xapian-core/backends/honey/honey_defs.h

   1 /** @file honey_defs.h
   2  * @brief Definitions, types, etc for use inside honey.
   3  */
   4 /* Copyright (C) 2010,2014,2015,2017,2018 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #ifndef XAPIAN_INCLUDED_HONEY_DEFS_H
  22 #define XAPIAN_INCLUDED_HONEY_DEFS_H
  23
  24 #include "internaltypes.h"
  25
  26 #define SST_SEARCH
  27
  28 /// Honey table extension.
  29 #define HONEY_TABLE_EXTENSION "honey"
  30
  31 /** Minimum size to pad a honey table to.
  32  *
  33  *  Having this minimum size means we can usually know from the size that a
  34  *  stub database file isn't a single file database.
  35  */
  36 #define HONEY_MIN_DB_SIZE 2048
  37
  38 /// Default B-tree block size.
  39 #define HONEY_DEFAULT_BLOCKSIZE 8192
  40
  41 /// Minimum B-tree block size.
  42 #define HONEY_MIN_BLOCKSIZE 2048
  43
  44 /// Maximum B-tree block size.
  45 #define HONEY_MAX_BLOCKSIZE 65536
  46
  47 /// Maximum key length.
  48 #define HONEY_MAX_KEY_LEN 255
  49
  50 // Maximum size of a document length chunk in bytes.
  51 #define HONEY_DOCLEN_CHUNK_MAX 2016
  52
  53 /** The largest docid value supported by honey.
  54  *
  55  *  The disk format supports 64-bit docids, but if Xapian::docid is narrower
  56  *  then it's the largest value supported by the type that matters here.
  57  */
  58 #define HONEY_MAX_DOCID Xapian::docid(0xffffffffffffffff)
  59
  60 namespace Honey {
  61
  62 enum table_type {
  63     POSTLIST,
  64     DOCDATA,
  65     TERMLIST,
  66     POSITION,
  67     SPELLING,
  68     SYNONYM,
  69     MAX_
  70 };
  71
  72 /// Postlist key second bytes when first byte is zero.
  73 enum {
  74     KEY_USER_METADATA = 0x00,
  75     KEY_VALUE_STATS = 0x01,
  76     KEY_VALUE_STATS_HI = 0x08,
  77     KEY_VALUE_CHUNK = 0x09,
  78     KEY_VALUE_CHUNK_HI = 0xe1, // (0xe1 for slots > 26)
  79     /* 0xe2-0xe6 inclusive unused currently. */
  80     /* 0xe7-0xee inclusive reserved for doc max wdf chunks. */
  81     /* 0xef-0xf6 inclusive reserved for unique terms chunks. */
  82     KEY_DOCLEN_CHUNK = 0xf7,
  83     KEY_DOCLEN_CHUNK_HI = 0xfe,
  84     KEY_POSTING_CHUNK = 0xff
  85 };
  86
  87 #define KEY_DOCLEN_PREFIX "\0\xf7"
  88
  89 static_assert(((KEY_VALUE_CHUNK_HI - KEY_VALUE_CHUNK) & 0x07) == 0,
  90               "No wasted values");
  91
  92 }
  93
  94 /// A block number in a honey Btree file.
  95 typedef uint4 honey_block_t;
  96
  97 /// The revision number of a honey database.
  98 typedef uint4 honey_revision_number_t;
  99
 100 /// How many entries there are in a table.
 101 typedef unsigned long long honey_tablesize_t;
 102
 103 #endif // XAPIAN_INCLUDED_HONEY_DEFS_H