hotime/vendor/github.com/mattn/go-sqlite3/sqlite3_opt_vtable.go
2020-04-29 23:14:06 +08:00

651 lines
17 KiB
Go

// Copyright (C) 2019 Yasuhiro Matsumoto <mattn.jp@gmail.com>.
//
// Use of this source code is governed by an MIT-style
// license that can be found in the LICENSE file.
// +build sqlite_vtable vtable
package sqlite3
/*
#cgo CFLAGS: -std=gnu99
#cgo CFLAGS: -DSQLITE_ENABLE_RTREE
#cgo CFLAGS: -DSQLITE_THREADSAFE
#cgo CFLAGS: -DSQLITE_ENABLE_FTS3
#cgo CFLAGS: -DSQLITE_ENABLE_FTS3_PARENTHESIS
#cgo CFLAGS: -DSQLITE_ENABLE_FTS4_UNICODE61
#cgo CFLAGS: -DSQLITE_TRACE_SIZE_LIMIT=15
#cgo CFLAGS: -DSQLITE_ENABLE_COLUMN_METADATA=1
#cgo CFLAGS: -Wno-deprecated-declarations
#ifndef USE_LIBSQLITE3
#include <sqlite3-binding.h>
#else
#include <sqlite3.h>
#endif
#include <stdlib.h>
#include <stdint.h>
#include <memory.h>
static inline char *_sqlite3_mprintf(char *zFormat, char *arg) {
return sqlite3_mprintf(zFormat, arg);
}
typedef struct goVTab goVTab;
struct goVTab {
sqlite3_vtab base;
void *vTab;
};
uintptr_t goMInit(void *db, void *pAux, int argc, char **argv, char **pzErr, int isCreate);
static int cXInit(sqlite3 *db, void *pAux, int argc, const char *const*argv, sqlite3_vtab **ppVTab, char **pzErr, int isCreate) {
void *vTab = (void *)goMInit(db, pAux, argc, (char**)argv, pzErr, isCreate);
if (!vTab || *pzErr) {
return SQLITE_ERROR;
}
goVTab *pvTab = (goVTab *)sqlite3_malloc(sizeof(goVTab));
if (!pvTab) {
*pzErr = sqlite3_mprintf("%s", "Out of memory");
return SQLITE_NOMEM;
}
memset(pvTab, 0, sizeof(goVTab));
pvTab->vTab = vTab;
*ppVTab = (sqlite3_vtab *)pvTab;
*pzErr = 0;
return SQLITE_OK;
}
static inline int cXCreate(sqlite3 *db, void *pAux, int argc, const char *const*argv, sqlite3_vtab **ppVTab, char **pzErr) {
return cXInit(db, pAux, argc, argv, ppVTab, pzErr, 1);
}
static inline int cXConnect(sqlite3 *db, void *pAux, int argc, const char *const*argv, sqlite3_vtab **ppVTab, char **pzErr) {
return cXInit(db, pAux, argc, argv, ppVTab, pzErr, 0);
}
char* goVBestIndex(void *pVTab, void *icp);
static inline int cXBestIndex(sqlite3_vtab *pVTab, sqlite3_index_info *info) {
char *pzErr = goVBestIndex(((goVTab*)pVTab)->vTab, info);
if (pzErr) {
if (pVTab->zErrMsg)
sqlite3_free(pVTab->zErrMsg);
pVTab->zErrMsg = pzErr;
return SQLITE_ERROR;
}
return SQLITE_OK;
}
char* goVRelease(void *pVTab, int isDestroy);
static int cXRelease(sqlite3_vtab *pVTab, int isDestroy) {
char *pzErr = goVRelease(((goVTab*)pVTab)->vTab, isDestroy);
if (pzErr) {
if (pVTab->zErrMsg)
sqlite3_free(pVTab->zErrMsg);
pVTab->zErrMsg = pzErr;
return SQLITE_ERROR;
}
if (pVTab->zErrMsg)
sqlite3_free(pVTab->zErrMsg);
sqlite3_free(pVTab);
return SQLITE_OK;
}
static inline int cXDisconnect(sqlite3_vtab *pVTab) {
return cXRelease(pVTab, 0);
}
static inline int cXDestroy(sqlite3_vtab *pVTab) {
return cXRelease(pVTab, 1);
}
typedef struct goVTabCursor goVTabCursor;
struct goVTabCursor {
sqlite3_vtab_cursor base;
void *vTabCursor;
};
uintptr_t goVOpen(void *pVTab, char **pzErr);
static int cXOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor) {
void *vTabCursor = (void *)goVOpen(((goVTab*)pVTab)->vTab, &(pVTab->zErrMsg));
goVTabCursor *pCursor = (goVTabCursor *)sqlite3_malloc(sizeof(goVTabCursor));
if (!pCursor) {
return SQLITE_NOMEM;
}
memset(pCursor, 0, sizeof(goVTabCursor));
pCursor->vTabCursor = vTabCursor;
*ppCursor = (sqlite3_vtab_cursor *)pCursor;
return SQLITE_OK;
}
static int setErrMsg(sqlite3_vtab_cursor *pCursor, char *pzErr) {
if (pCursor->pVtab->zErrMsg)
sqlite3_free(pCursor->pVtab->zErrMsg);
pCursor->pVtab->zErrMsg = pzErr;
return SQLITE_ERROR;
}
char* goVClose(void *pCursor);
static int cXClose(sqlite3_vtab_cursor *pCursor) {
char *pzErr = goVClose(((goVTabCursor*)pCursor)->vTabCursor);
if (pzErr) {
return setErrMsg(pCursor, pzErr);
}
sqlite3_free(pCursor);
return SQLITE_OK;
}
char* goVFilter(void *pCursor, int idxNum, char* idxName, int argc, sqlite3_value **argv);
static int cXFilter(sqlite3_vtab_cursor *pCursor, int idxNum, const char *idxStr, int argc, sqlite3_value **argv) {
char *pzErr = goVFilter(((goVTabCursor*)pCursor)->vTabCursor, idxNum, (char*)idxStr, argc, argv);
if (pzErr) {
return setErrMsg(pCursor, pzErr);
}
return SQLITE_OK;
}
char* goVNext(void *pCursor);
static int cXNext(sqlite3_vtab_cursor *pCursor) {
char *pzErr = goVNext(((goVTabCursor*)pCursor)->vTabCursor);
if (pzErr) {
return setErrMsg(pCursor, pzErr);
}
return SQLITE_OK;
}
int goVEof(void *pCursor);
static inline int cXEof(sqlite3_vtab_cursor *pCursor) {
return goVEof(((goVTabCursor*)pCursor)->vTabCursor);
}
char* goVColumn(void *pCursor, void *cp, int col);
static int cXColumn(sqlite3_vtab_cursor *pCursor, sqlite3_context *ctx, int i) {
char *pzErr = goVColumn(((goVTabCursor*)pCursor)->vTabCursor, ctx, i);
if (pzErr) {
return setErrMsg(pCursor, pzErr);
}
return SQLITE_OK;
}
char* goVRowid(void *pCursor, sqlite3_int64 *pRowid);
static int cXRowid(sqlite3_vtab_cursor *pCursor, sqlite3_int64 *pRowid) {
char *pzErr = goVRowid(((goVTabCursor*)pCursor)->vTabCursor, pRowid);
if (pzErr) {
return setErrMsg(pCursor, pzErr);
}
return SQLITE_OK;
}
char* goVUpdate(void *pVTab, int argc, sqlite3_value **argv, sqlite3_int64 *pRowid);
static int cXUpdate(sqlite3_vtab *pVTab, int argc, sqlite3_value **argv, sqlite3_int64 *pRowid) {
char *pzErr = goVUpdate(((goVTab*)pVTab)->vTab, argc, argv, pRowid);
if (pzErr) {
if (pVTab->zErrMsg)
sqlite3_free(pVTab->zErrMsg);
pVTab->zErrMsg = pzErr;
return SQLITE_ERROR;
}
return SQLITE_OK;
}
static sqlite3_module goModule = {
0, // iVersion
cXCreate, // xCreate - create a table
cXConnect, // xConnect - connect to an existing table
cXBestIndex, // xBestIndex - Determine search strategy
cXDisconnect, // xDisconnect - Disconnect from a table
cXDestroy, // xDestroy - Drop a table
cXOpen, // xOpen - open a cursor
cXClose, // xClose - close a cursor
cXFilter, // xFilter - configure scan constraints
cXNext, // xNext - advance a cursor
cXEof, // xEof
cXColumn, // xColumn - read data
cXRowid, // xRowid - read data
cXUpdate, // xUpdate - write data
// Not implemented
0, // xBegin - begin transaction
0, // xSync - sync transaction
0, // xCommit - commit transaction
0, // xRollback - rollback transaction
0, // xFindFunction - function overloading
0, // xRename - rename the table
0, // xSavepoint
0, // xRelease
0 // xRollbackTo
};
void goMDestroy(void*);
static int _sqlite3_create_module(sqlite3 *db, const char *zName, uintptr_t pClientData) {
return sqlite3_create_module_v2(db, zName, &goModule, (void*) pClientData, goMDestroy);
}
*/
import "C"
import (
"fmt"
"math"
"reflect"
"unsafe"
)
type sqliteModule struct {
c *SQLiteConn
name string
module Module
}
type sqliteVTab struct {
module *sqliteModule
vTab VTab
}
type sqliteVTabCursor struct {
vTab *sqliteVTab
vTabCursor VTabCursor
}
// Op is type of operations.
type Op uint8
// Op mean identity of operations.
const (
OpEQ Op = 2
OpGT = 4
OpLE = 8
OpLT = 16
OpGE = 32
OpMATCH = 64
OpLIKE = 65 /* 3.10.0 and later only */
OpGLOB = 66 /* 3.10.0 and later only */
OpREGEXP = 67 /* 3.10.0 and later only */
OpScanUnique = 1 /* Scan visits at most 1 row */
)
// InfoConstraint give information of constraint.
type InfoConstraint struct {
Column int
Op Op
Usable bool
}
// InfoOrderBy give information of order-by.
type InfoOrderBy struct {
Column int
Desc bool
}
func constraints(info *C.sqlite3_index_info) []InfoConstraint {
l := info.nConstraint
slice := (*[1 << 30]C.struct_sqlite3_index_constraint)(unsafe.Pointer(info.aConstraint))[:l:l]
cst := make([]InfoConstraint, 0, l)
for _, c := range slice {
var usable bool
if c.usable > 0 {
usable = true
}
cst = append(cst, InfoConstraint{
Column: int(c.iColumn),
Op: Op(c.op),
Usable: usable,
})
}
return cst
}
func orderBys(info *C.sqlite3_index_info) []InfoOrderBy {
l := info.nOrderBy
slice := (*[1 << 30]C.struct_sqlite3_index_orderby)(unsafe.Pointer(info.aOrderBy))[:l:l]
ob := make([]InfoOrderBy, 0, l)
for _, c := range slice {
var desc bool
if c.desc > 0 {
desc = true
}
ob = append(ob, InfoOrderBy{
Column: int(c.iColumn),
Desc: desc,
})
}
return ob
}
// IndexResult is a Go struct representation of what eventually ends up in the
// output fields for `sqlite3_index_info`
// See: https://www.sqlite.org/c3ref/index_info.html
type IndexResult struct {
Used []bool // aConstraintUsage
IdxNum int
IdxStr string
AlreadyOrdered bool // orderByConsumed
EstimatedCost float64
EstimatedRows float64
}
// mPrintf is a utility wrapper around sqlite3_mprintf
func mPrintf(format, arg string) *C.char {
cf := C.CString(format)
defer C.free(unsafe.Pointer(cf))
ca := C.CString(arg)
defer C.free(unsafe.Pointer(ca))
return C._sqlite3_mprintf(cf, ca)
}
//export goMInit
func goMInit(db, pClientData unsafe.Pointer, argc C.int, argv **C.char, pzErr **C.char, isCreate C.int) C.uintptr_t {
m := lookupHandle(uintptr(pClientData)).(*sqliteModule)
if m.c.db != (*C.sqlite3)(db) {
*pzErr = mPrintf("%s", "Inconsistent db handles")
return 0
}
args := make([]string, argc)
var A []*C.char
slice := reflect.SliceHeader{Data: uintptr(unsafe.Pointer(argv)), Len: int(argc), Cap: int(argc)}
a := reflect.NewAt(reflect.TypeOf(A), unsafe.Pointer(&slice)).Elem().Interface()
for i, s := range a.([]*C.char) {
args[i] = C.GoString(s)
}
var vTab VTab
var err error
if isCreate == 1 {
vTab, err = m.module.Create(m.c, args)
} else {
vTab, err = m.module.Connect(m.c, args)
}
if err != nil {
*pzErr = mPrintf("%s", err.Error())
return 0
}
vt := sqliteVTab{m, vTab}
*pzErr = nil
return C.uintptr_t(newHandle(m.c, &vt))
}
//export goVRelease
func goVRelease(pVTab unsafe.Pointer, isDestroy C.int) *C.char {
vt := lookupHandle(uintptr(pVTab)).(*sqliteVTab)
var err error
if isDestroy == 1 {
err = vt.vTab.Destroy()
} else {
err = vt.vTab.Disconnect()
}
if err != nil {
return mPrintf("%s", err.Error())
}
return nil
}
//export goVOpen
func goVOpen(pVTab unsafe.Pointer, pzErr **C.char) C.uintptr_t {
vt := lookupHandle(uintptr(pVTab)).(*sqliteVTab)
vTabCursor, err := vt.vTab.Open()
if err != nil {
*pzErr = mPrintf("%s", err.Error())
return 0
}
vtc := sqliteVTabCursor{vt, vTabCursor}
*pzErr = nil
return C.uintptr_t(newHandle(vt.module.c, &vtc))
}
//export goVBestIndex
func goVBestIndex(pVTab unsafe.Pointer, icp unsafe.Pointer) *C.char {
vt := lookupHandle(uintptr(pVTab)).(*sqliteVTab)
info := (*C.sqlite3_index_info)(icp)
csts := constraints(info)
res, err := vt.vTab.BestIndex(csts, orderBys(info))
if err != nil {
return mPrintf("%s", err.Error())
}
if len(res.Used) != len(csts) {
return mPrintf("Result.Used != expected value", "")
}
// Get a pointer to constraint_usage struct so we can update in place.
l := info.nConstraint
s := (*[1 << 30]C.struct_sqlite3_index_constraint_usage)(unsafe.Pointer(info.aConstraintUsage))[:l:l]
index := 1
for i := C.int(0); i < info.nConstraint; i++ {
if res.Used[i] {
s[i].argvIndex = C.int(index)
s[i].omit = C.uchar(1)
index++
}
}
info.idxNum = C.int(res.IdxNum)
idxStr := C.CString(res.IdxStr)
defer C.free(unsafe.Pointer(idxStr))
info.idxStr = idxStr
info.needToFreeIdxStr = C.int(0)
if res.AlreadyOrdered {
info.orderByConsumed = C.int(1)
}
info.estimatedCost = C.double(res.EstimatedCost)
info.estimatedRows = C.sqlite3_int64(res.EstimatedRows)
return nil
}
//export goVClose
func goVClose(pCursor unsafe.Pointer) *C.char {
vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
err := vtc.vTabCursor.Close()
if err != nil {
return mPrintf("%s", err.Error())
}
return nil
}
//export goMDestroy
func goMDestroy(pClientData unsafe.Pointer) {
m := lookupHandle(uintptr(pClientData)).(*sqliteModule)
m.module.DestroyModule()
}
//export goVFilter
func goVFilter(pCursor unsafe.Pointer, idxNum C.int, idxName *C.char, argc C.int, argv **C.sqlite3_value) *C.char {
vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
args := (*[(math.MaxInt32 - 1) / unsafe.Sizeof((*C.sqlite3_value)(nil))]*C.sqlite3_value)(unsafe.Pointer(argv))[:argc:argc]
vals := make([]interface{}, 0, argc)
for _, v := range args {
conv, err := callbackArgGeneric(v)
if err != nil {
return mPrintf("%s", err.Error())
}
vals = append(vals, conv.Interface())
}
err := vtc.vTabCursor.Filter(int(idxNum), C.GoString(idxName), vals)
if err != nil {
return mPrintf("%s", err.Error())
}
return nil
}
//export goVNext
func goVNext(pCursor unsafe.Pointer) *C.char {
vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
err := vtc.vTabCursor.Next()
if err != nil {
return mPrintf("%s", err.Error())
}
return nil
}
//export goVEof
func goVEof(pCursor unsafe.Pointer) C.int {
vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
err := vtc.vTabCursor.EOF()
if err {
return 1
}
return 0
}
//export goVColumn
func goVColumn(pCursor, cp unsafe.Pointer, col C.int) *C.char {
vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
c := (*SQLiteContext)(cp)
err := vtc.vTabCursor.Column(c, int(col))
if err != nil {
return mPrintf("%s", err.Error())
}
return nil
}
//export goVRowid
func goVRowid(pCursor unsafe.Pointer, pRowid *C.sqlite3_int64) *C.char {
vtc := lookupHandle(uintptr(pCursor)).(*sqliteVTabCursor)
rowid, err := vtc.vTabCursor.Rowid()
if err != nil {
return mPrintf("%s", err.Error())
}
*pRowid = C.sqlite3_int64(rowid)
return nil
}
//export goVUpdate
func goVUpdate(pVTab unsafe.Pointer, argc C.int, argv **C.sqlite3_value, pRowid *C.sqlite3_int64) *C.char {
vt := lookupHandle(uintptr(pVTab)).(*sqliteVTab)
var tname string
if n, ok := vt.vTab.(interface {
TableName() string
}); ok {
tname = n.TableName() + " "
}
err := fmt.Errorf("virtual %s table %sis read-only", vt.module.name, tname)
if v, ok := vt.vTab.(VTabUpdater); ok {
// convert argv
args := (*[(math.MaxInt32 - 1) / unsafe.Sizeof((*C.sqlite3_value)(nil))]*C.sqlite3_value)(unsafe.Pointer(argv))[:argc:argc]
vals := make([]interface{}, 0, argc)
for _, v := range args {
conv, err := callbackArgGeneric(v)
if err != nil {
return mPrintf("%s", err.Error())
}
// work around for SQLITE_NULL
x := conv.Interface()
if z, ok := x.([]byte); ok && z == nil {
x = nil
}
vals = append(vals, x)
}
switch {
case argc == 1:
err = v.Delete(vals[0])
case argc > 1 && vals[0] == nil:
var id int64
id, err = v.Insert(vals[1], vals[2:])
if err == nil {
*pRowid = C.sqlite3_int64(id)
}
case argc > 1:
err = v.Update(vals[1], vals[2:])
}
}
if err != nil {
return mPrintf("%s", err.Error())
}
return nil
}
// Module is a "virtual table module", it defines the implementation of a
// virtual tables. See: http://sqlite.org/c3ref/module.html
type Module interface {
// http://sqlite.org/vtab.html#xcreate
Create(c *SQLiteConn, args []string) (VTab, error)
// http://sqlite.org/vtab.html#xconnect
Connect(c *SQLiteConn, args []string) (VTab, error)
// http://sqlite.org/c3ref/create_module.html
DestroyModule()
}
// VTab describes a particular instance of the virtual table.
// See: http://sqlite.org/c3ref/vtab.html
type VTab interface {
// http://sqlite.org/vtab.html#xbestindex
BestIndex([]InfoConstraint, []InfoOrderBy) (*IndexResult, error)
// http://sqlite.org/vtab.html#xdisconnect
Disconnect() error
// http://sqlite.org/vtab.html#sqlite3_module.xDestroy
Destroy() error
// http://sqlite.org/vtab.html#xopen
Open() (VTabCursor, error)
}
// VTabUpdater is a type that allows a VTab to be inserted, updated, or
// deleted.
// See: https://sqlite.org/vtab.html#xupdate
type VTabUpdater interface {
Delete(interface{}) error
Insert(interface{}, []interface{}) (int64, error)
Update(interface{}, []interface{}) error
}
// VTabCursor describes cursors that point into the virtual table and are used
// to loop through the virtual table. See: http://sqlite.org/c3ref/vtab_cursor.html
type VTabCursor interface {
// http://sqlite.org/vtab.html#xclose
Close() error
// http://sqlite.org/vtab.html#xfilter
Filter(idxNum int, idxStr string, vals []interface{}) error
// http://sqlite.org/vtab.html#xnext
Next() error
// http://sqlite.org/vtab.html#xeof
EOF() bool
// http://sqlite.org/vtab.html#xcolumn
Column(c *SQLiteContext, col int) error
// http://sqlite.org/vtab.html#xrowid
Rowid() (int64, error)
}
// DeclareVTab declares the Schema of a virtual table.
// See: http://sqlite.org/c3ref/declare_vtab.html
func (c *SQLiteConn) DeclareVTab(sql string) error {
zSQL := C.CString(sql)
defer C.free(unsafe.Pointer(zSQL))
rv := C.sqlite3_declare_vtab(c.db, zSQL)
if rv != C.SQLITE_OK {
return c.lastError()
}
return nil
}
// CreateModule registers a virtual table implementation.
// See: http://sqlite.org/c3ref/create_module.html
func (c *SQLiteConn) CreateModule(moduleName string, module Module) error {
mname := C.CString(moduleName)
defer C.free(unsafe.Pointer(mname))
udm := sqliteModule{c, moduleName, module}
rv := C._sqlite3_create_module(c.db, mname, C.uintptr_t(newHandle(c, &udm)))
if rv != C.SQLITE_OK {
return c.lastError()
}
return nil
}