feat: Encodable (#123)

- [x] Create a new `Encodable` interface with an `Encode` function
matching the current `encode()` function call.
- [x] Change `encode` to check if the given object is `Encodable` and
using its `Encode` function if it is instead, bypassing all the encoder
code.
- [x] Create the `EncoderConfig` struct to be able to forward the
current configuration simply, should any `Encodable` be there.
- [x] Promote `bindings.WAFObject` to `libddwaf.WAFObject`
- [x] Add more helper methods on the `WAFObject` type

---------

Signed-off-by: Eliott Bouhana <[email protected]>

Author: eliottness

builder.go

@@ -72,7 +72,11 @@ func (b *Builder) AddOrUpdateConfig(path string, fragment any) (Diagnostics, err
 	var pinner runtime.Pinner
 	defer pinner.Unpin()
 
-	encoder := newMaxEncoder(&pinner)
+	encoder, err := newEncoder(newUnlimitedEncoderConfig(&pinner))
+	if err != nil {
+		return Diagnostics{}, fmt.Errorf("could not create encoder: %w", err)
+	}
+
 	frag, err := encoder.Encode(fragment)
 	if err != nil {
 		return Diagnostics{}, fmt.Errorf("could not encode the config fragment into a WAF object; %w", err)

context.go

@@ -6,6 +6,7 @@
 package libddwaf
 
 import (
+	"fmt"
 	"maps"
 	"runtime"
 	"sync"
@@ -192,11 +193,15 @@ func merge[K comparable, V any](a, b map[K][]V) (merged map[K][]V) {
 // ephemeral addresses are allowed to be null one at a time. In this case, Encode will return nil,
 // which is what we need to send to ddwaf_run to signal that the address data is empty.
 func (context *Context) encodeOneAddressType(pinner pin.Pinner, addressData map[string]any, timer timer.Timer) (*bindings.WAFObject, error) {
-	encoder := newLimitedEncoder(pinner, timer)
 	if addressData == nil {
 		return nil, nil
 	}
 
+	encoder, err := newEncoder(newEncoderConfig(pinner, timer))
+	if err != nil {
+		return nil, fmt.Errorf("could not create encoder: %w", err)
+	}
+
 	data, _ := encoder.Encode(addressData)
 	if len(encoder.truncations) > 0 {
 		context.mutex.Lock()