Add a --align flag to the "compress" subcommand

Author: asayers

cli/src/args.rs

@@ -8,7 +8,7 @@ use zeekstd::{CompressionLevel, SeekTable, seek_table};
 // 128 MiB
 const MMAP_THRESHOLD: u64 = 0x0010_0000;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Copy, Clone)]
 pub struct ByteValue(u32);
 
 impl ByteValue {
@@ -178,6 +178,9 @@ pub struct CompressArgs {
     #[arg(long, default_value = "uncompressed")]
     pub frame_size_policy: FrameSizePolicy,
 
+    #[arg(long)]
+    pub align: Option<ByteValue>,
+
     /// Provide a reference point for Zstandard's diff engine.
     #[arg(long)]
     pub patch_from: Option<PathBuf>,

cli/src/compress.rs

@@ -35,6 +35,7 @@ impl<W> Compressor<'_, W> {
 
         let encoder = EncodeOptions::with_cctx(cctx)
             .frame_size_policy(args.to_frame_size_policy())
+            .align(args.align.map(|x| x.as_u32()))
             .checksum_flag(!args.no_checksum)
             .compression_level(args.compression_level)
             .into_encoder(writer)