Create fs2.compression.checksum

build.sbt

@@ -185,7 +185,7 @@ lazy val core = crossProject(JVMPlatform, JSPlatform)
       "org.typelevel" %%% "cats-effect" % "3.2.9",
       "org.typelevel" %%% "cats-effect-laws" % "3.2.9" % Test,
       "org.typelevel" %%% "cats-effect-testkit" % "3.2.9" % Test,
-      "org.scodec" %%% "scodec-bits" % "1.1.28",
+      "org.scodec" %%% "scodec-bits" % "1.1.29",
       "org.typelevel" %%% "scalacheck-effect-munit" % "1.0.2" % Test,
       "org.typelevel" %%% "munit-cats-effect-3" % "1.0.5" % Test,
       "org.typelevel" %%% "discipline-munit" % "1.0.9" % Test

core/shared/src/main/scala/fs2/compression/checksum.scala

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2013 Functional Streams for Scala
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package fs2
+package compression
+
+import scodec.bits
+import scodec.bits.crc.CrcBuilder
+import scodec.bits.BitVector
+
+/** Provides various checksums as pipes. */
+object checksum {
+
+  /** Computes a CRC32 checksum.
+    * @see [[scodec.bits.crc.crc32]]
+    */
+  def crc32[F[_]]: Pipe[F, Byte, Byte] = fromCrcBuilder(bits.crc.crc32Builder)
+
+  /** Computes a CRC32C checksum.
+    * @see [[scodec.bits.crc.crc32c]]
+    */
+  def crc32c[F[_]]: Pipe[F, Byte, Byte] = fromCrcBuilder(bits.crc.crc32cBuilder)
+
+  /** Computes a CRC checksum using the specified polynomial.
+    * @see [[scodec.bits.crc]]
+    */
+  def crc[F[_]](
+      poly: BitVector,
+      initial: BitVector,
+      reflectInput: Boolean,
+      reflectOutput: Boolean,
+      finalXor: BitVector
+  ): Pipe[F, Byte, Byte] =
+    fromCrcBuilder(bits.crc.builder(poly, initial, reflectInput, reflectOutput, finalXor))
+
+  private def fromCrcBuilder[F[_]](builder: CrcBuilder[BitVector]): Pipe[F, Byte, Byte] =
+    _.chunks
+      .fold(builder)((builder, bits) => builder.updated(bits.toBitVector))
+      .map(b => Chunk.byteVector(b.result.bytes))
+      .unchunks
+
+}

core/shared/src/test/scala/fs2/ChecksumSuite.scala

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2013 Functional Streams for Scala
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package fs2
+
+import fs2.compression.checksum
+import org.scalacheck.Prop.forAll
+import scodec.bits.BitVector
+import scodec.bits.crc
+
+class ChecksumSuite extends Fs2Suite {
+
+  test("CRC32") {
+    forAll { (bytes: Stream[Pure, Byte]) =>
+      val result = bytes
+        .through(checksum.crc32)
+        .compile
+        .toVector
+      val expected = crc.crc32(BitVector(bytes.compile.toVector))
+      assertEquals(BitVector(result), expected)
+    }
+  }
+
+  test("CRC32C") {
+    forAll { (bytes: Stream[Pure, Byte]) =>
+      val result = bytes
+        .through(checksum.crc32c)
+        .compile
+        .toVector
+      val expected = crc.crc32c(BitVector(bytes.compile.toVector))
+      assertEquals(BitVector(result), expected)
+    }
+  }
+
+}