lbcd/jsonapi.go
Dave Collins 48bcbc5a22 Move result structs and funcs to jsonresults.go.
This commit moves all of the structs which deal with command results and
related functions to a new file named jsonresults.go.

This is in preparation of allowing custom results to be registered.

ok @jcvernaleo
2014-04-11 11:09:40 -05:00

800 lines
25 KiB
Go

// Copyright (c) 2013-2014 Conformal Systems LLC.
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package btcjson
import (
"encoding/json"
"fmt"
)
// Message contains a message to be sent to the bitcoin client.
type Message struct {
Jsonrpc string `json:"jsonrpc"`
Id interface{} `json:"id,omitempty"`
Method string `json:"method"`
Params interface{} `json:"params"`
}
// Reply is the general form of the reply from the bitcoin client.
// The form of the Result part varies from one command to the next so it
// is currently implemented as an interface.
type Reply struct {
Result interface{} `json:"result"`
Error *Error `json:"error"`
// This has to be a pointer for go to put a null in it when empty.
Id *interface{} `json:"id"`
}
// Error models the error field of the json returned by a bitcoin client. When
// there is no error, this should be a nil pointer to produce the null in the
// json that bitcoind produces.
type Error struct {
Code int `json:"code,omitempty"`
Message string `json:"message,omitempty"`
}
// Guarantee Error satisifies the builtin error interface
var _, _ error = Error{}, &Error{}
// Error returns a string describing the btcjson error. This
// satisifies the builtin error interface.
func (e Error) Error() string {
return fmt.Sprintf("%d: %s", e.Code, e.Message)
}
// jsonWithArgs takes a command, an id, and an interface which contains an
// array of the arguments for that command. It knows NOTHING about the commands
// so all error checking of the arguments must happen before it is called.
func jsonWithArgs(command string, id interface{}, args interface{}) ([]byte, error) {
rawMessage := Message{"1.0", id, command, args}
finalMessage, err := json.Marshal(rawMessage)
if err != nil {
return nil, err
}
return finalMessage, nil
}
// CreateMessage takes a string and the optional arguments for it. Then,
// if it is a recognized bitcoin json message, generates the json message ready
// to send off to the daemon or server.
// It is capable of handeling all of the commands from the standard client,
// described at:
// https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_Calls_list
//
// WARNING: This method is deprecated and may be removed in a future version.
// Do NOT use this as it does not work for all commands. Instead, use one of
// the New<command>Cmd functions to create a specific command.
func CreateMessage(message string, args ...interface{}) ([]byte, error) {
finalMessage, err := CreateMessageWithId(message, "btcd", args...)
return finalMessage, err
}
// CreateMessageWithId takes a string, an id, and the optional arguments for
// it. Then, if it is a recognized bitcoin json message, generates the json
// message ready to send off to the daemon or server. It is capable of handling
// all of the commands from the standard client, described at:
// https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_Calls_list
//
// WARNING: This method is deprecated and may be removed in a future version.
// Do NOT use this as it does not work for all commands. Instead, use one of
// the New<command>Cmd functions to create a specific command.
func CreateMessageWithId(message string, id interface{}, args ...interface{}) ([]byte, error) {
var finalMessage []byte
var err error
// Different commands have different required and optional arguments.
// Need to handle them based on that.
switch message {
// No args
case "getblockcount", "getblocknumber", "getconnectioncount",
"getdifficulty", "getgenerate", "gethashespersec", "getinfo",
"getmininginfo", "getpeerinfo", "getrawmempool",
"keypoolrefill", "listaddressgroupings", "listlockunspent",
"stop", "walletlock", "getbestblockhash":
if len(args) > 0 {
err = fmt.Errorf("Too many arguments for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One optional int
case "listaccounts":
if len(args) > 1 {
err = fmt.Errorf("Too many arguments for %s", message)
return finalMessage, err
}
if len(args) == 1 {
_, ok := args[0].(int)
if !ok {
err = fmt.Errorf("Argument must be int for %s", message)
return finalMessage, err
}
}
finalMessage, err = jsonWithArgs(message, id, args)
// One required int
case "getblockhash":
if len(args) != 1 {
err = fmt.Errorf("Missing argument for %s", message)
return finalMessage, err
}
_, ok := args[0].(int)
if !ok {
err = fmt.Errorf("Argument must be int for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One required float
case "settxfee":
if len(args) != 1 {
err = fmt.Errorf("Missing argument for %s", message)
return finalMessage, err
}
_, ok := args[0].(float64)
if !ok {
err = fmt.Errorf("Argument must be float64 for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One optional string
case "getmemorypool", "getnewaddress", "getwork", "help",
"getrawchangeaddress":
if len(args) > 1 {
err = fmt.Errorf("Too many arguments for %s", message)
return finalMessage, err
}
if len(args) == 1 {
_, ok := args[0].(string)
if !ok {
err = fmt.Errorf("Optional argument must be string for %s", message)
return finalMessage, err
}
}
finalMessage, err = jsonWithArgs(message, id, args)
// One required string
case "backupwallet", "decoderawtransaction", "dumpprivkey",
"encryptwallet", "getaccount", "getaccountaddress",
"getaddressesbyaccount", "getblock",
"gettransaction", "sendrawtransaction", "validateaddress":
if len(args) != 1 {
err = fmt.Errorf("%s requires one argument", message)
return finalMessage, err
}
_, ok := args[0].(string)
if !ok {
err = fmt.Errorf("Argument must be string for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// Two required strings
case "setaccount", "signmessage", "walletpassphrasechange", "addnode":
if len(args) != 2 {
err = fmt.Errorf("Missing arguments for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(string)
_, ok2 := args[1].(string)
if !ok1 || !ok2 {
err = fmt.Errorf("Arguments must be string for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One required string, one required int
case "walletpassphrase":
if len(args) != 2 {
err = fmt.Errorf("Missing arguments for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(string)
_, ok2 := args[1].(int)
if !ok1 || !ok2 {
err = fmt.Errorf("Arguments must be string and int for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// Three required strings
case "verifymessage":
if len(args) != 3 {
err = fmt.Errorf("Three arguments required for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(string)
_, ok2 := args[1].(string)
_, ok3 := args[2].(string)
if !ok1 || !ok2 || !ok3 {
err = fmt.Errorf("Arguments must be string for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One required bool, one optional string
case "getaddednodeinfo":
if len(args) > 2 || len(args) == 0 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(bool)
ok2 := true
if len(args) == 2 {
_, ok2 = args[1].(string)
}
if !ok1 || !ok2 {
err = fmt.Errorf("Arguments must be bool and optionally string for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One required bool, one optional int
case "setgenerate":
if len(args) > 2 || len(args) == 0 {
err = fmt.Errorf("Wrong number of argument for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(bool)
ok2 := true
if len(args) == 2 {
_, ok2 = args[1].(int)
}
if !ok1 || !ok2 {
err = fmt.Errorf("Arguments must be bool and optionally int for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One optional string, one optional int
case "getbalance", "getreceivedbyaccount":
if len(args) > 2 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
ok1 := true
ok2 := true
if len(args) >= 1 {
_, ok1 = args[0].(string)
}
if len(args) == 2 {
_, ok2 = args[1].(int)
}
if !ok1 || !ok2 {
err = fmt.Errorf("Optional arguments must be string and int for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One required string, one optional int
case "getrawtransaction", "getreceivedbyaddress":
if len(args) > 2 || len(args) == 0 {
err = fmt.Errorf("Wrong number of argument for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(string)
ok2 := true
if len(args) == 2 {
_, ok2 = args[1].(int)
}
if !ok1 || !ok2 {
err = fmt.Errorf("Arguments must be string and optionally int for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One required string, one optional string
// Strictly, the optional arg for submit block is an object, but
// bitcoind ignores it for now, so best to just allow string until
// support for it is complete.
case "submitblock":
if len(args) > 2 || len(args) == 0 {
err = fmt.Errorf("Wrong number of argument for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(string)
ok2 := true
if len(args) == 2 {
_, ok2 = args[1].(string)
}
if !ok1 || !ok2 {
err = fmt.Errorf("Arguments must be string and optionally string for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One optional int, one optional bool
case "listreceivedbyaccount", "listreceivedbyaddress":
if len(args) > 2 {
err = fmt.Errorf("Wrong number of argument for %s", message)
return finalMessage, err
}
ok1 := true
ok2 := true
if len(args) >= 1 {
_, ok1 = args[0].(int)
}
if len(args) == 2 {
_, ok2 = args[1].(bool)
}
if !ok1 || !ok2 {
err = fmt.Errorf("Optional arguments must be int and bool for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One optional string, two optional ints
case "listtransactions":
if len(args) > 3 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
ok1 := true
ok2 := true
ok3 := true
if len(args) >= 1 {
_, ok1 = args[0].(string)
}
if len(args) > 1 {
_, ok2 = args[1].(int)
}
if len(args) == 3 {
_, ok3 = args[2].(int)
}
if !ok1 || !ok2 || !ok3 {
err = fmt.Errorf("Optional arguments must be string and up to two ints for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One required string, one optional string, one optional bool
case "importprivkey":
if len(args) > 3 || len(args) == 0 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(string)
ok2 := true
ok3 := true
if len(args) > 1 {
_, ok2 = args[1].(string)
}
if len(args) == 3 {
_, ok3 = args[2].(bool)
}
if !ok1 || !ok2 || !ok3 {
err = fmt.Errorf("Arguments must be string and optionally string and bool for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// Two optional ints
case "listunspent":
if len(args) > 2 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
ok1 := true
ok2 := true
if len(args) >= 1 {
_, ok1 = args[0].(int)
}
if len(args) == 2 {
_, ok2 = args[1].(int)
}
if !ok1 || !ok2 {
err = fmt.Errorf("Optional arguments must be ints for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// Two optional strings
case "listsinceblock":
if len(args) > 2 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
ok1 := true
ok2 := true
if len(args) >= 1 {
_, ok1 = args[0].(string)
}
if len(args) == 2 {
_, ok2 = args[1].(string)
}
if !ok1 || !ok2 {
err = fmt.Errorf("Optional arguments must be strings for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// Two required strings, one required float, one optional int,
// two optional strings.
case "sendfrom":
if len(args) > 6 || len(args) < 3 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(string)
_, ok2 := args[1].(string)
_, ok3 := args[2].(float64)
ok4 := true
ok5 := true
ok6 := true
if len(args) >= 4 {
_, ok4 = args[3].(int)
}
if len(args) >= 5 {
_, ok5 = args[4].(string)
}
if len(args) == 6 {
_, ok6 = args[5].(string)
}
if !ok1 || !ok2 || !ok3 || !ok4 || !ok5 || !ok6 {
err = fmt.Errorf("Arguments must be string, string, float64 and optionally int and two strings for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// Two required strings, one required float, one optional int,
// one optional string.
case "move":
if len(args) > 5 || len(args) < 3 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(string)
_, ok2 := args[1].(string)
_, ok3 := args[2].(float64)
ok4 := true
ok5 := true
if len(args) >= 4 {
_, ok4 = args[3].(int)
}
if len(args) == 5 {
_, ok5 = args[4].(string)
}
if !ok1 || !ok2 || !ok3 || !ok4 || !ok5 {
err = fmt.Errorf("Arguments must be string, string, float64 and optionally int and string for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// One required strings, one required float, two optional strings
case "sendtoaddress":
if len(args) > 4 || len(args) < 2 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(string)
_, ok2 := args[1].(float64)
ok3 := true
ok4 := true
if len(args) >= 3 {
_, ok3 = args[2].(string)
}
if len(args) == 4 {
_, ok4 = args[3].(string)
}
if !ok1 || !ok2 || !ok3 || !ok4 {
err = fmt.Errorf("Arguments must be string, float64 and optionally two strings for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// required int, required pair of keys (string), optional string
case "addmultisignaddress":
if len(args) > 4 || len(args) < 3 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(int)
_, ok2 := args[1].(string)
_, ok3 := args[2].(string)
ok4 := true
if len(args) == 4 {
_, ok4 = args[2].(string)
}
if !ok1 || !ok2 || !ok3 || !ok4 {
err = fmt.Errorf("Arguments must be int, two string and optionally one for %s", message)
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// Must be a set of string, int, string, float (any number of those).
case "createrawtransaction":
if len(args)%4 != 0 || len(args) == 0 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
type vlist struct {
Txid string `json:"txid"`
Vout int `json:"vout"`
}
vList := make([]vlist, len(args)/4)
addresses := make(map[string]float64)
for i := 0; i < len(args)/4; i += 1 {
txid, ok1 := args[(i*4)+0].(string)
vout, ok2 := args[(i*4)+1].(int)
add, ok3 := args[(i*4)+2].(string)
amt, ok4 := args[(i*4)+3].(float64)
if !ok1 || !ok2 || !ok3 || !ok4 {
err = fmt.Errorf("Incorrect arguement types.")
return finalMessage, err
}
vList[i].Txid = txid
vList[i].Vout = vout
addresses[add] = amt
}
finalMessage, err = jsonWithArgs(message, id, []interface{}{vList, addresses})
// string, string/float pairs, optional int, and string
case "sendmany":
if len(args) < 3 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
var minconf int
var comment string
_, ok1 := args[0].(string)
if !ok1 {
err = fmt.Errorf("Incorrect arguement types.")
return finalMessage, err
}
addresses := make(map[string]float64)
for i := 1; i < len(args); i += 2 {
add, ok1 := args[i].(string)
if ok1 {
if len(args) > i+1 {
amt, ok2 := args[i+1].(float64)
if !ok2 {
err = fmt.Errorf("Incorrect arguement types.")
return finalMessage, err
}
// Put a single pair into addresses
addresses[add] = amt
} else {
comment = add
}
} else {
if _, ok := args[i].(int); ok {
minconf = args[i].(int)
}
if len(args)-1 > i {
if _, ok := args[i+1].(string); ok {
comment = args[i+1].(string)
}
}
}
}
finalMessage, err = jsonWithArgs(message, id, []interface{}{args[0].(string), addresses, minconf, comment})
// bool and an array of stuff
case "lockunspent":
if len(args) < 2 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(bool)
if !ok1 {
err = fmt.Errorf("Incorrect arguement types.")
return finalMessage, err
}
finalMessage, err = jsonWithArgs(message, id, args)
// one required string (hex) and optional sets of one string, one int,
// and one string along with another optional string.
case "signrawtransaction":
if len(args) < 1 {
err = fmt.Errorf("Wrong number of arguments for %s", message)
return finalMessage, err
}
_, ok1 := args[0].(string)
if !ok1 {
err = fmt.Errorf("Incorrect arguement types.")
return finalMessage, err
}
type txlist struct {
Txid string `json:"txid"`
Vout int `json:"vout"`
ScriptPubKey string `json:"scriptPubKey"`
}
txList := make([]txlist, 1)
if len(args) > 1 {
txid, ok2 := args[1].(string)
vout, ok3 := args[2].(int)
spkey, ok4 := args[3].(string)
if !ok1 || !ok2 || !ok3 || !ok4 {
err = fmt.Errorf("Incorrect arguement types.")
return finalMessage, err
}
txList[0].Txid = txid
txList[0].Vout = vout
txList[0].ScriptPubKey = spkey
}
/*
pkeyList := make([]string, (len(args)-1)/4)
for i := 0; i < len(args)/4; i += 1 {
fmt.Println(args[(i*4)+4])
txid, ok1 := args[(i*4)+1].(string)
vout, ok2 := args[(i*4)+2].(int)
spkey, ok3 := args[(i*4)+3].(string)
pkey, ok4 := args[(i*4)+4].(string)
if !ok1 || !ok2 || !ok3 || !ok4 {
err = fmt.Errorf("Incorrect arguement types.")
return finalMessage, err
}
txList[i].Txid = txid
txList[i].Vout = vout
txList[i].ScriptPubKey = spkey
pkeyList[i] = pkey
}
*/
finalMessage, err = jsonWithArgs(message, id, []interface{}{args[0].(string), txList})
// Any other message
default:
err = fmt.Errorf("Not a valid command: %s", message)
}
return finalMessage, err
}
// JSONGetMethod takes a message and tries to find the bitcoin command that it
// is in reply to so it can be processed further.
func JSONGetMethod(message []byte) (string, error) {
// Need this so we can tell what kind of message we are sending
// so we can unmarshal it properly.
var method string
var msg interface{}
err := json.Unmarshal(message, &msg)
if err != nil {
err := fmt.Errorf("Error, message does not appear to be valid json: %v", err)
return method, err
}
m := msg.(map[string]interface{})
for k, v := range m {
if k == "method" {
method = v.(string)
}
}
if method == "" {
err := fmt.Errorf("Error, no method specified.")
return method, err
}
return method, err
}
// TlsRpcCommand takes a message generated from one of the routines above
// along with the login/server information and any relavent PEM encoded
// certificates chains. It sends the command via https and returns a go struct
// with the result.
func TlsRpcCommand(user string, password string, server string, message []byte,
certificates []byte, skipverify bool) (Reply, error) {
return rpcCommand(user, password, server, message, true, certificates,
skipverify)
}
// RpcCommand takes a message generated from one of the routines above
// along with the login/server info, sends it, and gets a reply, returning
// a go struct with the result.
func RpcCommand(user string, password string, server string, message []byte) (Reply, error) {
return rpcCommand(user, password, server, message, false, nil, false)
}
func rpcCommand(user string, password string, server string, message []byte,
https bool, certificates []byte, skipverify bool) (Reply, error) {
var result Reply
method, err := JSONGetMethod(message)
if err != nil {
return result, err
}
body, err := rpcRawCommand(user, password, server, message, https,
certificates, skipverify)
if err != nil {
err := fmt.Errorf("Error getting json reply: %v", err)
return result, err
}
result, err = ReadResultCmd(method, body)
if err != nil {
err := fmt.Errorf("Error reading json message: %v", err)
return result, err
}
return result, err
}
// TlsRpcRawCommand takes a message generated from one of the routines above
// along with the login,server info and PEM encoded certificate chains for the
// server sends it, and gets a reply, returning
// the raw []byte response for use with ReadResultCmd.
func TlsRpcRawCommand(user string, password string, server string,
message []byte, certificates []byte, skipverify bool) ([]byte, error) {
return rpcRawCommand(user, password, server, message, true,
certificates, skipverify)
}
// RpcRawCommand takes a message generated from one of the routines above
// along with the login/server info, sends it, and gets a reply, returning
// the raw []byte response for use with ReadResultCmd.
func RpcRawCommand(user string, password string, server string, message []byte) ([]byte, error) {
return rpcRawCommand(user, password, server, message, false, nil, false)
}
// rpcRawCommand is a helper function for the above two functions.
func rpcRawCommand(user string, password string, server string,
message []byte, https bool, certificates []byte, skipverify bool) ([]byte, error) {
var result []byte
var msg interface{}
err := json.Unmarshal(message, &msg)
if err != nil {
err := fmt.Errorf("Error, message does not appear to be valid json: %v", err)
return result, err
}
resp, err := jsonRpcSend(user, password, server, message, https,
certificates, skipverify)
if err != nil {
err := fmt.Errorf("Error sending json message: " + err.Error())
return result, err
}
result, err = GetRaw(resp.Body)
if err != nil {
err := fmt.Errorf("Error getting json reply: %v", err)
return result, err
}
return result, err
}
// RpcSend sends the passed command to the provided server using the provided
// authentication details, waits for a reply, and returns a Go struct with the
// result.
func RpcSend(user string, password string, server string, cmd Cmd) (Reply, error) {
msg, err := cmd.MarshalJSON()
if err != nil {
return Reply{}, err
}
return RpcCommand(user, password, server, msg)
}
// TlsRpcSend sends the passed command to the provided server using the provided
// authentication details and PEM encoded certificate chain, waits for a reply,
// and returns a Go struct with the result.
func TlsRpcSend(user string, password string, server string, cmd Cmd,
certificates []byte, skipVerify bool) (Reply, error) {
msg, err := cmd.MarshalJSON()
if err != nil {
return Reply{}, err
}
return TlsRpcCommand(user, password, server, msg, certificates,
skipVerify)
}
// IsValidIdType checks that the Id field (which can go in any of the json
// messages) is valid. json rpc 1.0 allows any (json) type, but we still need
// to prevent values that cannot be marshalled from going in. json rpc 2.0
// (which bitcoind follows for some parts) only allows string, number, or null,
// so we restrict to that list. Ths is only necessary if you manually marshal
// a message. The normal btcjson functions only use string ids.
func IsValidIdType(id interface{}) bool {
switch id.(type) {
case int, int8, int16, int32, int64,
uint, uint8, uint16, uint32, uint64,
float32, float64,
string,
nil:
return true
default:
return false
}
}
// JSONToAmount Safely converts a floating point value to an int.
// Clearly not all floating point numbers can be converted to ints (there
// is no one-to-one mapping), but bitcoin's json api returns most numbers as
// floats which are not safe to use when handling money. Since bitcoins can
// only be divided in a limited way, this methods works for the amounts returned
// by the json api. It is not for general use.
// This follows the method described at:
// https://en.bitcoin.it/wiki/Proper_Money_Handling_%28JSON-RPC%29
func JSONToAmount(jsonAmount float64) (int64, error) {
var amount int64
var err error
if jsonAmount > 1.797693134862315708145274237317043567981e+300 {
err := fmt.Errorf("Error %v is too large to convert", jsonAmount)
return amount, err
}
if jsonAmount < -1.797693134862315708145274237317043567981e+300 {
err := fmt.Errorf("Error %v is too small to convert", jsonAmount)
return amount, err
}
tempVal := 1e8 * jsonAmount
// So we round properly. float won't == 0 and if it did, that
// would be converted fine anyway.
if tempVal < 0 {
tempVal = tempVal - 0.5
}
if tempVal > 0 {
tempVal = tempVal + 0.5
}
// Then just rely on the integer truncating
amount = int64(tempVal)
return amount, err
}