From c3da01c74a0681141e69e6e57c8033468a99349a Mon Sep 17 00:00:00 2001
From: Adin Schmahmann <adin.schmahmann@gmail.com>
Date: Tue, 30 May 2023 14:58:56 -0400
Subject: [PATCH] feat: remove block decoding global registry

---
 coding.go      | 50 +++-----------------------------------------------
 coding_test.go | 10 ++++------
 2 files changed, 7 insertions(+), 53 deletions(-)

diff --git a/coding.go b/coding.go
index e202f75..edd0251 100644
--- a/coding.go
+++ b/coding.go
@@ -1,62 +1,18 @@
 package format
 
 import (
-	"fmt"
-	"sync"
-
 	blocks "github.com/ipfs/go-block-format"
 )
 
 // DecodeBlockFunc functions decode blocks into nodes.
 type DecodeBlockFunc func(block blocks.Block) (Node, error)
 
-type BlockDecoder interface {
-	Register(codec uint64, decoder DecodeBlockFunc)
-	Decode(blocks.Block) (Node, error)
-}
-type safeBlockDecoder struct {
-	// Can be replaced with an RCU if necessary.
-	lock     sync.RWMutex
-	decoders map[uint64]DecodeBlockFunc
-}
-
-// Register registers decoder for all blocks with the passed codec.
-//
-// This will silently replace any existing registered block decoders.
-func (d *safeBlockDecoder) Register(codec uint64, decoder DecodeBlockFunc) {
-	d.lock.Lock()
-	defer d.lock.Unlock()
-	d.decoders[codec] = decoder
-}
-
-func (d *safeBlockDecoder) Decode(block blocks.Block) (Node, error) {
+// Decode decodes the given block using passed DecodeBlockFunc.
+func Decode(block blocks.Block, decoder DecodeBlockFunc) (Node, error) {
 	// Short-circuit by cast if we already have a Node.
 	if node, ok := block.(Node); ok {
 		return node, nil
 	}
 
-	ty := block.Cid().Type()
-
-	d.lock.RLock()
-	decoder, ok := d.decoders[ty]
-	d.lock.RUnlock()
-
-	if ok {
-		return decoder(block)
-	} else {
-		// TODO: get the *long* name for this format
-		return nil, fmt.Errorf("unrecognized object type: %d", ty)
-	}
-}
-
-var DefaultBlockDecoder BlockDecoder = &safeBlockDecoder{decoders: make(map[uint64]DecodeBlockFunc)}
-
-// Decode decodes the given block using the default BlockDecoder.
-func Decode(block blocks.Block) (Node, error) {
-	return DefaultBlockDecoder.Decode(block)
-}
-
-// Register registers block decoders with the default BlockDecoder.
-func Register(codec uint64, decoder DecodeBlockFunc) {
-	DefaultBlockDecoder.Register(codec, decoder)
+	return decoder(block)
 }
diff --git a/coding_test.go b/coding_test.go
index dad8498..77062a6 100644
--- a/coding_test.go
+++ b/coding_test.go
@@ -9,17 +9,15 @@ import (
 	mh "github.com/multiformats/go-multihash"
 )
 
-func init() {
-	Register(cid.Raw, func(b blocks.Block) (Node, error) {
+func TestDecode(t *testing.T) {
+	decoder := func(b blocks.Block) (Node, error) {
 		node := &EmptyNode{}
 		if b.RawData() != nil || !b.Cid().Equals(node.Cid()) {
 			return nil, errors.New("can only decode empty blocks")
 		}
 		return node, nil
-	})
-}
+	}
 
-func TestDecode(t *testing.T) {
 	id, err := cid.Prefix{
 		Version:  1,
 		Codec:    cid.Raw,
@@ -35,7 +33,7 @@ func TestDecode(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to create empty block: %s", err)
 	}
-	node, err := Decode(block)
+	node, err := Decode(block, decoder)
 	if err != nil {
 		t.Fatalf("failed to decode empty node: %s", err)
 	}