SugarDB/internal/volumes/modules/js/hash.js

// The keyword to trigger the command
var command = "JS.HASH"

// The string array of categories this command belongs to.
// This array can contain both built-in categories and new custom categories.
var categories = ["hash", "write", "fast"]

// The description of the command.
var description = "(JS.HASH key) This is an example of working with SugarDB hashes/maps in js scripts."

// Whether the command should be synced across the RAFT cluster.
var sync = true

/**
 *  keyExtractionFunc is a function that extracts the keys from the command and returns them to SugarDB.keyExtractionFunc
 *  The returned data from this function is used in the Access Control Layer to determine if the current connection is
 *  authorized to execute this command. The function must return a table that specifies which keys in this command
 *  are read keys and which ones are write keys.
 *  Example return: {readKeys: ["key1", "key2"], writeKeys: ["key3", "key4", "key5"]}
 *
 *  1. "command" is a string array representing the command that triggered this key extraction function.
 *
 *  2. "args" is a string array of the modifier args that were passed when loading the module into SugarDB.
 *  These args are passed to the key extraction function everytime it's invoked.
 */
function keyExtractionFunc(command, args) {
  if (command.length !== 2) {
    throw "wrong number of args, expected 1."
  }
  return {
    "readKeys": [],
    "writeKeys": [command[1]]
  }
}

/**
 * handlerFunc is the command's handler function. The function is passed some arguments that allow it to interact with
 * SugarDB. The function must return a valid RESP response or throw an error.
 * The handler function accepts the following args:
 *
 * 1. "context" is a table that contains some information about the environment this command has been executed in.
 *     Example: {protocol: 2, database: 0}
 *     This object contains the following properties:
 *     i) protocol - the protocol version of the client that executed the command (either 2 or 3).
 *     ii) database - the active database index of the client that executed the command.
 *
 * 2. "command" is the string array representing the command that triggered this handler function.
 *
 * 3. "keyExists" is a function that can be called to check if a list of keys exists in the SugarDB store database.
 *     This function accepts a string array of keys to check and returns a table with each key having a corresponding
 *     boolean value indicating whether it exists.
 *     Examples:
 *     i) Example invocation: keyExists(["key1", "key2", "key3"])
 *     ii) Example return: {key1: true, key2: false, key3: true}
 *
 * 4. "getValues" is a function that can be called to retrieve values from the SugarDB store database.
 *     The function accepts a string array of keys whose values we would like to fetch, and returns a table with each key
 *     containing the corresponding value from the store.
 *     The possible data types for the values are: number, string, nil, hash, set, zset
 *     Examples:
 *     i) Example invocation: getValues(["key1", "key2", "key3"])
 *     ii) Example return: {key1: 3.142, key2: nil, key3: "Pi"}
 *
 * 5. "setValues" is a function that can be called to set values in the active database in the SugarDB store.
 *     This function accepts a table with keys and the corresponding values to set for each key in the active database
 *     in the store.
 *     The accepted data types for the values are: number, string, nil, hash, set, zset.
 *     The setValues function does not return anything.
 *     Examples:
 *     i) Example invocation: setValues({key1: 3.142, key2: nil, key3: "Pi"})
 *
 * 6. "args" is a string array of the modifier args passed to the module at load time. These args are passed to the
 *    handler everytime it's invoked.
 */
function handlerFunc(ctx, command, keysExist, getValues, setValues, args) {
  // Initialize a new hash
  var h = new Hash();

  // Set values in the hash
  h.set({
    "field1": "value1",
    "field2": "value2",
    "field3": "value3",
    "field4": "value4"
  });

  // Set hash in the store
  var setVals = {}
  setVals[command[1]] = h
  setValues(setVals);

  // Check that the fields were correctly set in the database
  var hashValue = getValues([command[1]])[command[1]];
  console.assert(hashValue.get(["field1"]).field1 === "value1", "field1 not set correctly");
  console.assert(hashValue.get(["field2"]).field2 === "value2", "field2 not set correctly");
  console.assert(hashValue.get(["field3"]).field3 === "value3", "field3 not set correctly");
  console.assert(hashValue.get(["field4"]).field4 === "value4", "field4 not set correctly");

  // Test get method
  var retrieved = h.get(["field1", "field2"]);
  console.assert(retrieved.field1 === "value1", "get method failed for field1");
  console.assert(retrieved.field2 === "value2", "get method failed for field2");

  // Test exists method
  var exists = h.exists(["field1", "fieldX"]);
  console.assert(exists.field1 === true, "exists method failed for field1");
  console.assert(exists.fieldX === false, "exists method failed for fieldX");

  // Test setnx method
  var setnxCount = h.setnx({
    "field1": "new_value1", // Should not overwrite
    "field5": "value5" // Should set
  });
  console.assert(setnxCount === 1, "setnx did not set the correct number of fields");
  console.assert(h.get(["field1"]).field1 === "value1", "setnx overwrote field1");
  console.assert(h.get(["field5"]).field5 === "value5", "setnx failed to set field5");

  // Test del method
  var delCount = h.del(["field2", "field3"]);
  console.assert(delCount === 2, "del did not delete the correct number of fields");
  console.assert(h.exists(["field2"]).field2 === false, "del failed to delete field2");
  console.assert(h.exists(["field3"]).field3 === false, "del failed to delete field3");

  // Test len method
  console.assert(h.len() === 3, "len method returned incorrect value");

  // Retrieve and verify all remaining fields
  var remainingFields = h.all();
  console.assert(remainingFields.field1 === "value1", "field1 missing after deletion");
  console.assert(remainingFields.field4 === "value4", "field4 missing after deletion");
  console.assert(remainingFields.field5 === "value5", "field5 missing after deletion");

  // Return RESP response
  return "+OK\r\n";
}