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// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package rpc
import (
"fmt"
"math"
"math/big"
"reflect"
"strings"
"sync"
"gopkg.in/fatih/set.v0"
)
// API describes the set of methods offered over the RPC interface
type API struct {
Namespace string // namespace under which the rpc methods of Service are exposed
Version string // api version for DApp's
Service interface{} // receiver instance which holds the methods
Public bool // indication if the methods must be considered safe for public use
}
// callback is a method callback which was registered in the server
type callback struct {
rcvr reflect.Value // receiver of method
method reflect.Method // callback
argTypes []reflect.Type // input argument types
hasCtx bool // method's first argument is a context (not included in argTypes)
errPos int // err return idx, of -1 when method cannot return error
isSubscribe bool // indication if the callback is a subscription
}
// service represents a registered object
type service struct {
name string // name for service
rcvr reflect.Value // receiver of methods for the service
typ reflect.Type // receiver type
callbacks callbacks // registered handlers
subscriptions subscriptions // available subscriptions/notifications
}
// serverRequest is an incoming request
type serverRequest struct {
id interface{}
svcname string
rcvr reflect.Value
callb *callback
args []reflect.Value
isUnsubscribe bool
err Error
}
type serviceRegistry map[string]*service // collection of services
type callbacks map[string]*callback // collection of RPC callbacks
type subscriptions map[string]*callback // collection of subscription callbacks
type subscriptionRegistry map[string]*callback // collection of subscription callbacks
// Server represents a RPC server
type Server struct {
services serviceRegistry
muSubcriptions sync.Mutex // protects subscriptions
subscriptions subscriptionRegistry
run int32
codecsMu sync.Mutex
codecs *set.Set
}
// rpcRequest represents a raw incoming RPC request
type rpcRequest struct {
service string
method string
id interface{}
isPubSub bool
params interface{}
err Error // invalid batch element
}
// Error wraps RPC errors, which contain an error code in addition to the message.
type Error interface {
Error() string // returns the message
ErrorCode() int // returns the code
}
// ServerCodec implements reading, parsing and writing RPC messages for the server side of
// a RPC session. Implementations must be go-routine safe since the codec can be called in
// multiple go-routines concurrently.
type ServerCodec interface {
// Read next request
ReadRequestHeaders() ([]rpcRequest, bool, Error)
// Parse request argument to the given types
ParseRequestArguments([]reflect.Type, interface{}) ([]reflect.Value, Error)
// Assemble success response, expects response id and payload
CreateResponse(interface{}, interface{}) interface{}
// Assemble error response, expects response id and error
CreateErrorResponse(interface{}, Error) interface{}
// Assemble error response with extra information about the error through info
CreateErrorResponseWithInfo(id interface{}, err Error, info interface{}) interface{}
// Create notification response
CreateNotification(string, interface{}) interface{}
// Write msg to client.
Write(interface{}) error
// Close underlying data stream
Close()
// Closed when underlying connection is closed
Closed() <-chan interface{}
}
var (
pendingBlockNumber = big.NewInt(-2)
latestBlockNumber = big.NewInt(-1)
earliestBlockNumber = big.NewInt(0)
maxBlockNumber = big.NewInt(math.MaxInt64)
)
type BlockNumber int64
const (
PendingBlockNumber = BlockNumber(-2)
LatestBlockNumber = BlockNumber(-1)
)
// UnmarshalJSON parses the given JSON fragment into a BlockNumber. It supports:
// - "latest", "earliest" or "pending" as string arguments
// - the block number
// Returned errors:
// - an invalid block number error when the given argument isn't a known strings
// - an out of range error when the given block number is either too little or too large
func (bn *BlockNumber) UnmarshalJSON(data []byte) error {
input := strings.TrimSpace(string(data))
if len(input) >= 2 && input[0] == '"' && input[len(input)-1] == '"' {
input = input[1 : len(input)-1]
}
if len(input) == 0 {
*bn = BlockNumber(latestBlockNumber.Int64())
return nil
}
in := new(big.Int)
_, ok := in.SetString(input, 0)
if !ok { // test if user supplied string tag
strBlockNumber := input
if strBlockNumber == "latest" {
*bn = BlockNumber(latestBlockNumber.Int64())
return nil
}
if strBlockNumber == "earliest" {
*bn = BlockNumber(earliestBlockNumber.Int64())
return nil
}
if strBlockNumber == "pending" {
*bn = BlockNumber(pendingBlockNumber.Int64())
return nil
}
return fmt.Errorf(`invalid blocknumber %s`, data)
}
if in.Cmp(earliestBlockNumber) >= 0 && in.Cmp(maxBlockNumber) <= 0 {
*bn = BlockNumber(in.Int64())
return nil
}
return fmt.Errorf("blocknumber not in range [%d, %d]", earliestBlockNumber, maxBlockNumber)
}
func (bn BlockNumber) Int64() int64 {
return (int64)(bn)
}
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