go/sqlite3
1
0
Fork 0
mirror of https://github.com/ncruces/go-sqlite3.git synced 2026-01-11 21:49:13 +00:00
Code Issues Packages Projects Releases Wiki Activity

Custom aggregate functions.

Browse Source
This commit is contained in:
Nuno Cruces
2023-07-03 15:45:16 +01:00
parent 3844e81404
commit 1cc7ecfe8d
4 changed files with 85 additions and 65 deletions
Download Patch File Download Diff File Expand all files Collapse all files

65
func.go
View File

@@ -23,7 +23,7 @@ func (c *Conn) CreateCollation(name string, fn func(a, b []byte) int) error {
return nil
}
// CreateFunction defines a new scalar function.
// CreateFunction defines a new scalar SQL function.
//
// https://www.sqlite.org/c3ref/create_function.html
func (c *Conn) CreateFunction(name string, nArg int, flag FunctionFlag, fn func(ctx Context, arg ...Value)) error {
@@ -35,14 +35,15 @@ func (c *Conn) CreateFunction(name string, nArg int, flag FunctionFlag, fn func(
return c.error(r)
}
// CreateWindowFunction defines a new aggregate or window function.
// CreateWindowFunction defines a new aggregate or aggregate window SQL function.
// If fn returns a [WindowFunction], then an aggregate window function is created.
//
// https://www.sqlite.org/c3ref/create_function.html
func (c *Conn) CreateWindowFunction(name string, nArg int, flag FunctionFlag, fn AggregateFunction) error {
func (c *Conn) CreateWindowFunction(name string, nArg int, flag FunctionFlag, fn func() AggregateFunction) error {
call := c.api.createAggregate
namePtr := c.arena.string(name)
funcPtr := util.AddHandle(c.ctx, fn)
if _, ok := fn.(WindowFunction); ok {
if _, ok := fn().(WindowFunction); ok {
call = c.api.createWindow
}
r := c.call(call,
@@ -51,13 +52,6 @@ func (c *Conn) CreateWindowFunction(name string, nArg int, flag FunctionFlag, fn
return c.error(r)
}
// ScalarFunction is the interface a scalar function should implement.
//
// https://www.sqlite.org/appfunc.html
type ScalarFunction interface {
Func(ctx Context, arg ...Value)
}
// AggregateFunction is the interface an aggregate function should implement.
//
// https://www.sqlite.org/appfunc.html
@@ -97,8 +91,7 @@ func callbackCompare(ctx context.Context, mod api.Module, pApp, nKey1, pKey1, nK
func callbackFunc(ctx context.Context, mod api.Module, pCtx, nArg, pArg uint32) {
module := ctx.Value(moduleKey{}).(*module)
pApp := uint32(module.call(module.api.userData, uint64(pCtx)))
fn := util.GetHandle(ctx, pApp).(func(ctx Context, arg ...Value))
fn := callbackHandle(module, pCtx).(func(ctx Context, arg ...Value))
fn(Context{
module: module,
handle: pCtx,
@@ -107,8 +100,7 @@ func callbackFunc(ctx context.Context, mod api.Module, pCtx, nArg, pArg uint32)
func callbackStep(ctx context.Context, mod api.Module, pCtx, nArg, pArg uint32) {
module := ctx.Value(moduleKey{}).(*module)
pApp := uint32(module.call(module.api.userData, uint64(pCtx)))
fn := util.GetHandle(ctx, pApp).(AggregateFunction)
fn := callbackAggregate(module, pCtx, nil).(AggregateFunction)
fn.Step(Context{
module: module,
handle: pCtx,
@@ -116,20 +108,19 @@ func callbackStep(ctx context.Context, mod api.Module, pCtx, nArg, pArg uint32)
}
func callbackFinal(ctx context.Context, mod api.Module, pCtx uint32) {
var handle uint32
module := ctx.Value(moduleKey{}).(*module)
pApp := uint32(module.call(module.api.userData, uint64(pCtx)))
fn := util.GetHandle(ctx, pApp).(AggregateFunction)
fn := callbackAggregate(module, pCtx, &handle).(AggregateFunction)
fn.Final(Context{
module: module,
handle: pCtx,
final: true,
})
util.DelHandle(ctx, handle)
}
func callbackValue(ctx context.Context, mod api.Module, pCtx uint32) {
module := ctx.Value(moduleKey{}).(*module)
pApp := uint32(module.call(module.api.userData, uint64(pCtx)))
fn := util.GetHandle(ctx, pApp).(WindowFunction)
fn := callbackAggregate(module, pCtx, nil).(WindowFunction)
fn.Value(Context{
module: module,
handle: pCtx,
@@ -138,14 +129,44 @@ func callbackValue(ctx context.Context, mod api.Module, pCtx uint32) {
func callbackInverse(ctx context.Context, mod api.Module, pCtx, nArg, pArg uint32) {
module := ctx.Value(moduleKey{}).(*module)
pApp := uint32(module.call(module.api.userData, uint64(pCtx)))
fn := util.GetHandle(ctx, pApp).(WindowFunction)
fn := callbackAggregate(module, pCtx, nil).(WindowFunction)
fn.Inverse(Context{
module: module,
handle: pCtx,
}, callbackArgs(module, nArg, pArg)...)
}
func callbackHandle(module *module, pCtx uint32) any {
pApp := uint32(module.call(module.api.userData, uint64(pCtx)))
return util.GetHandle(module.ctx, pApp)
}
func callbackAggregate(module *module, pCtx uint32, delete *uint32) any {
var size uint64
if delete == nil {
size = ptrlen
}
ptr := uint32(module.call(module.api.aggregateCtx, uint64(pCtx), size))
if ptr != 0 {
if handle := util.ReadUint32(module.mod, ptr); handle != 0 {
fn := util.GetHandle(module.ctx, handle)
if delete != nil {
*delete = handle
}
if fn != nil {
return fn
}
}
}
fn := callbackHandle(module, pCtx).(func() AggregateFunction)()
if ptr != 0 {
util.WriteUint32(module.mod, ptr, util.AddHandle(module.ctx, fn))
}
return fn
}
func callbackArgs(module *module, nArg, pArg uint32) []Value {
args := make([]Value, nArg)
for i := range args {