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package rpcclient
import (
"bytes"
"encoding/json"
"fmt"
"io/ioutil"
"net"
"net/http"
"strings"
"sync"
"github.com/pkg/errors"
amino "github.com/tendermint/go-amino"
types "github.com/tendermint/tendermint/rpc/lib/types"
)
const (
protoHTTP = "http"
protoHTTPS = "https"
protoWSS = "wss"
protoWS = "ws"
protoTCP = "tcp"
)
//-------------------------------------------------------------
// HTTPClient is a common interface for JSON-RPC HTTP clients.
type HTTPClient interface {
// Call calls the given method with the params and returns a result.
Call(method string, params map[string]interface{}, result interface{}) (interface{}, error)
// Codec returns an amino codec used.
Codec() *amino.Codec
// SetCodec sets an amino codec.
SetCodec(*amino.Codec)
}
// JSONRPCCaller implementers can facilitate calling the JSON-RPC endpoint.
type JSONRPCCaller interface {
Call(method string, params map[string]interface{}, result interface{}) (interface{}, error)
}
//-------------------------------------------------------------
// JSONRPCClient is a JSON-RPC client, which sends POST HTTP requests to the
// remote server.
//
// Request values are amino encoded. Response is expected to be amino encoded.
// New amino codec is used if no other codec was set using SetCodec.
//
// JSONRPCClient is safe for concurrent use by multiple goroutines.
type JSONRPCClient struct {
address string
client *http.Client
cdc *amino.Codec
mtx sync.Mutex
nextReqID int
}
var _ HTTPClient = (*JSONRPCClient)(nil)
// Both JSONRPCClient and JSONRPCRequestBatch can facilitate calls to the JSON
// RPC endpoint.
var _ JSONRPCCaller = (*JSONRPCClient)(nil)
var _ JSONRPCCaller = (*JSONRPCRequestBatch)(nil)
// NewJSONRPCClient returns a JSONRPCClient pointed at the given address.
func NewJSONRPCClient(remote string) *JSONRPCClient {
return NewJSONRPCClientWithHTTPClient(remote, DefaultHTTPClient(remote))
}
// NewJSONRPCClientWithHTTPClient returns a JSONRPCClient pointed at the given address using a custom http client
// The function panics if the provided client is nil or remote is invalid.
func NewJSONRPCClientWithHTTPClient(remote string, client *http.Client) *JSONRPCClient {
if client == nil {
panic("nil http.Client provided")
}
clientAddress, err := toClientAddress(remote)
if err != nil {
panic(fmt.Sprintf("invalid remote %s: %s", remote, err))
}
return &JSONRPCClient{
address: clientAddress,
client: client,
cdc: amino.NewCodec(),
}
}
// Call issues a POST HTTP request. Requests are JSON encoded. Content-Type:
// text/json.
func (c *JSONRPCClient) Call(method string, params map[string]interface{}, result interface{}) (interface{}, error) {
id := c.nextRequestID()
request, err := types.MapToRequest(c.cdc, id, method, params)
if err != nil {
return nil, errors.Wrap(err, "failed to encode params")
}
requestBytes, err := json.Marshal(request)
if err != nil {
return nil, errors.Wrap(err, "failed to marshal request")
}
requestBuf := bytes.NewBuffer(requestBytes)
httpResponse, err := c.client.Post(c.address, "text/json", requestBuf)
if err != nil {
return nil, errors.Wrap(err, "Post failed")
}
defer httpResponse.Body.Close() // nolint: errcheck
responseBytes, err := ioutil.ReadAll(httpResponse.Body)
if err != nil {
return nil, errors.Wrap(err, "failed to read response body")
}
return unmarshalResponseBytes(c.cdc, responseBytes, id, result)
}
func (c *JSONRPCClient) Codec() *amino.Codec { return c.cdc }
func (c *JSONRPCClient) SetCodec(cdc *amino.Codec) { c.cdc = cdc }
// NewRequestBatch starts a batch of requests for this client.
func (c *JSONRPCClient) NewRequestBatch() *JSONRPCRequestBatch {
return &JSONRPCRequestBatch{
requests: make([]*jsonRPCBufferedRequest, 0),
client: c,
}
}
func (c *JSONRPCClient) sendBatch(requests []*jsonRPCBufferedRequest) ([]interface{}, error) {
reqs := make([]types.RPCRequest, 0, len(requests))
results := make([]interface{}, 0, len(requests))
for _, req := range requests {
reqs = append(reqs, req.request)
results = append(results, req.result)
}
// serialize the array of requests into a single JSON object
requestBytes, err := json.Marshal(reqs)
if err != nil {
return nil, errors.Wrap(err, "failed to marshal requests")
}
httpResponse, err := c.client.Post(c.address, "text/json", bytes.NewBuffer(requestBytes))
if err != nil {
return nil, errors.Wrap(err, "Post failed")
}
defer httpResponse.Body.Close() // nolint: errcheck
responseBytes, err := ioutil.ReadAll(httpResponse.Body)
if err != nil {
return nil, errors.Wrap(err, "failed to read response body")
}
// collect ids to check responses IDs in unmarshalResponseBytesArray
ids := make([]types.JSONRPCIntID, len(requests))
for i, req := range requests {
ids[i] = req.request.ID.(types.JSONRPCIntID)
}
return unmarshalResponseBytesArray(c.cdc, responseBytes, ids, results)
}
func (c *JSONRPCClient) nextRequestID() types.JSONRPCIntID {
c.mtx.Lock()
id := c.nextReqID
c.nextReqID++
c.mtx.Unlock()
return types.JSONRPCIntID(id)
}
//------------------------------------------------------------------------------------
// jsonRPCBufferedRequest encapsulates a single buffered request, as well as its
// anticipated response structure.
type jsonRPCBufferedRequest struct {
request types.RPCRequest
result interface{} // The result will be deserialized into this object.
}
// JSONRPCRequestBatch allows us to buffer multiple request/response structures
// into a single batch request. Note that this batch acts like a FIFO queue, and
// is thread-safe.
type JSONRPCRequestBatch struct {
client *JSONRPCClient
mtx sync.Mutex
requests []*jsonRPCBufferedRequest
}
// Count returns the number of enqueued requests waiting to be sent.
func (b *JSONRPCRequestBatch) Count() int {
b.mtx.Lock()
defer b.mtx.Unlock()
return len(b.requests)
}
func (b *JSONRPCRequestBatch) enqueue(req *jsonRPCBufferedRequest) {
b.mtx.Lock()
defer b.mtx.Unlock()
b.requests = append(b.requests, req)
}
// Clear empties out the request batch.
func (b *JSONRPCRequestBatch) Clear() int {
b.mtx.Lock()
defer b.mtx.Unlock()
return b.clear()
}
func (b *JSONRPCRequestBatch) clear() int {
count := len(b.requests)
b.requests = make([]*jsonRPCBufferedRequest, 0)
return count
}
// Send will attempt to send the current batch of enqueued requests, and then
// will clear out the requests once done. On success, this returns the
// deserialized list of results from each of the enqueued requests.
func (b *JSONRPCRequestBatch) Send() ([]interface{}, error) {
b.mtx.Lock()
defer func() {
b.clear()
b.mtx.Unlock()
}()
return b.client.sendBatch(b.requests)
}
// Call enqueues a request to call the given RPC method with the specified
// parameters, in the same way that the `JSONRPCClient.Call` function would.
func (b *JSONRPCRequestBatch) Call(
method string,
params map[string]interface{},
result interface{},
) (interface{}, error) {
id := b.client.nextRequestID()
request, err := types.MapToRequest(b.client.cdc, id, method, params)
if err != nil {
return nil, err
}
b.enqueue(&jsonRPCBufferedRequest{request: request, result: result})
return result, nil
}
//-------------------------------------------------------------
// protocol - client's protocol (for example, "http", "https", "wss", "ws", "tcp")
// trimmedS - rest of the address (for example, "192.0.2.1:25", "[2001:db8::1]:80") with "/" replaced with "."
func toClientAddrAndParse(remoteAddr string) (network string, trimmedS string, err error) {
protocol, address, err := parseRemoteAddr(remoteAddr)
if err != nil {
return "", "", err
}
// protocol to use for http operations, to support both http and https
var clientProtocol string
// default to http for unknown protocols (ex. tcp)
switch protocol {
case protoHTTP, protoHTTPS, protoWS, protoWSS:
clientProtocol = protocol
default:
clientProtocol = protoHTTP
}
// replace / with . for http requests (kvstore domain)
trimmedAddress := strings.Replace(address, "/", ".", -1)
return clientProtocol, trimmedAddress, nil
}
func toClientAddress(remoteAddr string) (string, error) {
clientProtocol, trimmedAddress, err := toClientAddrAndParse(remoteAddr)
if err != nil {
return "", err
}
return clientProtocol + "://" + trimmedAddress, nil
}
// network - name of the network (for example, "tcp", "unix")
// s - rest of the address (for example, "192.0.2.1:25", "[2001:db8::1]:80")
// TODO: Deprecate support for IP:PORT or /path/to/socket
func parseRemoteAddr(remoteAddr string) (network string, s string, err error) {
parts := strings.SplitN(remoteAddr, "://", 2)
var protocol, address string
switch len(parts) {
case 1:
// default to tcp if nothing specified
protocol, address = protoTCP, remoteAddr
case 2:
protocol, address = parts[0], parts[1]
default:
return "", "", fmt.Errorf("invalid addr: %s", remoteAddr)
}
return protocol, address, nil
}
func makeErrorDialer(err error) func(string, string) (net.Conn, error) {
return func(_ string, _ string) (net.Conn, error) {
return nil, err
}
}
func makeHTTPDialer(remoteAddr string) func(string, string) (net.Conn, error) {
protocol, address, err := parseRemoteAddr(remoteAddr)
if err != nil {
return makeErrorDialer(err)
}
// accept http(s) as an alias for tcp
switch protocol {
case protoHTTP, protoHTTPS:
protocol = protoTCP
}
return func(proto, addr string) (net.Conn, error) {
return net.Dial(protocol, address)
}
}
// DefaultHTTPClient is used to create an http client with some default parameters.
// We overwrite the http.Client.Dial so we can do http over tcp or unix.
// remoteAddr should be fully featured (eg. with tcp:// or unix://)
func DefaultHTTPClient(remoteAddr string) *http.Client {
return &http.Client{
Transport: &http.Transport{
// Set to true to prevent GZIP-bomb DoS attacks
DisableCompression: true,
Dial: makeHTTPDialer(remoteAddr),
},
}
}