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contract/sqlite3.go

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// Copyright (C) 2014 Yasuhiro Matsumoto <mattn.jp@gmail.com>.
// Copyright (C) 2018 G.J.R. Timmer <gjr.timmer@gmail.com>.
//
// Use of this source code is governed by an MIT-style
// license that can be found in the LICENSE file.

//go:build cgo
// +build cgo

package contract

/*
#cgo CFLAGS: -std=gnu99
#cgo CFLAGS: -Wno-return-local-addr
#cgo CFLAGS: -DSQLITE_THREADSAFE=1
#cgo CFLAGS: -DHAVE_USLEEP=1
#cgo CFLAGS: -DSQLITE_USE_URI=1
#cgo CFLAGS: -DSQLITE_ENABLE_JSON1
#cgo CFLAGS: -DSQLITE_ENABLE_COLUMN_METADATA
#cgo CFLAGS: -DSQLITE_DEFAULT_FOREIGN_KEYS=1
#cgo CFLAGS: -DSQLITE_OMIT_LOCALTIME
#cgo linux CFLAGS: -DHAVE_PREAD64=1 -DHAVE_PWRITE64=1
#cgo CFLAGS: -DSQLITE_TRACE_SIZE_LIMIT=15
#cgo CFLAGS: -DSQLITE_DISABLE_INTRINSIC
#cgo CFLAGS: -DOMIT_BRANCH_LOG
#cgo CFLAGS: -I${SRCDIR}/../libtool/include
#cgo LDFLAGS: ${SRCDIR}/../libtool/lib/liblmdb.a -lm
#include "sqlite3-binding.h"
#include <stdlib.h>
#include <string.h>

#ifdef __CYGWIN__
# include <errno.h>
#endif

#ifndef SQLITE_OPEN_READWRITE
# define SQLITE_OPEN_READWRITE 0
#endif

#ifndef SQLITE_OPEN_FULLMUTEX
# define SQLITE_OPEN_FULLMUTEX 0
#endif

#ifndef SQLITE_DETERMINISTIC
# define SQLITE_DETERMINISTIC 0
#endif

static int
_sqlite3_open_v2(const char *filename, sqlite3 **ppDb, int flags, const char *zVfs) {
#ifdef SQLITE_OPEN_URI
  return sqlite3_open_v2(filename, ppDb, flags | SQLITE_OPEN_URI, zVfs);
#else
  return sqlite3_open_v2(filename, ppDb, flags, zVfs);
#endif
}

static int
_sqlite3_bind_text(sqlite3_stmt *stmt, int n, char *p, int np) {
  return sqlite3_bind_text(stmt, n, p, np, SQLITE_TRANSIENT);
}

static int
_sqlite3_bind_blob(sqlite3_stmt *stmt, int n, void *p, int np) {
  return sqlite3_bind_blob(stmt, n, p, np, SQLITE_TRANSIENT);
}

#include <stdio.h>
#include <stdint.h>

static int
_sqlite3_exec(sqlite3* db, const char* pcmd, long long* rowid, long long* changes)
{
  int rv = sqlite3_exec(db, pcmd, 0, 0, 0);
  *rowid = (long long) sqlite3_last_insert_rowid(db);
  *changes = (long long) sqlite3_changes(db);
  return rv;
}

static int
_sqlite3_step(sqlite3_stmt* stmt, long long* rowid, long long* changes)
{
  int rv = sqlite3_step(stmt);
  sqlite3* db = sqlite3_db_handle(stmt);
  *rowid = (long long) sqlite3_last_insert_rowid(db);
  *changes = (long long) sqlite3_changes(db);
  return rv;
}

void _sqlite3_result_text(sqlite3_context* ctx, const char* s) {
  sqlite3_result_text(ctx, s, -1, &free);
}

void _sqlite3_result_blob(sqlite3_context* ctx, const void* b, int l) {
  sqlite3_result_blob(ctx, b, l, SQLITE_TRANSIENT);
}


int _sqlite3_create_function(
  sqlite3 *db,
  const char *zFunctionName,
  int nArg,
  int eTextRep,
  uintptr_t pApp,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
) {
  return sqlite3_create_function(db, zFunctionName, nArg, eTextRep, (void*) pApp, xFunc, xStep, xFinal);
}

void callbackTrampoline(sqlite3_context*, int, sqlite3_value**);
void stepTrampoline(sqlite3_context*, int, sqlite3_value**);
void doneTrampoline(sqlite3_context*);

int compareTrampoline(void*, int, char*, int, char*);
int commitHookTrampoline(void*);
void rollbackHookTrampoline(void*);
void updateHookTrampoline(void*, int, char*, char*, sqlite3_int64);

int authorizerTrampoline(void*, int, char*, char*, char*, char*);

#ifdef SQLITE_LIMIT_WORKER_THREADS
# define _SQLITE_HAS_LIMIT
# define SQLITE_LIMIT_LENGTH                    0
# define SQLITE_LIMIT_SQL_LENGTH                1
# define SQLITE_LIMIT_COLUMN                    2
# define SQLITE_LIMIT_EXPR_DEPTH                3
# define SQLITE_LIMIT_COMPOUND_SELECT           4
# define SQLITE_LIMIT_VDBE_OP                   5
# define SQLITE_LIMIT_FUNCTION_ARG              6
# define SQLITE_LIMIT_ATTACHED                  7
# define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
# define SQLITE_LIMIT_VARIABLE_NUMBER           9
# define SQLITE_LIMIT_TRIGGER_DEPTH            10
# define SQLITE_LIMIT_WORKER_THREADS           11
# else
# define SQLITE_LIMIT_WORKER_THREADS           11
#endif

static int _sqlite3_limit(sqlite3* db, int limitId, int newLimit) {
#ifndef _SQLITE_HAS_LIMIT
  return -1;
#else
  return sqlite3_limit(db, limitId, newLimit);
#endif
}

static int _sqlite3_disable_loadextfunc(sqlite3* db)
{
  int rv = sqlite3_enable_load_extension(db, 0);
  if (rv != SQLITE_OK) {
    return rv;
  }
  return sqlite3_db_config(db, SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, 1, NULL);
}
*/
import "C"
import (
    "context"
    "database/sql"
    "database/sql/driver"
    "errors"
    "fmt"
    "io"
    "net/url"
    "reflect"
    "runtime"
    "strings"
    "sync"
    "time"
    "unsafe"
)

// SQLiteTimestampFormats is timestamp formats understood by both this module
// and SQLite.  The first format in the slice will be used when saving time
// values into the database. When parsing a string from a timestamp or datetime
// column, the formats are tried in order.
var SQLiteTimestampFormats = []string{
    // By default, store timestamps with whatever timezone they come with.
    // When parsed, they will be returned with the same timezone.
    "2006-01-02 15:04:05.999999999-07:00",
    "2006-01-02T15:04:05.999999999-07:00",
    "2006-01-02 15:04:05.999999999",
    "2006-01-02T15:04:05.999999999",
    "2006-01-02 15:04:05",
    "2006-01-02T15:04:05",
    "2006-01-02 15:04",
    "2006-01-02T15:04",
    "2006-01-02",
}

const (
    columnDate      string = "date"
    columnDatetime  string = "datetime"
    columnTimestamp string = "timestamp"
)

func init() {
    sql.Register("litetree", &SQLiteDriver{})
}

// Version returns SQLite library version information.
func Version() (libVersion string, libVersionNumber int, sourceID string) {
    libVersion = C.GoString(C.sqlite3_libversion())
    libVersionNumber = int(C.sqlite3_libversion_number())
    sourceID = C.GoString(C.sqlite3_sourceid())
    return libVersion, libVersionNumber, sourceID
}

const (
    // used by authorizer and pre_update_hook
    SQLITE_DELETE = C.SQLITE_DELETE
    SQLITE_INSERT = C.SQLITE_INSERT
    SQLITE_UPDATE = C.SQLITE_UPDATE

    // used by authorzier - as return value
    SQLITE_OK     = C.SQLITE_OK
    SQLITE_IGNORE = C.SQLITE_IGNORE
    SQLITE_DENY   = C.SQLITE_DENY

    // different actions query tries to do - passed as argument to authorizer
    SQLITE_CREATE_INDEX        = C.SQLITE_CREATE_INDEX
    SQLITE_CREATE_TABLE        = C.SQLITE_CREATE_TABLE
    SQLITE_CREATE_TEMP_INDEX   = C.SQLITE_CREATE_TEMP_INDEX
    SQLITE_CREATE_TEMP_TABLE   = C.SQLITE_CREATE_TEMP_TABLE
    SQLITE_CREATE_TEMP_TRIGGER = C.SQLITE_CREATE_TEMP_TRIGGER
    SQLITE_CREATE_TEMP_VIEW    = C.SQLITE_CREATE_TEMP_VIEW
    SQLITE_CREATE_TRIGGER      = C.SQLITE_CREATE_TRIGGER
    SQLITE_CREATE_VIEW         = C.SQLITE_CREATE_VIEW
    SQLITE_CREATE_VTABLE       = C.SQLITE_CREATE_VTABLE
    SQLITE_DROP_INDEX          = C.SQLITE_DROP_INDEX
    SQLITE_DROP_TABLE          = C.SQLITE_DROP_TABLE
    SQLITE_DROP_TEMP_INDEX     = C.SQLITE_DROP_TEMP_INDEX
    SQLITE_DROP_TEMP_TABLE     = C.SQLITE_DROP_TEMP_TABLE
    SQLITE_DROP_TEMP_TRIGGER   = C.SQLITE_DROP_TEMP_TRIGGER
    SQLITE_DROP_TEMP_VIEW      = C.SQLITE_DROP_TEMP_VIEW
    SQLITE_DROP_TRIGGER        = C.SQLITE_DROP_TRIGGER
    SQLITE_DROP_VIEW           = C.SQLITE_DROP_VIEW
    SQLITE_DROP_VTABLE         = C.SQLITE_DROP_VTABLE
    SQLITE_PRAGMA              = C.SQLITE_PRAGMA
    SQLITE_READ                = C.SQLITE_READ
    SQLITE_SELECT              = C.SQLITE_SELECT
    SQLITE_TRANSACTION         = C.SQLITE_TRANSACTION
    SQLITE_ATTACH              = C.SQLITE_ATTACH
    SQLITE_DETACH              = C.SQLITE_DETACH
    SQLITE_ALTER_TABLE         = C.SQLITE_ALTER_TABLE
    SQLITE_REINDEX             = C.SQLITE_REINDEX
    SQLITE_ANALYZE             = C.SQLITE_ANALYZE
    SQLITE_FUNCTION            = C.SQLITE_FUNCTION
    SQLITE_SAVEPOINT           = C.SQLITE_SAVEPOINT
    SQLITE_COPY                = C.SQLITE_COPY
    /*SQLITE_RECURSIVE           = C.SQLITE_RECURSIVE*/
)

// SQLiteDriver implements driver.Driver.
type SQLiteDriver struct {
    Extensions  []string
    ConnectHook func(*SQLiteConn) error
}

// SQLiteConn implements driver.Conn.
type SQLiteConn struct {
    mu          sync.Mutex
    db          *C.sqlite3
    loc         *time.Location
    txlock      string
    funcs       []*functionInfo
    aggregators []*aggInfo
}

// SQLiteTx implements driver.Tx.
type SQLiteTx struct {
    c *SQLiteConn
}

// SQLiteStmt implements driver.Stmt.
type SQLiteStmt struct {
    mu     sync.Mutex
    c      *SQLiteConn
    s      *C.sqlite3_stmt
    t      string
    closed bool
    cls    bool
}

// SQLiteResult implements sql.Result.
type SQLiteResult struct {
    id      int64
    changes int64
}

// SQLiteRows implements driver.Rows.
type SQLiteRows struct {
    s        *SQLiteStmt
    nc       int
    cols     []string
    decltype []string
    cls      bool
    closed   bool
    done     chan struct{}
}

type functionInfo struct {
    f                 reflect.Value
    argConverters     []callbackArgConverter
    variadicConverter callbackArgConverter
    retConverter      callbackRetConverter
}

func (fi *functionInfo) Call(ctx *C.sqlite3_context, argv []*C.sqlite3_value) {
    args, err := callbackConvertArgs(argv, fi.argConverters, fi.variadicConverter)
    if err != nil {
        callbackError(ctx, err)
        return
    }

    ret := fi.f.Call(args)

    if len(ret) == 2 && ret[1].Interface() != nil {
        callbackError(ctx, ret[1].Interface().(error))
        return
    }

    err = fi.retConverter(ctx, ret[0])
    if err != nil {
        callbackError(ctx, err)
        return
    }
}

type aggInfo struct {
    constructor reflect.Value

    // Active aggregator objects for aggregations in flight. The
    // aggregators are indexed by a counter stored in the aggregation
    // user data space provided by sqlite.
    active map[int64]reflect.Value
    next   int64

    stepArgConverters     []callbackArgConverter
    stepVariadicConverter callbackArgConverter

    doneRetConverter callbackRetConverter
}

func (ai *aggInfo) agg(ctx *C.sqlite3_context) (int64, reflect.Value, error) {
    aggIdx := (*int64)(C.sqlite3_aggregate_context(ctx, C.int(8)))
    if *aggIdx == 0 {
        *aggIdx = ai.next
        ret := ai.constructor.Call(nil)
        if len(ret) == 2 && ret[1].Interface() != nil {
            return 0, reflect.Value{}, ret[1].Interface().(error)
        }
        if ret[0].IsNil() {
            return 0, reflect.Value{}, errors.New("aggregator constructor returned nil state")
        }
        ai.next++
        ai.active[*aggIdx] = ret[0]
    }
    return *aggIdx, ai.active[*aggIdx], nil
}

func (ai *aggInfo) Step(ctx *C.sqlite3_context, argv []*C.sqlite3_value) {
    _, agg, err := ai.agg(ctx)
    if err != nil {
        callbackError(ctx, err)
        return
    }

    args, err := callbackConvertArgs(argv, ai.stepArgConverters, ai.stepVariadicConverter)
    if err != nil {
        callbackError(ctx, err)
        return
    }

    ret := agg.MethodByName("Step").Call(args)
    if len(ret) == 1 && ret[0].Interface() != nil {
        callbackError(ctx, ret[0].Interface().(error))
        return
    }
}

func (ai *aggInfo) Done(ctx *C.sqlite3_context) {
    idx, agg, err := ai.agg(ctx)
    if err != nil {
        callbackError(ctx, err)
        return
    }
    defer func() { delete(ai.active, idx) }()

    ret := agg.MethodByName("Done").Call(nil)
    if len(ret) == 2 && ret[1].Interface() != nil {
        callbackError(ctx, ret[1].Interface().(error))
        return
    }

    err = ai.doneRetConverter(ctx, ret[0])
    if err != nil {
        callbackError(ctx, err)
        return
    }
}

// Commit transaction.
func (tx *SQLiteTx) Commit() error {
    _, err := tx.c.exec(context.Background(), "COMMIT", nil)
    if err != nil && err.(Error).Code == C.SQLITE_BUSY {
        // sqlite3 will leave the transaction open in this scenario.
        // However, database/sql considers the transaction complete once we
        // return from Commit() - we must clean up to honour its semantics.
        tx.c.exec(context.Background(), "ROLLBACK", nil)
    }
    return err
}

// Rollback transaction.
func (tx *SQLiteTx) Rollback() error {
    _, err := tx.c.exec(context.Background(), "ROLLBACK", nil)
    return err
}

// RegisterCollation makes a Go function available as a collation.
//
// cmp receives two UTF-8 strings, a and b. The result should be 0 if
// a==b, -1 if a < b, and +1 if a > b.
//
// cmp must always return the same result given the same
// inputs. Additionally, it must have the following properties for all
// strings A, B and C: if A==B then B==A; if A==B and B==C then A==C;
// if A<B then B>A; if A<B and B<C then A<C.
//
// If cmp does not obey these constraints, sqlite3's behavior is
// undefined when the collation is used.
func (c *SQLiteConn) RegisterCollation(name string, cmp func(string, string) int) error {
    handle := newHandle(c, cmp)
    cname := C.CString(name)
    defer C.free(unsafe.Pointer(cname))
    rv := C.sqlite3_create_collation(c.db, cname, C.SQLITE_UTF8, unsafe.Pointer(handle), (*[0]byte)(unsafe.Pointer(C.compareTrampoline)))
    if rv != C.SQLITE_OK {
        return c.lastError()
    }
    return nil
}

// RegisterCommitHook sets the commit hook for a connection.
//
// If the callback returns non-zero the transaction will become a rollback.
//
// If there is an existing commit hook for this connection, it will be
// removed. If callback is nil the existing hook (if any) will be removed
// without creating a new one.
func (c *SQLiteConn) RegisterCommitHook(callback func() int) {
    if callback == nil {
        C.sqlite3_commit_hook(c.db, nil, nil)
    } else {
        C.sqlite3_commit_hook(c.db, (*[0]byte)(C.commitHookTrampoline), unsafe.Pointer(newHandle(c, callback)))
    }
}

// RegisterRollbackHook sets the rollback hook for a connection.
//
// If there is an existing rollback hook for this connection, it will be
// removed. If callback is nil the existing hook (if any) will be removed
// without creating a new one.
func (c *SQLiteConn) RegisterRollbackHook(callback func()) {
    if callback == nil {
        C.sqlite3_rollback_hook(c.db, nil, nil)
    } else {
        C.sqlite3_rollback_hook(c.db, (*[0]byte)(C.rollbackHookTrampoline), unsafe.Pointer(newHandle(c, callback)))
    }
}

// RegisterUpdateHook sets the update hook for a connection.
//
// The parameters to the callback are the operation (one of the constants
// SQLITE_INSERT, SQLITE_DELETE, or SQLITE_UPDATE), the database name, the
// table name, and the rowid.
//
// If there is an existing update hook for this connection, it will be
// removed. If callback is nil the existing hook (if any) will be removed
// without creating a new one.
func (c *SQLiteConn) RegisterUpdateHook(callback func(int, string, string, int64)) {
    if callback == nil {
        C.sqlite3_update_hook(c.db, nil, nil)
    } else {
        C.sqlite3_update_hook(c.db, (*[0]byte)(C.updateHookTrampoline), unsafe.Pointer(newHandle(c, callback)))
    }
}

// RegisterAuthorizer sets the authorizer for connection.
//
// The parameters to the callback are the operation (one of the constants
// SQLITE_INSERT, SQLITE_DELETE, or SQLITE_UPDATE), and 1 to 3 arguments,
// depending on operation. More details see:
// https://www.sqlite.org/c3ref/c_alter_table.html
func (c *SQLiteConn) RegisterAuthorizer(callback func(int, string, string, string) int) {
    if callback == nil {
        C.sqlite3_set_authorizer(c.db, nil, nil)
    } else {
        C.sqlite3_set_authorizer(c.db, (*[0]byte)(C.authorizerTrampoline), unsafe.Pointer(newHandle(c, callback)))
    }
}

// RegisterFunc makes a Go function available as a SQLite function.
//
// The Go function can have arguments of the following types: any
// numeric type except complex, bool, []byte, string and
// interface{}. interface{} arguments are given the direct translation
// of the SQLite data type: int64 for INTEGER, float64 for FLOAT,
// []byte for BLOB, string for TEXT.
//
// The function can additionally be variadic, as long as the type of
// the variadic argument is one of the above.
//
// If pure is true. SQLite will assume that the function's return
// value depends only on its inputs, and make more aggressive
// optimizations in its queries.
//
// See _example/go_custom_funcs for a detailed example.
func (c *SQLiteConn) RegisterFunc(name string, impl interface{}, pure bool) error {
    var fi functionInfo
    fi.f = reflect.ValueOf(impl)
    t := fi.f.Type()
    if t.Kind() != reflect.Func {
        return errors.New("Non-function passed to RegisterFunc")
    }
    if t.NumOut() != 1 && t.NumOut() != 2 {
        return errors.New("SQLite functions must return 1 or 2 values")
    }
    if t.NumOut() == 2 && !t.Out(1).Implements(reflect.TypeOf((*error)(nil)).Elem()) {
        return errors.New("Second return value of SQLite function must be error")
    }

    numArgs := t.NumIn()
    if t.IsVariadic() {
        numArgs--
    }

    for i := 0; i < numArgs; i++ {
        conv, err := callbackArg(t.In(i))
        if err != nil {
            return err
        }
        fi.argConverters = append(fi.argConverters, conv)
    }

    if t.IsVariadic() {
        conv, err := callbackArg(t.In(numArgs).Elem())
        if err != nil {
            return err
        }
        fi.variadicConverter = conv
        // Pass -1 to sqlite so that it allows any number of
        // arguments. The call helper verifies that the minimum number
        // of arguments is present for variadic functions.
        numArgs = -1
    }

    conv, err := callbackRet(t.Out(0))
    if err != nil {
        return err
    }
    fi.retConverter = conv

    // fi must outlast the database connection, or we'll have dangling pointers.
    c.funcs = append(c.funcs, &fi)

    cname := C.CString(name)
    defer C.free(unsafe.Pointer(cname))
    opts := C.SQLITE_UTF8
    if pure {
        opts |= C.SQLITE_DETERMINISTIC
    }
    rv := sqlite3CreateFunction(c.db, cname, C.int(numArgs), C.int(opts), newHandle(c, &fi), C.callbackTrampoline, nil, nil)
    if rv != C.SQLITE_OK {
        return c.lastError()
    }
    return nil
}

func sqlite3CreateFunction(db *C.sqlite3, zFunctionName *C.char, nArg C.int, eTextRep C.int, pApp uintptr, xFunc unsafe.Pointer, xStep unsafe.Pointer, xFinal unsafe.Pointer) C.int {
    return C._sqlite3_create_function(db, zFunctionName, nArg, eTextRep, C.uintptr_t(pApp), (*[0]byte)(xFunc), (*[0]byte)(xStep), (*[0]byte)(xFinal))
}

// RegisterAggregator makes a Go type available as a SQLite aggregation function.
//
// Because aggregation is incremental, it's implemented in Go with a
// type that has 2 methods: func Step(values) accumulates one row of
// data into the accumulator, and func Done() ret finalizes and
// returns the aggregate value. "values" and "ret" may be any type
// supported by RegisterFunc.
//
// RegisterAggregator takes as implementation a constructor function
// that constructs an instance of the aggregator type each time an
// aggregation begins. The constructor must return a pointer to a
// type, or an interface that implements Step() and Done().
//
// The constructor function and the Step/Done methods may optionally
// return an error in addition to their other return values.
//
// See _example/go_custom_funcs for a detailed example.
func (c *SQLiteConn) RegisterAggregator(name string, impl interface{}, pure bool) error {
    var ai aggInfo
    ai.constructor = reflect.ValueOf(impl)
    t := ai.constructor.Type()
    if t.Kind() != reflect.Func {
        return errors.New("non-function passed to RegisterAggregator")
    }
    if t.NumOut() != 1 && t.NumOut() != 2 {
        return errors.New("SQLite aggregator constructors must return 1 or 2 values")
    }
    if t.NumOut() == 2 && !t.Out(1).Implements(reflect.TypeOf((*error)(nil)).Elem()) {
        return errors.New("Second return value of SQLite function must be error")
    }
    if t.NumIn() != 0 {
        return errors.New("SQLite aggregator constructors must not have arguments")
    }

    agg := t.Out(0)
    switch agg.Kind() {
    case reflect.Ptr, reflect.Interface:
    default:
        return errors.New("SQlite aggregator constructor must return a pointer object")
    }
    stepFn, found := agg.MethodByName("Step")
    if !found {
        return errors.New("SQlite aggregator doesn't have a Step() function")
    }
    step := stepFn.Type
    if step.NumOut() != 0 && step.NumOut() != 1 {
        return errors.New("SQlite aggregator Step() function must return 0 or 1 values")
    }
    if step.NumOut() == 1 && !step.Out(0).Implements(reflect.TypeOf((*error)(nil)).Elem()) {
        return errors.New("type of SQlite aggregator Step() return value must be error")
    }

    stepNArgs := step.NumIn()
    start := 0
    if agg.Kind() == reflect.Ptr {
        // Skip over the method receiver
        stepNArgs--
        start++
    }
    if step.IsVariadic() {
        stepNArgs--
    }
    for i := start; i < start+stepNArgs; i++ {
        conv, err := callbackArg(step.In(i))
        if err != nil {
            return err
        }
        ai.stepArgConverters = append(ai.stepArgConverters, conv)
    }
    if step.IsVariadic() {
        conv, err := callbackArg(t.In(start + stepNArgs).Elem())
        if err != nil {
            return err
        }
        ai.stepVariadicConverter = conv
        // Pass -1 to sqlite so that it allows any number of
        // arguments. The call helper verifies that the minimum number
        // of arguments is present for variadic functions.
        stepNArgs = -1
    }

    doneFn, found := agg.MethodByName("Done")
    if !found {
        return errors.New("SQlite aggregator doesn't have a Done() function")
    }
    done := doneFn.Type
    doneNArgs := done.NumIn()
    if agg.Kind() == reflect.Ptr {
        // Skip over the method receiver
        doneNArgs--
    }
    if doneNArgs != 0 {
        return errors.New("SQlite aggregator Done() function must have no arguments")
    }
    if done.NumOut() != 1 && done.NumOut() != 2 {
        return errors.New("SQLite aggregator Done() function must return 1 or 2 values")
    }
    if done.NumOut() == 2 && !done.Out(1).Implements(reflect.TypeOf((*error)(nil)).Elem()) {
        return errors.New("second return value of SQLite aggregator Done() function must be error")
    }

    conv, err := callbackRet(done.Out(0))
    if err != nil {
        return err
    }
    ai.doneRetConverter = conv
    ai.active = make(map[int64]reflect.Value)
    ai.next = 1

    // ai must outlast the database connection, or we'll have dangling pointers.
    c.aggregators = append(c.aggregators, &ai)

    cname := C.CString(name)
    defer C.free(unsafe.Pointer(cname))
    opts := C.SQLITE_UTF8
    if pure {
        opts |= C.SQLITE_DETERMINISTIC
    }
    rv := sqlite3CreateFunction(c.db, cname, C.int(stepNArgs), C.int(opts), newHandle(c, &ai), nil, C.stepTrampoline, C.doneTrampoline)
    if rv != C.SQLITE_OK {
        return c.lastError()
    }
    return nil
}

// AutoCommit return which currently auto commit or not.
func (c *SQLiteConn) AutoCommit() bool {
    return int(C.sqlite3_get_autocommit(c.db)) != 0
}

func (c *SQLiteConn) lastError() error {
    return lastError(c.db)
}

func lastError(db *C.sqlite3) error {
    rv := C.sqlite3_errcode(db)
    if rv == C.SQLITE_OK {
        return nil
    }
    return Error{
        Code:         ErrNo(rv),
        ExtendedCode: ErrNoExtended(C.sqlite3_extended_errcode(db)),
        err:          C.GoString(C.sqlite3_errmsg(db)),
    }
}

// Exec implements Execer.
func (c *SQLiteConn) Exec(query string, args []driver.Value) (driver.Result, error) {
    list := make([]namedValue, len(args))
    for i, v := range args {
        list[i] = namedValue{
            Ordinal: i + 1,
            Value:   v,
        }
    }
    return c.exec(context.Background(), query, list)
}

func (c *SQLiteConn) exec(ctx context.Context, query string, args []namedValue) (driver.Result, error) {
    start := 0
    for {
        s, err := c.prepare(ctx, query)
        if err != nil {
            return nil, err
        }
        var res driver.Result
        if s.(*SQLiteStmt).s != nil {
            na := s.NumInput()
            if len(args) < na {
                s.Close()
                return nil, fmt.Errorf("not enough args to execute query: want %d got %d", na, len(args))
            }
            for i := 0; i < na; i++ {
                args[i].Ordinal -= start
            }
            res, err = s.(*SQLiteStmt).exec(ctx, args[:na])
            if err != nil && err != driver.ErrSkip {
                s.Close()
                return nil, err
            }
            args = args[na:]
            start += na
        }
        tail := s.(*SQLiteStmt).t
        s.Close()
        if tail == "" {
            return res, nil
        }
        query = tail
    }
}

type namedValue struct {
    Name    string
    Ordinal int
    Value   driver.Value
}

// Query implements Queryer.
func (c *SQLiteConn) Query(query string, args []driver.Value) (driver.Rows, error) {
    list := make([]namedValue, len(args))
    for i, v := range args {
        list[i] = namedValue{
            Ordinal: i + 1,
            Value:   v,
        }
    }
    return c.query(context.Background(), query, list)
}

func (c *SQLiteConn) query(ctx context.Context, query string, args []namedValue) (driver.Rows, error) {
    start := 0
    for {
        s, err := c.prepare(ctx, query)
        if err != nil {
            return nil, err
        }
        s.(*SQLiteStmt).cls = true
        na := s.NumInput()
        if len(args) < na {
            return nil, fmt.Errorf("not enough args to execute query: want %d got %d", na, len(args))
        }
        for i := 0; i < na; i++ {
            args[i].Ordinal -= start
        }
        rows, err := s.(*SQLiteStmt).query(ctx, args[:na])
        if err != nil && err != driver.ErrSkip {
            s.Close()
            return rows, err
        }
        args = args[na:]
        start += na
        tail := s.(*SQLiteStmt).t
        if tail == "" {
            return rows, nil
        }
        rows.Close()
        s.Close()
        query = tail
    }
}

// Begin transaction.
func (c *SQLiteConn) Begin() (driver.Tx, error) {
    return c.begin(context.Background())
}

func (c *SQLiteConn) begin(ctx context.Context) (driver.Tx, error) {
    if _, err := c.exec(ctx, c.txlock, nil); err != nil {
        return nil, err
    }
    return &SQLiteTx{c}, nil
}

func errorString(err Error) string {
    return C.GoString(C.sqlite3_errstr(C.int(err.Code)))
}

// Open database and return a new connection.
//
// A pragma can take either zero or one argument.
// The argument is may be either in parentheses or it may be separated from
// the pragma name by an equal sign. The two syntaxes yield identical results.
// In many pragmas, the argument is a boolean. The boolean can be one of:
//
//    1 yes true on
//    0 no false off
//
// You can specify a DSN string using a URI as the filename.
//
//    test.db
//    file:test.db?cache=shared&mode=memory
//    :memory:
//    file::memory:
//
//    mode
//      Access mode of the database.
//      https://www.sqlite.org/c3ref/open.html
//      Values:
//       - ro
//       - rw
//       - rwc
//       - memory
//
//    shared
//      SQLite Shared-Cache Mode
//      https://www.sqlite.org/sharedcache.html
//      Values:
//        - shared
//        - private
//
//    immutable=Boolean
//      The immutable parameter is a boolean query parameter that indicates
//      that the database file is stored on read-only media. When immutable is set,
//      SQLite assumes that the database file cannot be changed,
//      even by a process with higher privilege,
//      and so the database is opened read-only and all locking and change detection is disabled.
//      Caution: Setting the immutable property on a database file that
//      does in fact change can result in incorrect query results and/or SQLITE_CORRUPT errors.
//
// go-sqlite3 adds the following query parameters to those used by SQLite:
//
//    _loc=XXX
//      Specify location of time format. It's possible to specify "auto".
//
//    _mutex=XXX
//      Specify mutex mode. XXX can be "no", "full".
//
//    _txlock=XXX
//      Specify locking behavior for transactions.  XXX can be "immediate",
//      "deferred", "exclusive".
//
//    _auto_vacuum=X | _vacuum=X
//      0 | none - Auto Vacuum disabled
//      1 | full - Auto Vacuum FULL
//      2 | incremental - Auto Vacuum Incremental
//
//    _busy_timeout=XXX"| _timeout=XXX
//      Specify value for sqlite3_busy_timeout.
//
//    _case_sensitive_like=Boolean | _cslike=Boolean
//      https://www.sqlite.org/pragma.html#pragma_case_sensitive_like
//      Default or disabled the LIKE operation is case-insensitive.
//      When enabling this options behaviour of LIKE will become case-sensitive.
//
//    _defer_foreign_keys=Boolean | _defer_fk=Boolean
//      Defer Foreign Keys until outermost transaction is committed.
//
//    _foreign_keys=Boolean | _fk=Boolean
//      Enable or disable enforcement of foreign keys.
//
//    _ignore_check_constraints=Boolean
//      This pragma enables or disables the enforcement of CHECK constraints.
//      The default setting is off, meaning that CHECK constraints are enforced by default.
//
//    _journal_mode=MODE | _journal=MODE
//      Set journal mode for the databases associated with the current connection.
//      https://www.sqlite.org/pragma.html#pragma_journal_mode
//
//    _locking_mode=X | _locking=X
//      Sets the database connection locking-mode.
//      The locking-mode is either NORMAL or EXCLUSIVE.
//      https://www.sqlite.org/pragma.html#pragma_locking_mode
//
//    _query_only=Boolean
//      The query_only pragma prevents all changes to database files when enabled.
//
//    _recursive_triggers=Boolean | _rt=Boolean
//      Enable or disable recursive triggers.
//
//    _secure_delete=Boolean|FAST
//      When secure_delete is on, SQLite overwrites deleted content with zeros.
//      https://www.sqlite.org/pragma.html#pragma_secure_delete
//
//    _synchronous=X | _sync=X
//      Change the setting of the "synchronous" flag.
//      https://www.sqlite.org/pragma.html#pragma_synchronous
//
//    _writable_schema=Boolean
//      When this pragma is on, the SQLITE_MASTER tables in which database
//      can be changed using ordinary UPDATE, INSERT, and DELETE statements.
//      Warning: misuse of this pragma can easily result in a corrupt database file.
func (d *SQLiteDriver) Open(dsn string) (driver.Conn, error) {
    if C.sqlite3_threadsafe() == 0 {
        return nil, errors.New("sqlite library was not compiled for thread-safe operation")
    }

    // Options
    var loc *time.Location
    txlock := "BEGIN"

    // PRAGMA's
    queryOnly := -1

    pos := strings.IndexRune(dsn, '?')
    if pos >= 1 {
        params, err := url.ParseQuery(dsn[pos+1:])
        if err != nil {
            return nil, err
        }

        // Query Only (_query_only)
        //
        // https://www.sqlite.org/pragma.html#pragma_query_only
        //
        if val := params.Get("_query_only"); val != "" {
            switch strings.ToLower(val) {
            case "0", "no", "false", "off":
                queryOnly = 0
            case "1", "yes", "true", "on":
                queryOnly = 1
            default:
                return nil, fmt.Errorf("Invalid _query_only: %v, expecting boolean value of '0 1 false true no yes off on'", val)
            }
        }

        if !strings.HasPrefix(dsn, "file:") {
            dsn = dsn[:pos]
        }
    }

    var db *C.sqlite3
    name := C.CString(dsn)
    defer C.free(unsafe.Pointer(name))
    rv := C._sqlite3_open_v2(name, &db, C.SQLITE_OPEN_READWRITE|C.SQLITE_OPEN_CREATE, nil)
    if rv != 0 {
        return nil, Error{Code: ErrNo(rv)}
    }
    if db == nil {
        return nil, errors.New("sqlite succeeded without returning a database")
    }

    exec := func(s string) error {
        cs := C.CString(s)
        rv := C.sqlite3_exec(db, cs, nil, nil, nil)
        C.free(unsafe.Pointer(cs))
        if rv != C.SQLITE_OK {
            return lastError(db)
        }
        return nil
    }

    rv = C._sqlite3_disable_loadextfunc(db)
    if rv != C.SQLITE_OK {
        C.sqlite3_close_v2(db)
        return nil, Error{Code: ErrNo(rv)}
    }

    // USER AUTHENTICATION
    //
    // User Authentication is always performed even when
    // sqlite_userauth is not compiled in, because without user authentication
    // the authentication is a no-op.
    //
    // Workflow
    //    - Authenticate
    //        ON::SUCCESS        => Continue
    //        ON::SQLITE_AUTH => Return error and exit Open(...)
    //
    //  - Activate User Authentication
    //        Check if the user wants to activate User Authentication.
    //        If so then first create a temporary AuthConn to the database
    //        This is possible because we are already succesfully authenticated.
    //
    //    - Check if `sqlite_user`` table exists
    //        YES                => Add the provided user from DSN as Admin User and
    //                           activate user authentication.
    //        NO                => Continue
    //

    // Create connection to SQLite
    conn := &SQLiteConn{db: db, loc: loc, txlock: txlock}

    // Query Only
    if queryOnly > -1 {
        if err := exec(fmt.Sprintf("PRAGMA query_only = %d;", queryOnly)); err != nil {
            C.sqlite3_close_v2(db)
            return nil, err
        }
    }

    if d.ConnectHook != nil {
        if err := d.ConnectHook(conn); err != nil {
            conn.Close()
            return nil, err
        }
    }
    runtime.SetFinalizer(conn, (*SQLiteConn).Close)
    return conn, nil
}

// Close the connection.
func (c *SQLiteConn) Close() error {
    rv := C.sqlite3_close_v2(c.db)
    if rv != C.SQLITE_OK {
        return c.lastError()
    }
    deleteHandles(c)
    c.mu.Lock()
    c.db = nil
    c.mu.Unlock()
    runtime.SetFinalizer(c, nil)
    return nil
}

func (c *SQLiteConn) dbConnOpen() bool {
    if c == nil {
        return false
    }
    c.mu.Lock()
    defer c.mu.Unlock()
    return c.db != nil
}

// Prepare the query string. Return a new statement.
func (c *SQLiteConn) Prepare(query string) (driver.Stmt, error) {
    return c.prepare(context.Background(), query)
}

func (c *SQLiteConn) prepare(ctx context.Context, query string) (driver.Stmt, error) {
    pquery := C.CString(query)
    defer C.free(unsafe.Pointer(pquery))
    var s *C.sqlite3_stmt
    var tail *C.char
    rv := C.sqlite3_prepare_v2(c.db, pquery, -1, &s, &tail)
    if rv != C.SQLITE_OK {
        return nil, c.lastError()
    }
    var t string
    if tail != nil && *tail != '\000' {
        t = strings.TrimSpace(C.GoString(tail))
    }
    ss := &SQLiteStmt{c: c, s: s, t: t}
    runtime.SetFinalizer(ss, (*SQLiteStmt).Close)
    return ss, nil
}

// Run-Time Limit Categories.
// See: http://www.sqlite.org/c3ref/c_limit_attached.html
const (
    SQLITE_LIMIT_LENGTH              = C.SQLITE_LIMIT_LENGTH
    SQLITE_LIMIT_SQL_LENGTH          = C.SQLITE_LIMIT_SQL_LENGTH
    SQLITE_LIMIT_COLUMN              = C.SQLITE_LIMIT_COLUMN
    SQLITE_LIMIT_EXPR_DEPTH          = C.SQLITE_LIMIT_EXPR_DEPTH
    SQLITE_LIMIT_COMPOUND_SELECT     = C.SQLITE_LIMIT_COMPOUND_SELECT
    SQLITE_LIMIT_VDBE_OP             = C.SQLITE_LIMIT_VDBE_OP
    SQLITE_LIMIT_FUNCTION_ARG        = C.SQLITE_LIMIT_FUNCTION_ARG
    SQLITE_LIMIT_ATTACHED            = C.SQLITE_LIMIT_ATTACHED
    SQLITE_LIMIT_LIKE_PATTERN_LENGTH = C.SQLITE_LIMIT_LIKE_PATTERN_LENGTH
    SQLITE_LIMIT_VARIABLE_NUMBER     = C.SQLITE_LIMIT_VARIABLE_NUMBER
    SQLITE_LIMIT_TRIGGER_DEPTH       = C.SQLITE_LIMIT_TRIGGER_DEPTH
    SQLITE_LIMIT_WORKER_THREADS      = C.SQLITE_LIMIT_WORKER_THREADS
)

// GetFilename returns the absolute path to the file containing
// the requested schema. When passed an empty string, it will
// instead use the database's default schema: "main".
// See: sqlite3_db_filename, https://www.sqlite.org/c3ref/db_filename.html
func (c *SQLiteConn) GetFilename(schemaName string) string {
    if schemaName == "" {
        schemaName = "main"
    }
    return C.GoString(C.sqlite3_db_filename(c.db, C.CString(schemaName)))
}

// GetLimit returns the current value of a run-time limit.
// See: sqlite3_limit, http://www.sqlite.org/c3ref/limit.html
func (c *SQLiteConn) GetLimit(id int) int {
    return int(C._sqlite3_limit(c.db, C.int(id), -1))
}

// SetLimit changes the value of a run-time limits.
// Then this method returns the prior value of the limit.
// See: sqlite3_limit, http://www.sqlite.org/c3ref/limit.html
func (c *SQLiteConn) SetLimit(id int, newVal int) int {
    return int(C._sqlite3_limit(c.db, C.int(id), C.int(newVal)))
}

func (c *SQLiteConn) DBCacheFlush() error {
    rv := C.sqlite3_db_cacheflush(c.db)
    if rv != C.SQLITE_OK {
        return c.lastError()
    }
    return nil
}

// Close the statement.
func (s *SQLiteStmt) Close() error {
    s.mu.Lock()
    defer s.mu.Unlock()
    if s.closed {
        return nil
    }
    s.closed = true
    if !s.c.dbConnOpen() {
        return errors.New("sqlite statement with already closed database connection")
    }
    rv := C.sqlite3_finalize(s.s)
    s.s = nil
    if rv != C.SQLITE_OK {
        return s.c.lastError()
    }
    runtime.SetFinalizer(s, nil)
    return nil
}

// NumInput return a number of parameters.
func (s *SQLiteStmt) NumInput() int {
    return int(C.sqlite3_bind_parameter_count(s.s))
}

type bindArg struct {
    n int
    v driver.Value
}

var placeHolder = []byte{0}

func (s *SQLiteStmt) bind(args []namedValue) error {
    rv := C.sqlite3_reset(s.s)
    if rv != C.SQLITE_ROW && rv != C.SQLITE_OK && rv != C.SQLITE_DONE {
        return s.c.lastError()
    }

    for i, v := range args {
        if v.Name != "" {
            cname := C.CString(":" + v.Name)
            args[i].Ordinal = int(C.sqlite3_bind_parameter_index(s.s, cname))
            C.free(unsafe.Pointer(cname))
        }
    }

    for _, arg := range args {
        n := C.int(arg.Ordinal)
        switch v := arg.Value.(type) {
        case nil:
            rv = C.sqlite3_bind_null(s.s, n)
        case string:
            if len(v) == 0 {
                rv = C._sqlite3_bind_text(s.s, n, (*C.char)(unsafe.Pointer(&placeHolder[0])), C.int(0))
            } else {
                b := []byte(v)
                rv = C._sqlite3_bind_text(s.s, n, (*C.char)(unsafe.Pointer(&b[0])), C.int(len(b)))
            }
        case int64:
            rv = C.sqlite3_bind_int64(s.s, n, C.sqlite3_int64(v))
        case bool:
            if v {
                rv = C.sqlite3_bind_int(s.s, n, 1)
            } else {
                rv = C.sqlite3_bind_int(s.s, n, 0)
            }
        case float64:
            rv = C.sqlite3_bind_double(s.s, n, C.double(v))
        case []byte:
            if v == nil {
                rv = C.sqlite3_bind_null(s.s, n)
            } else {
                ln := len(v)
                if ln == 0 {
                    v = placeHolder
                }
                rv = C._sqlite3_bind_blob(s.s, n, unsafe.Pointer(&v[0]), C.int(ln))
            }
        case time.Time:
            b := []byte(v.Format(SQLiteTimestampFormats[0]))
            rv = C._sqlite3_bind_text(s.s, n, (*C.char)(unsafe.Pointer(&b[0])), C.int(len(b)))
        }
        if rv != C.SQLITE_OK {
            return s.c.lastError()
        }
    }
    return nil
}

// Query the statement with arguments. Return records.
func (s *SQLiteStmt) Query(args []driver.Value) (driver.Rows, error) {
    list := make([]namedValue, len(args))
    for i, v := range args {
        list[i] = namedValue{
            Ordinal: i + 1,
            Value:   v,
        }
    }
    return s.query(context.Background(), list)
}

func (s *SQLiteStmt) query(ctx context.Context, args []namedValue) (driver.Rows, error) {
    if err := s.bind(args); err != nil {
        return nil, err
    }

    rows := &SQLiteRows{
        s:        s,
        nc:       int(C.sqlite3_column_count(s.s)),
        cols:     nil,
        decltype: nil,
        cls:      s.cls,
        closed:   false,
        done:     make(chan struct{}),
    }

    if ctxdone := ctx.Done(); ctxdone != nil {
        go func(db *C.sqlite3) {
            select {
            case <-ctxdone:
                select {
                case <-rows.done:
                default:
                    C.sqlite3_interrupt(db)
                    rows.Close()
                }
            case <-rows.done:
            }
        }(s.c.db)
    }

    return rows, nil
}

// LastInsertId teturn last inserted ID.
func (r *SQLiteResult) LastInsertId() (int64, error) {
    return r.id, nil
}

// RowsAffected return how many rows affected.
func (r *SQLiteResult) RowsAffected() (int64, error) {
    return r.changes, nil
}

// Exec execute the statement with arguments. Return result object.
func (s *SQLiteStmt) Exec(args []driver.Value) (driver.Result, error) {
    list := make([]namedValue, len(args))
    for i, v := range args {
        list[i] = namedValue{
            Ordinal: i + 1,
            Value:   v,
        }
    }
    return s.exec(context.Background(), list)
}

func (s *SQLiteStmt) exec(ctx context.Context, args []namedValue) (driver.Result, error) {
    if err := s.bind(args); err != nil {
        C.sqlite3_reset(s.s)
        C.sqlite3_clear_bindings(s.s)
        return nil, err
    }

    if ctxdone := ctx.Done(); ctxdone != nil {
        done := make(chan struct{})
        defer close(done)
        go func(db *C.sqlite3) {
            select {
            case <-done:
            case <-ctxdone:
                select {
                case <-done:
                default:
                    C.sqlite3_interrupt(db)
                }
            }
        }(s.c.db)
    }

    var rowid, changes C.longlong
    rv := C._sqlite3_step(s.s, &rowid, &changes)
    if rv != C.SQLITE_ROW && rv != C.SQLITE_OK && rv != C.SQLITE_DONE {
        err := s.c.lastError()
        C.sqlite3_reset(s.s)
        C.sqlite3_clear_bindings(s.s)
        return nil, err
    }

    return &SQLiteResult{id: int64(rowid), changes: int64(changes)}, nil
}

// Close the rows.
func (rc *SQLiteRows) Close() error {
    rc.s.mu.Lock()
    if rc.s.closed || rc.closed {
        rc.s.mu.Unlock()
        return nil
    }
    rc.closed = true
    if rc.done != nil {
        close(rc.done)
    }
    if rc.cls {
        rc.s.mu.Unlock()
        return rc.s.Close()
    }
    rv := C.sqlite3_reset(rc.s.s)
    if rv != C.SQLITE_OK {
        rc.s.mu.Unlock()
        return rc.s.c.lastError()
    }
    rc.s.mu.Unlock()
    return nil
}

// Columns return column names.
func (rc *SQLiteRows) Columns() []string {
    rc.s.mu.Lock()
    defer rc.s.mu.Unlock()
    if rc.s.s != nil && rc.nc != len(rc.cols) {
        rc.cols = make([]string, rc.nc)
        for i := 0; i < rc.nc; i++ {
            rc.cols[i] = C.GoString(C.sqlite3_column_name(rc.s.s, C.int(i)))
        }
    }
    return rc.cols
}

func (rc *SQLiteRows) declTypes() []string {
    if rc.s.s != nil && rc.decltype == nil {
        rc.decltype = make([]string, rc.nc)
        for i := 0; i < rc.nc; i++ {
            rc.decltype[i] = strings.ToLower(C.GoString(C.sqlite3_column_decltype(rc.s.s, C.int(i))))
        }
    }
    return rc.decltype
}

// DeclTypes return column types.
func (rc *SQLiteRows) DeclTypes() []string {
    rc.s.mu.Lock()
    defer rc.s.mu.Unlock()
    return rc.declTypes()
}

// Next move cursor to next.
func (rc *SQLiteRows) Next(dest []driver.Value) error {
    rc.s.mu.Lock()
    defer rc.s.mu.Unlock()
    if rc.s.closed {
        return io.EOF
    }
    rv := C.sqlite3_step(rc.s.s)
    if rv == C.SQLITE_DONE {
        return io.EOF
    }
    if rv != C.SQLITE_ROW {
        rv = C.sqlite3_reset(rc.s.s)
        if rv != C.SQLITE_OK {
            return rc.s.c.lastError()
        }
        return nil
    }

    rc.declTypes()

    for i := range dest {
        switch C.sqlite3_column_type(rc.s.s, C.int(i)) {
        case C.SQLITE_INTEGER:
            val := int64(C.sqlite3_column_int64(rc.s.s, C.int(i)))
            switch rc.decltype[i] {
            case columnTimestamp, columnDatetime, columnDate:
                var t time.Time
                // Assume a millisecond unix timestamp if it's 13 digits -- too
                // large to be a reasonable timestamp in seconds.
                if val > 1e12 || val < -1e12 {
                    val *= int64(time.Millisecond) // convert ms to nsec
                    t = time.Unix(0, val)
                } else {
                    t = time.Unix(val, 0)
                }
                t = t.UTC()
                if rc.s.c.loc != nil {
                    t = t.In(rc.s.c.loc)
                }
                dest[i] = t
            case "boolean":
                dest[i] = val > 0
            default:
                dest[i] = val
            }
        case C.SQLITE_FLOAT:
            dest[i] = float64(C.sqlite3_column_double(rc.s.s, C.int(i)))
        case C.SQLITE_BLOB:
            p := C.sqlite3_column_blob(rc.s.s, C.int(i))
            if p == nil {
                dest[i] = nil
                continue
            }
            n := int(C.sqlite3_column_bytes(rc.s.s, C.int(i)))
            switch dest[i].(type) {
            default:
                slice := make([]byte, n)
                copy(slice[:], (*[1 << 30]byte)(p)[0:n])
                dest[i] = slice
            }
        case C.SQLITE_NULL:
            dest[i] = nil
        case C.SQLITE_TEXT:
            var err error
            var timeVal time.Time

            n := int(C.sqlite3_column_bytes(rc.s.s, C.int(i)))
            s := C.GoStringN((*C.char)(unsafe.Pointer(C.sqlite3_column_text(rc.s.s, C.int(i)))), C.int(n))

            switch rc.decltype[i] {
            case columnTimestamp, columnDatetime, columnDate:
                var t time.Time
                s = strings.TrimSuffix(s, "Z")
                for _, format := range SQLiteTimestampFormats {
                    if timeVal, err = time.ParseInLocation(format, s, time.UTC); err == nil {
                        t = timeVal
                        break
                    }
                }
                if err != nil {
                    // The column is a time value, so return the zero time on parse failure.
                    t = time.Time{}
                }
                if rc.s.c.loc != nil {
                    t = t.In(rc.s.c.loc)
                }
                dest[i] = t
            default:
                dest[i] = []byte(s)
            }

        }
    }
    return nil
}