Documentation
¶
Overview ¶
Package rpcclient is used to do jsonrpc calls with Flashbots request signatures (X-Flashbots-Signature header)
Implemenation and interface is a slightly modified copy of https://github.com/ybbus/jsonrpc The differences are: * we handle case when Flashbots API returns errors incorrectly according to jsonrpc protocol (backwards compatibility) * we don't support object params in the Call API. When you do Call with one object we set params to be [object] instead of object * we can sign request body with ecdsa
Index ¶
Constants ¶
const ( // This error code is set in the error reponse when interacting with Flashbots RPC that has broken error response // see docs for RPCClientOpts.RejectBrokenFlashbotsErrors FlashbotsBrokenErrorResponseCode = -32088 )
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type HTTPError ¶
type HTTPError struct {
Code int
// contains filtered or unexported fields
}
HTTPError represents a error that occurred on HTTP level.
An error of type HTTPError is returned when a HTTP error occurred (status code) and the body could not be parsed to a valid RPCResponse object that holds a RPCError.
Otherwise a RPCResponse object is returned with a RPCError field that is not nil.
type RPCClient ¶
type RPCClient interface {
// Call is used to send a JSON-RPC request to the server endpoint.
//
// The spec states, that params can only be an array or an object, no primitive values.
// We don't support object params in call interface and we always wrap params into array.
// Use NewRequestWithObjectParam to create a request with object param.
//
// 1. no params: params field is omitted. e.g. Call(ctx, "getinfo")
//
// 2. single params primitive value: value is wrapped in array. e.g. Call(ctx, "getByID", 1423)
//
// 3. single params value array: array value is wrapped into array (use CallRaw to pass array to params without wrapping). e.g. Call(ctx, "storePerson", []*Person{&Person{Name: "Alex"}})
//
// 4. single object or multiple params values: always wrapped in array. e.g. Call(ctx, "setDetails", "Alex, 35, "Germany", true)
//
// Examples:
// Call(ctx, "getinfo") -> {"method": "getinfo"}
// Call(ctx, "getPersonId", 123) -> {"method": "getPersonId", "params": [123]}
// Call(ctx, "setName", "Alex") -> {"method": "setName", "params": ["Alex"]}
// Call(ctx, "setMale", true) -> {"method": "setMale", "params": [true]}
// Call(ctx, "setNumbers", []int{1, 2, 3}) -> {"method": "setNumbers", "params": [[1, 2, 3]]}
// Call(ctx, "setNumbers", []int{1, 2, 3}...) -> {"method": "setNumbers", "params": [1, 2, 3]}
// Call(ctx, "setNumbers", 1, 2, 3) -> {"method": "setNumbers", "params": [1, 2, 3]}
// Call(ctx, "savePerson", &Person{Name: "Alex", Age: 35}) -> {"method": "savePerson", "params": [{"name": "Alex", "age": 35}]}
// Call(ctx, "setPersonDetails", "Alex", 35, "Germany") -> {"method": "setPersonDetails", "params": ["Alex", 35, "Germany"}}
//
// for more information, see the examples or the unit tests
Call(ctx context.Context, method string, params ...any) (*RPCResponse, error)
// CallRaw is like Call() but without magic in the requests.Params field.
// The RPCRequest object is sent exactly as you provide it.
// See docs: NewRequest, RPCRequest
//
// It is recommended to first consider Call() and CallFor()
CallRaw(ctx context.Context, request *RPCRequest) (*RPCResponse, error)
// CallFor is a very handy function to send a JSON-RPC request to the server endpoint
// and directly specify an object to store the response.
//
// out: will store the unmarshaled object, if request was successful.
// should always be provided by references. can be nil even on success.
// the behaviour is the same as expected from json.Unmarshal()
//
// method and params: see Call() function
//
// if the request was not successful (network, http error) or the rpc response returns an error,
// an error is returned. if it was an JSON-RPC error it can be casted
// to *RPCError.
//
CallFor(ctx context.Context, out any, method string, params ...any) error
// CallBatch invokes a list of RPCRequests in a single batch request.
//
// Most convenient is to use the following form:
// CallBatch(ctx, RPCRequests{
// NewRequest("myMethod1", 1, 2, 3),
// NewRequest("myMethod2", "Test"),
// })
//
// You can create the []*RPCRequest array yourself, but it is not recommended and you should notice the following:
// - field Params is sent as provided, so Params: 2 forms an invalid json (correct would be Params: []int{2})
// - you can use the helper function Params(1, 2, 3) to use the same format as in Call()
// - field JSONRPC is overwritten and set to value: "2.0"
// - field ID is overwritten and set incrementally and maps to the array position (e.g. requests[5].ID == 5)
//
//
// Returns RPCResponses that is of type []*RPCResponse
// - note that a list of RPCResponses can be received unordered so it can happen that: responses[i] != responses[i].ID
// - RPCPersponses is enriched with helper functions e.g.: responses.HasError() returns true if one of the responses holds an RPCError
CallBatch(ctx context.Context, requests RPCRequests) (RPCResponses, error)
// CallBatchRaw invokes a list of RPCRequests in a single batch request.
// It sends the RPCRequests parameter is it passed (no magic, no id autoincrement).
//
// Consider to use CallBatch() instead except you have some good reason not to.
//
// CallBatchRaw(ctx, RPCRequests{
// &RPCRequest{
// ID: 123, // this won't be replaced in CallBatchRaw
// JSONRPC: "wrong", // this won't be replaced in CallBatchRaw
// Method: "myMethod1",
// Params: []int{1}, // there is no magic, be sure to only use array or object
// },
// })
//
// Returns RPCResponses that is of type []*RPCResponse
// - note that a list of RPCResponses can be received unordered
// - the id's must be mapped against the id's you provided
// - RPCPersponses is enriched with helper functions e.g.: responses.HasError() returns true if one of the responses holds an RPCError
CallBatchRaw(ctx context.Context, requests RPCRequests) (RPCResponses, error)
}
RPCClient sends JSON-RPC requests over HTTP to the provided JSON-RPC backend.
RPCClient is created using the factory function NewClient().
func NewClient ¶
NewClient returns a new RPCClient instance with default configuration.
endpoint: JSON-RPC service URL to which JSON-RPC requests are sent.
func NewClientWithOpts ¶
func NewClientWithOpts(endpoint string, opts *RPCClientOpts) RPCClient
NewClientWithOpts returns a new RPCClient instance with custom configuration.
endpoint: JSON-RPC service URL to which JSON-RPC requests are sent.
opts: RPCClientOpts is used to provide custom configuration.
type RPCClientOpts ¶
type RPCClientOpts struct {
HTTPClient *http.Client
CustomHeaders map[string]string
AllowUnknownFields bool
DefaultRequestID int
// If Signer is set requset body will be signed and signature will be set in the X-Flashbots-Signature header
Signer *signature.Signer
// if true client will return error when server responds with errors like {"error": "text"}
// otherwise this response will be converted to equivalent {"error": {"message": "text", "code": FlashbotsBrokenErrorResponseCode}}
// Bad errors are always rejected for batch requests
RejectBrokenFlashbotsErrors bool
}
RPCClientOpts can be provided to NewClientWithOpts() to change configuration of RPCClient.
HTTPClient: provide a custom http.Client (e.g. to set a proxy, or tls options)
CustomHeaders: provide custom headers, e.g. to set BasicAuth
AllowUnknownFields: allows the rpc response to contain fields that are not defined in the rpc response specification.
type RPCError ¶
type RPCError struct {
Code int `json:"code"`
Message string `json:"message"`
Data any `json:"data,omitempty"`
}
RPCError represents a JSON-RPC error object if an RPC error occurred.
Code holds the error code.
Message holds a short error message.
Data holds additional error data, may be nil.
type RPCRequest ¶
type RPCRequest struct {
Method string `json:"method"`
Params any `json:"params,omitempty"`
ID int `json:"id"`
JSONRPC string `json:"jsonrpc"`
}
RPCRequest represents a JSON-RPC request object.
Method: string containing the method to be invoked
Params: can be nil. if not must be an json array or object
ID: may always be set to 0 (default can be changed) for single requests. Should be unique for every request in one batch request.
JSONRPC: must always be set to "2.0" for JSON-RPC version 2.0
See: http://www.jsonrpc.org/specification#request_object
Most of the time you shouldn't create the RPCRequest object yourself. The following functions do that for you: Call(), CallFor(), NewRequest()
If you want to create it yourself (e.g. in batch or CallRaw()) you can potentially create incorrect rpc requests:
request := &RPCRequest{
Method: "myMethod",
Params: 2, <-- invalid since a single primitive value must be wrapped in an array
}
correct:
request := &RPCRequest{
Method: "myMethod",
Params: []int{2},
}
func NewRequest ¶
func NewRequest(method string, params ...any) *RPCRequest
NewRequest returns a new RPCRequest that can be created using the same convenient parameter syntax as Call()
Default RPCRequest id is 0. If you want to use an id other than 0, use NewRequestWithID() or set the ID field of the returned RPCRequest manually.
e.g. NewRequest("myMethod", "Alex", 35, true)
func NewRequestWithID ¶
func NewRequestWithID(id int, method string, params ...any) *RPCRequest
NewRequestWithID returns a new RPCRequest that can be created using the same convenient parameter syntax as Call()
e.g. NewRequestWithID(123, "myMethod", "Alex", 35, true)
func NewRequestWithObjectParam ¶
func NewRequestWithObjectParam(id int, method string, params any) *RPCRequest
NewRequestWithObjectParam returns a new RPCRequest that uses param object without wrapping it into array
e.g. NewRequestWithID(struct{}{}) -> {"params": {}}
type RPCRequests ¶
type RPCRequests []*RPCRequest
RPCRequests is of type []*RPCRequest. This type is used to provide helper functions on the request list.
type RPCResponse ¶
type RPCResponse struct {
JSONRPC string `json:"jsonrpc"`
Result any `json:"result,omitempty"`
Error *RPCError `json:"error,omitempty"`
ID int `json:"id"`
}
RPCResponse represents a JSON-RPC response object.
Result: holds the result of the rpc call if no error occurred, nil otherwise. can be nil even on success.
Error: holds an RPCError object if an error occurred. must be nil on success.
ID: may always be 0 for single requests. is unique for each request in a batch call (see CallBatch())
JSONRPC: must always be set to "2.0" for JSON-RPC version 2.0
See: http://www.jsonrpc.org/specification#response_object
func (*RPCResponse) GetBool ¶
func (RPCResponse *RPCResponse) GetBool() (bool, error)
GetBool converts the rpc response to a bool and returns it.
If result was not a bool an error is returned.
func (*RPCResponse) GetFloat ¶
func (RPCResponse *RPCResponse) GetFloat() (float64, error)
GetFloat converts the rpc response to float64 and returns it.
If result was not an float64 an error is returned.
func (*RPCResponse) GetInt ¶
func (RPCResponse *RPCResponse) GetInt() (int64, error)
GetInt converts the rpc response to an int64 and returns it.
If result was not an integer an error is returned.
func (*RPCResponse) GetObject ¶
func (RPCResponse *RPCResponse) GetObject(toType any) error
GetObject converts the rpc response to an arbitrary type.
The function works as you would expect it from json.Unmarshal()
func (*RPCResponse) GetString ¶
func (RPCResponse *RPCResponse) GetString() (string, error)
GetString converts the rpc response to a string and returns it.
If result was not a string an error is returned.
type RPCResponses ¶
type RPCResponses []*RPCResponse
RPCResponses is of type []*RPCResponse. This type is used to provide helper functions on the result list.
func (RPCResponses) AsMap ¶
func (res RPCResponses) AsMap() map[int]*RPCResponse
AsMap returns the responses as map with response id as key.
func (RPCResponses) GetByID ¶
func (res RPCResponses) GetByID(id int) *RPCResponse
GetByID returns the response object of the given id, nil if it does not exist.
func (RPCResponses) HasError ¶
func (res RPCResponses) HasError() bool
HasError returns true if one of the response objects has Error field != nil.
Source Files