Export DBTangle type

This commit is contained in:
Jacob Karlsson 2024-06-05 17:25:51 +02:00
parent 995c70fe68
commit 37022b8969
3 changed files with 162 additions and 124 deletions

158
lib/db-tangle.js Normal file
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@ -0,0 +1,158 @@
const pull = require('pull-stream')
const p = require('node:util').promisify
const MsgV4 = require('./msg-v4')
/**
* @typedef {string} MsgID
* @typedef {import('./msg-v4').Msg} Msg
*/
/**
* @typedef {{
* id?: never;
* msg?: never;
* received?: never;
* }} RecDeleted
*
* @typedef {{
* id: MsgID;
* msg: Msg;
* received: number;
* }} RecPresent
*
* @typedef {RecPresent | RecDeleted} Rec
*/
/**
* @template T
* @typedef {[T] extends [void] ?
* (...args: [Error] | []) => void :
* (...args: [Error] | [null, T]) => void
* } CB
*/
class DBTangle extends MsgV4.Tangle {
/** @type {(msgID: MsgID, cb: CB<Msg>) => void} */
#getMsg
/**
* @param {MsgID} rootID
* @param {(msgID: MsgID, cb: CB<Msg>) => void} getMsg
*/
constructor(rootID, getMsg) {
super(rootID)
this.#getMsg = getMsg
}
/**
* @param {MsgID} rootID
* @param {AsyncIterable<Rec>} recordsIter
* @param {(msgID: MsgID, cb: any) => void} getMsg
* @return {Promise<DBTangle>}
*/
static async init(rootID, recordsIter, getMsg) {
const dbtangle = new DBTangle(rootID, getMsg)
for await (const rec of recordsIter) {
if (!rec.msg) continue
dbtangle.add(rec.id, rec.msg)
}
return dbtangle
}
/**
* Given a set of msgs (`msgIDs`) in this tangle, find all "deletable" and
* "erasable" msgs that precede that set.
*
* *Deletables* are msgs that precede `msgsIDs` but are not important in any
* validation path toward the root, and thus can be deleted.
*
* *Erasables* are msgs that precede `msgsIDs` and can be erased without
* losing a validation path toward the root.
* @param {Array<MsgID>} msgIDs
* @returns {{ deletables: Set<MsgID>, erasables: Set<MsgID> } | null}
*/
getDeletablesAndErasables(...msgIDs) {
// Determine erasables
const erasables = new Set()
const minimum = this.getMinimumAmong(msgIDs)
for (const msgID of minimum) {
const trail = this.shortestPathToRoot(msgID)
if (!trail) return null
for (const id of trail) {
erasables.add(id)
}
}
// Determine deletables
const deletables = new Set()
const sorted = this.topoSort()
for (const msgID of sorted) {
if (erasables.has(msgID)) continue
if (minimum.some((min) => this.precedes(msgID, min))) {
deletables.add(msgID)
}
}
return { deletables, erasables }
}
/**
* @param {Array<string>=} minSet
* @param {Array<string>=} maxSet
* @param {CB<Array<Msg>>=} cb
* @return {Promise<Array<Msg>>|void}
*/
slice(minSet = [], maxSet = [], cb) {
// @ts-ignore
if (cb === undefined) return p(this.slice).bind(this)(minSet, maxSet)
const minSetGood = minSet.filter((msgID) => this.has(msgID))
const maxSetGood = maxSet.filter((msgID) => this.has(msgID))
const minSetTight = this.getMinimumAmong(minSetGood)
const trail = new Set()
for (const msgID of minSetTight) {
const path = this.shortestPathToRoot(msgID)
if (!path) return cb(Error("Couldn't get shortest path to root when slicing dbtangle"))
for (const msgID of path) {
trail.add(msgID)
}
}
const msgs = /**@type {Array<Msg>}*/ ([])
pull(
pull.values(this.topoSort()),
pull.asyncMap((msgID, cb) => {
this.#getMsg(msgID, (err, msg) => {
if (err) return cb(err)
cb(null, { id: msgID, msg })
})
}),
pull.drain(
(rec) => {
if (trail.has(rec.id)) {
if (rec.msg) msgs.push({ ...rec.msg, data: null })
}
const isMin = minSetGood.includes(rec.id)
const isMax = maxSetGood.includes(rec.id)
const isBeforeMin = minSetGood.some((min) =>
this.precedes(rec.id, min)
)
const isAfterMax = maxSetGood.some((max) =>
this.precedes(max, rec.id)
)
if (!isMin && isBeforeMin) return
if (!isMax && isAfterMax) return
if (rec.msg) msgs.push(rec.msg)
},
(err) => {
if (err) return cb(Error('DBTangle.slice() failed', { cause: err }))
return cb(null, msgs)
}
)
)
}
}
module.exports = DBTangle

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@ -8,6 +8,7 @@ const pull = require('pull-stream')
const p = require('node:util').promisify const p = require('node:util').promisify
const Log = require('./log') const Log = require('./log')
const MsgV4 = require('./msg-v4') const MsgV4 = require('./msg-v4')
const DBTangle = require('./db-tangle')
const { const {
SIGNATURE_TAG_ACCOUNT_ADD, SIGNATURE_TAG_ACCOUNT_ADD,
ACCOUNT_SELF, ACCOUNT_SELF,
@ -93,130 +94,6 @@ function assertValidConfig(config) {
} }
} }
class DBTangle extends MsgV4.Tangle {
/** @type {(msgID: MsgID, cb: CB<Msg>) => void} */
#getMsg
/**
* @param {MsgID} rootID
* @param {(msgID: MsgID, cb: CB<Msg>) => void} getMsg
*/
constructor(rootID, getMsg) {
super(rootID)
this.#getMsg = getMsg
}
/**
* @param {MsgID} rootID
* @param {AsyncIterable<Rec>} recordsIter
* @param {(msgID: MsgID, cb: any) => void} getMsg
* @return {Promise<DBTangle>}
*/
static async init(rootID, recordsIter, getMsg) {
const dbtangle = new DBTangle(rootID, getMsg)
for await (const rec of recordsIter) {
if (!rec.msg) continue
dbtangle.add(rec.id, rec.msg)
}
return dbtangle
}
/**
* Given a set of msgs (`msgIDs`) in this tangle, find all "deletable" and
* "erasable" msgs that precede that set.
*
* *Deletables* are msgs that precede `msgsIDs` but are not important in any
* validation path toward the root, and thus can be deleted.
*
* *Erasables* are msgs that precede `msgsIDs` and can be erased without
* losing a validation path toward the root.
* @param {Array<MsgID>} msgIDs
* @returns {{ deletables: Set<MsgID>, erasables: Set<MsgID> } | null}
*/
getDeletablesAndErasables(...msgIDs) {
// Determine erasables
const erasables = new Set()
const minimum = this.getMinimumAmong(msgIDs)
for (const msgID of minimum) {
const trail = this.shortestPathToRoot(msgID)
if (!trail) return null
for (const id of trail) {
erasables.add(id)
}
}
// Determine deletables
const deletables = new Set()
const sorted = this.topoSort()
for (const msgID of sorted) {
if (erasables.has(msgID)) continue
if (minimum.some((min) => this.precedes(msgID, min))) {
deletables.add(msgID)
}
}
return { deletables, erasables }
}
/**
* @param {Array<string>=} minSet
* @param {Array<string>=} maxSet
* @param {CB<Array<Msg>>=} cb
* @return {Promise<Array<Msg>>|void}
*/
slice(minSet = [], maxSet = [], cb) {
// @ts-ignore
if (cb === undefined) return p(this.slice).bind(this)(minSet, maxSet)
const minSetGood = minSet.filter((msgID) => this.has(msgID))
const maxSetGood = maxSet.filter((msgID) => this.has(msgID))
const minSetTight = this.getMinimumAmong(minSetGood)
const trail = new Set()
for (const msgID of minSetTight) {
const path = this.shortestPathToRoot(msgID)
if (!path) return cb(Error("Couldn't get shortest path to root when slicing dbtangle"))
for (const msgID of path) {
trail.add(msgID)
}
}
const msgs = /**@type {Array<Msg>}*/ ([])
pull(
pull.values(this.topoSort()),
pull.asyncMap((msgID, cb) => {
this.#getMsg(msgID, (err, msg) => {
if (err) return cb(err)
cb(null, { id: msgID, msg })
})
}),
pull.drain(
(rec) => {
if (trail.has(rec.id)) {
if (rec.msg) msgs.push({ ...rec.msg, data: null })
}
const isMin = minSetGood.includes(rec.id)
const isMax = maxSetGood.includes(rec.id)
const isBeforeMin = minSetGood.some((min) =>
this.precedes(rec.id, min)
)
const isAfterMax = maxSetGood.some((max) =>
this.precedes(max, rec.id)
)
if (!isMin && isBeforeMin) return
if (!isMax && isAfterMax) return
if (rec.msg) msgs.push(rec.msg)
},
(err) => {
if (err) return cb(Error('DBTangle.slice() failed', { cause: err }))
return cb(null, msgs)
}
)
)
}
}
/** /**
* @param {Peer} peer * @param {Peer} peer
* @param {Config} config * @param {Config} config

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@ -24,6 +24,9 @@
}, },
"./msg-v4": { "./msg-v4": {
"require": "./lib/msg-v4/index.js" "require": "./lib/msg-v4/index.js"
},
"./db-tangle": {
"require": "./lib/db-tangle.js"
} }
}, },
"dependencies": { "dependencies": {