drizzle liquidity

functions/src/drizzle-liquidity.ts

@@ -0,0 +1,61 @@
+import * as functions from 'firebase-functions'
+import * as admin from 'firebase-admin'
+
+import { CPMMContract } from '../../common/contract'
+import { batchedWaitAll } from '../../common/util/promise'
+import { APIError } from '../../common/api'
+import { addCpmmLiquidity } from 'common/calculate-cpmm'
+import { formatMoney } from 'common/util/format'
+
+const firestore = admin.firestore()
+
+export const drizzleLiquidity = functions.pubsub
+  .schedule('every 2 minutes')
+  .onRun(async () => {
+    const snap = await firestore
+      .collection('contracts')
+      .where('subsidyPool', '>', 1e-7)
+      .get()
+    const contractIds = snap.docs.map((doc) => doc.id)
+
+    await batchedWaitAll(
+      contractIds.map((cid) => () => drizzleMarket(cid)),
+      10
+    )
+  })
+
+const drizzleMarket = async (contractId: string) => {
+  await firestore.runTransaction(async (trans) => {
+    const snap = await trans.get(firestore.doc(`contracts/${contractId}`))
+    const contract = snap.data() as CPMMContract
+    const { subsidyPool, pool, p, slug } = contract
+    if (subsidyPool ?? 0 < 1e-7) return
+
+    const r = Math.random()
+    const amount = subsidyPool <= 1 ? subsidyPool : r * 0.02 * subsidyPool
+
+    const { newPool, newP } = addCpmmLiquidity(pool, p, amount)
+
+    if (!isFinite(newP)) {
+      throw new APIError(
+        500,
+        'Liquidity injection rejected due to overflow error.'
+      )
+    }
+
+    await trans.update(firestore.doc(`contracts/${contract.id}`), {
+      pool: newPool,
+      p: newP,
+      subsidyPool: subsidyPool - amount,
+    })
+
+    console.log(
+      'added subsidy',
+      formatMoney(amount),
+      'of',
+      formatMoney(subsidyPool),
+      'pool to',
+      slug
+    )
+  })
+}

functions/src/index.ts

@@ -31,6 +31,7 @@ export * from './reset-weekly-emails-flags'
 export * from './on-update-contract-follow'
 export * from './on-update-like'
 export * from './weekly-portfolio-emails'
+export * from './drizzle-liquidity'
 
 // v2
 export * from './health'