Add codec FFI layer with Zstd encoding support

Cargo.toml

@@ -2,6 +2,9 @@
 members = [
     "crates/decoder/core",
     "crates/decoder/zstd-ffi",
+    "crates/encoder/core",
+    "crates/encoder/zstd-ffi",
+    "crates/codec-ffi",
 ]
 resolver = "3"
 
@@ -12,6 +15,20 @@ license = "MIT OR Apache-2.0"
 publish = false
 
 [workspace.dependencies]
+# Internal crates: pure-Rust logic lives in the `core` crates (reusable by other
+# Rust projects as plain rlibs); the `ffi` crates hold the C ABI; `codec-ffi` is
+# the single staticlib aggregator linked by Go.
 morph-da-decoder-core = { path = "crates/decoder/core" }
+morph-da-decoder-ffi = { path = "crates/decoder/zstd-ffi" }
+morph-da-encoder-core = { path = "crates/encoder/core" }
+morph-da-encoder-ffi = { path = "crates/encoder/zstd-ffi" }
+
+# External: decoder uses the pure-Rust `ruzstd`; encoder wraps the C `libzstd`
+# via the `zstd` crate. Their C symbols do not overlap.
 ruzstd = "0.8.3"
-hex = "0.4.3"
+# `experimental` exposes LiteralCompressionMode / include_magicbytes (Magicless
+# frame format), required by the Morph DA encoder parameter rules.
+zstd = { git = "https://github.com/morph-l2/zstd-rs.git", branch = "zstd-dev", features = [
+    "experimental",
+] }
+hex = "0.4.3"

Makefile

@@ -19,23 +19,23 @@ else
   GOARCH := unsupported
 endif
 
-FFI_LIB := target/release/libmorph_da_zstd_decode.a
-GO_LIB := bindings/decoder/zstd/libmorph_da_zstd_decode_$(GOOS)_$(GOARCH).a
-LINUX_AMD64_LIB := bindings/decoder/zstd/libmorph_da_zstd_decode_linux_amd64.a
+FFI_LIB := target/release/libmorph_da_zstd.a
+GO_LIB := bindings/codec/zstd/libmorph_da_zstd_$(GOOS)_$(GOARCH).a
+LINUX_AMD64_LIB := bindings/codec/zstd/libmorph_da_zstd_linux_amd64.a
 CENTOS7_BUILD_OUT := build/out
-CENTOS7_FFI_LIB := $(CENTOS7_BUILD_OUT)/libmorph_da_zstd_decode_linux_amd64.a
+CENTOS7_FFI_LIB := $(CENTOS7_BUILD_OUT)/libmorph_da_zstd_linux_amd64.a
 DARWIN_DEPLOYMENT_TARGET ?= 11.0
 
 ifeq ($(GOOS),darwin)
   FFI_BUILD_ENV := MACOSX_DEPLOYMENT_TARGET=$(DARWIN_DEPLOYMENT_TARGET)
 endif
 
-.PHONY: build-zstd-ffi install-decoder-bindings build-zstd-ffi-linux-amd64 install-decoder-bindings-linux-amd64 linux-amd64-decoder-bindings test rust-test go-test clean
+.PHONY: build-zstd-ffi install-codec-bindings build-zstd-ffi-linux-amd64 install-codec-bindings-linux-amd64 linux-amd64-codec-bindings test rust-test go-test clean
 
 build-zstd-ffi:
-	$(FFI_BUILD_ENV) cargo build -p morph-da-decoder-ffi --release
+	$(FFI_BUILD_ENV) cargo build -p morph-da-codec-ffi --release
 
-install-decoder-bindings: build-zstd-ffi
+install-codec-bindings: build-zstd-ffi
 	cp $(FFI_LIB) $(GO_LIB)
 
 build-zstd-ffi-linux-amd64:
@@ -45,19 +45,19 @@ build-zstd-ffi-linux-amd64:
 		--output type=local,dest=$(CENTOS7_BUILD_OUT) \
 		.
 
-install-decoder-bindings-linux-amd64: build-zstd-ffi-linux-amd64
+install-codec-bindings-linux-amd64: build-zstd-ffi-linux-amd64
 	cp $(CENTOS7_FFI_LIB) $(LINUX_AMD64_LIB)
 
 
 rust-test:
 	cargo test --workspace
 
-go-test: install-decoder-bindings
-	cd bindings/decoder && go test ./...
+go-test: install-codec-bindings
+	cd bindings/codec && go test ./...
 
 test: rust-test go-test
 
 clean:
 	cargo clean
-	rm -f bindings/decoder/zstd/*.a
+	rm -f bindings/codec/zstd/*.a
 	rm -rf $(CENTOS7_BUILD_OUT)

README.md

@@ -1,19 +1,29 @@
 # morph-da-codec
 
-Morph DA zstd decoder shared by Rust zkVM guest code and Go node code.(There will be encoder in the future)
+Morph DA zstd codec (encoder + decoder) shared by Rust zkVM guest code and Go node code.
+
+The encoder and decoder are compiled into a single staticlib and exposed to Go through the `bindings/codec/zstd` package:
+
+- `CompressMorphDABatch` — compress a batch into a magic-less zstd frame;
+- `DecompressMorphDABatch` — decompress a frame produced by the encoder.
 
 ## Semantics
 
-- input payload omits zstd magic bytes;
-- decoder prepends `28 b5 2f fd` internally;
-- only the first complete zstd frame is decoded;
-- bytes after the first frame are ignored;
+Encoder and decoder share the same frame format:
+
+- the frame omits the zstd magic bytes (`28 b5 2f fd`); the decoder prepends them internally;
+- a single frame is produced, with content size included so the decoder can validate it;
+- literal compression is disabled (raw literal bytes) and the window log is capped at 17.
+
+Decoder specifics:
+
+- only the first complete frame is decoded; bytes after it are ignored;
 - first frame content size is required and validated.
 
 ## Build
 
 ```sh
 make build-zstd-ffi
-make install-decoder-bindings
+make install-codec-bindings
 make test
 ```