mirror of
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121 lines
3.6 KiB
CoffeeScript
121 lines
3.6 KiB
CoffeeScript
strInject = (s1, pos, s2) -> s1[...pos] + s2 + s1[pos..]
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strRemove = (s1, pos, length) -> s1[...pos] + s1[(pos + length)..]
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module.exports = ConcatManager =
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normalizeUpdate: (update) ->
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updates = []
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for op in update.op
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updates.push
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op: [op]
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meta:
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start_ts: update.meta.ts
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end_ts: update.meta.ts
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user_id: update.meta.user_id
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return updates
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MAX_TIME_BETWEEN_UPDATES: oneMinute = 60 * 1000
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concatTwoUpdates: (firstUpdate, secondUpdate) ->
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firstUpdate =
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op: firstUpdate.op
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meta:
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user_id: firstUpdate.meta.user_id or null
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start_ts: firstUpdate.meta.start_ts or firstUpdate.meta.ts
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end_ts: firstUpdate.meta.end_ts or firstUpdate.meta.ts
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secondUpdate =
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op: secondUpdate.op
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meta:
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user_id: secondUpdate.meta.user_id or null
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start_ts: secondUpdate.meta.start_ts or secondUpdate.meta.ts
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end_ts: secondUpdate.meta.end_ts or secondUpdate.meta.ts
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if firstUpdate.meta.user_id != secondUpdate.meta.user_id
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return [firstUpdate, secondUpdate]
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if secondUpdate.meta.start_ts - firstUpdate.meta.end_ts > ConcatManager.MAX_TIME_BETWEEN_UPDATES
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return [firstUpdate, secondUpdate]
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firstOp = firstUpdate.op[0]
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secondOp = secondUpdate.op[0]
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# Two inserts
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if firstOp.i? and secondOp.i? and firstOp.p <= secondOp.p <= (firstOp.p + firstOp.i.length)
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return [
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meta:
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start_ts: firstUpdate.meta.start_ts
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end_ts: secondUpdate.meta.end_ts
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user_id: firstUpdate.meta.user_id
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op: [
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p: firstOp.p
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i: strInject(firstOp.i, secondOp.p - firstOp.p, secondOp.i)
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]
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]
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# Two deletes
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else if firstOp.d? and secondOp.d? and secondOp.p <= firstOp.p <= (secondOp.p + secondOp.d.length)
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return [
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meta:
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start_ts: firstUpdate.meta.start_ts
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end_ts: secondUpdate.meta.end_ts
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user_id: firstUpdate.meta.user_id
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op: [
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p: secondOp.p
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d: strInject(secondOp.d, firstOp.p - secondOp.p, firstOp.d)
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]
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]
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# An insert and then a delete
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else if firstOp.i? and secondOp.d? and firstOp.p <= secondOp.p <= (firstOp.p + firstOp.i.length)
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offset = secondOp.p - firstOp.p
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insertedText = firstOp.i.slice(offset, offset + secondOp.d.length)
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if insertedText == secondOp.d
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insert = strRemove(firstOp.i, offset, secondOp.d.length)
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return [] if insert == ""
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return [
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meta:
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start_ts: firstUpdate.meta.start_ts
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end_ts: secondUpdate.meta.end_ts
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user_id: firstUpdate.meta.user_id
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op: [
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p: firstOp.p
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i: insert
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]
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]
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else
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# This shouldn't be possible!
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return [firstUpdate, secondUpdate]
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else if firstOp.d? and secondOp.i? and firstOp.p == secondOp.p
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offset = firstOp.d.indexOf(secondOp.i)
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if offset == -1
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return [firstUpdate, secondUpdate]
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headD = firstOp.d.slice(0, offset)
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inserted = firstOp.d.slice(offset, secondOp.i.length)
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tailD = firstOp.d.slice(offset + secondOp.i.length)
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headP = firstOp.p
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tailP = firstOp.p + secondOp.i.length
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updates = []
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if headD != ""
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updates.push
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meta:
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start_ts: firstUpdate.meta.start_ts
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end_ts: secondUpdate.meta.end_ts
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user_id: firstUpdate.meta.user_id
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op: [
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p: headP
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d: headD
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]
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if tailD != ""
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updates.push
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meta:
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start_ts: firstUpdate.meta.start_ts
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end_ts: secondUpdate.meta.end_ts
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user_id: firstUpdate.meta.user_id
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op: [
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p: tailP
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d: tailD
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]
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if updates.length == 2
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updates[0].meta.start_ts = updates[0].meta.end_ts = firstUpdate.meta.start_ts
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updates[1].meta.start_ts = updates[1].meta.end_ts = secondUpdate.meta.end_ts
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return updates
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else
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return [firstUpdate, secondUpdate]
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