Module: Redis::LibIdentity

Defined in:
lib/redis/lib_identity.rb

Overview

Reports redis-rb as the connecting library via CLIENT SETINFO.

redis-client builds its own LIB-NAME as redis-client(<driver_info>) and always reports its own version as LIB-VER, which would identify redis-client rather than redis-rb to the server. We append a second pair of CLIENT SETINFO commands, which wins because the command is last-write-wins, so that CLIENT LIST / CLIENT INFO report lib-name=redis-rb and lib-ver=<Redis::VERSION>.

Libraries built on top of redis-rb can still identify themselves by passing driver_info, in which case they are reported inside the parentheses, e.g. lib-name=redis-rb(my-gem_v1.0.0). The official convention for such suffixes is <name>_v<version> (matching (?<custom-name>[ -~]+)[ -~]v(?<custom-version>[\d\.]+)), with ; delimiting multiple suffixes and parentheses avoided inside them — see https://redis.io/docs/latest/commands/client-setinfo/. Passing driver_info: false disables CLIENT SETINFO entirely, for peers that can't tolerate unknown commands during the handshake (e.g. some proxies).

Applications that use redis-client directly are left untouched: the override only applies to configurations whose driver_info was built by this module.

Constant Summary collapse

MARKER =

Follows the official suffix convention, so that the transient pair redis-client itself builds from this value (lib-name=redis-client(redis-rb_v<version>)) is well-formed too.

"redis-rb_v"
LIB_NAME = 
"redis-rb"
SEPARATOR = 
";"
OWN_INFO =

Interpolated strings are not frozen by the magic comment; explicit freezes keep these constants Ractor-shareable (lazy module ivars here would raise Ractor::IsolationError).

"#{MARKER}#{Redis::VERSION}".freeze
OWN_PREFIX = 
"#{OWN_INFO}#{SEPARATOR}".freeze
INVALID_CHARS =

CLIENT SETINFO values must be printable ASCII with no spaces — the server rejects anything else, and redis-client swallows that error, which would silently leave lib-name empty. Parentheses are excluded as well: they delimit the suffix in lib-name=redis-rb(<suffix>), so a suffix containing them would corrupt the reported name.

/(?:[^!-~]|[()])+/

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.driver_info(downstream = nil) ⇒ Object

Combines redis-rb's own identity with the driver_info a downstream library passed in, so that both can be recovered when the connection prelude is built. false is passed through untouched and, being falsy, turns CLIENT SETINFO off wholesale (redis-client gates its own commands on driver_info too). Any other non-String, non-Array value is also passed through, leaving redis-client to reject it.



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# File 'lib/redis/lib_identity.rb', line 48

def driver_info(downstream = nil)
  case downstream
  when nil then OWN_INFO
  when String then combine(downstream)
  when Array then combine(downstream.join(SEPARATOR))
  else downstream
  end
end

.ours?(info) ⇒ Boolean

True only for values driver_info produced: exactly our own identity, or our identity followed by a downstream library's. Matching on the bare MARKER prefix instead would also capture a direct redis-client user whose own driver_info merely starts with redis-rb_v (say redis-rb_viewer-1.0) and would silently discard their identity.

Returns:

  • (Boolean) 


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# File 'lib/redis/lib_identity.rb', line 61

def ours?(info)
  info.is_a?(String) && (info == OWN_INFO || info.start_with?(OWN_PREFIX))
end

.setinfo_commands(info) ⇒ Object 



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# File 'lib/redis/lib_identity.rb', line 65

def setinfo_commands(info)
  [
    ["CLIENT", "SETINFO", "LIB-NAME", lib_name(info)].freeze,
    ["CLIENT", "SETINFO", "LIB-VER", Redis::VERSION].freeze,
  ].freeze
end

Instance Method Details

#connection_prelude ⇒ Object 



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# File 'lib/redis/lib_identity.rb', line 87

def connection_prelude
  prelude = super
  info = driver_info
  return prelude unless LibIdentity.ours?(info)

  # `CLIENT SETINFO` is last-write-wins, so appending after the commands `redis-client`
  # already built overrides them, without having to recognise or remove them.
  (prelude + LibIdentity.setinfo_commands(info)).freeze
end