ethers.js/utils/abi-coder.js

533 lines
15 KiB
JavaScript

'use strict';
// See: https://github.com/ethereum/wiki/wiki/Ethereum-Contract-ABI
var throwError = require('../utils/throw-error');
var utils = (function() {
var convert = require('../utils/convert.js');
var utf8 = require('../utils/utf8.js');
return {
defineProperty: require('../utils/properties.js').defineProperty,
arrayify: convert.arrayify,
padZeros: convert.padZeros,
bigNumberify: require('../utils/bignumber.js').bigNumberify,
getAddress: require('../utils/address').getAddress,
concat: convert.concat,
toUtf8Bytes: utf8.toUtf8Bytes,
toUtf8String: utf8.toUtf8String,
hexlify: convert.hexlify,
};
})();
var paramTypeBytes = new RegExp(/^bytes([0-9]*)$/);
var paramTypeNumber = new RegExp(/^(u?int)([0-9]*)$/);
var paramTypeArray = new RegExp(/^(.*)\[([0-9]*)\]$/);
var defaultCoerceFunc = function(type, value) {
var match = type.match(paramTypeNumber)
if (match && parseInt(match[2]) <= 48) { return value.toNumber(); }
return value;
}
var coderNull = function(coerceFunc) {
return {
name: 'null',
type: '',
encode: function(value) {
return utils.arrayify([]);
},
decode: function(data, offset) {
if (offset > data.length) { throw new Error('invalid null'); }
return {
consumed: 0,
value: coerceFunc('null', undefined)
}
},
dynamic: false
};
}
var coderNumber = function(coerceFunc, size, signed, localName) {
var name = ((signed ? 'int': 'uint') + (size * 8));
return {
localName: localName,
name: name,
type: name,
encode: function(value) {
value = utils.bigNumberify(value).toTwos(size * 8).maskn(size * 8);
//value = value.toTwos(size * 8).maskn(size * 8);
if (signed) {
value = value.fromTwos(size * 8).toTwos(256);
}
return utils.padZeros(utils.arrayify(value), 32);
},
decode: function(data, offset) {
var junkLength = 32 - size;
var value = utils.bigNumberify(data.slice(offset + junkLength, offset + 32));
if (signed) {
value = value.fromTwos(size * 8);
} else {
value = value.maskn(size * 8);
}
//if (size <= 6) { value = value.toNumber(); }
return {
consumed: 32,
value: coerceFunc(name, value),
}
}
};
}
var uint256Coder = coderNumber(function(type, value) { return value; }, 32, false);
var coderBoolean = function(coerceFunc, localName) {
return {
localName: localName,
name: 'boolean',
type: 'boolean',
encode: function(value) {
return uint256Coder.encode(value ? 1: 0);
},
decode: function(data, offset) {
var result = uint256Coder.decode(data, offset);
return {
consumed: result.consumed,
value: coerceFunc('boolean', !result.value.isZero())
}
}
}
}
var coderFixedBytes = function(coerceFunc, length, localName) {
var name = ('bytes' + length);
return {
localName: localName,
name: name,
type: name,
encode: function(value) {
value = utils.arrayify(value);
if (length === 32) { return value; }
var result = new Uint8Array(32);
result.set(value);
return result;
},
decode: function(data, offset) {
if (data.length < offset + 32) { throwError('invalid bytes' + length); }
return {
consumed: 32,
value: coerceFunc(name, utils.hexlify(data.slice(offset, offset + length)))
}
}
};
}
var coderAddress = function(coerceFunc, localName) {
return {
localName: localName,
name: 'address',
type: 'address',
encode: function(value) {
value = utils.arrayify(utils.getAddress(value));
var result = new Uint8Array(32);
result.set(value, 12);
return result;
},
decode: function(data, offset) {
if (data.length < offset + 32) { throwError('invalid address'); }
return {
consumed: 32,
value: coerceFunc('address', utils.getAddress(utils.hexlify(data.slice(offset + 12, offset + 32))))
}
}
}
}
function _encodeDynamicBytes(value) {
var dataLength = parseInt(32 * Math.ceil(value.length / 32));
var padding = new Uint8Array(dataLength - value.length);
return utils.concat([
uint256Coder.encode(value.length),
value,
padding
]);
}
function _decodeDynamicBytes(data, offset) {
if (data.length < offset + 32) { throwError('invalid bytes'); }
var length = uint256Coder.decode(data, offset).value;
length = length.toNumber();
if (data.length < offset + 32 + length) { throwError('invalid bytes'); }
return {
consumed: parseInt(32 + 32 * Math.ceil(length / 32)),
value: data.slice(offset + 32, offset + 32 + length),
}
}
var coderDynamicBytes = function(coerceFunc, localName) {
return {
localName: localName,
name: 'bytes',
type: 'bytes',
encode: function(value) {
return _encodeDynamicBytes(utils.arrayify(value));
},
decode: function(data, offset) {
var result = _decodeDynamicBytes(data, offset);
result.value = coerceFunc('bytes', utils.hexlify(result.value));
return result;
},
dynamic: true
};
}
var coderString = function(coerceFunc, localName) {
return {
localName: localName,
name: 'string',
type: 'string',
encode: function(value) {
return _encodeDynamicBytes(utils.toUtf8Bytes(value));
},
decode: function(data, offset) {
var result = _decodeDynamicBytes(data, offset);
result.value = coerceFunc('string', utils.toUtf8String(result.value));
return result;
},
dynamic: true
};
}
function alignSize(size) {
return parseInt(32 * Math.ceil(size / 32));
}
function pack(coders, values) {
if (Array.isArray(values)) {
if (coders.length !== values.length) {
throwError('types/values mismatch', { type: type, values: values });
}
} else if (values && typeof(values) === 'object') {
var arrayValues = [];
coders.forEach(function(coder) {
arrayValues.push(values[coder.localName]);
});
values = arrayValues;
} else {
throwError('invalid value', { type: 'tuple', values: values });
}
var parts = [];
coders.forEach(function(coder, index) {
parts.push({ dynamic: coder.dynamic, value: coder.encode(values[index]) });
});
var staticSize = 0, dynamicSize = 0;
parts.forEach(function(part, index) {
if (part.dynamic) {
staticSize += 32;
dynamicSize += alignSize(part.value.length);
} else {
staticSize += alignSize(part.value.length);
}
});
var offset = 0, dynamicOffset = staticSize;
var data = new Uint8Array(staticSize + dynamicSize);
parts.forEach(function(part, index) {
if (part.dynamic) {
//uint256Coder.encode(dynamicOffset).copy(data, offset);
data.set(uint256Coder.encode(dynamicOffset), offset);
offset += 32;
//part.value.copy(data, dynamicOffset); @TODO
data.set(part.value, dynamicOffset);
dynamicOffset += alignSize(part.value.length);
} else {
//part.value.copy(data, offset); @TODO
data.set(part.value, offset);
offset += alignSize(part.value.length);
}
});
return data;
}
function unpack(coders, data, offset) {
var baseOffset = offset;
var consumed = 0;
var value = [];
coders.forEach(function(coder) {
if (coder.dynamic) {
var dynamicOffset = uint256Coder.decode(data, offset);
var result = coder.decode(data, baseOffset + dynamicOffset.value.toNumber());
// The dynamic part is leap-frogged somewhere else; doesn't count towards size
result.consumed = dynamicOffset.consumed;
} else {
var result = coder.decode(data, offset);
}
if (result.value != undefined) {
value.push(result.value);
}
offset += result.consumed;
consumed += result.consumed;
});
coders.forEach(function(coder, index) {
var name = coder.localName;
if (!name) { return; }
if (typeof(name) === 'object') { name = name.name; }
if (!name) { return; }
if (name === 'length') { name = '_length'; }
if (value[name] != null) { return; }
value[name] = value[index];
});
return {
value: value,
consumed: consumed
}
return result;
}
function coderArray(coerceFunc, coder, length, localName) {
var type = (coder.type + '[' + (length >= 0 ? length: '') + ']');
return {
coder: coder,
localName: localName,
length: length,
name: 'array',
type: type,
encode: function(value) {
if (!Array.isArray(value)) { throwError('invalid array'); }
var count = length;
var result = new Uint8Array(0);
if (count === -1) {
count = value.length;
result = uint256Coder.encode(count);
}
if (count !== value.length) { throwError('size mismatch'); }
var coders = [];
value.forEach(function(value) { coders.push(coder); });
return utils.concat([result, pack(coders, value)]);
},
decode: function(data, offset) {
// @TODO:
//if (data.length < offset + length * 32) { throw new Error('invalid array'); }
var consumed = 0;
var count = length;
if (count === -1) {
var decodedLength = uint256Coder.decode(data, offset);
count = decodedLength.value.toNumber();
consumed += decodedLength.consumed;
offset += decodedLength.consumed;
}
var coders = [];
for (var i = 0; i < count; i++) { coders.push(coder); }
var result = unpack(coders, data, offset);
result.consumed += consumed;
result.value = coerceFunc(type, result.value);
return result;
},
dynamic: (length === -1 || coder.dynamic)
}
}
function coderTuple(coerceFunc, coders, localName) {
var dynamic = false;
var types = [];
coders.forEach(function(coder) {
if (coder.dynamic) { dynamic = true; }
types.push(coder.type);
});
var type = ('tuple(' + types.join(',') + ')');
return {
coders: coders,
localName: localName,
name: 'tuple',
type: type,
encode: function(value) {
return pack(coders, value);
},
decode: function(data, offset) {
var result = unpack(coders, data, offset);
result.value = coerceFunc(type, result.value);
return result;
},
dynamic: dynamic
};
}
/*
function getTypes(coders) {
var type = coderTuple(coders).type;
return type.substring(6, type.length - 1);
}
*/
function splitNesting(value) {
var result = [];
var accum = '';
var depth = 0;
for (var offset = 0; offset < value.length; offset++) {
var c = value[offset];
if (c === ',' && depth === 0) {
result.push(accum);
accum = '';
} else {
accum += c;
if (c === '(') {
depth++;
} else if (c === ')') {
depth--;
if (depth === -1) {
throw new Error('unbalanced parenthsis');
}
}
}
}
result.push(accum);
return result;
}
var paramTypeSimple = {
address: coderAddress,
bool: coderBoolean,
string: coderString,
bytes: coderDynamicBytes,
};
function getParamCoder(coerceFunc, type, localName) {
var coder = paramTypeSimple[type];
if (coder) { return coder(coerceFunc, localName); }
var match = type.match(paramTypeNumber);
if (match) {
var size = parseInt(match[2] || 256);
if (size === 0 || size > 256 || (size % 8) !== 0) {
throwError('invalid type', { type: type });
}
return coderNumber(coerceFunc, size / 8, (match[1] === 'int'), localName);
}
var match = type.match(paramTypeBytes);
if (match) {
var size = parseInt(match[1]);
if (size === 0 || size > 32) {
throwError('invalid type ' + type);
}
return coderFixedBytes(coerceFunc, size, localName);
}
var match = type.match(paramTypeArray);
if (match) {
var size = parseInt(match[2] || -1);
return coderArray(coerceFunc, getParamCoder(coerceFunc, match[1], localName), size, localName);
}
if (type.substring(0, 6) === 'tuple(' && type.substring(type.length - 1) === ')') {
var coders = [];
var names = [];
if (localName && typeof(localName) === 'object') {
if (Array.isArray(localName.names)) { names = localName.names; }
if (typeof(localName.name) === 'string') { localName = localName.name; }
}
splitNesting(type.substring(6, type.length - 1)).forEach(function(type, index) {
coders.push(getParamCoder(coerceFunc, type, names[index]));
});
return coderTuple(coerceFunc, coders, localName);
}
if (type === '') {
return coderNull(coerceFunc);
}
throwError('invalid type', { type: type });
}
function Coder(coerceFunc) {
if (!(this instanceof Coder)) { throw new Error('missing new'); }
if (!coerceFunc) { coerceFunc = defaultCoerceFunc; }
utils.defineProperty(this, 'coerceFunc', coerceFunc);
}
utils.defineProperty(Coder.prototype, 'encode', function(names, types, values) {
// Names is optional, so shift over all the parameters if not provided
if (arguments.length < 3) {
values = types;
types = names;
names = null;
}
if (types.length !== values.length) { throwError('types/values mismatch', {types: types, values: values}); }
var coders = [];
types.forEach(function(type, index) {
coders.push(getParamCoder(this.coerceFunc, type, (names ? names[index]: undefined)));
}, this);
return utils.hexlify(coderTuple(this.coerceFunc, coders).encode(values));
});
utils.defineProperty(Coder.prototype, 'decode', function(names, types, data) {
// Names is optional, so shift over all the parameters if not provided
if (arguments.length < 3) {
data = types;
types = names;
names = null;
}
data = utils.arrayify(data);
var coders = [];
types.forEach(function(type, index) {
coders.push(getParamCoder(this.coerceFunc, type, (names ? names[index]: undefined)));
}, this);
return coderTuple(this.coerceFunc, coders).decode(data, 0).value;
});
utils.defineProperty(Coder, 'defaultCoder', new Coder());
module.exports = Coder