFF *bit_buff,char *buffer,uint length);
- static uint fill_and_get_bits(BIT_BUFF *bit_buff,uint count);
- static void fill_buffer(BIT_BUFF *bit_buff);
- static uint max_bit(uint value);
- #ifdef HAVE_MMAP
- static void _nisam_mempack_get_block_info(BLOCK_INFO *info,uint ref_length,
- uchar *header);
- #endif
- static uint mask[]=
- {
- 0x00000000,
- 0x00000001, 0x00000003, 0x00000007, 0x0000000f,
- 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff,
- 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff,
- 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff,
- #if BITS_SAVED > 16
- 0x0001ffff, 0x0003ffff, 0x0007ffff, 0x000fffff,
- 0x001fffff, 0x003fffff, 0x007fffff, 0x00ffffff,
- 0x01ffffff, 0x03ffffff, 0x07ffffff, 0x0fffffff,
- 0x1fffffff, 0x3fffffff, 0x7fffffff, 0xffffffff,
- #endif
- };
- /* Read all packed info, allocate memory and fix field structs */
- my_bool _nisam_read_pack_info(N_INFO *info, pbool fix_keys)
- {
- File file;
- int diff_length;
- uint i,trees,huff_tree_bits,rec_reflength,length;
- uint16 *decode_table,*tmp_buff;
- ulong elements,intervall_length;
- char *disk_cache,*intervall_buff;
- uchar header[32];
- ISAM_SHARE *share=info->s;
- BIT_BUFF bit_buff;
- DBUG_ENTER("_nisam_read_pack_info");
- if (nisam_quick_table_bits < 4)
- nisam_quick_table_bits=4;
- else if (nisam_quick_table_bits > MAX_QUICK_TABLE_BITS)
- nisam_quick_table_bits=MAX_QUICK_TABLE_BITS;
- file=info->dfile;
- my_errno=0;
- if (my_read(file,(byte*) header,sizeof(header),MYF(MY_NABP)))
- {
- if (!my_errno)
- my_errno=HA_ERR_END_OF_FILE;
- DBUG_RETURN(1);
- }
- if (memcmp((byte*) header,(byte*) nisam_pack_file_magic,4))
- {
- my_errno=HA_ERR_WRONG_IN_RECORD;
- DBUG_RETURN(1);
- }
- share->pack.header_length=uint4korr(header+4);
- share->min_pack_length=(uint) uint4korr(header+8);
- share->max_pack_length=(uint) uint4korr(header+12);
- set_if_bigger(share->base.pack_reclength,share->max_pack_length);
- elements=uint4korr(header+16);
- intervall_length=uint4korr(header+20);
- trees=uint2korr(header+24);
- share->pack.ref_length=header[26];
- rec_reflength=header[27];
- diff_length=(int) rec_reflength - (int) share->base.rec_reflength;
- if (fix_keys)
- share->rec_reflength=rec_reflength;
- share->base.min_block_length=share->min_pack_length+share->pack.ref_length;
- if (!(share->decode_trees=(DECODE_TREE*)
- my_malloc((uint) (trees*sizeof(DECODE_TREE)+
- intervall_length*sizeof(byte)),
- MYF(MY_WME))))
- DBUG_RETURN(1);
- intervall_buff=(byte*) (share->decode_trees+trees);
- length=(uint) (elements*2+trees*(1 << nisam_quick_table_bits));
- if (!(share->decode_tables=(uint16*)
- my_malloc((length+512)*sizeof(uint16)+
- (uint) (share->pack.header_length+7),
- MYF(MY_WME | MY_ZEROFILL))))
- {
- my_free((gptr) share->decode_trees,MYF(0));
- DBUG_RETURN(1);
- }
- tmp_buff=share->decode_tables+length;
- disk_cache=(byte*) (tmp_buff+512);
- if (my_read(file,disk_cache,
- (uint) (share->pack.header_length-sizeof(header)),
- MYF(MY_NABP)))
- {
- my_free((gptr) share->decode_trees,MYF(0));
- my_free((gptr) share->decode_tables,MYF(0));
- DBUG_RETURN(1);
- }
- huff_tree_bits=max_bit(trees ? trees-1 : 0);
- init_bit_buffer(&bit_buff,disk_cache,
- (uint) (share->pack.header_length-sizeof(header)));
- /* Read new info for each field */
- for (i=0 ; i < share->base.fields ; i++)
- {
- share->rec[i].base_type=(enum en_fieldtype) get_bits(&bit_buff,4);
- share->rec[i].pack_type=(uint) get_bits(&bit_buff,4);
- share->rec[i].space_length_bits=get_bits(&bit_buff,4);
- share->rec[i].huff_tree=share->decode_trees+(uint) get_bits(&bit_buff,
- huff_tree_bits);
- share->rec[i].unpack=get_unpack_function(share->rec+i);
- }
- skipp_to_next_byte(&bit_buff);
- decode_table=share->decode_tables;
- for (i=0 ; i < trees ; i++)
- read_huff_table(&bit_buff,share->decode_trees+i,&decode_table,
- &intervall_buff,tmp_buff);
- decode_table=(uint16*)
- my_realloc((gptr) share->decode_tables,
- (uint) ((byte*) decode_table - (byte*) share->decode_tables),
- MYF(MY_HOLD_ON_ERROR));
- {
- my_ptrdiff_t diff=PTR_BYTE_DIFF(decode_table,share->decode_tables);
- share->decode_tables=decode_table;
- for (i=0 ; i < trees ; i++)
- share->decode_trees[i].table=ADD_TO_PTR(share->decode_trees[i].table,
- diff, uint16*);
- }
- /* Fix record-ref-length for keys */
- if (fix_keys)
- {
- for (i=0 ; i < share->base.keys ; i++)
- {
- share->keyinfo[i].base.keylength+=(uint16) diff_length;
- share->keyinfo[i].base.minlength+=(uint16) diff_length;
- share->keyinfo[i].base.maxlength+=(uint16) diff_length;
- share->keyinfo[i].seg[share->keyinfo[i].base.keysegs].base.length=
- (uint16) rec_reflength;
- }
- }
- if (bit_buff.error || bit_buff.pos < bit_buff.end)
- { /* info_length was wrong */
- my_errno=HA_ERR_WRONG_IN_RECORD;
- my_free((gptr) share->decode_trees,MYF(0));
- my_free((gptr) share->decode_tables,MYF(0));
- DBUG_RETURN(1);
- }
- DBUG_RETURN(0);
- }
- /* Read on huff-code-table from datafile */
- static void read_huff_table(BIT_BUFF *bit_buff, DECODE_TREE *decode_tree,
- uint16 **decode_table, byte **intervall_buff,
- uint16 *tmp_buff)
- {
- uint min_chr,elements,char_bits,offset_bits,size,intervall_length,table_bits,
- next_free_offset;
- uint16 *ptr,*end;
- LINT_INIT(ptr);
- if (!get_bits(bit_buff,1))
- {
- min_chr=get_bits(bit_buff,8);
- elements=get_bits(bit_buff,9);
- char_bits=get_bits(bit_buff,5);
- offset_bits=get_bits(bit_buff,5);
- intervall_length=0;
- ptr=tmp_buff;
- }
- else
- {
- min_chr=0;
- elements=get_bits(bit_buff,15);
- intervall_length=get_bits(bit_buff,16);
- char_bits=get_bits(bit_buff,5);
- offset_bits=get_bits(bit_buff,5);
- decode_tree->quick_table_bits=0;
- ptr= *decode_table;
- }
- size=elements*2-2;
- for (end=ptr+size ; ptr < end ; ptr++)
- {
- if (get_bit(bit_buff))
- *ptr= (uint16) get_bits(bit_buff,offset_bits);
- else
- *ptr= (uint16) (IS_CHAR + (get_bits(bit_buff,char_bits) + min_chr));
- }
- skipp_to_next_byte(bit_buff);
- decode_tree->table= *decode_table;
- decode_tree->intervalls= *intervall_buff;
- if (! intervall_length)
- {
- table_bits=find_longest_bitstream(tmp_buff);
- if (table_bits > nisam_quick_table_bits)
- table_bits=nisam_quick_table_bits;
- next_free_offset= (1 << table_bits);
- make_quick_table(*decode_table,tmp_buff,&next_free_offset,0,table_bits,
- table_bits);
- (*decode_table)+= next_free_offset;
- decode_tree->quick_table_bits=table_bits;
- }
- else
- {
- (*decode_table)=end;
- bit_buff->pos-= bit_buff->bits/8;
- memcpy(*intervall_buff,bit_buff->pos,(size_t) intervall_length);
- (*intervall_buff)+=intervall_length;
- bit_buff->pos+=intervall_length;
- bit_buff->bits=0;
- }
- return;
- }
- static void make_quick_table(uint16 *to_table, uint16 *decode_table, uint *next_free_offset, uint value, uint bits, uint max_bits)
- {
- if (!bits--)
- {
- to_table[value]= (uint16) *next_free_offset;
- *next_free_offset=copy_decode_table(to_table, *next_free_offset,
- decode_table);
- return;
- }
- if (!(*decode_table & IS_CHAR))
- {
- make_quick_table(to_table,decode_table+ *decode_table,
- next_free_offset,value,bits,max_bits);
- }
- else
- fill_quick_table(to_table+value,bits,max_bits,(uint) *decode_table);
- decode_table++;
- value|= (1 << bits);
- if (!(*decode_table & IS_CHAR))
- {
- make_quick_table(to_table,decode_table+ *decode_table,
- next_free_offset,value,bits,max_bits);
- }
- else
- fill_quick_table(to_table+value,bits,max_bits,(uint) *decode_table);
- return;
- }
- static void fill_quick_table(uint16 *table, uint bits, uint max_bits, uint value)
- {
- uint16 *end;
- value|=(max_bits-bits) << 8;
- for (end=table+ (1 << bits) ;
- table < end ;
- *table++ = (uint16) value | IS_CHAR) ;
- }
- static uint copy_decode_table(uint16 *to_pos, uint offset, uint16 *decode_table)
- {
- uint prev_offset;
- prev_offset= offset;
- if (!(*decode_table & IS_CHAR))
- {
- to_pos[offset]=2;
- offset=copy_decode_table(to_pos,offset+2,decode_table+ *decode_table);
- }
- else
- {
- to_pos[offset]= *decode_table;
- offset+=2;
- }
- decode_table++;
- if (!(*decode_table & IS_CHAR))
- {
- to_pos[prev_offset+1]=(uint16) (offset-prev_offset-1);
- offset=copy_decode_table(to_pos,offset,decode_table+ *decode_table);
- }
- else
- to_pos[prev_offset+1]= *decode_table;
- return offset;
- }
- static uint find_longest_bitstream(uint16 *table)
- {
- uint length=1,length2;
- if (!(*table & IS_CHAR))
- length=find_longest_bitstream(table+ *table)+1;
- table++;
- if (!(*table & IS_CHAR))
- {
- length2=find_longest_bitstream(table+ *table)+1;
- length=max(length,length2);
- }
- return length;
- }
- /* Read record from datafile */
- /* Returns length of packed record, -1 if error */
- int _nisam_read_pack_record(N_INFO *info, ulong filepos, byte *buf)
- {
- BLOCK_INFO block_info;
- File file;
- DBUG_ENTER("_nisam_read_pack_record");
- if (filepos == NI_POS_ERROR)
- DBUG_RETURN(-1); /* _search() didn't find record */
- file=info->dfile;
- if (_nisam_pack_get_block_info(&block_info,info->s->pack.ref_length,file,
- filepos))
- goto err;
- if (my_read(file,(byte*) info->rec_buff,block_info.rec_len,MYF(MY_NABP)))
- goto panic;
- info->update|= HA_STATE_AKTIV;
- DBUG_RETURN(_nisam_pack_rec_unpack(info,buf,info->rec_buff,
- block_info.rec_len));
- panic:
- my_errno=HA_ERR_WRONG_IN_RECORD;
- err:
- DBUG_RETURN(-1);
- }
- int _nisam_pack_rec_unpack(register N_INFO *info, register byte *to,
- byte *from, uint reclength)
- {
- byte *end_field;
- reg3 N_RECINFO *end;
- N_RECINFO *current_field;
- ISAM_SHARE *share=info->s;
- DBUG_ENTER("_nisam_pack_rec_unpack");
- init_bit_buffer(&info->bit_buff,from,reclength);
- for (current_field=share->rec, end=current_field+share->base.fields ;
- current_field < end ;
- current_field++,to=end_field)
- {
- end_field=to+current_field->base.length;
- (*current_field->unpack)(current_field,&info->bit_buff,(uchar*) to,
- (uchar*) end_field);
- }
- if (! info->bit_buff.error &&
- info->bit_buff.pos - info->bit_buff.bits/8 == info->bit_buff.end)
- DBUG_RETURN(0);
- my_errno=HA_ERR_WRONG_IN_RECORD;
- info->update&= ~HA_STATE_AKTIV;
- DBUG_RETURN(-1);
- } /* _nisam_pack_rec_unpack */
- /* Return function to unpack field */
- static void (*get_unpack_function(N_RECINFO *rec))(N_RECINFO *, BIT_BUFF *, uchar *, uchar *)
- {
- switch (rec->base_type) {
- case FIELD_SKIP_ZERO:
- if (rec->pack_type & PACK_TYPE_ZERO_FILL)
- return &uf_zerofill_skipp_zero;
- return &uf_skipp_zero;
- case FIELD_NORMAL:
- if (rec->pack_type & PACK_TYPE_SPACE_FIELDS)
- return &uf_space_normal;
- if (rec->pack_type & PACK_TYPE_ZERO_FILL)
- return &uf_zerofill_normal;
- return &decode_bytes;
- case FIELD_SKIP_ENDSPACE:
- if (rec->pack_type & PACK_TYPE_SPACE_FIELDS)
- {
- if (rec->pack_type & PACK_TYPE_SELECTED)
- return &uf_space_endspace_selected;
- return &uf_space_endspace;
- }
- if (rec->pack_type & PACK_TYPE_SELECTED)
- return &uf_endspace_selected;
- return &uf_endspace;
- case FIELD_SKIP_PRESPACE:
- if (rec->pack_type & PACK_TYPE_SPACE_FIELDS)
- {
- if (rec->pack_type & PACK_TYPE_SELECTED)
- return &uf_space_prespace_selected;
- return &uf_space_prespace;
- }
- if (rec->pack_type & PACK_TYPE_SELECTED)
- return &uf_prespace_selected;
- return &uf_prespace;
- case FIELD_CONSTANT:
- return &uf_constant;
- case FIELD_INTERVALL:
- return &uf_intervall;
- case FIELD_ZERO:
- return &uf_zero;
- case FIELD_BLOB: /* Write this sometimes.. */
- case FIELD_LAST:
- default:
- return 0; /* This should never happend */
- }
- }
- /* De different functions to unpack a field */
- static void uf_zerofill_skipp_zero(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- if (get_bit(bit_buff))
- bzero((char*) to,(uint) (end-to));
- else
- {
- #ifdef WORDS_BIGENDIAN
- bzero((char*) to,rec->space_length_bits);
- decode_bytes(rec,bit_buff,to+rec->space_length_bits,end);
- #else
- end-=rec->space_length_bits;
- decode_bytes(rec,bit_buff,to,end);
- bzero((byte*) end,rec->space_length_bits);
- #endif
- }
- }
- static void uf_skipp_zero(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- if (get_bit(bit_buff))
- bzero((char*) to,(uint) (end-to));
- else
- decode_bytes(rec,bit_buff,to,end);
- }
- static void uf_space_normal(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- if (get_bit(bit_buff))
- bfill((byte*) to,(end-to),' ');
- else
- decode_bytes(rec,bit_buff,to,end);
- }
- static void uf_space_endspace_selected(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- uint spaces;
- if (get_bit(bit_buff))
- bfill((byte*) to,(end-to),' ');
- else
- {
- if (get_bit(bit_buff))
- {
- if ((spaces=get_bits(bit_buff,rec->space_length_bits))+to > end)
- {
- bit_buff->error=1;
- return;
- }
- if (to+spaces != end)
- decode_bytes(rec,bit_buff,to,end-spaces);
- bfill((byte*) end-spaces,spaces,' ');
- }
- else
- decode_bytes(rec,bit_buff,to,end);
- }
- }
- static void uf_endspace_selected(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- uint spaces;
- if (get_bit(bit_buff))
- {
- if ((spaces=get_bits(bit_buff,rec->space_length_bits))+to > end)
- {
- bit_buff->error=1;
- return;
- }
- if (to+spaces != end)
- decode_bytes(rec,bit_buff,to,end-spaces);
- bfill((byte*) end-spaces,spaces,' ');
- }
- else
- decode_bytes(rec,bit_buff,to,end);
- }
- static void uf_space_endspace(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- uint spaces;
- if (get_bit(bit_buff))
- bfill((byte*) to,(end-to),' ');
- else
- {
- if ((spaces=get_bits(bit_buff,rec->space_length_bits))+to > end)
- {
- bit_buff->error=1;
- return;
- }
- if (to+spaces != end)
- decode_bytes(rec,bit_buff,to,end-spaces);
- bfill((byte*) end-spaces,spaces,' ');
- }
- }
- static void uf_endspace(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to,
- uchar *end)
- {
- uint spaces;
- if ((spaces=get_bits(bit_buff,rec->space_length_bits))+to > end)
- {
- bit_buff->error=1;
- return;
- }
- if (to+spaces != end)
- decode_bytes(rec,bit_buff,to,end-spaces);
- bfill((byte*) end-spaces,spaces,' ');
- }
- static void uf_space_prespace_selected(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- uint spaces;
- if (get_bit(bit_buff))
- bfill((byte*) to,(end-to),' ');
- else
- {
- if (get_bit(bit_buff))
- {
- if ((spaces=get_bits(bit_buff,rec->space_length_bits))+to > end)
- {
- bit_buff->error=1;
- return;
- }
- bfill((byte*) to,spaces,' ');
- if (to+spaces != end)
- decode_bytes(rec,bit_buff,to+spaces,end);
- }
- else
- decode_bytes(rec,bit_buff,to,end);
- }
- }
- static void uf_prespace_selected(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- uint spaces;
- if (get_bit(bit_buff))
- {
- if ((spaces=get_bits(bit_buff,rec->space_length_bits))+to > end)
- {
- bit_buff->error=1;
- return;
- }
- bfill((byte*) to,spaces,' ');
- if (to+spaces != end)
- decode_bytes(rec,bit_buff,to+spaces,end);
- }
- else
- decode_bytes(rec,bit_buff,to,end);
- }
- static void uf_space_prespace(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- uint spaces;
- if (get_bit(bit_buff))
- bfill((byte*) to,(end-to),' ');
- else
- {
- if ((spaces=get_bits(bit_buff,rec->space_length_bits))+to > end)
- {
- bit_buff->error=1;
- return;
- }
- bfill((byte*) to,spaces,' ');
- if (to+spaces != end)
- decode_bytes(rec,bit_buff,to+spaces,end);
- }
- }
- static void uf_prespace(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- uint spaces;
- if ((spaces=get_bits(bit_buff,rec->space_length_bits))+to > end)
- {
- bit_buff->error=1;
- return;
- }
- bfill((byte*) to,spaces,' ');
- if (to+spaces != end)
- decode_bytes(rec,bit_buff,to+spaces,end);
- }
- static void uf_zerofill_normal(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- #ifdef WORDS_BIGENDIAN
- bzero((char*) to,rec->space_length_bits);
- decode_bytes(rec,bit_buff,(uchar*) to+rec->space_length_bits,end);
- #else
- end-=rec->space_length_bits;
- decode_bytes(rec,bit_buff,(uchar*) to,end);
- bzero((byte*) end,rec->space_length_bits);
- #endif
- }
- static void uf_constant(N_RECINFO *rec,
- BIT_BUFF *bit_buff __attribute__((unused)),
- uchar *to, uchar *end)
- {
- memcpy(to,rec->huff_tree->intervalls,(size_t) (end-to));
- }
- static void uf_intervall(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- reg1 uint field_length=(uint) (end-to);
- memcpy(to,rec->huff_tree->intervalls+field_length*decode_pos(bit_buff,
- rec->huff_tree),
- (size_t) field_length);
- }
- /*ARGSUSED*/
- static void uf_zero(N_RECINFO *rec __attribute__((unused)),
- BIT_BUFF *bit_buff __attribute__((unused)),
- uchar *to, uchar *end)
- {
- bzero((char*) to,(uint) (end-to));
- }
- /* Functions to decode of buffer of bits */
- #if BITS_SAVED == 64
- static void decode_bytes(rec,bit_buff,to,end)
- N_RECINFO *rec;
- BIT_BUFF *bit_buff;
- uchar *to,*end;
- {
- reg1 uint bits,low_byte;
- reg3 uint16 *pos;
- reg4 uint table_bits,table_and;
- DECODE_TREE *decode_tree;
- decode_tree=rec->decode_tree;
- bits=bit_buff->bits; /* Save in reg for quicker access */
- table_bits=decode_tree->quick_table_bits;
- table_and= (1 << table_bits)-1;
- do
- {
- if (bits <= 32)
- {
- if (bit_buff->pos > bit_buff->end+4)
- return; /* Can't be right */
- bit_buff->current_byte= (bit_buff->current_byte << 32) +
- ((((uint) bit_buff->pos[3])) +
- (((uint) bit_buff->pos[2]) << 8) +
- (((uint) bit_buff->pos[1]) << 16) +
- (((uint) bit_buff->pos[0]) << 24));
- bit_buff->pos+=4;
- bits+=32;
- }
- /* First use info in quick_table */
- low_byte=(uint) (bit_buff->current_byte >> (bits - table_bits)) & table_and;
- low_byte=decode_tree->table[low_byte];
- if (low_byte & IS_CHAR)
- {
- *to++ = (low_byte & 255); /* Found char in quick table */
- bits-= ((low_byte >> 8) & 31); /* Remove bits used */
- }
- else
- { /* Map through rest of decode-table */
- pos=decode_tree->table+low_byte;
- bits-=table_bits;
- for (;;)
- {
- low_byte=(uint) (bit_buff->current_byte >> (bits-8));
- decode_bytes_test_bit(0);
- decode_bytes_test_bit(1);
- decode_bytes_test_bit(2);
- decode_bytes_test_bit(3);
- decode_bytes_test_bit(4);
- decode_bytes_test_bit(5);
- decode_bytes_test_bit(6);
- decode_bytes_test_bit(7);
- bits-=8;
- }
- *to++ = *pos;
- }
- } while (to != end);
- bit_buff->bits=bits;
- return;
- }
- #else
- static void decode_bytes(N_RECINFO *rec, BIT_BUFF *bit_buff, uchar *to, uchar *end)
- {
- reg1 uint bits,low_byte;
- reg3 uint16 *pos;
- reg4 uint table_bits,table_and;
- DECODE_TREE *decode_tree;
- decode_tree=rec->huff_tree;
- bits=bit_buff->bits; /* Save in reg for quicker access */
- table_bits=decode_tree->quick_table_bits;
- table_and= (1 << table_bits)-1;
- do
- {
- if (bits < table_bits)
- {
- if (bit_buff->pos > bit_buff->end+1)
- return; /* Can't be right */
- #if BITS_SAVED == 32
- bit_buff->current_byte= (bit_buff->current_byte << 24) +
- (((uint) ((uchar) bit_buff->pos[2]))) +
- (((uint) ((uchar) bit_buff->pos[1])) << 8) +
- (((uint) ((uchar) bit_buff->pos[0])) << 16);
- bit_buff->pos+=3;
- bits+=24;
- #else
- if (bits) /* We must have at leasts 9 bits */
- {
- bit_buff->current_byte= (bit_buff->current_byte << 8) +
- (uint) ((uchar) bit_buff->pos[0]);
- bit_buff->pos++;
- bits+=8;
- }
- else
- {
- bit_buff->current_byte= ((uint) ((uchar) bit_buff->pos[0]) << 8) +
- ((uint) ((uchar) bit_buff->pos[1]));
- bit_buff->pos+=2;
- bits+=16;
- }
- #endif
- }
- /* First use info in quick_table */
- low_byte=(bit_buff->current_byte >> (bits - table_bits)) & table_and;
- low_byte=decode_tree->table[low_byte];
- if (low_byte & IS_CHAR)
- {
- *to++ = (low_byte & 255); /* Found char in quick table */
- bits-= ((low_byte >> 8) & 31); /* Remove bits used */
- }
- else
- { /* Map through rest of decode-table */
- pos=decode_tree->table+low_byte;
- bits-=table_bits;
- for (;;)
- {
- if (bits < 8)
- { /* We don't need to check end */
- #if BITS_SAVED == 32
- bit_buff->current_byte= (bit_buff->current_byte << 24) +
- (((uint) ((uchar) bit_buff->pos[2]))) +
- (((uint) ((uchar) bit_buff->pos[1])) << 8) +
- (((uint) ((uchar) bit_buff->pos[0])) << 16);
- bit_buff->pos+=3;
- bits+=24;
- #else
- bit_buff->current_byte= (bit_buff->current_byte << 8) +
- (uint) ((uchar) bit_buff->pos[0]);
- bit_buff->pos+=1;
- bits+=8;
- #endif
- }
- low_byte=(uint) (bit_buff->current_byte >> (bits-8));
- decode_bytes_test_bit(0);
- decode_bytes_test_bit(1);
- decode_bytes_test_bit(2);
- decode_bytes_test_bit(3);
- decode_bytes_test_bit(4);
- decode_bytes_test_bit(5);
- decode_bytes_test_bit(6);
- decode_bytes_test_bit(7);
- bits-=8;
- }
- *to++ = (uchar) *pos;
- }
- } while (to != end);
- bit_buff->bits=bits;
- return;
- }
- #endif /* BIT_SAVED == 64 */
- static uint decode_pos(BIT_BUFF *bit_buff, DECODE_TREE *decode_tree)
- {
- uint16 *pos=decode_tree->table;
- for (;;)
- {
- if (get_bit(bit_buff))
- pos++;
- if (*pos & IS_CHAR)
- return (uint) (*pos & ~IS_CHAR);
- pos+= *pos;
- }
- }
- int _nisam_read_rnd_pack_record(N_INFO *info, byte *buf,
- register ulong filepos,
- int skipp_deleted_blocks)
- {
- uint b_type;
- BLOCK_INFO block_info;
- ISAM_SHARE *share=info->s;
- DBUG_ENTER("_nisam_read_rnd_pack_record");
- if (filepos >= share->state.data_file_length)
- {
- my_errno= HA_ERR_END_OF_FILE;
- goto err;
- }
- if (info->opt_flag & READ_CACHE_USED)
- {
- if (_nisam_read_cache(&info->rec_cache,(byte*) block_info.header,filepos,
- share->pack.ref_length, skipp_deleted_blocks))
- goto err;
- b_type=_nisam_pack_get_block_info(&block_info,share->pack.ref_length,-1,
- filepos);
- }
- else
- b_type=_nisam_pack_get_block_info(&block_info,share->pack.ref_length,
- info->dfile,filepos);
- if (b_type)
- goto err;
- #ifndef DBUG_OFF
- if (block_info.rec_len > share->max_pack_length)
- {
- my_errno=HA_ERR_WRONG_IN_RECORD;
- goto err;
- }
- #endif
- if (info->opt_flag & READ_CACHE_USED)
- {
- if (_nisam_read_cache(&info->rec_cache,(byte*) info->rec_buff,
- block_info.filepos, block_info.rec_len,
- skipp_deleted_blocks))
- goto err;
- }
- else
- {
- if (my_read(info->dfile,(byte*) info->rec_buff,block_info.rec_len,
- MYF(MY_NABP)))
- goto err;
- }
- info->packed_length=block_info.rec_len;
- info->lastpos=filepos;
- info->nextpos=block_info.filepos+block_info.rec_len;
- info->update|= HA_STATE_AKTIV | HA_STATE_KEY_CHANGED;
- DBUG_RETURN (_nisam_pack_rec_unpack(info,buf,info->rec_buff,
- block_info.rec_len));
- err:
- DBUG_RETURN(-1);
- }
- /* Read and process header from a huff-record-file */
- uint _nisam_pack_get_block_info(BLOCK_INFO *info, uint ref_length, File file,
- ulong filepos)
- {
- uchar *header=info->header;
- if (file >= 0)
- {
- VOID(my_seek(file,filepos,MY_SEEK_SET,MYF(0)));
- if (my_read(file,(char*) header,ref_length,MYF(MY_NABP)))
- return BLOCK_FATAL_ERROR;
- }
- DBUG_DUMP("header",(byte*) header,ref_length);
- switch (ref_length) {
- case 1:
- info->rec_len=header[0];
- info->filepos=filepos+1;
- break;
- case 2:
- info->rec_len=uint2korr(header);
- info->filepos=filepos+2;
- break;
- case 3:
- info->rec_len=(uint) (uint3korr(header));
- info->filepos=filepos+3;
- break;
- default: break;
- }
- return 0;
- }
- /* routines for bit buffer */
- /* Buffer must be 6 byte bigger */
- static void init_bit_buffer(BIT_BUFF *bit_buff, char *buffer, uint length)
- {
- bit_buff->pos=(uchar*) buffer;
- bit_buff->end=(uchar*) buffer+length;
- bit_buff->bits=bit_buff->error=0;
- bit_buff->current_byte=0; /* Avoid purify errors */
- }
- static uint fill_and_get_bits(BIT_BUFF *bit_buff, uint count)
- {
- uint tmp;
- count-=bit_buff->bits;
- tmp=(bit_buff->current_byte & mask[bit_buff->bits]) << count;
- fill_buffer(bit_buff);
- bit_buff->bits=BITS_SAVED - count;
- return tmp+(bit_buff->current_byte >> (BITS_SAVED - count));
- }
- /* Fill in empty bit_buff->current_byte from buffer */
- /* Sets bit_buff->error if buffer is exhausted */
- static void fill_buffer(BIT_BUFF *bit_buff)
- {
- if (bit_buff->pos >= bit_buff->end)
- {
- bit_buff->error= 1;
- bit_buff->current_byte=0;
- return;
- }
- #if BITS_SAVED == 64
- bit_buff->current_byte= ((((uint) ((uchar) bit_buff->pos[7]))) +
- (((uint) ((uchar) bit_buff->pos[6])) << 8) +
- (((uint) ((uchar) bit_buff->pos[5])) << 16) +
- (((uint) ((uchar) bit_buff->pos[4])) << 24) +
- ((ulonglong)
- ((((uint) ((uchar) bit_buff->pos[3]))) +
- (((uint) ((uchar) bit_buff->pos[2])) << 8) +
- (((uint) ((uchar) bit_buff->pos[1])) << 16) +
- (((uint) ((uchar) bit_buff->pos[0])) << 24)) << 32));
- bit_buff->pos+=8;
- #else
- #if BITS_SAVED == 32
- bit_buff->current_byte= (((uint) ((uchar) bit_buff->pos[3])) +
- (((uint) ((uchar) bit_buff->pos[2])) << 8) +
- (((uint) ((uchar) bit_buff->pos[1])) << 16) +
- (((uint) ((uchar) bit_buff->pos[0])) << 24));
- bit_buff->pos+=4;
- #else
- bit_buff->current_byte= (uint) (((uint) ((uchar) bit_buff->pos[1]))+
- (((uint) ((uchar) bit_buff->pos[0])) << 8));
- bit_buff->pos+=2;
- #endif
- #endif
- }
- /* Get number of bits neaded to represent value */
- static uint max_bit(register uint value)
- {
- reg2 uint power=1;
- while ((value>>=1))
- power++;
- return (power);
- }
- /*****************************************************************************
- Some redefined functions to handle files when we are using memmap
- *****************************************************************************/
- #ifdef HAVE_MMAP
- #include <sys/mman.h>
- static int _nisam_read_mempack_record(N_INFO *info,ulong filepos,byte *buf);
- static int _nisam_read_rnd_mempack_record(N_INFO*, byte *,ulong, int);
- #ifndef MAP_NORESERVE
- #define MAP_NORESERVE 0 /* For irix */
- #endif
- #ifndef MAP_FAILED
- #define MAP_FAILED -1
- #endif
- my_bool _nisam_memmap_file(N_INFO *info)
- {
- byte *file_map;
- ISAM_SHARE *share=info->s;
- DBUG_ENTER("_nisam_memmap_file");
- if (!info->s->file_map)
- {
- if (my_seek(info->dfile,0L,MY_SEEK_END,MYF(0)) <
- share->state.data_file_length+MEMMAP_EXTRA_MARGIN)
- {
- DBUG_PRINT("warning",("File isn't extended for memmap"));
- DBUG_RETURN(0);
- }
- file_map=(byte*)
- mmap(0,share->state.data_file_length+MEMMAP_EXTRA_MARGIN,PROT_READ,
- MAP_SHARED | MAP_NORESERVE,info->dfile,0L);
- if (file_map == (byte*) MAP_FAILED)
- {
- DBUG_PRINT("warning",("mmap failed: errno: %d",errno));
- my_errno=errno;
- DBUG_RETURN(0);
- }
- info->s->file_map=file_map;
- }
- info->opt_flag|= MEMMAP_USED;
- info->read_record=share->read_record=_nisam_read_mempack_record;
- share->read_rnd=_nisam_read_rnd_mempack_record;
- DBUG_RETURN(1);
- }
- void _nisam_unmap_file(N_INFO *info)
- {
- if (info->s->file_map)
- (void) munmap((caddr_t) info->s->file_map,
- (size_t) info->s->state.data_file_length+
- MEMMAP_EXTRA_MARGIN);
- }
- static void _nisam_mempack_get_block_info(BLOCK_INFO *info, uint ref_length,
- uchar *header)
- {
- if (ref_length == 1) /* This is most usual */
- info->rec_len=header[0];
- else if (ref_length == 2)
- info->rec_len=uint2korr(header);
- else
- info->rec_len=(uint) (uint3korr(header));
- }
- static int _nisam_read_mempack_record(N_INFO *info, ulong filepos, byte *buf)
- {
- BLOCK_INFO block_info;
- ISAM_SHARE *share=info->s;
- DBUG_ENTER("ni_read_mempack_record");
- if (filepos == NI_POS_ERROR)
- DBUG_RETURN(-1); /* _search() didn't find record */
- _nisam_mempack_get_block_info(&block_info,share->pack.ref_length,
- (uchar*) share->file_map+filepos);
- DBUG_RETURN(_nisam_pack_rec_unpack(info,buf,share->file_map+
- share->pack.ref_length+filepos,
- block_info.rec_len));
- }
- /*ARGSUSED*/
- static int _nisam_read_rnd_mempack_record(N_INFO *info, byte *buf,
- register ulong filepos,
- int skipp_deleted_blocks
- __attribute__((unused)))
- {
- BLOCK_INFO block_info;
- ISAM_SHARE *share=info->s;
- DBUG_ENTER("_nisam_read_rnd_mempack_record");
- if (filepos >= share->state.data_file_length)
- {
- my_errno=HA_ERR_END_OF_FILE;
- goto err;
- }
- _nisam_mempack_get_block_info(&block_info,share->pack.ref_length,
- (uchar*) share->file_map+filepos);
- #ifndef DBUG_OFF
- if (block_info.rec_len > info->s->max_pack_length)
- {
- my_errno=HA_ERR_WRONG_IN_RECORD;
- goto err;
- }
- #endif
- info->packed_length=block_info.rec_len;
- info->lastpos=filepos;
- info->nextpos=filepos+share->pack.ref_length+block_info.rec_len;
- info->update|= HA_STATE_AKTIV | HA_STATE_KEY_CHANGED;
- DBUG_RETURN (_nisam_pack_rec_unpack(info,buf,share->file_map+
- share->pack.ref_length+filepos,
- block_info.rec_len));
- err:
- DBUG_RETURN(-1);
- }
- #endif /* HAVE_MMAP */