/*
** 2009 Nov 12
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
******************************************************************************
**
*/
#ifndef _FTSINT_H
#define _FTSINT_H
#if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
# define NDEBUG 1
#endif
#include "sqlite3.h"
#include "fts3_tokenizer.h"
#include "fts3_hash.h"
/*
** This constant controls how often segments are merged. Once there are
** FTS3_MERGE_COUNT segments of level N, they are merged into a single
** segment of level N+1.
*/
#define FTS3_MERGE_COUNT 16
/*
** This is the maximum amount of data (in bytes) to store in the
** Fts3Table.pendingTerms hash table. Normally, the hash table is
** populated as documents are inserted/updated/deleted in a transaction
** and used to create a new segment when the transaction is committed.
** However if this limit is reached midway through a transaction, a new
** segment is created and the hash table cleared immediately.
*/
#define FTS3_MAX_PENDING_DATA (1*1024*1024)
/*
** Macro to return the number of elements in an array. SQLite has a
** similar macro called ArraySize(). Use a different name to avoid
** a collision when building an amalgamation with built-in FTS3.
*/
#define SizeofArray(X) ((int)(sizeof(X)/sizeof(X[0])))
/*
** Maximum length of a varint encoded integer. The varint format is different
** from that used by SQLite, so the maximum length is 10, not 9.
*/
#define FTS3_VARINT_MAX 10
/*
** The testcase() macro is only used by the amalgamation. If undefined,
** make it a no-op.
*/
#ifndef testcase
# define testcase(X)
#endif
/*
** Terminator values for position-lists and column-lists.
*/
#define POS_COLUMN (1) /* Column-list terminator */
#define POS_END (0) /* Position-list terminator */
/*
** This section provides definitions to allow the
** FTS3 extension to be compiled outside of the
** amalgamation.
*/
#ifndef SQLITE_AMALGAMATION
/*
** Macros indicating that conditional expressions are always true or
** false.
*/
#ifdef SQLITE_COVERAGE_TEST
# define ALWAYS(x) (1)
# define NEVER(X) (0)
#else
# define ALWAYS(x) (x)
# define NEVER(X) (x)
#endif
/*
** Internal types used by SQLite.
*/
typedef unsigned char u8; /* 1-byte (or larger) unsigned integer */
typedef short int i16; /* 2-byte (or larger) signed integer */
typedef unsigned int u32; /* 4-byte unsigned integer */
typedef sqlite3_uint64 u64; /* 8-byte unsigned integer */
/*
** Macro used to suppress compiler warnings for unused parameters.
*/
#define UNUSED_PARAMETER(x) (void)(x)
#endif
typedef struct Fts3Table Fts3Table;
typedef struct Fts3Cursor Fts3Cursor;
typedef struct Fts3Expr Fts3Expr;
typedef struct Fts3Phrase Fts3Phrase;
typedef struct Fts3PhraseToken Fts3PhraseToken;
typedef struct Fts3SegFilter Fts3SegFilter;
typedef struct Fts3DeferredToken Fts3DeferredToken;
typedef struct Fts3SegReader Fts3SegReader;
typedef struct Fts3SegReaderCursor Fts3SegReaderCursor;
/*
** A connection to a fulltext index is an instance of the following
** structure. The xCreate and xConnect methods create an instance
** of this structure and xDestroy and xDisconnect free that instance.
** All other methods receive a pointer to the structure as one of their
** arguments.
*/
struct Fts3Table {
sqlite3_vtab base; /* Base class used by SQLite core */
sqlite3 *db; /* The database connection */
const char *zDb; /* logical database name */
const char *zName; /* virtual table name */
int nColumn; /* number of named columns in virtual table */
char **azColumn; /* column names. malloced */
sqlite3_tokenizer *pTokenizer; /* tokenizer for inserts and queries */
/* Precompiled statements used by the implementation. Each of these
** statements is run and reset within a single virtual table API call.
*/
sqlite3_stmt *aStmt[24];
char *zReadExprlist;
char *zWriteExprlist;
int nNodeSize; /* Soft limit for node size */
u8 bHasStat; /* True if %_stat table exists */
u8 bHasDocsize; /* True if %_docsize table exists */
int nPgsz; /* Page size for host database */
char *zSegmentsTbl; /* Name of %_segments table */
sqlite3_blob *pSegments; /* Blob handle open on %_segments table */
/* The following hash table is used to buffer pending index updates during
** transactions. Variable nPendingData estimates the memory size of the
** pending data, including hash table overhead, but not malloc overhead.
** When nPendingData exceeds nMaxPendingData, the buffer is flushed
** automatically. Variable iPrevDocid is the docid of the most recently
** inserted record.
*/
int nMaxPendingData;
int nPendingData;
sqlite_int64 iPrevDocid;
Fts3Hash pendingTerms;
};
/*
** When the core wants to read from the virtual table, it creates a
** virtual table cursor (an instance of the following structure) using
** the xOpen method. Cursors are destroyed using the xClose method.
*/
struct Fts3Cursor {
sqlite3_vtab_cursor base; /* Base class used by SQLite core */
i16 eSearch; /* Search strategy (see below) */
u8 isEof; /* True if at End Of Results */
u8 isRequireSeek; /* True if must seek pStmt to %_content row */
sqlite3_stmt *pStmt; /* Prepared statement in use by the cursor */
Fts3Expr *pExpr; /* Parsed MATCH query string */
int nPhrase; /* Number of matchable phrases in query */
Fts3DeferredToken *pDeferred; /* Deferred search tokens, if any */
sqlite3_int64 iPrevId; /* Previous id read from aDoclist */
char *pNextId; /* Pointer into the body of aDoclist */
char *aDoclist; /* List of docids for full-text queries */
int nDoclist; /* Size of buffer at aDoclist */
int eEvalmode; /* An FTS3_EVAL_XX constant */
int nRowAvg; /* Average size of database rows, in pages */
int isMatchinfoNeeded; /* True when aMatchinfo[] needs filling in */
u32 *aMatchinfo; /* Information about most recent match */
int nMatchinfo; /* Number of elements in aMatchinfo[] */
char *zMatchinfo; /* Matchinfo specification */
};
#define FTS3_EVAL_FILTER 0
#define FTS3_EVAL_NEXT 1
#define FTS3_EVAL_MATCHINFO 2
/*
** The Fts3Cursor.eSearch member is always set to one of the following.
** Actualy, Fts3Cursor.eSearch can be greater than or equal to
** FTS3_FULLTEXT_SEARCH. If so, then Fts3Cursor.eSearch - 2 is the index
** of the column to be searched. For example, in
**
** CREATE VIRTUAL TABLE ex1 USING fts3(a,b,c,d);
** SELECT docid FROM ex1 WHERE b MATCH 'one two three';
**
** Because the LHS of the MATCH operator is 2nd column "b",
** Fts3Cursor.eSearch will be set to FTS3_FULLTEXT_SEARCH+1. (+0 for a,
** +1 for b, +2 for c, +3 for d.) If the LHS of MATCH were "ex1"
** indicating that all columns should be searched,
** then eSearch would be set to FTS3_FULLTEXT_SEARCH+4.
*/
#define FTS3_FULLSCAN_SEARCH 0 /* Linear scan of %_content table */
#define FTS3_DOCID_SEARCH 1 /* Lookup by rowid on %_content table */
#define FTS3_FULLTEXT_SEARCH 2 /* Full-text index search */
/*
** A "phrase" is a sequence of one or more tokens that must match in
** sequence. A single token is the base case and the most common case.
** For a sequence of tokens contained in double-quotes (i.e. "one two three")
** nToken will be the number of tokens in the string.
**
** The nDocMatch and nMatch variables contain data that may be used by the
** matchinfo() function. They are populated when the full-text index is
** queried for hits on the phrase. If one or more tokens in the phrase
** are deferred, the nDocMatch and nMatch variables are populated based
** on the assumption that the
*/
struct Fts3PhraseToken {
char *z; /* Text of the token */
int n; /* Number of bytes in buffer z */
int isPrefix; /* True if token ends with a "*" character */
int bFulltext; /* True if full-text index was used */
Fts3SegReaderCursor *pSegcsr; /* Segment-reader for this token */
Fts3DeferredToken *pDeferred; /* Deferred token object for this token */
};
struct Fts3Phrase {
/* Variables populated by fts3_expr.c when parsing a MATCH expression */
int nToken; /* Number of tokens in the phrase */
int iColumn; /* Index of column this phrase must match */
int isNot; /* Phrase prefixed by unary not (-) operator */
Fts3PhraseToken aToken[1]; /* One entry for each token in the phrase */
};
/*
** A tree of these objects forms the RHS of a MATCH operator.
**
** If Fts3Expr.eType is either FTSQUERY_NEAR or FTSQUERY_PHRASE and isLoaded
** is true, then aDoclist points to a malloced buffer, size nDoclist bytes,
** containing the results of the NEAR or phrase query in FTS3 doclist
** format. As usual, the initial "Length" field found in doclists stored
** on disk is omitted from this buffer.
**
** Variable pCurrent always points to the start of a docid field within
** aDoclist. Since the doclist is usually scanned in docid order, this can
** be used to accelerate seeking to the required docid within the doclist.
*/
struct Fts3Expr {
int eType; /* One of the FTSQUERY_XXX values defined below */
int nNear; /* Valid if eType==FTSQUERY_NEAR */
Fts3Expr *pParent; /* pParent->pLeft==this or pParent->pRight==this */
Fts3Expr *pLeft; /* Left operand */
Fts3Expr *pRight; /* Right operand */
Fts3Phrase *pPhrase; /* Valid if eType==FTSQUERY_PHRASE */
int isLoaded; /* True if aDoclist/nDoclist are initialized. */
char *aDoclist; /* Buffer containing doclist */
int nDoclist; /* Size of aDoclist in bytes */
sqlite3_int64 iCurrent;
char *pCurrent;
};
/*
** Candidate values for Fts3Query.eType. Note that the order of the first
** four values is in order of precedence when parsing expressions. For
** example, the following:
**
** "a OR b AND c NOT d NEAR e"
**
** is equivalent to:
**
** "a OR (b AND (c NOT (d NEAR e)))"
*/
#define FTSQUERY_NEAR 1
#define FTSQUERY_NOT 2
#define FTSQUERY_AND 3
#define FTSQUERY_OR 4
#define FTSQUERY_PHRASE 5
/* fts3_write.c */
int sqlite3Fts3UpdateMethod(sqlite3_vtab*,int,sqlite3_value**,sqlite3_int64*);
int sqlite3Fts3PendingTermsFlush(Fts3Table *);
void sqlite3Fts3PendingTermsClear(Fts3Table *);
int sqlite3Fts3Optimize(Fts3Table *);
int sqlite3Fts3SegReaderNew(int, sqlite3_int64,
sqlite3_int64, sqlite3_int64, const char *, int, Fts3SegReader**);
int sqlite3Fts3SegReaderPending(Fts3Table*,const char*,int,int,Fts3SegReader**);
void sqlite3Fts3SegReaderFree(Fts3SegReader *);
int sqlite3Fts3SegReaderCost(Fts3Cursor *, Fts3SegReader *, int *);
int sqlite3Fts3AllSegdirs(Fts3Table*, int, sqlite3_stmt **);
int sqlite3Fts3ReadLock(Fts3Table *);
int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*);
int sqlite3Fts3SelectDoctotal(Fts3Table *, sqlite3_stmt **);
int sqlite3Fts3SelectDocsize(Fts3Table *, sqlite3_int64, sqlite3_stmt **);
void sqlite3Fts3FreeDeferredTokens(Fts3Cursor *);
int sqlite3Fts3DeferToken(Fts3Cursor *, Fts3PhraseToken *, int);
int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *);
void sqlite3Fts3FreeDeferredDoclists(Fts3Cursor *);
char *sqlite3Fts3DeferredDoclist(Fts3DeferredToken *, int *);
void sqlite3Fts3SegmentsClose(Fts3Table *);
#define FTS3_SEGCURSOR_PENDING -1
#define FTS3_SEGCURSOR_ALL -2
int sqlite3Fts3SegReaderStart(Fts3Table*, Fts3SegReaderCursor*, Fts3SegFilter*);
int sqlite3Fts3SegReaderStep(Fts3Table *, Fts3SegReaderCursor *);
void sqlite3Fts3SegReaderFinish(Fts3SegReaderCursor *);
int sqlite3Fts3SegReaderCursor(
Fts3Table *, int, const char *, int, int, int, Fts3SegReaderCursor *);
/* Flags allowed as part of the 4th argument to SegmentReaderIterate() */
#define FTS3_SEGMENT_REQUIRE_POS 0x00000001
#define FTS3_SEGMENT_IGNORE_EMPTY 0x00000002
#define FTS3_SEGMENT_COLUMN_FILTER 0x00000004
#define FTS3_SEGMENT_PREFIX 0x00000008
#define FTS3_SEGMENT_SCAN 0x00000010
/* Type passed as 4th argument to SegmentReaderIterate() */
struct Fts3SegFilter {
const char *zTerm;
int nTerm;
int iCol;
int flags;
};
struct Fts3SegReaderCursor {
/* Used internally by sqlite3Fts3SegReaderXXX() calls */
Fts3SegReader **apSegment; /* Array of Fts3SegReader objects */
int nSegment; /* Size of apSegment array */
int nAdvance; /* How many seg-readers to advance */
Fts3SegFilter *pFilter; /* Pointer to filter object */
char *aBuffer; /* Buffer to merge doclists in */
int nBuffer; /* Allocated size of aBuffer[] in bytes */
/* Cost of running this iterator. Used by fts3.c only. */
int nCost;
/* Output values. Valid only after Fts3SegReaderStep() returns SQLITE_ROW. */
char *zTerm; /* Pointer to term buffer */
int nTerm; /* Size of zTerm in bytes */
char *aDoclist; /* Pointer to doclist buffer */
int nDoclist; /* Size of aDoclist[] in bytes */
};
/* fts3.c */
int sqlite3Fts3PutVarint(char *, sqlite3_int64);
int sqlite3Fts3GetVarint(const char *, sqlite_int64 *);
int sqlite3Fts3GetVarint32(const char *, int *);
int sqlite3Fts3VarintLen(sqlite3_uint64);
void sqlite3Fts3Dequote(char *);
char *sqlite3Fts3FindPositions(Fts3Expr *, sqlite3_int64, int);
int sqlite3Fts3ExprLoadDoclist(Fts3Cursor *, Fts3Expr *);
int sqlite3Fts3ExprLoadFtDoclist(Fts3Cursor *, Fts3Expr *, char **, int *);
int sqlite3Fts3ExprNearTrim(Fts3Expr *, Fts3Expr *, int);
/* fts3_tokenizer.c */
const char *sqlite3Fts3NextToken(const char *, int *);
int sqlite3Fts3InitHashTable(sqlite3 *, Fts3Hash *, const char *);
int sqlite3Fts3InitTokenizer(Fts3Hash *pHash, const char *,
sqlite3_tokenizer **, char **
);
int sqlite3Fts3IsIdChar(char);
/* fts3_snippet.c */
void sqlite3Fts3Offsets(sqlite3_context*, Fts3Cursor*);
void sqlite3Fts3Snippet(sqlite3_context *, Fts3Cursor *, const char *,
const char *, const char *, int, int
);
void sqlite3Fts3Matchinfo(sqlite3_context *, Fts3Cursor *, const char *);
/* fts3_expr.c */
int sqlite3Fts3ExprParse(sqlite3_tokenizer *,
char **, int, int, const char *, int, Fts3Expr **
);
void sqlite3Fts3ExprFree(Fts3Expr *);
#ifdef SQLITE_TEST
int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
#endif
/* fts3_aux.c */
int sqlite3Fts3InitAux(sqlite3 *db);
#endif /* _FTSINT_H */