BufferedIO: Use a buffer with Encoding.default_external

redis-client when parsing a string first attempt to encode
it as `Encoding.default_external` and if invalid, fallbacks to
encode it as binary.

By having the buffer encoded with the default external encoding
we save having to change the encoding once on every parsed string.

Co-authored-by: Aaron Patterson <[email protected]>

Author: byroot

benchmark/drivers_ruby.md

@@ -7,53 +7,53 @@ redis-server: `Redis server v=7.0.12 sha=00000000:0 malloc=libc bits=64 build=a1
 
 ```
 ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin23]
-             hiredis:     5346.6 i/s
-                ruby:     2984.3 i/s - 1.79x  slower
+             hiredis:     5369.2 i/s
+                ruby:     3095.8 i/s - 1.73x  slower
 
 ```
 
 ### large string x 100
 
 ```
 ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin23]
-             hiredis:      304.2 i/s
-                ruby:      204.1 i/s - 1.49x  slower
+             hiredis:      303.9 i/s
+                ruby:      217.9 i/s - 1.39x  slower
 
 ```
 
 ### small list x 100
 
 ```
 ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin23]
-             hiredis:     2612.0 i/s
-                ruby:     1240.8 i/s - 2.11x  slower
+             hiredis:     2706.0 i/s
+                ruby:     1325.4 i/s - 2.04x  slower
 
 ```
 
 ### large list
 
 ```
 ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin23]
-             hiredis:     6772.7 i/s
-                ruby:     1540.7 i/s - 4.40x  slower
+             hiredis:     6827.5 i/s
+                ruby:     1755.0 i/s - 3.89x  slower
 
 ```
 
 ### small hash x 100
 
 ```
 ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin23]
-             hiredis:     3293.2 i/s
-                ruby:     1234.0 i/s - 2.67x  slower
+             hiredis:     3453.2 i/s
+                ruby:     1359.5 i/s - 2.54x  slower
 
 ```
 
 ### large hash
 
 ```
 ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin23]
-             hiredis:     1421.7 i/s
-                ruby:     1481.0 i/s - same-ish: difference falls within error
+             hiredis:     1655.5 i/s
+                ruby:     1666.5 i/s - same-ish: difference falls within error
 
 ```
 

benchmark/drivers_yjit.md

@@ -7,53 +7,53 @@ redis-server: `Redis server v=7.0.12 sha=00000000:0 malloc=libc bits=64 build=a1
 
 ```
 ruby 3.3.0 (2023-12-25 revision 5124f9ac75) +YJIT [arm64-darwin23]
-             hiredis:     6723.1 i/s
-                ruby:     5507.5 i/s - 1.22x  slower
+             hiredis:     6795.5 i/s
+                ruby:     5696.7 i/s - 1.19x  slower
 
 ```
 
 ### large string x 100
 
 ```
 ruby 3.3.0 (2023-12-25 revision 5124f9ac75) +YJIT [arm64-darwin23]
-             hiredis:      290.8 i/s
-                ruby:      335.2 i/s - same-ish: difference falls within error
+             hiredis:      291.0 i/s
+                ruby:      339.3 i/s - same-ish: difference falls within error
 
 ```
 
 ### small list x 100
 
 ```
 ruby 3.3.0 (2023-12-25 revision 5124f9ac75) +YJIT [arm64-darwin23]
-             hiredis:     3686.7 i/s
-                ruby:     2437.1 i/s - 1.51x  slower
+             hiredis:     3661.1 i/s
+                ruby:     2351.8 i/s - 1.56x  slower
 
 ```
 
 ### large list
 
 ```
 ruby 3.3.0 (2023-12-25 revision 5124f9ac75) +YJIT [arm64-darwin23]
-             hiredis:     6725.9 i/s
-                ruby:     4990.0 i/s - 1.35x  slower
+             hiredis:     6839.3 i/s
+                ruby:     5330.8 i/s - 1.28x  slower
 
 ```
 
 ### small hash x 100
 
 ```
 ruby 3.3.0 (2023-12-25 revision 5124f9ac75) +YJIT [arm64-darwin23]
-             hiredis:     3893.0 i/s
-                ruby:     2994.7 i/s - 1.30x  slower
+             hiredis:     3966.9 i/s
+                ruby:     3243.4 i/s - 1.22x  slower
 
 ```
 
 ### large hash
 
 ```
 ruby 3.3.0 (2023-12-25 revision 5124f9ac75) +YJIT [arm64-darwin23]
-             hiredis:     4303.3 i/s
-                ruby:     4244.6 i/s - same-ish: difference falls within error
+             hiredis:     4609.7 i/s
+                ruby:     4612.8 i/s - same-ish: difference falls within error
 
 ```
 

lib/redis_client/ruby_connection/buffered_io.rb

@@ -12,7 +12,7 @@ class BufferedIO
 
       def initialize(io, read_timeout:, write_timeout:, chunk_size: 4096)
         @io = io
-        @buffer = "".b
+        @buffer = "".dup.force_encoding(Encoding.default_external)
         @offset = 0
         @chunk_size = chunk_size
         @read_timeout = read_timeout

lib/redis_client/ruby_connection/resp3.rb

@@ -144,7 +144,6 @@ def parse(io)
 
     def parse_string(io)
       str = io.gets_chomp
-      str.force_encoding(Encoding.default_external)
       str.force_encoding(Encoding::BINARY) unless str.valid_encoding?
       str.freeze
     end
@@ -221,7 +220,6 @@ def parse_blob(io)
       return if bytesize < 0 # RESP2 nil type
 
       str = io.read_chomp(bytesize)
-      str.force_encoding(Encoding.default_external)
       str.force_encoding(Encoding::BINARY) unless str.valid_encoding?
       str
     end