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package client
import (
"bytes"
"encoding/json"
"fmt"
"io/ioutil"
"net"
"net/http"
"net/url"
"strings"
"sync"
types "github.com/tendermint/tendermint/rpc/jsonrpc/types"
)
const (
protoHTTP = "http"
protoHTTPS = "https"
protoWSS = "wss"
protoWS = "ws"
protoTCP = "tcp"
)
//-------------------------------------------------------------
// Parsed URL structure
type parsedURL struct {
url.URL
}
// Parse URL and set defaults
func newParsedURL(remoteAddr string) (*parsedURL, error) {
u, err := url.Parse(remoteAddr)
if err != nil {
return nil, err
}
// default to tcp if nothing specified
if u.Scheme == "" {
u.Scheme = protoTCP
}
return &parsedURL{*u}, nil
}
// Change protocol to HTTP for unknown protocols and TCP protocol - useful for RPC connections
func (u *parsedURL) SetDefaultSchemeHTTP() {
// protocol to use for http operations, to support both http and https
switch u.Scheme {
case protoHTTP, protoHTTPS, protoWS, protoWSS:
// known protocols not changed
default:
// default to http for unknown protocols (ex. tcp)
u.Scheme = protoHTTP
}
}
// Get full address without the protocol - useful for Dialer connections
func (u parsedURL) GetHostWithPath() string {
// Remove protocol, userinfo and # fragment, assume opaque is empty
return u.Host + u.EscapedPath()
}
// Get a trimmed address - useful for WS connections
func (u parsedURL) GetTrimmedHostWithPath() string {
// replace / with . for http requests (kvstore domain)
return strings.Replace(u.GetHostWithPath(), "/", ".", -1)
}
// Get a trimmed address with protocol - useful as address in RPC connections
func (u parsedURL) GetTrimmedURL() string {
return u.Scheme + "://" + u.GetTrimmedHostWithPath()
}
//-------------------------------------------------------------
// 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)
}
// Caller implementers can facilitate calling the JSON-RPC endpoint.
type Caller interface {
Call(method string, params map[string]interface{}, result interface{}) (interface{}, error)
}
//-------------------------------------------------------------
// Client is a JSON-RPC client, which sends POST HTTP requests to the
// remote server.
//
// Client is safe for concurrent use by multiple goroutines.
type Client struct {
address string
username string
password string
client *http.Client
mtx sync.Mutex
nextReqID int
}
var _ HTTPClient = (*Client)(nil)
// Both Client and RequestBatch can facilitate calls to the JSON
// RPC endpoint.
var _ Caller = (*Client)(nil)
var _ Caller = (*RequestBatch)(nil)
// New returns a Client pointed at the given address.
// An error is returned on invalid remote. The function panics when remote is nil.
func New(remote string) (*Client, error) {
httpClient, err := DefaultHTTPClient(remote)
if err != nil {
return nil, err
}
return NewWithHTTPClient(remote, httpClient)
}
// NewWithHTTPClient returns a Client pointed at the given
// address using a custom http client. An error is returned on invalid remote.
// The function panics when remote is nil.
func NewWithHTTPClient(remote string, client *http.Client) (*Client, error) {
if client == nil {
panic("nil http.Client provided")
}
parsedURL, err := newParsedURL(remote)
if err != nil {
return nil, fmt.Errorf("invalid remote %s: %s", remote, err)
}
parsedURL.SetDefaultSchemeHTTP()
address := parsedURL.GetTrimmedURL()
username := parsedURL.User.Username()
password, _ := parsedURL.User.Password()
rpcClient := &Client{
address: address,
username: username,
password: password,
client: client,
}
return rpcClient, nil
}
// Call issues a POST HTTP request. Requests are JSON encoded. Content-Type:
// text/json.
func (c *Client) Call(method string, params map[string]interface{}, result interface{}) (interface{}, error) {
id := c.nextRequestID()
request, err := types.MapToRequest(id, method, params)
if err != nil {
return nil, fmt.Errorf("failed to encode params: %w", err)
}
requestBytes, err := json.Marshal(request)
if err != nil {
return nil, fmt.Errorf("failed to marshal request: %w", err)
}
requestBuf := bytes.NewBuffer(requestBytes)
httpRequest, err := http.NewRequest(http.MethodPost, c.address, requestBuf)
if err != nil {
return nil, fmt.Errorf("request failed: %w", err)
}
httpRequest.Header.Set("Content-Type", "text/json")
if c.username != "" || c.password != "" {
httpRequest.SetBasicAuth(c.username, c.password)
}
httpResponse, err := c.client.Do(httpRequest)
if err != nil {
return nil, fmt.Errorf("post failed: %w", err)
}
defer httpResponse.Body.Close() // nolint: errcheck
responseBytes, err := ioutil.ReadAll(httpResponse.Body)
if err != nil {
return nil, fmt.Errorf("failed to read response body: %w", err)
}
return unmarshalResponseBytes(responseBytes, id, result)
}
// NewRequestBatch starts a batch of requests for this client.
func (c *Client) NewRequestBatch() *RequestBatch {
return &RequestBatch{
requests: make([]*jsonRPCBufferedRequest, 0),
client: c,
}
}
func (c *Client) 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, fmt.Errorf("failed to marshal requests: %w", err)
}
httpRequest, err := http.NewRequest(http.MethodPost, c.address, bytes.NewBuffer(requestBytes))
if err != nil {
return nil, fmt.Errorf("request failed: %w", err)
}
httpRequest.Header.Set("Content-Type", "text/json")
if c.username != "" || c.password != "" {
httpRequest.SetBasicAuth(c.username, c.password)
}
httpResponse, err := c.client.Do(httpRequest)
if err != nil {
return nil, fmt.Errorf("post failed: %w", err)
}
defer httpResponse.Body.Close() // nolint: errcheck
responseBytes, err := ioutil.ReadAll(httpResponse.Body)
if err != nil {
return nil, fmt.Errorf("failed to read response body: %w", err)
}
// 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(responseBytes, ids, results)
}
func (c *Client) 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.
}
// RequestBatch 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 RequestBatch struct {
client *Client
mtx sync.Mutex
requests []*jsonRPCBufferedRequest
}
// Count returns the number of enqueued requests waiting to be sent.
func (b *RequestBatch) Count() int {
b.mtx.Lock()
defer b.mtx.Unlock()
return len(b.requests)
}
func (b *RequestBatch) enqueue(req *jsonRPCBufferedRequest) {
b.mtx.Lock()
defer b.mtx.Unlock()
b.requests = append(b.requests, req)
}
// Clear empties out the request batch.
func (b *RequestBatch) Clear() int {
b.mtx.Lock()
defer b.mtx.Unlock()
return b.clear()
}
func (b *RequestBatch) 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 *RequestBatch) 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 `Client.Call` function would.
func (b *RequestBatch) Call(
method string,
params map[string]interface{},
result interface{},
) (interface{}, error) {
id := b.client.nextRequestID()
request, err := types.MapToRequest(id, method, params)
if err != nil {
return nil, err
}
b.enqueue(&jsonRPCBufferedRequest{request: request, result: result})
return result, nil
}
//-------------------------------------------------------------
func makeHTTPDialer(remoteAddr string) (func(string, string) (net.Conn, error), error) {
u, err := newParsedURL(remoteAddr)
if err != nil {
return nil, err
}
protocol := u.Scheme
// accept http(s) as an alias for tcp
switch protocol {
case protoHTTP, protoHTTPS:
protocol = protoTCP
}
dialFn := func(proto, addr string) (net.Conn, error) {
return net.Dial(protocol, u.GetHostWithPath())
}
return dialFn, nil
}
// 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://).
// An error will be returned in case of invalid remoteAddr.
func DefaultHTTPClient(remoteAddr string) (*http.Client, error) {
dialFn, err := makeHTTPDialer(remoteAddr)
if err != nil {
return nil, err
}
client := &http.Client{
Transport: &http.Transport{
// Set to true to prevent GZIP-bomb DoS attacks
DisableCompression: true,
Dial: dialFn,
},
}
return client, nil
}