/* ** 2001 September 15 ** ** 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. ** ************************************************************************* ** Internal interface definitions for SQLite. ** ** @(#) $Id: sqliteInt.h,v 1.779 2008/10/07 23:46:38 drh Exp $ */ #ifndef _SQLITEINT_H_ #define _SQLITEINT_H_ /* ** Include the configuration header output by 'configure' if we're using the ** autoconf-based build */ #ifdef _HAVE_SQLITE_CONFIG_H #include "config.h" #endif #include "sqliteLimit.h" /* Disable nuisance warnings on Borland compilers */ #if defined(__BORLANDC__) #pragma warn -rch /* unreachable code */ #pragma warn -ccc /* Condition is always true or false */ #pragma warn -aus /* Assigned value is never used */ #pragma warn -csu /* Comparing signed and unsigned */ #pragma warn -spa /* Suspicous pointer arithmetic */ #endif /* Needed for various definitions... */ #ifndef _GNU_SOURCE # define _GNU_SOURCE #endif /* ** Include standard header files as necessary */ #ifdef HAVE_STDINT_H #include #endif #ifdef HAVE_INTTYPES_H #include #endif /* ** A macro used to aid in coverage testing. When doing coverage ** testing, the condition inside the argument must be evaluated ** both true and false in order to get full branch coverage. ** This macro can be inserted to ensure adequate test coverage ** in places where simple condition/decision coverage is inadequate. */ #ifdef SQLITE_COVERAGE_TEST void sqlite3Coverage(int); # define testcase(X) if( X ){ sqlite3Coverage(__LINE__); } #else # define testcase(X) #endif /* ** The ALWAYS and NEVER macros surround boolean expressions which ** are intended to always be true or false, respectively. Such ** expressions could be omitted from the code completely. But they ** are included in a few cases in order to enhance the resilience ** of SQLite to unexpected behavior - to make the code "self-healing" ** or "ductile" rather than being "brittle" and crashing at the first ** hint of unplanned behavior. ** ** When doing coverage testing ALWAYS and NEVER are hard-coded to ** be true and false so that the unreachable code then specify will ** not be counted as untested code. */ #ifdef SQLITE_COVERAGE_TEST # define ALWAYS(X) (1) # define NEVER(X) (0) #else # define ALWAYS(X) (X) # define NEVER(X) (X) #endif /* ** The macro unlikely() is a hint that surrounds a boolean ** expression that is usually false. Macro likely() surrounds ** a boolean expression that is usually true. GCC is able to ** use these hints to generate better code, sometimes. */ #if defined(__GNUC__) && 0 # define likely(X) __builtin_expect((X),1) # define unlikely(X) __builtin_expect((X),0) #else # define likely(X) !!(X) # define unlikely(X) !!(X) #endif /* * This macro is used to "hide" some ugliness in casting an int * value to a ptr value under the MSVC 64-bit compiler. Casting * non 64-bit values to ptr types results in a "hard" error with * the MSVC 64-bit compiler which this attempts to avoid. * * A simple compiler pragma or casting sequence could not be found * to correct this in all situations, so this macro was introduced. * * It could be argued that the intptr_t type could be used in this * case, but that type is not available on all compilers, or * requires the #include of specific headers which differs between * platforms. */ #define SQLITE_INT_TO_PTR(X) ((void*)&((char*)0)[X]) #define SQLITE_PTR_TO_INT(X) ((int)(((char*)X)-(char*)0)) /* ** These #defines should enable >2GB file support on Posix if the ** underlying operating system supports it. If the OS lacks ** large file support, or if the OS is windows, these should be no-ops. ** ** Ticket #2739: The _LARGEFILE_SOURCE macro must appear before any ** system #includes. Hence, this block of code must be the very first ** code in all source files. ** ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch ** on the compiler command line. This is necessary if you are compiling ** on a recent machine (ex: RedHat 7.2) but you want your code to work ** on an older machine (ex: RedHat 6.0). If you compile on RedHat 7.2 ** without this option, LFS is enable. But LFS does not exist in the kernel ** in RedHat 6.0, so the code won't work. Hence, for maximum binary ** portability you should omit LFS. ** ** Similar is true for MacOS. LFS is only supported on MacOS 9 and later. */ #ifndef SQLITE_DISABLE_LFS # define _LARGE_FILE 1 # ifndef _FILE_OFFSET_BITS # define _FILE_OFFSET_BITS 64 # endif # define _LARGEFILE_SOURCE 1 #endif /* ** The SQLITE_THREADSAFE macro must be defined as either 0 or 1. ** Older versions of SQLite used an optional THREADSAFE macro. ** We support that for legacy */ #if !defined(SQLITE_THREADSAFE) #if defined(THREADSAFE) # define SQLITE_THREADSAFE THREADSAFE #else # define SQLITE_THREADSAFE 1 #endif #endif /* ** The SQLITE_DEFAULT_MEMSTATUS macro must be defined as either 0 or 1. ** It determines whether or not the features related to ** SQLITE_CONFIG_MEMSTATUS are availabe by default or not. This value can ** be overridden at runtime using the sqlite3_config() API. */ #if !defined(SQLITE_DEFAULT_MEMSTATUS) # define SQLITE_DEFAULT_MEMSTATUS 1 #endif /* ** Exactly one of the following macros must be defined in order to ** specify which memory allocation subsystem to use. ** ** SQLITE_SYSTEM_MALLOC // Use normal system malloc() ** SQLITE_MEMDEBUG // Debugging version of system malloc() ** SQLITE_MEMORY_SIZE // internal allocator #1 ** SQLITE_MMAP_HEAP_SIZE // internal mmap() allocator ** SQLITE_POW2_MEMORY_SIZE // internal power-of-two allocator ** ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as ** the default. */ #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\ defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\ defined(SQLITE_POW2_MEMORY_SIZE)>1 # error "At most one of the following compile-time configuration options\ is allows: SQLITE_SYSTEM_MALLOC, SQLITE_MEMDEBUG, SQLITE_MEMORY_SIZE,\ SQLITE_MMAP_HEAP_SIZE, SQLITE_POW2_MEMORY_SIZE" #endif #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\ defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\ defined(SQLITE_POW2_MEMORY_SIZE)==0 # define SQLITE_SYSTEM_MALLOC 1 #endif /* ** If SQLITE_MALLOC_SOFT_LIMIT is defined, then try to keep the ** sizes of memory allocations below this value where possible. */ #if defined(SQLITE_POW2_MEMORY_SIZE) && !defined(SQLITE_MALLOC_SOFT_LIMIT) # define SQLITE_MALLOC_SOFT_LIMIT 1024 #endif /* ** We need to define _XOPEN_SOURCE as follows in order to enable ** recursive mutexes on most unix systems. But Mac OS X is different. ** The _XOPEN_SOURCE define causes problems for Mac OS X we are told, ** so it is omitted there. See ticket #2673. ** ** Later we learn that _XOPEN_SOURCE is poorly or incorrectly ** implemented on some systems. So we avoid defining it at all ** if it is already defined or if it is unneeded because we are ** not doing a threadsafe build. Ticket #2681. ** ** See also ticket #2741. */ #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE # define _XOPEN_SOURCE 500 /* Needed to enable pthread recursive mutexes */ #endif /* ** The TCL headers are only needed when compiling the TCL bindings. */ #if defined(SQLITE_TCL) || defined(TCLSH) # include #endif /* ** Many people are failing to set -DNDEBUG=1 when compiling SQLite. ** Setting NDEBUG makes the code smaller and run faster. So the following ** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1 ** option is set. Thus NDEBUG becomes an opt-in rather than an opt-out ** feature. */ #if !defined(NDEBUG) && !defined(SQLITE_DEBUG) # define NDEBUG 1 #endif #include "sqlite3.h" #include "hash.h" #include "parse.h" #include #include #include #include #include /* ** If compiling for a processor that lacks floating point support, ** substitute integer for floating-point */ #ifdef SQLITE_OMIT_FLOATING_POINT # define double sqlite_int64 # define LONGDOUBLE_TYPE sqlite_int64 # ifndef SQLITE_BIG_DBL # define SQLITE_BIG_DBL (0x7fffffffffffffff) # endif # define SQLITE_OMIT_DATETIME_FUNCS 1 # define SQLITE_OMIT_TRACE 1 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT #endif #ifndef SQLITE_BIG_DBL # define SQLITE_BIG_DBL (1e99) #endif /* ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0 ** afterward. Having this macro allows us to cause the C compiler ** to omit code used by TEMP tables without messy #ifndef statements. */ #ifdef SQLITE_OMIT_TEMPDB #define OMIT_TEMPDB 1 #else #define OMIT_TEMPDB 0 #endif /* ** If the following macro is set to 1, then NULL values are considered ** distinct when determining whether or not two entries are the same ** in a UNIQUE index. This is the way PostgreSQL, Oracle, DB2, MySQL, ** OCELOT, and Firebird all work. The SQL92 spec explicitly says this ** is the way things are suppose to work. ** ** If the following macro is set to 0, the NULLs are indistinct for ** a UNIQUE index. In this mode, you can only have a single NULL entry ** for a column declared UNIQUE. This is the way Informix and SQL Server ** work. */ #define NULL_DISTINCT_FOR_UNIQUE 1 /* ** The "file format" number is an integer that is incremented whenever ** the VDBE-level file format changes. The following macros define the ** the default file format for new databases and the maximum file format ** that the library can read. */ #define SQLITE_MAX_FILE_FORMAT 4 #ifndef SQLITE_DEFAULT_FILE_FORMAT # define SQLITE_DEFAULT_FILE_FORMAT 1 #endif /* ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified ** on the command-line */ #ifndef SQLITE_TEMP_STORE # define SQLITE_TEMP_STORE 1 #endif /* ** GCC does not define the offsetof() macro so we'll have to do it ** ourselves. */ #ifndef offsetof #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD)) #endif /* ** Check to see if this machine uses EBCDIC. (Yes, believe it or ** not, there are still machines out there that use EBCDIC.) */ #if 'A' == '\301' # define SQLITE_EBCDIC 1 #else # define SQLITE_ASCII 1 #endif /* ** Integers of known sizes. These typedefs might change for architectures ** where the sizes very. Preprocessor macros are available so that the ** types can be conveniently redefined at compile-type. Like this: ** ** cc '-DUINTPTR_TYPE=long long int' ... */ #ifndef UINT32_TYPE # ifdef HAVE_UINT32_T # define UINT32_TYPE uint32_t # else # define UINT32_TYPE unsigned int # endif #endif #ifndef UINT16_TYPE # ifdef HAVE_UINT16_T # define UINT16_TYPE uint16_t # else # define UINT16_TYPE unsigned short int # endif #endif #ifndef INT16_TYPE # ifdef HAVE_INT16_T # define INT16_TYPE int16_t # else # define INT16_TYPE short int # endif #endif #ifndef UINT8_TYPE # ifdef HAVE_UINT8_T # define UINT8_TYPE uint8_t # else # define UINT8_TYPE unsigned char # endif #endif #ifndef INT8_TYPE # ifdef HAVE_INT8_T # define INT8_TYPE int8_t # else # define INT8_TYPE signed char # endif #endif #ifndef LONGDOUBLE_TYPE # define LONGDOUBLE_TYPE long double #endif typedef sqlite_int64 i64; /* 8-byte signed integer */ typedef sqlite_uint64 u64; /* 8-byte unsigned integer */ typedef UINT32_TYPE u32; /* 4-byte unsigned integer */ typedef UINT16_TYPE u16; /* 2-byte unsigned integer */ typedef INT16_TYPE i16; /* 2-byte signed integer */ typedef UINT8_TYPE u8; /* 1-byte unsigned integer */ typedef INT8_TYPE i8; /* 1-byte signed integer */ /* ** Macros to determine whether the machine is big or little endian, ** evaluated at runtime. */ #ifdef SQLITE_AMALGAMATION const int sqlite3one; #else extern const int sqlite3one; #endif #if defined(i386) || defined(__i386__) || defined(_M_IX86) # define SQLITE_BIGENDIAN 0 # define SQLITE_LITTLEENDIAN 1 # define SQLITE_UTF16NATIVE SQLITE_UTF16LE #else # define SQLITE_BIGENDIAN (*(char *)(&sqlite3one)==0) # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1) # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE) #endif /* ** Constants for the largest and smallest possible 64-bit signed integers. ** These macros are designed to work correctly on both 32-bit and 64-bit ** compilers. */ #define LARGEST_INT64 (0xffffffff|(((i64)0x7fffffff)<<32)) #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64) /* ** An instance of the following structure is used to store the busy-handler ** callback for a given sqlite handle. ** ** The sqlite.busyHandler member of the sqlite struct contains the busy ** callback for the database handle. Each pager opened via the sqlite ** handle is passed a pointer to sqlite.busyHandler. The busy-handler ** callback is currently invoked only from within pager.c. */ typedef struct BusyHandler BusyHandler; struct BusyHandler { int (*xFunc)(void *,int); /* The busy callback */ void *pArg; /* First arg to busy callback */ int nBusy; /* Incremented with each busy call */ }; /* ** Name of the master database table. The master database table ** is a special table that holds the names and attributes of all ** user tables and indices. */ #define MASTER_NAME "sqlite_master" #define TEMP_MASTER_NAME "sqlite_temp_master" /* ** The root-page of the master database table. */ #define MASTER_ROOT 1 /* ** The name of the schema table. */ #define SCHEMA_TABLE(x) ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME) /* ** A convenience macro that returns the number of elements in ** an array. */ #define ArraySize(X) (sizeof(X)/sizeof(X[0])) /* ** The following value as a destructor means to use sqlite3DbFree(). ** This is an internal extension to SQLITE_STATIC and SQLITE_TRANSIENT. */ #define SQLITE_DYNAMIC ((sqlite3_destructor_type)sqlite3DbFree) /* ** When SQLITE_OMIT_WSD is defined, it means that the target platform does ** not support Writable Static Data (WSD) such as global and static variables. ** All variables must either be on the stack or dynamically allocated from ** the heap. When WSD is unsupported, the variable declarations scattered ** throughout the SQLite code must become constants instead. The SQLITE_WSD ** macro is used for this purpose. And instead of referencing the variable ** directly, we use its constant as a key to lookup the run-time allocated ** buffer that holds real variable. The constant is also the initializer ** for the run-time allocated buffer. ** ** In the usually case where WSD is supported, the SQLITE_WSD and GLOBAL ** macros become no-ops and have zero performance impact. */ #ifdef SQLITE_OMIT_WSD #define SQLITE_WSD const #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v))) #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config) int sqlite3_wsd_init(int N, int J); void *sqlite3_wsd_find(void *K, int L); #else #define SQLITE_WSD #define GLOBAL(t,v) v #define sqlite3GlobalConfig sqlite3Config #endif /* ** Forward references to structures */ typedef struct AggInfo AggInfo; typedef struct AuthContext AuthContext; typedef struct Bitvec Bitvec; typedef struct CollSeq CollSeq; typedef struct Column Column; typedef struct Db Db; typedef struct Schema Schema; typedef struct Expr Expr; typedef struct ExprList ExprList; typedef struct FKey FKey; typedef struct FuncDef FuncDef; typedef struct FuncDefHash FuncDefHash; typedef struct IdList IdList; typedef struct Index Index; typedef struct KeyClass KeyClass; typedef struct KeyInfo KeyInfo; typedef struct Lookaside Lookaside; typedef struct LookasideSlot LookasideSlot; typedef struct Module Module; typedef struct NameContext NameContext; typedef struct Parse Parse; typedef struct Select Select; typedef struct SrcList SrcList; typedef struct StrAccum StrAccum; typedef struct Table Table; typedef struct TableLock TableLock; typedef struct Token Token; typedef struct TriggerStack TriggerStack; typedef struct TriggerStep TriggerStep; typedef struct Trigger Trigger; typedef struct UnpackedRecord UnpackedRecord; typedef struct Walker Walker; typedef struct WhereInfo WhereInfo; typedef struct WhereLevel WhereLevel; /* ** Defer sourcing vdbe.h and btree.h until after the "u8" and ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque ** pointer types (i.e. FuncDef) defined above. */ #include "btree.h" #include "vdbe.h" #include "pager.h" #include "pcache.h" #include "os.h" #include "mutex.h" /* ** Each database file to be accessed by the system is an instance ** of the following structure. There are normally two of these structures ** in the sqlite.aDb[] array. aDb[0] is the main database file and ** aDb[1] is the database file used to hold temporary tables. Additional ** databases may be attached. */ struct Db { char *zName; /* Name of this database */ Btree *pBt; /* The B*Tree structure for this database file */ u8 inTrans; /* 0: not writable. 1: Transaction. 2: Checkpoint */ u8 safety_level; /* How aggressive at synching data to disk */ void *pAux; /* Auxiliary data. Usually NULL */ void (*xFreeAux)(void*); /* Routine to free pAux */ Schema *pSchema; /* Pointer to database schema (possibly shared) */ }; /* ** An instance of the following structure stores a database schema. ** ** If there are no virtual tables configured in this schema, the ** Schema.db variable is set to NULL. After the first virtual table ** has been added, it is set to point to the database connection ** used to create the connection. Once a virtual table has been ** added to the Schema structure and the Schema.db variable populated, ** only that database connection may use the Schema to prepare ** statements. */ struct Schema { int schema_cookie; /* Database schema version number for this file */ Hash tblHash; /* All tables indexed by name */ Hash idxHash; /* All (named) indices indexed by name */ Hash trigHash; /* All triggers indexed by name */ Hash aFKey; /* Foreign keys indexed by to-table */ Table *pSeqTab; /* The sqlite_sequence table used by AUTOINCREMENT */ u8 file_format; /* Schema format version for this file */ u8 enc; /* Text encoding used by this database */ u16 flags; /* Flags associated with this schema */ int cache_size; /* Number of pages to use in the cache */ #ifndef SQLITE_OMIT_VIRTUALTABLE sqlite3 *db; /* "Owner" connection. See comment above */ #endif }; /* ** These macros can be used to test, set, or clear bits in the ** Db.flags field. */ #define DbHasProperty(D,I,P) (((D)->aDb[I].pSchema->flags&(P))==(P)) #define DbHasAnyProperty(D,I,P) (((D)->aDb[I].pSchema->flags&(P))!=0) #define DbSetProperty(D,I,P) (D)->aDb[I].pSchema->flags|=(P) #define DbClearProperty(D,I,P) (D)->aDb[I].pSchema->flags&=~(P) /* ** Allowed values for the DB.flags field. ** ** The DB_SchemaLoaded flag is set after the database schema has been ** read into internal hash tables. ** ** DB_UnresetViews means that one or more views have column names that ** have been filled out. If the schema changes, these column names might ** changes and so the view will need to be reset. */ #define DB_SchemaLoaded 0x0001 /* The schema has been loaded */ #define DB_UnresetViews 0x0002 /* Some views have defined column names */ #define DB_Empty 0x0004 /* The file is empty (length 0 bytes) */ /* ** The number of different kinds of things that can be limited ** using the sqlite3_limit() interface. */ #define SQLITE_N_LIMIT (SQLITE_LIMIT_VARIABLE_NUMBER+1) /* ** Lookaside malloc is a set of fixed-size buffers that can be used ** to satisify small transient memory allocation requests for objects ** associated with a particular database connection. The use of ** lookaside malloc provides a significant performance enhancement ** (approx 10%) by avoiding numerous malloc/free requests while parsing ** SQL statements. ** ** The Lookaside structure holds configuration information about the ** lookaside malloc subsystem. Each available memory allocation in ** the lookaside subsystem is stored on a linked list of LookasideSlot ** objects. */ struct Lookaside { u16 sz; /* Size of each buffer in bytes */ u8 bEnabled; /* True if use lookaside. False to ignore it */ u8 bMalloced; /* True if pStart obtained from sqlite3_malloc() */ int nOut; /* Number of buffers currently checked out */ int mxOut; /* Highwater mark for nOut */ LookasideSlot *pFree; /* List of available buffers */ void *pStart; /* First byte of available memory space */ void *pEnd; /* First byte past end of available space */ }; struct LookasideSlot { LookasideSlot *pNext; /* Next buffer in the list of free buffers */ }; /* ** A hash table for function definitions. ** ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots. ** Collisions are on the FuncDef.pHash chain. */ struct FuncDefHash { FuncDef *a[23]; /* Hash table for functions */ }; /* ** Each database is an instance of the following structure. ** ** The sqlite.lastRowid records the last insert rowid generated by an ** insert statement. Inserts on views do not affect its value. Each ** trigger has its own context, so that lastRowid can be updated inside ** triggers as usual. The previous value will be restored once the trigger ** exits. Upon entering a before or instead of trigger, lastRowid is no ** longer (since after version 2.8.12) reset to -1. ** ** The sqlite.nChange does not count changes within triggers and keeps no ** context. It is reset at start of sqlite3_exec. ** The sqlite.lsChange represents the number of changes made by the last ** insert, update, or delete statement. It remains constant throughout the ** length of a statement and is then updated by OP_SetCounts. It keeps a ** context stack just like lastRowid so that the count of changes ** within a trigger is not seen outside the trigger. Changes to views do not ** affect the value of lsChange. ** The sqlite.csChange keeps track of the number of current changes (since ** the last statement) and is used to update sqlite_lsChange. ** ** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16 ** store the most recent error code and, if applicable, string. The ** internal function sqlite3Error() is used to set these variables ** consistently. */ struct sqlite3 { sqlite3_vfs *pVfs; /* OS Interface */ int nDb; /* Number of backends currently in use */ Db *aDb; /* All backends */ int flags; /* Miscellanous flags. See below */ int openFlags; /* Flags passed to sqlite3_vfs.xOpen() */ int errCode; /* Most recent error code (SQLITE_*) */ int errMask; /* & result codes with this before returning */ u8 autoCommit; /* The auto-commit flag. */ u8 temp_store; /* 1: file 2: memory 0: default */ u8 mallocFailed; /* True if we have seen a malloc failure */ u8 dfltLockMode; /* Default locking-mode for attached dbs */ u8 dfltJournalMode; /* Default journal mode for attached dbs */ signed char nextAutovac; /* Autovac setting after VACUUM if >=0 */ int nextPagesize; /* Pagesize after VACUUM if >0 */ int nTable; /* Number of tables in the database */ CollSeq *pDfltColl; /* The default collating sequence (BINARY) */ i64 lastRowid; /* ROWID of most recent insert (see above) */ i64 priorNewRowid; /* Last randomly generated ROWID */ int magic; /* Magic number for detect library misuse */ int nChange; /* Value returned by sqlite3_changes() */ int nTotalChange; /* Value returned by sqlite3_total_changes() */ sqlite3_mutex *mutex; /* Connection mutex */ int aLimit[SQLITE_N_LIMIT]; /* Limits */ struct sqlite3InitInfo { /* Information used during initialization */ int iDb; /* When back is being initialized */ int newTnum; /* Rootpage of table being initialized */ u8 busy; /* TRUE if currently initializing */ } init; int nExtension; /* Number of loaded extensions */ void **aExtension; /* Array of shared libraray handles */ struct Vdbe *pVdbe; /* List of active virtual machines */ int activeVdbeCnt; /* Number of vdbes currently executing */ void (*xTrace)(void*,const char*); /* Trace function */ void *pTraceArg; /* Argument to the trace function */ void (*xProfile)(void*,const char*,u64); /* Profiling function */ void *pProfileArg; /* Argument to profile function */ void *pCommitArg; /* Argument to xCommitCallback() */ int (*xCommitCallback)(void*); /* Invoked at every commit. */ void *pRollbackArg; /* Argument to xRollbackCallback() */ void (*xRollbackCallback)(void*); /* Invoked at every commit. */ void *pUpdateArg; void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64); void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*); void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*); void *pCollNeededArg; sqlite3_value *pErr; /* Most recent error message */ char *zErrMsg; /* Most recent error message (UTF-8 encoded) */ char *zErrMsg16; /* Most recent error message (UTF-16 encoded) */ union { volatile int isInterrupted; /* True if sqlite3_interrupt has been called */ double notUsed1; /* Spacer */ } u1; Lookaside lookaside; /* Lookaside malloc configuration */ #ifndef SQLITE_OMIT_AUTHORIZATION int (*xAuth)(void*,int,const char*,const char*,const char*,const char*); /* Access authorization function */ void *pAuthArg; /* 1st argument to the access auth function */ #endif #ifndef SQLITE_OMIT_PROGRESS_CALLBACK int (*xProgress)(void *); /* The progress callback */ void *pProgressArg; /* Argument to the progress callback */ int nProgressOps; /* Number of opcodes for progress callback */ #endif #ifndef SQLITE_OMIT_VIRTUALTABLE Hash aModule; /* populated by sqlite3_create_module() */ Table *pVTab; /* vtab with active Connect/Create method */ sqlite3_vtab **aVTrans; /* Virtual tables with open transactions */ int nVTrans; /* Allocated size of aVTrans */ #endif FuncDefHash aFunc; /* Hash table of connection functions */ Hash aCollSeq; /* All collating sequences */ BusyHandler busyHandler; /* Busy callback */ int busyTimeout; /* Busy handler timeout, in msec */ Db aDbStatic[2]; /* Static space for the 2 default backends */ #ifdef SQLITE_SSE sqlite3_stmt *pFetch; /* Used by SSE to fetch stored statements */ #endif }; /* ** A macro to discover the encoding of a database. */ #define ENC(db) ((db)->aDb[0].pSchema->enc) /* ** Possible values for the sqlite.flags and or Db.flags fields. ** ** On sqlite.flags, the SQLITE_InTrans value means that we have ** executed a BEGIN. On Db.flags, SQLITE_InTrans means a statement ** transaction is active on that particular database file. */ #define SQLITE_VdbeTrace 0x00000001 /* True to trace VDBE execution */ #define SQLITE_InTrans 0x00000008 /* True if in a transaction */ #define SQLITE_InternChanges 0x00000010 /* Uncommitted Hash table changes */ #define SQLITE_FullColNames 0x00000020 /* Show full column names on SELECT */ #define SQLITE_ShortColNames 0x00000040 /* Show short columns names */ #define SQLITE_CountRows 0x00000080 /* Count rows changed by INSERT, */ /* DELETE, or UPDATE and return */ /* the count using a callback. */ #define SQLITE_NullCallback 0x00000100 /* Invoke the callback once if the */ /* result set is empty */ #define SQLITE_SqlTrace 0x00000200 /* Debug print SQL as it executes */ #define SQLITE_VdbeListing 0x00000400 /* Debug listings of VDBE programs */ #define SQLITE_WriteSchema 0x00000800 /* OK to update SQLITE_MASTER */ #define SQLITE_NoReadlock 0x00001000 /* Readlocks are omitted when ** accessing read-only databases */ #define SQLITE_IgnoreChecks 0x00002000 /* Do not enforce check constraints */ #define SQLITE_ReadUncommitted 0x00004000 /* For shared-cache mode */ #define SQLITE_LegacyFileFmt 0x00008000 /* Create new databases in format 1 */ #define SQLITE_FullFSync 0x00010000 /* Use full fsync on the backend */ #define SQLITE_LoadExtension 0x00020000 /* Enable load_extension */ #define SQLITE_RecoveryMode 0x00040000 /* Ignore schema errors */ #define SQLITE_SharedCache 0x00080000 /* Cache sharing is enabled */ #define SQLITE_Vtab 0x00100000 /* There exists a virtual table */ /* ** Possible values for the sqlite.magic field. ** The numbers are obtained at random and have no special meaning, other ** than being distinct from one another. */ #define SQLITE_MAGIC_OPEN 0xa029a697 /* Database is open */ #define SQLITE_MAGIC_CLOSED 0x9f3c2d33 /* Database is closed */ #define SQLITE_MAGIC_SICK 0x4b771290 /* Error and awaiting close */ #define SQLITE_MAGIC_BUSY 0xf03b7906 /* Database currently in use */ #define SQLITE_MAGIC_ERROR 0xb5357930 /* An SQLITE_MISUSE error occurred */ /* ** Each SQL function is defined by an instance of the following ** structure. A pointer to this structure is stored in the sqlite.aFunc ** hash table. When multiple functions have the same name, the hash table ** points to a linked list of these structures. */ struct FuncDef { i16 nArg; /* Number of arguments. -1 means unlimited */ u8 iPrefEnc; /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */ u8 flags; /* Some combination of SQLITE_FUNC_* */ void *pUserData; /* User data parameter */ FuncDef *pNext; /* Next function with same name */ void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */ void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */ void (*xFinalize)(sqlite3_context*); /* Aggregate finializer */ char *zName; /* SQL name of the function. */ FuncDef *pHash; /* Next with a different name but the same hash */ }; /* ** Possible values for FuncDef.flags */ #define SQLITE_FUNC_LIKE 0x01 /* Candidate for the LIKE optimization */ #define SQLITE_FUNC_CASE 0x02 /* Case-sensitive LIKE-type function */ #define SQLITE_FUNC_EPHEM 0x04 /* Ephermeral. Delete with VDBE */ #define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */ /* ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are ** used to create the initializers for the FuncDef structures. ** ** FUNCTION(zName, nArg, iArg, bNC, xFunc) ** Used to create a scalar function definition of a function zName ** implemented by C function xFunc that accepts nArg arguments. The ** value passed as iArg is cast to a (void*) and made available ** as the user-data (sqlite3_user_data()) for the function. If ** argument bNC is true, then the FuncDef.needCollate flag is set. ** ** AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal) ** Used to create an aggregate function definition implemented by ** the C functions xStep and xFinal. The first four parameters ** are interpreted in the same way as the first 4 parameters to ** FUNCTION(). ** ** LIKEFUNC(zName, nArg, pArg, flags) ** Used to create a scalar function definition of a function zName ** that accepts nArg arguments and is implemented by a call to C ** function likeFunc. Argument pArg is cast to a (void *) and made ** available as the function user-data (sqlite3_user_data()). The ** FuncDef.flags variable is set to the value passed as the flags ** parameter. */ #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \ {nArg, SQLITE_UTF8, bNC*8, SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName} #define LIKEFUNC(zName, nArg, arg, flags) \ {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName} #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \ {nArg, SQLITE_UTF8, nc*8, SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal, #zName} /* ** Each SQLite module (virtual table definition) is defined by an ** instance of the following structure, stored in the sqlite3.aModule ** hash table. */ struct Module { const sqlite3_module *pModule; /* Callback pointers */ const char *zName; /* Name passed to create_module() */ void *pAux; /* pAux passed to create_module() */ void (*xDestroy)(void *); /* Module destructor function */ }; /* ** information about each column of an SQL table is held in an instance ** of this structure. */ struct Column { char *zName; /* Name of this column */ Expr *pDflt; /* Default value of this column */ char *zType; /* Data type for this column */ char *zColl; /* Collating sequence. If NULL, use the default */ u8 notNull; /* True if there is a NOT NULL constraint */ u8 isPrimKey; /* True if this column is part of the PRIMARY KEY */ char affinity; /* One of the SQLITE_AFF_... values */ #ifndef SQLITE_OMIT_VIRTUALTABLE u8 isHidden; /* True if this column is 'hidden' */ #endif }; /* ** A "Collating Sequence" is defined by an instance of the following ** structure. Conceptually, a collating sequence consists of a name and ** a comparison routine that defines the order of that sequence. ** ** There may two seperate implementations of the collation function, one ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine ** native byte order. When a collation sequence is invoked, SQLite selects ** the version that will require the least expensive encoding ** translations, if any. ** ** The CollSeq.pUser member variable is an extra parameter that passed in ** as the first argument to the UTF-8 comparison function, xCmp. ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function, ** xCmp16. ** ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the ** collating sequence is undefined. Indices built on an undefined ** collating sequence may not be read or written. */ struct CollSeq { char *zName; /* Name of the collating sequence, UTF-8 encoded */ u8 enc; /* Text encoding handled by xCmp() */ u8 type; /* One of the SQLITE_COLL_... values below */ void *pUser; /* First argument to xCmp() */ int (*xCmp)(void*,int, const void*, int, const void*); void (*xDel)(void*); /* Destructor for pUser */ }; /* ** Allowed values of CollSeq.type: */ #define SQLITE_COLL_BINARY 1 /* The default memcmp() collating sequence */ #define SQLITE_COLL_NOCASE 2 /* The built-in NOCASE collating sequence */ #define SQLITE_COLL_REVERSE 3 /* The built-in REVERSE collating sequence */ #define SQLITE_COLL_USER 0 /* Any other user-defined collating sequence */ /* ** A sort order can be either ASC or DESC. */ #define SQLITE_SO_ASC 0 /* Sort in ascending order */ #define SQLITE_SO_DESC 1 /* Sort in ascending order */ /* ** Column affinity types. ** ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and ** 't' for SQLITE_AFF_TEXT. But we can save a little space and improve ** the speed a little by numbering the values consecutively. ** ** But rather than start with 0 or 1, we begin with 'a'. That way, ** when multiple affinity types are concatenated into a string and ** used as the P4 operand, they will be more readable. ** ** Note also that the numeric types are grouped together so that testing ** for a numeric type is a single comparison. */ #define SQLITE_AFF_TEXT 'a' #define SQLITE_AFF_NONE 'b' #define SQLITE_AFF_NUMERIC 'c' #define SQLITE_AFF_INTEGER 'd' #define SQLITE_AFF_REAL 'e' #define sqlite3IsNumericAffinity(X) ((X)>=SQLITE_AFF_NUMERIC) /* ** The SQLITE_AFF_MASK values masks off the significant bits of an ** affinity value. */ #define SQLITE_AFF_MASK 0x67 /* ** Additional bit values that can be ORed with an affinity without ** changing the affinity. */ #define SQLITE_JUMPIFNULL 0x08 /* jumps if either operand is NULL */ #define SQLITE_STOREP2 0x10 /* Store result in reg[P2] rather than jump */ /* ** Each SQL table is represented in memory by an instance of the ** following structure. ** ** Table.zName is the name of the table. The case of the original ** CREATE TABLE statement is stored, but case is not significant for ** comparisons. ** ** Table.nCol is the number of columns in this table. Table.aCol is a ** pointer to an array of Column structures, one for each column. ** ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of ** the column that is that key. Otherwise Table.iPKey is negative. Note ** that the datatype of the PRIMARY KEY must be INTEGER for this field to ** be set. An INTEGER PRIMARY KEY is used as the rowid for each row of ** the table. If a table has no INTEGER PRIMARY KEY, then a random rowid ** is generated for each row of the table. TF_HasPrimaryKey is set if ** the table has any PRIMARY KEY, INTEGER or otherwise. ** ** Table.tnum is the page number for the root BTree page of the table in the ** database file. If Table.iDb is the index of the database table backend ** in sqlite.aDb[]. 0 is for the main database and 1 is for the file that ** holds temporary tables and indices. If TF_Ephemeral is set ** then the table is stored in a file that is automatically deleted ** when the VDBE cursor to the table is closed. In this case Table.tnum ** refers VDBE cursor number that holds the table open, not to the root ** page number. Transient tables are used to hold the results of a ** sub-query that appears instead of a real table name in the FROM clause ** of a SELECT statement. */ struct Table { sqlite3 *db; /* Associated database connection. Might be NULL. */ char *zName; /* Name of the table or view */ int iPKey; /* If not negative, use aCol[iPKey] as the primary key */ int nCol; /* Number of columns in this table */ Column *aCol; /* Information about each column */ Index *pIndex; /* List of SQL indexes on this table. */ int tnum; /* Root BTree node for this table (see note above) */ Select *pSelect; /* NULL for tables. Points to definition if a view. */ u16 nRef; /* Number of pointers to this Table */ u8 tabFlags; /* Mask of TF_* values */ u8 keyConf; /* What to do in case of uniqueness conflict on iPKey */ Trigger *pTrigger; /* List of SQL triggers on this table */ FKey *pFKey; /* Linked list of all foreign keys in this table */ char *zColAff; /* String defining the affinity of each column */ #ifndef SQLITE_OMIT_CHECK Expr *pCheck; /* The AND of all CHECK constraints */ #endif #ifndef SQLITE_OMIT_ALTERTABLE int addColOffset; /* Offset in CREATE TABLE stmt to add a new column */ #endif #ifndef SQLITE_OMIT_VIRTUALTABLE Module *pMod; /* Pointer to the implementation of the module */ sqlite3_vtab *pVtab; /* Pointer to the module instance */ int nModuleArg; /* Number of arguments to the module */ char **azModuleArg; /* Text of all module args. [0] is module name */ #endif Schema *pSchema; /* Schema that contains this table */ Table *pNextZombie; /* Next on the Parse.pZombieTab list */ }; /* ** Allowed values for Tabe.tabFlags. */ #define TF_Readonly 0x01 /* Read-only system table */ #define TF_Ephemeral 0x02 /* An emphermal table */ #define TF_HasPrimaryKey 0x04 /* Table has a primary key */ #define TF_Autoincrement 0x08 /* Integer primary key is autoincrement */ #define TF_Virtual 0x10 /* Is a virtual table */ #define TF_NeedMetadata 0x20 /* aCol[].zType and aCol[].pColl missing */ /* ** Test to see whether or not a table is a virtual table. This is ** done as a macro so that it will be optimized out when virtual ** table support is omitted from the build. */ #ifndef SQLITE_OMIT_VIRTUALTABLE # define IsVirtual(X) (((X)->tabFlags & TF_Virtual)!=0) # define IsHiddenColumn(X) ((X)->isHidden) #else # define IsVirtual(X) 0 # define IsHiddenColumn(X) 0 #endif /* ** Each foreign key constraint is an instance of the following structure. ** ** A foreign key is associated with two tables. The "from" table is ** the table that contains the REFERENCES clause that creates the foreign ** key. The "to" table is the table that is named in the REFERENCES clause. ** Consider this example: ** ** CREATE TABLE ex1( ** a INTEGER PRIMARY KEY, ** b INTEGER CONSTRAINT fk1 REFERENCES ex2(x) ** ); ** ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2". ** ** Each REFERENCES clause generates an instance of the following structure ** which is attached to the from-table. The to-table need not exist when ** the from-table is created. The existance of the to-table is not checked ** until an attempt is made to insert data into the from-table. ** ** The sqlite.aFKey hash table stores pointers to this structure ** given the name of a to-table. For each to-table, all foreign keys ** associated with that table are on a linked list using the FKey.pNextTo ** field. */ struct FKey { Table *pFrom; /* The table that constains the REFERENCES clause */ FKey *pNextFrom; /* Next foreign key in pFrom */ char *zTo; /* Name of table that the key points to */ FKey *pNextTo; /* Next foreign key that points to zTo */ int nCol; /* Number of columns in this key */ struct sColMap { /* Mapping of columns in pFrom to columns in zTo */ int iFrom; /* Index of column in pFrom */ char *zCol; /* Name of column in zTo. If 0 use PRIMARY KEY */ } *aCol; /* One entry for each of nCol column s */ u8 isDeferred; /* True if constraint checking is deferred till COMMIT */ u8 updateConf; /* How to resolve conflicts that occur on UPDATE */ u8 deleteConf; /* How to resolve conflicts that occur on DELETE */ u8 insertConf; /* How to resolve conflicts that occur on INSERT */ }; /* ** SQLite supports many different ways to resolve a constraint ** error. ROLLBACK processing means that a constraint violation ** causes the operation in process to fail and for the current transaction ** to be rolled back. ABORT processing means the operation in process ** fails and any prior changes from that one operation are backed out, ** but the transaction is not rolled back. FAIL processing means that ** the operation in progress stops and returns an error code. But prior ** changes due to the same operation are not backed out and no rollback ** occurs. IGNORE means that the particular row that caused the constraint ** error is not inserted or updated. Processing continues and no error ** is returned. REPLACE means that preexisting database rows that caused ** a UNIQUE constraint violation are removed so that the new insert or ** update can proceed. Processing continues and no error is reported. ** ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys. ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the ** same as ROLLBACK for DEFERRED keys. SETNULL means that the foreign ** key is set to NULL. CASCADE means that a DELETE or UPDATE of the ** referenced table row is propagated into the row that holds the ** foreign key. ** ** The following symbolic values are used to record which type ** of action to take. */ #define OE_None 0 /* There is no constraint to check */ #define OE_Rollback 1 /* Fail the operation and rollback the transaction */ #define OE_Abort 2 /* Back out changes but do no rollback transaction */ #define OE_Fail 3 /* Stop the operation but leave all prior changes */ #define OE_Ignore 4 /* Ignore the error. Do not do the INSERT or UPDATE */ #define OE_Replace 5 /* Delete existing record, then do INSERT or UPDATE */ #define OE_Restrict 6 /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */ #define OE_SetNull 7 /* Set the foreign key value to NULL */ #define OE_SetDflt 8 /* Set the foreign key value to its default */ #define OE_Cascade 9 /* Cascade the changes */ #define OE_Default 99 /* Do whatever the default action is */ /* ** An instance of the following structure is passed as the first ** argument to sqlite3VdbeKeyCompare and is used to control the ** comparison of the two index keys. */ struct KeyInfo { sqlite3 *db; /* The database connection */ u8 enc; /* Text encoding - one of the TEXT_Utf* values */ u16 nField; /* Number of entries in aColl[] */ u8 *aSortOrder; /* If defined an aSortOrder[i] is true, sort DESC */ CollSeq *aColl[1]; /* Collating sequence for each term of the key */ }; /* ** An instance of the following structure holds information about a ** single index record that has already been parsed out into individual ** values. ** ** A record is an object that contains one or more fields of data. ** Records are used to store the content of a table row and to store ** the key of an index. A blob encoding of a record is created by ** the OP_MakeRecord opcode of the VDBE and is disassemblied by the ** OP_Column opcode. ** ** This structure holds a record that has already been disassembled ** into its constitutent fields. */ struct UnpackedRecord { KeyInfo *pKeyInfo; /* Collation and sort-order information */ u16 nField; /* Number of entries in apMem[] */ u16 flags; /* Boolean settings. UNPACKED_... below */ Mem *aMem; /* Values */ }; /* ** Allowed values of UnpackedRecord.flags */ #define UNPACKED_NEED_FREE 0x0001 /* Memory is from sqlite3Malloc() */ #define UNPACKED_NEED_DESTROY 0x0002 /* apMem[]s should all be destroyed */ #define UNPACKED_IGNORE_ROWID 0x0004 /* Ignore trailing rowid on key1 */ #define UNPACKED_INCRKEY 0x0008 /* Make this key an epsilon larger */ #define UNPACKED_PREFIX_MATCH 0x0010 /* A prefix match is considered OK */ /* ** Each SQL index is represented in memory by an ** instance of the following structure. ** ** The columns of the table that are to be indexed are described ** by the aiColumn[] field of this structure. For example, suppose ** we have the following table and index: ** ** CREATE TABLE Ex1(c1 int, c2 int, c3 text); ** CREATE INDEX Ex2 ON Ex1(c3,c1); ** ** In the Table structure describing Ex1, nCol==3 because there are ** three columns in the table. In the Index structure describing ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed. ** The value of aiColumn is {2, 0}. aiColumn[0]==2 because the ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[]. ** The second column to be indexed (c1) has an index of 0 in ** Ex1.aCol[], hence Ex2.aiColumn[1]==0. ** ** The Index.onError field determines whether or not the indexed columns ** must be unique and what to do if they are not. When Index.onError=OE_None, ** it means this is not a unique index. Otherwise it is a unique index ** and the value of Index.onError indicate the which conflict resolution ** algorithm to employ whenever an attempt is made to insert a non-unique ** element. */ struct Index { char *zName; /* Name of this index */ int nColumn; /* Number of columns in the table used by this index */ int *aiColumn; /* Which columns are used by this index. 1st is 0 */ unsigned *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */ Table *pTable; /* The SQL table being indexed */ int tnum; /* Page containing root of this index in database file */ u8 onError; /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */ u8 autoIndex; /* True if is automatically created (ex: by UNIQUE) */ char *zColAff; /* String defining the affinity of each column */ Index *pNext; /* The next index associated with the same table */ Schema *pSchema; /* Schema containing this index */ u8 *aSortOrder; /* Array of size Index.nColumn. True==DESC, False==ASC */ char **azColl; /* Array of collation sequence names for index */ }; /* ** Each token coming out of the lexer is an instance of ** this structure. Tokens are also used as part of an expression. ** ** Note if Token.z==0 then Token.dyn and Token.n are undefined and ** may contain random values. Do not make any assuptions about Token.dyn ** and Token.n when Token.z==0. */ struct Token { const unsigned char *z; /* Text of the token. Not NULL-terminated! */ unsigned dyn : 1; /* True for malloced memory, false for static */ unsigned n : 31; /* Number of characters in this token */ }; /* ** An instance of this structure contains information needed to generate ** code for a SELECT that contains aggregate functions. ** ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a ** pointer to this structure. The Expr.iColumn field is the index in ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate ** code for that node. ** ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the ** original Select structure that describes the SELECT statement. These ** fields do not need to be freed when deallocating the AggInfo structure. */ struct AggInfo { u8 directMode; /* Direct rendering mode means take data directly ** from source tables rather than from accumulators */ u8 useSortingIdx; /* In direct mode, reference the sorting index rather ** than the source table */ int sortingIdx; /* Cursor number of the sorting index */ ExprList *pGroupBy; /* The group by clause */ int nSortingColumn; /* Number of columns in the sorting index */ struct AggInfo_col { /* For each column used in source tables */ Table *pTab; /* Source table */ int iTable; /* Cursor number of the source table */ int iColumn; /* Column number within the source table */ int iSorterColumn; /* Column number in the sorting index */ int iMem; /* Memory location that acts as accumulator */ Expr *pExpr; /* The original expression */ } *aCol; int nColumn; /* Number of used entries in aCol[] */ int nColumnAlloc; /* Number of slots allocated for aCol[] */ int nAccumulator; /* Number of columns that show through to the output. ** Additional columns are used only as parameters to ** aggregate functions */ struct AggInfo_func { /* For each aggregate function */ Expr *pExpr; /* Expression encoding the function */ FuncDef *pFunc; /* The aggregate function implementation */ int iMem; /* Memory location that acts as accumulator */ int iDistinct; /* Ephermeral table used to enforce DISTINCT */ } *aFunc; int nFunc; /* Number of entries in aFunc[] */ int nFuncAlloc; /* Number of slots allocated for aFunc[] */ }; /* ** Each node of an expression in the parse tree is an instance ** of this structure. ** ** Expr.op is the opcode. The integer parser token codes are reused ** as opcodes here. For example, the parser defines TK_GE to be an integer ** code representing the ">=" operator. This same integer code is reused ** to represent the greater-than-or-equal-to operator in the expression ** tree. ** ** Expr.pRight and Expr.pLeft are subexpressions. Expr.pList is a list ** of argument if the expression is a function. ** ** Expr.token is the operator token for this node. For some expressions ** that have subexpressions, Expr.token can be the complete text that gave ** rise to the Expr. In the latter case, the token is marked as being ** a compound token. ** ** An expression of the form ID or ID.ID refers to a column in a table. ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is ** the integer cursor number of a VDBE cursor pointing to that table and ** Expr.iColumn is the column number for the specific column. If the ** expression is used as a result in an aggregate SELECT, then the ** value is also stored in the Expr.iAgg column in the aggregate so that ** it can be accessed after all aggregates are computed. ** ** If the expression is a function, the Expr.iTable is an integer code ** representing which function. If the expression is an unbound variable ** marker (a question mark character '?' in the original SQL) then the ** Expr.iTable holds the index number for that variable. ** ** If the expression is a subquery then Expr.iColumn holds an integer ** register number containing the result of the subquery. If the ** subquery gives a constant result, then iTable is -1. If the subquery ** gives a different answer at different times during statement processing ** then iTable is the address of a subroutine that computes the subquery. ** ** The Expr.pSelect field points to a SELECT statement. The SELECT might ** be the right operand of an IN operator. Or, if a scalar SELECT appears ** in an expression the opcode is TK_SELECT and Expr.pSelect is the only ** operand. ** ** If the Expr is of type OP_Column, and the table it is selecting from ** is a disk table or the "old.*" pseudo-table, then pTab points to the ** corresponding table definition. */ struct Expr { u8 op; /* Operation performed by this node */ char affinity; /* The affinity of the column or 0 if not a column */ u16 flags; /* Various flags. See below */ CollSeq *pColl; /* The collation type of the column or 0 */ Expr *pLeft, *pRight; /* Left and right subnodes */ ExprList *pList; /* A list of expressions used as function arguments ** or in " IN (aCol[] or ->aFunc[] */ int iRightJoinTable; /* If EP_FromJoin, the right table of the join */ Select *pSelect; /* When the expression is a sub-select. Also the ** right side of " IN (