[Rust] update how "use declarations" are generated, now deriving Defa…

…ults for enums (#952)

* Fixed several issues:
#1: LibRsDef explicitly us crate:: to disambiguate from built in mods like bool
#2: Added acting_version field to Composite structs to fix compilation errors when using Composite structs.  This is an incomplete implementation because the parent doesn't pass the acting_version to the composite because you need to change the signature of wrap(parent, offset) to include the acting_version, so this version just ensures that if the acting_version isn't set on the composite, it disregards the version check.
#3: fixed primitiveArrayDecoder to return an empty array of the right size if less than version required.

* [Rust] removed 'acting_version' field from SubGroup decoder

* [Rust] updated RustGenerator::generateEnum() to support derive "Default" instead of generating impl

* fixed formatting issue

* [Rust] updated how 'use declarations' are generated to prevent "ambiguous glob re-exports" warnings from rust compiler

---------

Co-authored-by: Adam Krieg <adam@talostrading.com>
Co-authored-by: Michael Ward <mward@drw.com>

rust/Cargo.toml

@@ -17,7 +17,7 @@ baseline_bigendian = { path = "../generated/rust/baseline-bigendian" }
 nested_composite_name = { path = "../generated/rust/nested-composite-name" }
 
 [dev-dependencies]
-criterion = "0.3"
+criterion = "0.5"
 
 [[bench]]
 name = "car_benchmark"

rust/benches/car_benchmark.rs

@@ -1,5 +1,6 @@
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
 use examples_uk_co_real_logic_sbe_benchmarks::*;
+use car_codec::encoder::*;
 
 const MANUFACTURER: &[u8] = b"MANUFACTURER";
 const MODEL: &[u8] = b"MODEL";

rust/benches/md_benchmark.rs

@@ -1,5 +1,6 @@
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
 use examples_uk_co_real_logic_sbe_benchmarks_fix::*;
+use market_data_incremental_refresh_trades_codec::encoder::*;
 
 struct State {
     buffer: Vec<u8>,

rust/tests/baseline_test.rs

@@ -2,6 +2,7 @@ use std::fs::File;
 use std::io::prelude::*;
 
 use examples_baseline::*;
+use car_codec::encoder::*;
 
 fn read_sbe_file_generated_from_java_example() -> std::io::Result<Vec<u8>> {
     // Generated by the generateCarExampleDataFile gradle task.

rust/tests/big_endian_test.rs

@@ -1,4 +1,5 @@
 use baseline_bigendian::*;
+use car_codec::encoder::*;
 
 #[test]
 fn big_endian_baseline_example() -> SbeResult<()> {

rust/tests/extension_test.rs

@@ -2,6 +2,7 @@ use std::fs::File;
 use std::io::prelude::*;
 
 use examples_extension::*;
+use car_codec::encoder::*;
 
 fn read_sbe_file_generated_from_java_example() -> std::io::Result<Vec<u8>> {
     // Generated by the generateCarExampleDataFile gradle task.

rust/tests/issue_895_test.rs

@@ -1,10 +1,12 @@
-use ::issue_895::*;
+use issue_895::{
+    issue_895_codec::{decoder::Issue895Decoder, encoder::Issue895Encoder},
+    MessageHeaderDecoder, ReadBuf, SbeResult, WriteBuf, ENCODED_LENGTH, SBE_BLOCK_LENGTH,
+    SBE_SCHEMA_ID, SBE_SCHEMA_VERSION, SBE_TEMPLATE_ID,
+};
 
 fn create_encoder(buffer: &mut Vec<u8>) -> Issue895Encoder {
-    let issue_895 = Issue895Encoder::default().wrap(
-        WriteBuf::new(buffer.as_mut_slice()),
-        ENCODED_LENGTH,
-    );
+    let issue_895 =
+        Issue895Encoder::default().wrap(WriteBuf::new(buffer.as_mut_slice()), ENCODED_LENGTH);
     let mut header = issue_895.header(0);
     header.parent().unwrap()
 }
@@ -72,4 +74,4 @@ fn issue_895_double_none() -> SbeResult<()> {
     assert_eq!(None, decoder.optional_double());
 
     Ok(())
-}
+}

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/rust/LibRsDef.java

@@ -81,7 +81,7 @@ void generate() throws IOException
             // add re-export of modules
             for (final String module : modules)
             {
-                indent(libRs, 0, "pub use %s::*;\n", toLowerSnakeCase(module));
+                indent(libRs, 0, "pub use crate::%s::*;\n", toLowerSnakeCase(module));
             }
             indent(libRs, 0, "\n");
 

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/rust/RustGenerator.java

@@ -15,6 +15,7 @@
  */
 package uk.co.real_logic.sbe.generation.rust;
 
+import org.agrona.Strings;
 import org.agrona.Verify;
 import org.agrona.generation.OutputManager;
 import uk.co.real_logic.sbe.PrimitiveType;
@@ -119,7 +120,7 @@ public void generate() throws IOException
             indent(writer, 0, "version = \"0.1.0\"\n");
             indent(writer, 0, "authors = [\"sbetool\"]\n");
             indent(writer, 0, "description = \"%s\"\n", ir.description());
-            indent(writer, 0, "edition = \"2018\"\n\n");
+            indent(writer, 0, "edition = \"2021\"\n\n");
             indent(writer, 0, "[lib]\n");
             indent(writer, 0, "name = \"%s\"\n", namespace);
             indent(writer, 0, "path = \"src/lib.rs\"\n");
@@ -151,8 +152,8 @@ public void generate() throws IOException
             try (Writer out = outputManager.createOutput(codecModName))
             {
                 indent(out, 0, "use crate::*;\n\n");
-                indent(out, 0, "pub use encoder::*;\n");
-                indent(out, 0, "pub use decoder::*;\n\n");
+                indent(out, 0, "pub use encoder::%sEncoder;\n", formatStructName(msgToken.name()));
+                indent(out, 0, "pub use decoder::%sDecoder;\n\n", formatStructName(msgToken.name()));
                 final String blockLengthType = blockLengthType();
                 final String templateIdType = rustTypeName(ir.headerStructure().templateIdType());
                 final String schemaIdType = rustTypeName(ir.headerStructure().schemaIdType());
@@ -274,7 +275,18 @@ static void generateEncoderGroups(
             final Token numInGroupToken = Generators.findFirst("numInGroup", tokens, index);
             final PrimitiveType numInGroupPrimitiveType = numInGroupToken.encoding().primitiveType();
 
-            indent(sb, level, "/// GROUP ENCODER\n");
+            final String description = groupToken.description();
+            if (!Strings.isEmpty(description))
+            {
+                indent(sb, level, "/// GROUP ENCODER (id=%s, description='%s')\n",
+                    groupToken.id(), description);
+            }
+            else
+            {
+                indent(sb, level, "/// GROUP ENCODER (id=%s)\n",
+                    groupToken.id());
+            }
+
             assert 4 == groupHeaderTokenCount;
             indent(sb, level, "#[inline]\n");
             indent(sb, level, "pub fn %s(self, count: %s, %1$s: %3$s<Self>) -> %3$s<Self> {\n",
@@ -553,7 +565,7 @@ private static void generateCompositeDecoder(
                 decoderName,
                 decoderTypeName);
 
-            indent(sb, level + 1, "if self.acting_version < %d {\n", fieldToken.version());
+            indent(sb, level + 1, "if self.acting_version > 0 && self.acting_version < %d {\n", fieldToken.version());
             indent(sb, level + 2, "return Either::Left(self);\n");
             indent(sb, level + 1, "}\n\n");
 
@@ -587,7 +599,7 @@ private static void generateBitSetDecoder(
 
         if (bitsetToken.version() > 0)
         {
-            indent(sb, level + 1, "if self.acting_version < %d {\n", bitsetToken.version());
+            indent(sb, level + 1, "if self.acting_version > 0 && self.acting_version < %d {\n", bitsetToken.version());
             indent(sb, level + 2, "return %s::default();\n", structTypeName);
             indent(sb, level + 1, "}\n\n");
         }
@@ -647,7 +659,7 @@ private static void generatePrimitiveArrayDecoder(
 
         if (fieldToken.version() > 0)
         {
-            indent(sb, level + 1, "if self.acting_version < %d {\n", fieldToken.version());
+            indent(sb, level + 1, "if self.acting_version > 0 && self.acting_version < %d {\n", fieldToken.version());
             indent(sb, level + 2, "return [%s; %d];\n", encoding.applicableNullValue(), arrayLength);
             indent(sb, level + 1, "}\n\n");
         }
@@ -756,7 +768,7 @@ private static void generatePrimitiveOptionalDecoder(
 
         if (fieldToken.version() > 0)
         {
-            indent(sb, level + 1, "if self.acting_version < %d {\n", fieldToken.version());
+            indent(sb, level + 1, "if self.acting_version > 0 && self.acting_version < %d {\n", fieldToken.version());
             indent(sb, level + 2, "return None;\n");
             indent(sb, level + 1, "}\n\n");
         }
@@ -809,7 +821,7 @@ private static void generatePrimitiveRequiredDecoder(
 
         if (fieldToken.version() > 0)
         {
-            indent(sb, level + 1, "if self.acting_version < %d {\n", fieldToken.version());
+            indent(sb, level + 1, "if self.acting_version > 0 && self.acting_version < %d {\n", fieldToken.version());
             indent(sb, level + 2, "return %s;\n",
                 generateRustLiteral(encoding.primitiveType(), encoding.applicableNullValue().toString()));
             indent(sb, level + 1, "}\n\n");
@@ -897,9 +909,19 @@ static void generateDecoderGroups(
             i = collectVarData(tokens, i, varData);
 
             final String groupName = decoderName(formatStructName(groupToken.name()));
-            indent(sb, level, "/// GROUP DECODER\n");
-            assert 4 == groupHeaderTokenCount;
+            final String description = groupToken.description();
+            if (!Strings.isEmpty(description))
+            {
+                indent(sb, level, "/// GROUP DECODER (id=%s, description='%s')\n",
+                    groupToken.id(), description);
+            }
+            else
+            {
+                indent(sb, level, "/// GROUP DECODER (id=%s)\n",
+                    groupToken.id());
+            }
 
+            assert 4 == groupHeaderTokenCount;
             indent(sb, level, "#[inline]\n");
             if (groupToken.version() > 0)
             {
@@ -910,18 +932,14 @@ static void generateDecoderGroups(
                 indent(sb, level + 2, "return None;\n");
                 indent(sb, level + 1, "}\n\n");
 
-                indent(sb, level + 1, "let acting_version = self.acting_version;\n");
-                indent(sb, level + 1, "Some(%s::default().wrap(self, acting_version as usize))\n",
-                    groupName);
+                indent(sb, level + 1, "Some(%s::default().wrap(self))\n", groupName);
             }
             else
             {
                 indent(sb, level, "pub fn %s(self) -> %2$s<Self> {\n",
                     formatFunctionName(groupName), groupName);
 
-                indent(sb, level + 1, "let acting_version = self.acting_version;\n");
-                indent(sb, level + 1, "%s::default().wrap(self, acting_version as usize)\n",
-                    groupName);
+                indent(sb, level + 1, "%s::default().wrap(self)\n", groupName);
             }
             indent(sb, level, "}\n\n");
 
@@ -958,7 +976,8 @@ static void generateDecoderVarData(
             {
                 if (varDataToken.version() > 0)
                 {
-                    indent(sb, level + 1, "if self.acting_version < %d {\n", varDataToken.version());
+                    indent(sb, level + 1, "if self.acting_version > 0 && self.acting_version < %d {\n",
+                        varDataToken.version());
                     indent(sb, level + 2, "return (self.parent.as_ref().unwrap().get_limit(), 0);\n");
                     indent(sb, level + 1, "}\n\n");
                 }
@@ -973,7 +992,8 @@ static void generateDecoderVarData(
             {
                 if (varDataToken.version() > 0)
                 {
-                    indent(sb, level + 1, "if self.acting_version < %d {\n", varDataToken.version());
+                    indent(sb, level + 1, "if self.acting_version > 0 && self.acting_version < %d {\n",
+                        varDataToken.version());
                     indent(sb, level + 2, "return (self.get_limit(), 0);\n");
                     indent(sb, level + 1, "}\n\n");
                 }
@@ -992,7 +1012,8 @@ static void generateDecoderVarData(
 
             if (varDataToken.version() > 0)
             {
-                indent(sb, level + 1, "if self.acting_version < %d {\n", varDataToken.version());
+                indent(sb, level + 1, "if self.acting_version > 0 && self.acting_version < %d {\n",
+                    varDataToken.version());
                 indent(sb, level + 2, "return &[] as &[u8];\n");
                 indent(sb, level + 1, "}\n\n");
             }
@@ -1199,7 +1220,7 @@ private static void generateEnum(
             throw new IllegalArgumentException("No valid values provided for enum " + originalEnumName);
         }
 
-        indent(writer, 0, "#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]\n");
+        indent(writer, 0, "#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]\n");
         final String primitiveType = rustTypeName(messageBody.get(0).encoding().primitiveType());
         indent(writer, 0, "#[repr(%s)]\n", primitiveType);
         indent(writer, 0, "pub enum %s {\n", enumRustName);
@@ -1216,16 +1237,11 @@ private static void generateEnum(
             final Encoding encoding = messageBody.get(0).encoding();
             final CharSequence nullVal = generateRustLiteral(encoding.primitiveType(),
                 encoding.applicableNullValue().toString());
+            indent(writer, 1, "#[default]\n");
             indent(writer, 1, "NullVal = %s, \n", nullVal);
         }
         indent(writer, 0, "}\n");
 
-        // Default implementation to support Default in other structs
-        indent(writer, 0, "impl Default for %s {\n", enumRustName);
-        indent(writer, 1, "#[inline]\n");
-        indent(writer, 1, "fn default() -> Self { %s::%s }\n", enumRustName, "NullVal");
-        indent(writer, 0, "}\n");
-
         // From impl
         indent(writer, 0, "impl From<%s> for %s {\n", primitiveType, enumRustName);
         indent(writer, 1, "#[inline]\n");
@@ -1271,8 +1287,8 @@ private static void generateComposite(
         {
             indent(out, 0, "use crate::*;\n\n");
 
-            indent(out, 0, "pub use encoder::*;\n");
-            indent(out, 0, "pub use decoder::*;\n\n");
+            indent(out, 0, "pub use encoder::%sEncoder;\n", formatStructName(compositeName));
+            indent(out, 0, "pub use decoder::%sDecoder;\n\n", formatStructName(compositeName));
 
             final int encodedLength = tokens.get(0).encodedLength();
             if (encodedLength > 0)

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/rust/RustUtil.java

@@ -260,7 +260,7 @@ private static String sanitizeMethodOrProperty(final String name)
     {
         if (shadowsKeyword(name))
         {
-            return name + "_";
+            return "r#" + name;
         }
         else
         {
@@ -310,7 +310,7 @@ enum ReservedKeyword
         {
             for (final ReservedKeyword value : ReservedKeyword.values())
             {
-                LOWER_CASE_NAMES.add(value.name());
+                LOWER_CASE_NAMES.add(value.name().toLowerCase());
             }
         }
 

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/rust/SubGroup.java

@@ -157,7 +157,6 @@ void generateDecoder(
         indent(sb, level - 1, "pub struct %s<P> {\n", name);
         indent(sb, level, "parent: Option<P>,\n");
         indent(sb, level, "block_length: usize,\n");
-        indent(sb, level, "acting_version: usize,\n");
         indent(sb, level, "count: %s,\n", rustTypeName(numInGroupPrimitiveType));
         indent(sb, level, "index: usize,\n");
         indent(sb, level, "offset: usize,\n");
@@ -174,7 +173,6 @@ void generateDecoder(
         indent(sb, level, "pub fn wrap(\n");
         indent(sb, level + 1, "mut self,\n");
         indent(sb, level + 1, "mut parent: P,\n");
-        indent(sb, level + 1, "acting_version: usize,\n");
         indent(sb, level, ") -> Self {\n");
         indent(sb, level + 1, "let initial_offset = parent.get_limit();\n");
         indent(sb, level + 1, "let block_length = parent.get_buf().get_%s_at(initial_offset) as usize;\n",
@@ -186,7 +184,6 @@ void generateDecoder(
 
         indent(sb, level + 1, "self.parent = Some(parent);\n");
         indent(sb, level + 1, "self.block_length = block_length;\n");
-        indent(sb, level + 1, "self.acting_version = acting_version;\n");
         indent(sb, level + 1, "self.count = count;\n");
         indent(sb, level + 1, "self.index = usize::MAX;\n");
         indent(sb, level + 1, "self.offset = 0;\n");

sbe-tool/src/test/java/uk/co/real_logic/sbe/generation/rust/RustUtilTest.java

@@ -136,6 +136,8 @@ void functionNameCasing()
         assertEquals("pricenull_9", formatFunctionName("PRICENULL9"));
         assertEquals("price_9_book", formatFunctionName("PRICE9Book"));
         assertEquals("issue_435", formatFunctionName("issue435"));
+        assertEquals("r#type", formatFunctionName("type"));
+
         assertEquals("upper_case", formatFunctionName("UPPERCase"));
         assertEquals("no_md_entries", formatFunctionName("NoMDEntries"));
         assertEquals("md_entry_type_book", formatFunctionName("MD_EntryTYPEBook"));