Module: Valkey::Commands::ScriptingCommands

Included in:
Valkey::Commands
Defined in:
lib/valkey/commands/scripting_commands.rb

Overview

this module contains commands related to list data type.

See Also:

Instance Method Summary collapse

Instance Method Details

#eval(script, *rest, keys: nil, args: nil) ⇒ Object

Execute a Lua script on the server.

Since the eval is not available in the rust backend using the load and invoke script

Examples:

Execute a simple script

valkey.eval("return 1")
  # => 1

Execute script with keys and arguments

valkey.eval("return KEYS[1] .. ARGV[1]", keys: ["mykey"], args: ["myarg"])
  # => "mykeynyarg"

Execute script with multiple keys and arguments

valkey.eval("return #KEYS + #ARGV", keys: ["key1", "key2"], args: ["arg1", "arg2", "arg3"])
  # => 5

Execute script that returns different data types

valkey.eval("return {1, 'hello', true, nil}")
  # => [1, "hello", true, nil]

Positional form, matching redis-rb's eval(script, keys, argv)

valkey.eval("return KEYS[1] .. ARGV[1]", ["mykey"], ["myarg"])
  # => "mykeynyarg"

Parameters:

  • script (String) —

    the Lua script to execute

  • keys (Array<String>) (defaults to: nil) —

    array of key names that the script will access

  • args (Array<Object>) (defaults to: nil) —

    array of arguments to pass to the script

Returns:

  • (Object) —

    the result of the script execution

Raises:

  • (ArgumentError) —

    if script is empty

  • (CommandError) —

    if script execution fails



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# File 'lib/valkey/commands/scripting_commands.rb', line 145

def eval(script, *rest, keys: nil, args: nil)
  # Validate script parameter
  raise ArgumentError, "script must be a string" unless script.is_a?(String)
  raise ArgumentError, "script cannot be empty" if script.empty?

  # Accept redis-rb's flexible positional form - eval(script, keys, argv)
  # - in addition to the keyword form, mirroring the same treatment
  # applied to evalsha (see that method for the full rationale).
  keys ||= rest[0] || []
  args ||= rest[1] || []

  # Validate and convert keys and args to strings
  begin
    keys = Array(keys).map(&:to_s)
    args = Array(args).map(&:to_s)
  rescue StandardError => e
    raise ArgumentError, "failed to convert keys or args to strings: #{e.message}"
  end

  # Load script to get SHA1 hash, then execute via invoke_script
  sha = script_load(script)
  invoke_script(sha, keys: keys, args: args)
end

#eval_ro(script, keys: [], args: []) ⇒ Object

Execute a read-only Lua script on the server.

This is a read-only variant of EVAL that cannot execute commands that modify data. It can be routed to read replicas.

Examples:

Execute a read-only script

valkey.eval_ro("return redis.call('get', KEYS[1])", keys: ["mykey"])
  # => "myvalue"

Parameters:

  • script (String) —

    the Lua script to execute

  • keys (Array<String>) (defaults to: []) —

    array of key names that the script will access

  • args (Array<Object>) (defaults to: []) —

    array of arguments to pass to the script

Returns:

  • (Object) —

    the result of the script execution

Raises:

  • (ArgumentError)

See Also:



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# File 'lib/valkey/commands/scripting_commands.rb', line 236

def eval_ro(script, keys: [], args: [])
  raise ArgumentError, "script must be a string" unless script.is_a?(String)
  raise ArgumentError, "script cannot be empty" if script.empty?

  keys = Array(keys).map(&:to_s)
  args = Array(args).map(&:to_s)

  sha = script_load(script)
  invoke_script(sha, keys: keys, args: args)
end

#evalsha(sha, *rest, keys: nil, args: nil) ⇒ Object

Execute a cached Lua script by its SHA1 hash.

Since evalsha is not available in rust backend using invoke script

Examples:

Execute a cached script

sha = valkey.script_load("return 1")
valkey.evalsha(sha)
  # => 1

Execute cached script with parameters

script = "return KEYS[1] .. ':' .. ARGV[1]"
sha = valkey.script_load(script)
valkey.evalsha(sha, keys: ["user"], args: ["123"])
  # => "user:123"

Handle script not found error

begin
  valkey.evalsha("nonexistent_sha", keys: [], args: [])
rescue Valkey::CommandError => e
  puts "Script not found: #{e.message}"
end

Positional form, matching redis-rb's evalsha(sha, keys, argv)

valkey.evalsha(sha, ["user"], ["123"])
  # => "user:123"

Parameters:

  • sha (String) —

    the SHA1 hash of the script to execute

  • keys (Array<String>) (defaults to: nil) —

    array of key names that the script will access

  • args (Array<Object>) (defaults to: nil) —

    array of arguments to pass to the script

Returns:

  • (Object) —

    the result of the script execution

Raises:

  • (ArgumentError) —

    if SHA1 hash format is invalid

  • (CommandError) —

    if script is not found or execution fails



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# File 'lib/valkey/commands/scripting_commands.rb', line 198

def evalsha(sha, *rest, keys: nil, args: nil)
  # Validate SHA1 hash parameter
  raise ArgumentError, "sha1 hash must be a string" unless sha.is_a?(String)
  raise ArgumentError, "sha1 hash must be a 40-character hexadecimal string" unless valid_sha1?(sha)

  # Accept redis-rb's flexible positional form - evalsha(sha, keys, argv)
  # - in addition to the keyword form, so code written against redis-rb's
  # API (e.g. redis_display_id) doesn't need to special-case this client.
  keys ||= rest[0] || []
  args ||= rest[1] || []

  # Validate and convert keys and args to strings
  begin
    keys = Array(keys).map(&:to_s)
    args = Array(args).map(&:to_s)
  rescue StandardError => e
    raise ArgumentError, "failed to convert keys or args to strings: #{e.message}"
  end

  # Execute cached script via invoke_script
  invoke_script(sha, keys: keys, args: args)
end

#evalsha_ro(sha, keys: [], args: []) ⇒ Object

Execute a cached read-only Lua script by its SHA1 hash.

This is a read-only variant of EVALSHA that cannot execute commands that modify data. It can be routed to read replicas.

Examples:

Execute a cached read-only script

sha = valkey.script_load("return redis.call('get', KEYS[1])")
valkey.evalsha_ro(sha, keys: ["mykey"])
  # => "myvalue"

Parameters:

  • sha (String) —

    the SHA1 hash of the script to execute

  • keys (Array<String>) (defaults to: []) —

    array of key names that the script will access

  • args (Array<Object>) (defaults to: []) —

    array of arguments to pass to the script

Returns:

  • (Object) —

    the result of the script execution

Raises:

  • (ArgumentError)

See Also:



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# File 'lib/valkey/commands/scripting_commands.rb', line 263

def evalsha_ro(sha, keys: [], args: [])
  raise ArgumentError, "sha1 hash must be a string" unless sha.is_a?(String)
  raise ArgumentError, "sha1 hash must be a 40-character hexadecimal string" unless valid_sha1?(sha)

  keys = Array(keys).map(&:to_s)
  args = Array(args).map(&:to_s)

  invoke_script(sha, keys: keys, args: args)
end

#invoke_script(script, args: [], keys: []) ⇒ Object 



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# File 'lib/valkey/commands/scripting_commands.rb', line 273

def invoke_script(script, args: [], keys: [])
  # Must hold onto the returned buffers (_arg_bufs/_keys_bufs) for the
  # lifetime of this method - they back arg_ptrs/keys_ptrs, and letting
  # them go out of scope (e.g. by only capturing the first 2 return
  # values) makes them eligible for GC before the native call below
  # reads through those pointers, corrupting ARGV/KEYS with freed memory.
  arg_ptrs, arg_lens, _arg_bufs, flattened_args = build_command_args(args)
  keys_ptrs, keys_lens, _keys_bufs, flattened_keys = build_command_args(keys)

  route = ""
  route_buf = FFI::MemoryPointer.from_string(route)

  # Use from_string to ensure proper null termination
  sha = FFI::MemoryPointer.from_string(script)

  begin
    res = Bindings.invoke_script(
      @connection,
      0,
      sha,
      flattened_keys.size,
      keys_ptrs,
      keys_lens,
      flattened_args.size,
      arg_ptrs,
      arg_lens,
      route_buf,
      route.bytesize,
      0 # span_ptr for OpenTelemetry (0 = no span)
    )

    convert_response(res)
  ensure
    Bindings.free_command_result(res) if res && !res.null?
  end
end

#script(subcommand, args = nil, options: {}) ⇒ String, ...

Control remote script registry.

Examples:

Load a script

sha = valkey.script(:load, "return 1")
  # => <sha of this script>

Check if a script exists

valkey.script(:exists, sha)
  # => true

Check if multiple scripts exist

valkey.script(:exists, [sha, other_sha])
  # => [true, false]

Flush the script registry

valkey.script(:flush)
  # => "OK"

Kill a running script

valkey.script(:kill)
  # => "OK"

Parameters:

  • subcommand (String) —

    e.g. exists, flush, load, kill

  • args (Array<String>) (defaults to: nil) —

    depends on subcommand

Returns:

  • (String, Boolean, Array<Boolean>, ...) —

    depends on subcommand

See Also:



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# File 'lib/valkey/commands/scripting_commands.rb', line 34

def script(subcommand, args = nil, options: {})
  subcommand = subcommand.to_s.downcase

  if args.nil?
    send("script_#{subcommand}", **options)
  else
    send("script_#{subcommand}", args)
  end

  # if subcommand == "exists"
  #   arg = args.first
  #
  #   send_command([:script, :exists, arg]) do |reply|
  #     reply = reply.map { |r| Boolify.call(r) }
  #
  #     if arg.is_a?(Array)
  #       reply
  #     else
  #       reply.first
  #     end
  #   end
  # else
  #   send_command([:script, subcommand] + args)
  # end
end

#script_debug(mode) ⇒ String

Set the debug mode for subsequent scripts executed with EVAL.

Examples:

Enable script debugging

valkey.script_debug("YES")
  # => "OK"

Disable script debugging

valkey.script_debug("NO")
  # => "OK"

Parameters:

  • mode (String) —

    debug mode: "YES", "SYNC", or "NO"

Returns:

  • (String) —

    "OK"

See Also:



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# File 'lib/valkey/commands/scripting_commands.rb', line 99

def script_debug(mode)
  send_command(RequestType::SCRIPT_DEBUG, [mode.to_s.upcase])
end

#script_exists(args) ⇒ Object 



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# File 'lib/valkey/commands/scripting_commands.rb', line 72

def script_exists(args)
  send_command(RequestType::SCRIPT_EXISTS, Array(args)) do |reply|
    if args.is_a?(Array)
      reply
    else
      reply.first
    end
  end
end

#script_flush(sync: false, async: false) ⇒ Object 



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# File 'lib/valkey/commands/scripting_commands.rb', line 60

def script_flush(sync: false, async: false)
  args = []

  if async
    args << "async"
  elsif sync
    args << "sync"
  end

  send_command(RequestType::SCRIPT_FLUSH, args)
end

#script_kill ⇒ Object 



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# File 'lib/valkey/commands/scripting_commands.rb', line 82

def script_kill
  send_command(RequestType::SCRIPT_KILL)
end

#script_load(script) ⇒ Object 



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# File 'lib/valkey/commands/scripting_commands.rb', line 103

def script_load(script)
  script = script.first if script.is_a?(Array)

  buf = FFI::MemoryPointer.new(:char, script.bytesize)
  buf.put_bytes(0, script)

  result = Bindings.store_script(buf, script.bytesize)

  begin
    hash_buffer = Bindings::ScriptHashBuffer.new(result)
    hash_buffer[:ptr].read_string(hash_buffer[:len])
  ensure
    Bindings.free_script_hash_buffer(result) if result && !result.null?
  end
end