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58 lines
1.7 KiB
58 lines
1.7 KiB
1 month ago
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var N = 1e7
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var M = 10
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/*
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benchmark encoding and decoding N random integers.
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A number is encoded into a buffer, (the buffer is reused so
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that allocation does not affect the benchmark)
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to test the effect on performance of invalid records
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(i.e. too short, with the Most Significant Byte missing)
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every M items, attempt to decode from a shorter slice of the buffer.
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This will probably be produce an invalid result. We do not
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need to write into that buffer - because it refurs to the same memory as
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the full size buffer.
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run with INVALID=1 to include N/M invalid decodes.
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results:
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with no invalid decodes, I get about 2428 decodes/ms
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with invalid decodes:
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old code that overruns buffer: 1122 decodes/ms
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check length & return undefined: 2439 decodecs/ms
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check length & return NaN: 2434 d/ms
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check length & return -1: 2400 d/ms
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conclusion, it doesn't make a significant difference whether
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what is returned to show an invalid read,
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but if you overrun the buffer the cost is considerable.
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recomendation: return undefined
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*/
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var buffer = new Buffer(8)
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var _buffer = buffer.slice(0, 4)
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var varint = require('./')
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var l = N
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var invalid = 0
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includeInvalid = !!process.env.INVALID
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var start = Date.now()
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while (l--) {
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var int = Math.floor(Math.random()*0x01fffffffffffff)
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varint.encode(int, buffer, 0)
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//console.log(int, varint.decode(buffer, 0))
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//every 1000 varints, do one that will be too short,
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//measure
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if(includeInvalid && !(l%M)) {
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if(undefined == varint.decode(_buffer, 0))
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invalid ++
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} else
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if(int !== varint.decode(buffer, 0))
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throw new Error('decode was incorrect')
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}
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console.log('decode&encode/ms, invalidDecodes')
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console.log(N/(Date.now() - start) + ',', invalid)
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