Slatedb Clojure Example

slatedb_example.clj

(comment
   ;; deps.edn
   ;; io.slatedb/slatedb {:mvn/version "0.11.0"}
   ;; cheshire/cheshire {:mvn/version "6.1.0"}
 
  (require '[cheshire.core :as json])
 
  (io.slatedb.SlateDb/initLogging io.slatedb.SlateDbConfig$LogLevel/INFO)

  (def db-path (java.nio.file.Path/of "local-cache"
                                      (into-array String [])))

  (def object-store-url "gs://your-google-cloud-storage-bucket/")

  ;; Build a db with local disk cache enabled
  (time
    (with-open [builder (io.slatedb.SlateDb/builder
                          (.toString db-path)
                          object-store-url
                          nil)]
      (def db (.build
                (-> builder
                    (.withSettingsJson
                      (-> (io.slatedb.SlateDb/settingsDefault)
                          (json/parse-string)
                          (assoc-in ["object_store_cache_options"
                                     "root_folder"]
                                    (str db-path))
                          (json/generate-string))))))))

  (def db
    (time (io.slatedb.SlateDb/open (.toString db-path) object-store-url nil)))

  ;; Put + Get
  (def key (.getBytes "hello-key" java.nio.charset.StandardCharsets/UTF_8))
  (def value (.getBytes "hello-value" java.nio.charset.StandardCharsets/UTF_8))

  (.put db key value)

  (def loaded (.get db key))
  (String. loaded java.nio.charset.StandardCharsets/UTF_8)

  ;; Delete
  (.delete db key)

  ;; Batch write
  (def batch (io.slatedb.SlateDb/newWriteBatch))
  (.put batch (.getBytes "hello-a" java.nio.charset.StandardCharsets/UTF_8)
        (.getBytes "value-a" java.nio.charset.StandardCharsets/UTF_8))
  (.put batch (.getBytes "hello-b" java.nio.charset.StandardCharsets/UTF_8)
        (.getBytes "value-b" java.nio.charset.StandardCharsets/UTF_8))
  (.write db batch)
  (.close batch)

  ;; Scan by prefix
  (def iter (.scanPrefix db (.getBytes "hello-" java.nio.charset.StandardCharsets/UTF_8)))
  (loop []
    (when-let [kv (.next iter)]
      (println (str (String. (.key kv) java.nio.charset.StandardCharsets/UTF_8)
                    "="
                    (String. (.value kv) java.nio.charset.StandardCharsets/UTF_8)))
      (recur)))
  (.close iter)

  (.close db)
  )