package host
import (
"context"
"encoding/json"
extism "github.com/extism/go-sdk"
)
type ConfigGetRequest struct {
Key string `json:"key"`
}
type ConfigGetResponse struct {
Value string `json:"value,omitempty"`
Exists bool `json:"exists,omitempty"`
}
type ConfigGetIntRequest struct {
Key string `json:"key"`
}
type ConfigGetIntResponse struct {
Value int64 `json:"value,omitempty"`
Exists bool `json:"exists,omitempty"`
}
type ConfigKeysRequest struct {
Prefix string `json:"prefix"`
}
type ConfigKeysResponse struct {
Keys []string `json:"keys,omitempty"`
}
func RegisterConfigHostFunctions(service ConfigService) []extism.HostFunction {
return []extism.HostFunction{
newConfigGetHostFunction(service),
newConfigGetIntHostFunction(service),
newConfigKeysHostFunction(service),
}
}
func newConfigGetHostFunction(service ConfigService) extism.HostFunction {
return extism.NewHostFunctionWithStack(
"config_get",
func(ctx context.Context, p *extism.CurrentPlugin, stack []uint64) {
reqBytes, err := p.ReadBytes(stack[0])
if err != nil {
configWriteError(p, stack, err)
return
}
var req ConfigGetRequest
if err := json.Unmarshal(reqBytes, &req); err != nil {
configWriteError(p, stack, err)
return
}
value, exists := service.Get(ctx, req.Key)
resp := ConfigGetResponse{
Value: value,
Exists: exists,
}
configWriteResponse(p, stack, resp)
},
[]extism.ValueType{extism.ValueTypePTR},
[]extism.ValueType{extism.ValueTypePTR},
)
}
func newConfigGetIntHostFunction(service ConfigService) extism.HostFunction {
return extism.NewHostFunctionWithStack(
"config_getint",
func(ctx context.Context, p *extism.CurrentPlugin, stack []uint64) {
reqBytes, err := p.ReadBytes(stack[0])
if err != nil {
configWriteError(p, stack, err)
return
}
var req ConfigGetIntRequest
if err := json.Unmarshal(reqBytes, &req); err != nil {
configWriteError(p, stack, err)
return
}
value, exists := service.GetInt(ctx, req.Key)
resp := ConfigGetIntResponse{
Value: value,
Exists: exists,
}
configWriteResponse(p, stack, resp)
},
[]extism.ValueType{extism.ValueTypePTR},
[]extism.ValueType{extism.ValueTypePTR},
)
}
func newConfigKeysHostFunction(service ConfigService) extism.HostFunction {
return extism.NewHostFunctionWithStack(
"config_keys",
func(ctx context.Context, p *extism.CurrentPlugin, stack []uint64) {
reqBytes, err := p.ReadBytes(stack[0])
if err != nil {
configWriteError(p, stack, err)
return
}
var req ConfigKeysRequest
if err := json.Unmarshal(reqBytes, &req); err != nil {
configWriteError(p, stack, err)
return
}
keys := service.Keys(ctx, req.Prefix)
resp := ConfigKeysResponse{
Keys: keys,
}
configWriteResponse(p, stack, resp)
},
[]extism.ValueType{extism.ValueTypePTR},
[]extism.ValueType{extism.ValueTypePTR},
)
}
func configWriteResponse(p *extism.CurrentPlugin, stack []uint64, resp any) {
respBytes, err := json.Marshal(resp)
if err != nil {
configWriteError(p, stack, err)
return
}
respPtr, err := p.WriteBytes(respBytes)
if err != nil {
stack[0] = 0
return
}
stack[0] = respPtr
}
func configWriteError(p *extism.CurrentPlugin, stack []uint64, err error) {
errResp := struct {
Error string `json:"error"`
}{Error: err.Error()}
respBytes, _ := json.Marshal(errResp)
respPtr, _ := p.WriteBytes(respBytes)
stack[0] = respPtr
}