Add zstd support on legacy record and ensure no variable is referred …

…before definition (#138)

* fix if statement logic and add zstd check

* fix if statement logic and add zstd uncompress

* fix imports

* avoid variable be used before definition

* Remove unused import from legacy_records.py

---------

Co-authored-by: Alexandre Souza <alexandre.souza@axonius.com>

kafka/record/default_records.py

@@ -115,6 +115,8 @@ def _assert_has_codec(self, compression_type: int) -> None:
             checker, name = codecs.has_lz4, "lz4"
         elif compression_type == self.CODEC_ZSTD:
             checker, name = codecs.has_zstd, "zstd"
+        else:
+            checker, name = lambda: False, "Unknown"
         if not checker():
             raise UnsupportedCodecError(
                 f"Libraries for {name} compression codec not found")
@@ -525,6 +527,8 @@ def _maybe_compress(self) -> bool:
                 compressed = lz4_encode(data)
             elif self._compression_type == self.CODEC_ZSTD:
                 compressed = zstd_encode(data)
+            else:
+                compressed = ''  # unknown
             compressed_size = len(compressed)
             if len(data) <= compressed_size:
                 # We did not get any benefit from compression, lets send

kafka/record/legacy_records.py

@@ -49,8 +49,8 @@
 from kafka.record.util import calc_crc32
 
 from kafka.codec import (
-    gzip_encode, snappy_encode, lz4_encode, lz4_encode_old_kafka,
-    gzip_decode, snappy_decode, lz4_decode, lz4_decode_old_kafka,
+    gzip_encode, snappy_encode, lz4_encode, lz4_encode_old_kafka, zstd_encode,
+    gzip_decode, snappy_decode, lz4_decode, lz4_decode_old_kafka, zstd_decode
 )
 import kafka.codec as codecs
 from kafka.errors import CorruptRecordException, UnsupportedCodecError
@@ -110,6 +110,7 @@ class LegacyRecordBase:
     CODEC_GZIP = 0x01
     CODEC_SNAPPY = 0x02
     CODEC_LZ4 = 0x03
+    CODEC_ZSTD = 0x04
     TIMESTAMP_TYPE_MASK = 0x08
 
     LOG_APPEND_TIME = 1
@@ -124,6 +125,10 @@ def _assert_has_codec(self, compression_type: int) -> None:
             checker, name = codecs.has_snappy, "snappy"
         elif compression_type == self.CODEC_LZ4:
             checker, name = codecs.has_lz4, "lz4"
+        elif compression_type == self.CODEC_ZSTD:
+            checker, name = codecs.has_zstd, "zstd"
+        else:
+            checker, name = lambda: False, "Unknown"
         if not checker():
             raise UnsupportedCodecError(
                 f"Libraries for {name} compression codec not found")
@@ -195,6 +200,10 @@ def _decompress(self, key_offset: int) -> bytes:
                 uncompressed = lz4_decode_old_kafka(data.tobytes())
             else:
                 uncompressed = lz4_decode(data.tobytes())
+        elif compression_type == self.CODEC_ZSTD:
+            uncompressed = zstd_decode(data)
+        else:
+            raise ValueError("Unknown Compression Type - %s" % compression_type)
         return uncompressed
 
     def _read_header(self, pos: int) -> Union[Tuple[int, int, int, int, int, None], Tuple[int, int, int, int, int, int]]: