154 lines
4.0 KiB
JavaScript
154 lines
4.0 KiB
JavaScript
'use strict';
|
|
|
|
const inherits = require('inherits');
|
|
const Reporter = require('../base/reporter').Reporter;
|
|
const Buffer = require('safer-buffer').Buffer;
|
|
|
|
function DecoderBuffer(base, options) {
|
|
Reporter.call(this, options);
|
|
if (!Buffer.isBuffer(base)) {
|
|
this.error('Input not Buffer');
|
|
return;
|
|
}
|
|
|
|
this.base = base;
|
|
this.offset = 0;
|
|
this.length = base.length;
|
|
}
|
|
inherits(DecoderBuffer, Reporter);
|
|
exports.DecoderBuffer = DecoderBuffer;
|
|
|
|
DecoderBuffer.isDecoderBuffer = function isDecoderBuffer(data) {
|
|
if (data instanceof DecoderBuffer) {
|
|
return true;
|
|
}
|
|
|
|
// Or accept compatible API
|
|
const isCompatible = typeof data === 'object' &&
|
|
Buffer.isBuffer(data.base) &&
|
|
data.constructor.name === 'DecoderBuffer' &&
|
|
typeof data.offset === 'number' &&
|
|
typeof data.length === 'number' &&
|
|
typeof data.save === 'function' &&
|
|
typeof data.restore === 'function' &&
|
|
typeof data.isEmpty === 'function' &&
|
|
typeof data.readUInt8 === 'function' &&
|
|
typeof data.skip === 'function' &&
|
|
typeof data.raw === 'function';
|
|
|
|
return isCompatible;
|
|
};
|
|
|
|
DecoderBuffer.prototype.save = function save() {
|
|
return { offset: this.offset, reporter: Reporter.prototype.save.call(this) };
|
|
};
|
|
|
|
DecoderBuffer.prototype.restore = function restore(save) {
|
|
// Return skipped data
|
|
const res = new DecoderBuffer(this.base);
|
|
res.offset = save.offset;
|
|
res.length = this.offset;
|
|
|
|
this.offset = save.offset;
|
|
Reporter.prototype.restore.call(this, save.reporter);
|
|
|
|
return res;
|
|
};
|
|
|
|
DecoderBuffer.prototype.isEmpty = function isEmpty() {
|
|
return this.offset === this.length;
|
|
};
|
|
|
|
DecoderBuffer.prototype.readUInt8 = function readUInt8(fail) {
|
|
if (this.offset + 1 <= this.length)
|
|
return this.base.readUInt8(this.offset++, true);
|
|
else
|
|
return this.error(fail || 'DecoderBuffer overrun');
|
|
};
|
|
|
|
DecoderBuffer.prototype.skip = function skip(bytes, fail) {
|
|
if (!(this.offset + bytes <= this.length))
|
|
return this.error(fail || 'DecoderBuffer overrun');
|
|
|
|
const res = new DecoderBuffer(this.base);
|
|
|
|
// Share reporter state
|
|
res._reporterState = this._reporterState;
|
|
|
|
res.offset = this.offset;
|
|
res.length = this.offset + bytes;
|
|
this.offset += bytes;
|
|
return res;
|
|
};
|
|
|
|
DecoderBuffer.prototype.raw = function raw(save) {
|
|
return this.base.slice(save ? save.offset : this.offset, this.length);
|
|
};
|
|
|
|
function EncoderBuffer(value, reporter) {
|
|
if (Array.isArray(value)) {
|
|
this.length = 0;
|
|
this.value = value.map(function(item) {
|
|
if (!EncoderBuffer.isEncoderBuffer(item))
|
|
item = new EncoderBuffer(item, reporter);
|
|
this.length += item.length;
|
|
return item;
|
|
}, this);
|
|
} else if (typeof value === 'number') {
|
|
if (!(0 <= value && value <= 0xff))
|
|
return reporter.error('non-byte EncoderBuffer value');
|
|
this.value = value;
|
|
this.length = 1;
|
|
} else if (typeof value === 'string') {
|
|
this.value = value;
|
|
this.length = Buffer.byteLength(value);
|
|
} else if (Buffer.isBuffer(value)) {
|
|
this.value = value;
|
|
this.length = value.length;
|
|
} else {
|
|
return reporter.error('Unsupported type: ' + typeof value);
|
|
}
|
|
}
|
|
exports.EncoderBuffer = EncoderBuffer;
|
|
|
|
EncoderBuffer.isEncoderBuffer = function isEncoderBuffer(data) {
|
|
if (data instanceof EncoderBuffer) {
|
|
return true;
|
|
}
|
|
|
|
// Or accept compatible API
|
|
const isCompatible = typeof data === 'object' &&
|
|
data.constructor.name === 'EncoderBuffer' &&
|
|
typeof data.length === 'number' &&
|
|
typeof data.join === 'function';
|
|
|
|
return isCompatible;
|
|
};
|
|
|
|
EncoderBuffer.prototype.join = function join(out, offset) {
|
|
if (!out)
|
|
out = Buffer.alloc(this.length);
|
|
if (!offset)
|
|
offset = 0;
|
|
|
|
if (this.length === 0)
|
|
return out;
|
|
|
|
if (Array.isArray(this.value)) {
|
|
this.value.forEach(function(item) {
|
|
item.join(out, offset);
|
|
offset += item.length;
|
|
});
|
|
} else {
|
|
if (typeof this.value === 'number')
|
|
out[offset] = this.value;
|
|
else if (typeof this.value === 'string')
|
|
out.write(this.value, offset);
|
|
else if (Buffer.isBuffer(this.value))
|
|
this.value.copy(out, offset);
|
|
offset += this.length;
|
|
}
|
|
|
|
return out;
|
|
};
|