Merge pull request #398 from Shnatsel/safe-rust-zstd-2

Add safe Rust zstd decoding backend

Cargo.toml

@@ -25,6 +25,7 @@ fax34 = { package = "fax", version = "0.2.6", optional = true }
 flate2 = { version = "1.0.20", optional = true }
 weezl = { version = "0.2.1", optional = true }
 zstd = { version = "0.13", optional = true }
+zrip-decode = { version = "0.8.2", features = ["paranoid"], optional = true }
 zune-jpeg = { version = "0.5.1", optional = true }
 image-webp = {version = "0.2.4", optional = true }
 
@@ -45,6 +46,9 @@ jpeg = ["dep:zune-jpeg"]
 lzw = ["dep:weezl"]
 webp = ["dep:image-webp"]
 zstd = ["dep:zstd"]
+# Fully safe Rust but somewhat slower Zstd decoding.
+# When both zstd and zstd-safe-rust are enabled, zstd takes precedence.
+zstd-safe-rust = ["dep:zrip-decode"]
 
 [[bench]]
 name = "lzw"

src/decoder/image.rs

@@ -720,6 +720,8 @@ impl Image {
             )),
             #[cfg(feature = "zstd")]
             CompressionMethod::ZSTD => Box::new(zstd::Decoder::new(reader)?),
+            #[cfg(all(not(feature = "zstd"), feature = "zstd-safe-rust"))]
+            CompressionMethod::ZSTD => Box::new(zrip_decode::streaming::FrameDecoder::new(reader)),
             CompressionMethod::PackBits => Box::new(PackBitsReader::new(reader, compressed_length)),
             #[cfg(feature = "deflate")]
             CompressionMethod::Deflate | CompressionMethod::OldDeflate => {

tests/decode_images.rs

@@ -827,7 +827,7 @@ fn test_predictor_3_gray_f32() {
 }
 
 #[test]
-#[cfg(feature = "zstd")]
+#[cfg(any(feature = "zstd", feature = "zstd-safe-rust"))]
 fn test_zstd_compression() {
     // gdal_translate -co COMPRESS=ZSTD -co ZSTD_LEVEL=20 int16.tif int16_zstd.tif
     test_image_sum_i16("int16_zstd.tif", ColorType::Gray(16), 354396);