Created
July 13, 2024 12:58
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Scala Native 0.5, Gears, Roach, Postgres, multi-threading
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| //> using dep "ch.epfl.lamp::gears::0.2.0" | |
| //> using dep "com.indoorvivants.roach::core::0.1.0" | |
| //> using nativeVersion 0.5.4 | |
| //> using option -Wunused:all | |
| //> using platform "scala-native" | |
| //> using repository sonatype:snapshots | |
| //> using scala 3.5.0-RC4 | |
| import gears.async.*, default.given | |
| import roach.*, codecs.* | |
| import scalanative.unsafe.Zone | |
| val connectionString = | |
| "postgresql://postgres:mysecretpassword@localhost:5432/postgres" | |
| def read(limit: Int)(using Database, Zone): Vector[(String, Boolean)] = | |
| // select some data from postgres | |
| sql"select typname, typisdefined from pg_type limit $int4" | |
| // pass the parameter, and read the results as a (String, Boolean) tuple | |
| .all(limit, name ~ bool) | |
| @main def hello = | |
| val builder = List.newBuilder[(String, Boolean)] | |
| val parallelism = 500 | |
| val limit = 100 | |
| Zone: | |
| Async.blocking: | |
| // create shared postgres connection | |
| Pool.single(connectionString): pool => | |
| List | |
| .fill(parallelism): | |
| Future: | |
| // lease a connection | |
| pool.withLease: | |
| read(limit).foreach: (name, b) => | |
| builder.synchronized: | |
| builder += name -> b | |
| .awaitAll | |
| assert(builder.result().size == parallelism * limit) | |
| assert(builder.result().distinct.size == limit) | |
| println("🔥Scala Native is multi-threaded!") |
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