added comments

zetaclient/bitcoin/bitcoin_rpc_fallback.go

@@ -17,12 +17,14 @@ import (
 
 var _ interfaces.BTCRPCClient = &RPCClientFallback{}
 
+// RPCClientFallback - a decorator type for adding fallback capability to bitcoin rpc client
 type RPCClientFallback struct {
 	btcConfig  config.BTCConfig
 	rpcClients *common.ClientQueue
 	logger     zerolog.Logger
 }
 
+// NewRPCClientFallback - Constructor, reads config and connects to each client in the endpoint list
 func NewRPCClientFallback(cfg config.BTCConfig, logger zerolog.Logger) (*RPCClientFallback, error) {
 	if len(cfg.Endpoints) == 0 {
 		return nil, errors.New("invalid endpoints")
@@ -56,6 +58,10 @@ func NewRPCClientFallback(cfg config.BTCConfig, logger zerolog.Logger) (*RPCClie
 	return &rpcClientFallback, nil
 }
 
+// Below is an implementation of the BTCRPCClient interface. The logic is similar for all functions, the first client
+// in the queue is used to attempt the rpc call. If this fails then it will attempt to call the next client in the list
+// until it has tried them all.
+
 func (R *RPCClientFallback) GetNetworkInfo() (*btcjson.GetNetworkInfoResult, error) {
 	var res *btcjson.GetNetworkInfoResult
 	var err error

zetaclient/common/client_queue.go

@@ -1,23 +1,28 @@
 package common
 
+// ClientQueue - Generic data structure to keep track of fallback clients used to connect to EVM and Bitcoin nodes
 type ClientQueue struct {
 	clientList []any
 }
 
+// NewClientQueue - constructor
 func NewClientQueue() *ClientQueue {
 	return &ClientQueue{
 		clientList: []any{},
 	}
 }
 
+// Append - adds another client to the end of the queue
 func (c *ClientQueue) Append(item any) {
 	c.clientList = append(c.clientList, item)
 }
 
+// Length - returns total length of queue or number of clients
 func (c *ClientQueue) Length() int {
 	return len(c.clientList)
 }
 
+// Next - rotates list of clients by moving the first to the last
 func (c *ClientQueue) Next() {
 	if len(c.clientList) < 1 {
 		return
@@ -26,6 +31,7 @@ func (c *ClientQueue) Next() {
 	c.clientList = append(c.clientList[1:], c.clientList[:1]...)
 }
 
+// First - returns the first client in the list or highest priority
 func (c *ClientQueue) First() any {
 	if len(c.clientList) < 1 {
 		return nil

zetaclient/evm/evm_rpc_fallback.go

@@ -57,7 +57,9 @@ func NewEthClientFallback(evmCfg config.EVMConfig, logger zerolog.Logger) (*EthC
 	return &ethClientFallback, nil
 }
 
-// The following functions are wrappers for EVMRPCClient interface
+// The following functions are wrappers for EVMRPCClient interface. The logic is similar for all functions, the first client
+// in the queue is used to attempt the rpc call. If this fails then it will attempt to call the next client in the list
+// until it is successful or returns an error when the list of clients have been exhausted.
 
 func (e *EthClientFallback) CodeAt(ctx context.Context, contract ethcommon.Address, blockNumber *big.Int) ([]byte, error) {
 	var res []byte