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94 lines
2.5 KiB
94 lines
2.5 KiB
'use strict' |
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var bindexOf = require('buffer-indexof') |
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var equalSign = new Buffer('=') |
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module.exports = function (opts) { |
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var binary = opts ? opts.binary : false |
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var that = {} |
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that.encode = function (data, buf, offset) { |
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if (!data) data = {} |
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if (!offset) offset = 0 |
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if (!buf) buf = new Buffer(that.encodingLength(data) + offset) |
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var oldOffset = offset |
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var keys = Object.keys(data) |
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if (keys.length === 0) { |
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buf[offset] = 0 |
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offset++ |
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} |
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keys.forEach(function (key) { |
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var val = data[key] |
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var oldOffset = offset |
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offset++ |
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if (val === true) { |
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offset += buf.write(key, offset) |
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} else if (Buffer.isBuffer(val)) { |
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offset += buf.write(key + '=', offset) |
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var len = val.length |
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val.copy(buf, offset, 0, len) |
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offset += len |
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} else { |
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offset += buf.write(key + '=' + val, offset) |
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} |
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buf[oldOffset] = offset - oldOffset - 1 |
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}) |
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that.encode.bytes = offset - oldOffset |
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return buf |
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} |
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that.decode = function (buf, offset, len) { |
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if (!offset) offset = 0 |
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if (!Number.isFinite(len)) len = buf.length |
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var data = {} |
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var oldOffset = offset |
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while (offset < len) { |
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var b = decodeBlock(buf, offset) |
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var i = bindexOf(b, equalSign) |
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offset += decodeBlock.bytes |
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if (b.length === 0) continue // ignore: most likely a single zero byte |
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if (i === -1) data[b.toString().toLowerCase()] = true |
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else if (i === 0) continue // ignore: invalid key-length |
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else { |
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var key = b.slice(0, i).toString().toLowerCase() |
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if (key in data) continue // ignore: overwriting not allowed |
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data[key] = binary ? b.slice(i + 1) : b.slice(i + 1).toString() |
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} |
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} |
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that.decode.bytes = offset - oldOffset |
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return data |
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} |
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that.encodingLength = function (data) { |
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if (!data) return 1 // 1 byte (single empty byte) |
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var keys = Object.keys(data) |
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if (keys.length === 0) return 1 // 1 byte (single empty byte) |
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return keys.reduce(function (total, key) { |
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var val = data[key] |
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total += Buffer.byteLength(key) + 1 // +1 byte to store field length |
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if (Buffer.isBuffer(val)) total += val.length + 1 // +1 byte to fit equal sign |
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else if (val !== true) total += Buffer.byteLength(String(val)) + 1 // +1 byte to fit equal sign |
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return total |
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}, 0) |
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} |
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return that |
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} |
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function decodeBlock (buf, offset) { |
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var len = buf[offset] |
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var to = offset + 1 + len |
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var b = buf.slice(offset + 1, to > buf.length ? buf.length : to) |
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decodeBlock.bytes = len + 1 |
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return b |
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}
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